JP7341707B2 - Two-component developer - Google Patents

Description

The present invention relates to a two-component developer used in electrophotographic systems, electrostatic recording systems, electrostatic printing systems, and toner jet systems.

In recent years, as electrophotographic full-color copying machines have become widespread, the demand for high-speed printing and energy saving has further increased. In order to support high-speed printing, technology to melt toner more quickly in the fixing process is being considered, and technology to shorten the time for various controls during one job and between jobs is also being considered to improve productivity. has been done. Furthermore, as an energy-saving measure, a technique for fixing toner at a lower temperature is being considered in order to reduce power consumption in the fixing process.
In order to cope with high-speed printing and improve low-temperature fixability, there is a method of lowering the glass transition point and softening point of the binder resin of the toner and using a binder resin having sharp melting properties. In recent years, many toners containing crystalline polyester as a resin having sharp melt properties have been proposed. However, crystalline polyester has been a material with problems in terms of charge stability in a high temperature, high humidity environment, particularly in terms of maintaining chargeability after being left in a high temperature, high humidity environment.
In order to solve these problems, progress is being made in developing carriers for two-component developers that can improve the charging properties of toners even when toners with high low-temperature fixability are used.

For example, in Patent Document 1, in order to stabilize the chargeability of a toner using a crystalline polyester resin, a highly chargeable resin is used as a carrier coating resin to improve the chargeability.
On the other hand, various toners using crystalline vinyl resins as crystalline resins having sharp melt properties have been proposed.
For example, Patent Document 2 proposes a toner that achieves both low-temperature fixability and chargeability by using an acrylate resin having crystallinity in the side chain.

Japanese Patent Application Publication No. 2014-174454 Japanese Patent Application Publication No. 2014-130243

However, it has been found that the carrier described in Patent Document 1 has a problem in that charging rises slowly.
Furthermore, it has been found that a two-component developer using a crystalline vinyl resin as a binder resin, such as that disclosed in Patent Document 2, also has a slow rise in charging.
If the charge build-up is slow, when printing an image with a high printing ratio immediately after printing an image with a low printing ratio, the amount of charge between the toner existing in the developing machine and the toner newly supplied into the developing machine will change. The image density gradually fluctuates due to the difference between the two images. This tendency is particularly noticeable in low humidity environments.
An object of the present invention is to provide a two-component developer that solves the above problems. Specifically, it is an object of the present invention to provide a two-component developer that has charging stability even in a high-temperature, high-humidity environment, is less likely to cause density fluctuations regardless of the image printing ratio, and has a fast charging rise.

A first aspect of the present invention is a two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
The binder resin includes a first monomer unit derived from a first polymerizable monomer and a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer. Contains a polymer A having a monomer unit,
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content ratio of the first monomer unit in the polymer A is based on the total number of moles of all monomer units in the polymer A, 10 . 0 mol% to 60.0 mol%,
The content ratio of the second monomer unit in the polymer A is 20.0 mol% to 95.0 mol% based on the total number of moles of all monomer units in the polymer A,
When the SP value of the first monomer unit is SP ₁₁ (J/cm ³ ) ^0.5 and the SP value of the second monomer unit is SP ₂₁ (J/cm ³ ) ^0.5 , the following formula Satisfy (1) to (2),
3.00≦(SP ₂₁ −SP ₁₁ )≦25.00 (1)
21.00≦SP ₂₁ ...(2)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a) and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The content of the monomer unit (a) in the polymer B is 10.0 mol% to 70.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The content of the monomer unit (b) in the polymer B is 30.0 mol% to 90.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . The two-component developer is characterized in that it satisfies the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4)
Further, a second aspect of the present invention is a two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
A polymer A in which the binder resin is a polymer of a composition containing a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. Contains
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content ratio of the first polymerizable monomer in the composition is based on the total number of moles of all polymerizable monomers in the composition, 10 . 0 mol% to 60.0 mol%,
The content of the second polymerizable monomer in the composition is 20.0 mol% to 95.0 mol% based on the total number of moles of all polymerizable monomers in the composition. can be,
The SP value of the first polymerizable monomer is SP ₁₂ (J/cm ³ ) ^0.5 , and the SP value of the second polymerizable monomer is SP ₂₂ (J/cm ³ ) ^0.5 . Then, the following formulas (5) to (6) are satisfied,
0.60≦(SP ₂₂ −SP ₁₂ )≦15.00 (5)
18.30≦SP ₂₂ ...(6)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a) and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The content of the monomer unit (a) in the polymer B is 10.0 mol% to 70.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The content of the monomer unit (b) in the polymer B is 30.0 mol% to 90.0 mol% based on the total number of moles of all monomer units in the polymer B,
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . The two-component developer is characterized in that it satisfies the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4)

According to the present invention, it is possible to provide a two-component developer that has charging stability even in a high temperature and high humidity environment and has a fast charging rise that is resistant to fluctuations in density regardless of the image printing ratio.

An explanatory diagram of regions R1 and R2 related to the magnetic carrier of the two-component developer of the present invention Schematic diagram of triboelectric charge measuring device

［式（Ｚ）中、Ｒ_Ｚ１は、水素原子、又はアルキル基（好ましくは炭素数１～３のアルキル基であり、より好ましくはメチル基）を表し、Ｒ_Ｚ２は、任意の置換基を表す。］
結晶性樹脂とは、示差走査熱量計（ＤＳＣ）測定において明確な吸熱ピークを示す樹脂を指す。 In the present invention, the description of "XX to YY" or "XX to YY" expressing a numerical range means a numerical range including the lower limit and upper limit, which are the end points, unless otherwise specified.
In the present invention, (meth)acrylic ester means acrylic ester and/or methacrylic ester.
In the present invention, the term "monomer unit" refers to one section of a carbon-carbon bond in the main chain in which vinyl monomers in a polymer are polymerized. Vinyl monomer is the following formula (
Z).

[In formula (Z), R _Z1 represents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group), and R _Z2 represents an arbitrary substituent . ]
A crystalline resin refers to a resin that exhibits a clear endothermic peak in differential scanning calorimetry (DSC) measurement.

A first aspect of the present invention is a two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
The binder resin includes a first monomer unit derived from a first polymerizable monomer, and a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer. Contains a polymer A having a monomer unit,
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content ratio of the first monomer unit in the polymer A is 5.0 mol% to 60.0 mol% based on the total number of moles of all monomer units in the polymer A,
The content ratio of the second monomer unit in the polymer A is 20.0 mol% to 95.0 mol% based on the total number of moles of all monomer units in the polymer A,
When the SP value of the first monomer unit is SP ₁₁ (J/cm ³ ) ^0.5 and the SP value of the second monomer unit is SP ₂₁ (J/cm ³ ) ^0.5 , the following formula Satisfy (1) to (2),
3.00≦(SP ₂₁ −SP ₁₁ )≦25.00 (1)
21.00≦SP ₂₁ ...(2)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a), and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . The two-component developer is characterized in that it satisfies the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4)

A second aspect of the present invention is a two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
The binder resin is a polymer A of a composition containing a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. Contains
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content of the first polymerizable monomer in the composition is 5.0 mol% to 60.0 mol% based on the total number of moles of all polymerizable monomers in the composition. can be,
The content of the second polymerizable monomer in the composition is 20.0 mol% to 95.0 mol% based on the total number of moles of all polymerizable monomers in the composition. can be,
The SP value of the first polymerizable monomer is SP ₁₂ (J/cm ³ ) ^0.5 , and the SP value of the second polymerizable monomer is SP ₂₂ (J/cm ³ ) ^0.5 . Then, the following formulas (5) to (6) are satisfied,
0.60≦(SP ₂₂ −SP ₁₂ )≦15.00 (5)
18.30≦SP ₂₂ ...(6)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a), and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . A two-component developer characterized by satisfying the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4)

The present inventors believe that the mechanism by which the effects of the present invention are exerted is as follows.
It is thought that the speed at which the charge of the two-component developer rises is determined by the frequency with which the charge moves from the surface of the carrier particles to the surface of the toner particles. It is conventionally known that the charging rise speed of toner particles can be increased by coating the surface of carrier particles with a highly polar resin.
However, in studies conducted by the present inventors, it has been found that when a crystalline vinyl resin is used as the binder resin, the rate at which the toner particles are charged does not increase sufficiently. This is thought to be due to charge transfer from the surface of the carrier particle to the surface of the toner particle, or spread of charge from the local area where the charge transfer occurs to the entire toner particle or the entire carrier particle, which is rate-determining.

As a result of studies on changing the composition of the binder resin, it has been found that the presence of a monomer unit with a high SP value in the crystalline vinyl resin slightly improves the rise in charging. It is thought that this is because the presence of a monomer unit with a high SP value makes it easier for charge to move from the surface of the carrier particle to the surface of the toner particle in a localized area where a highly polar monomer unit exists on the surface of the toner particle. However, depending on the composition, charge retention under a high-temperature, high-humidity environment may deteriorate.
The present inventors conducted extensive studies and determined the molar ratio of monomer units derived from multiple polymerizable monomers of the binder resin, the SP value, and the difference in SP value, as well as the multiple polymerizability of the coating resin on the surface of the carrier particle. It has been discovered that the above problems can be solved by controlling the molar ratio of monomer units derived from the monomers and the SP value within a specific range, leading to the present invention.

When a monomer unit with a high SP value is present in the vinyl resin contained in the binder resin of the toner particle, a monomer unit with a low SP value and a monomer unit with a high SP value are present on the surface of the toner particle. Further, the magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core. When two or more types of monomer units with different SP values are present in the coating resin, a monomer unit with a low SP value and a monomer unit with a high SP value will be present on the surface.
It has been found that when these conditions are met, the charging rise speed of the developer increases. Furthermore, it has been found that charge retention under high temperature and high humidity environments is improved. These mechanisms are speculated as follows.

As mentioned above, it is considered that the transfer of charge from the surface of the carrier particle to the surface of the toner particle is likely to occur mainly when the polar portion of the coating resin on the surface of the carrier particle and the polar portion of the surface of the toner particle come into contact. Further, it is considered that the non-polar portion of the coating resin on the surface of the carrier particle and the non-polar portion of the surface of the toner particle each have high hydrophobicity, so that they can easily approach each other without water intervening.
Due to these effects, the frequency of charge transfer from the coating resin on the surface of the carrier particles to the surface of the toner particles became higher, and it is believed that the charging rise speed of the developer was improved. In other words, the polar part existing on the surface of the toner particle and the polar part existing in the coating resin on the surface of the carrier particle, and the non-polar part existing on the surface of the toner particle and the non-polar part existing in the coating resin on the surface of the carrier particle each interact with each other. It is believed that this action improves the charging start-up speed of the developer.
Furthermore, when monomer units with high SP values and monomer units with low SP values aggregate on the toner particle surface to form a structure similar to a block copolymer, the polar blocks on the toner particle surface Therefore, it is thought that charge retention in a high-temperature, high-humidity environment is improved by holding electrons in a non-localized manner by a plurality of adjacent polar groups within the block.
Here, also in the coating resin on the surface of the carrier particles, monomer units with high SP values and monomer units with low SP values may aggregate to form a structure similar to a block copolymer. In this case, considering the difference in size between carrier particles and toner particles, if the size of the block of coating resin on the surface of the carrier particle is smaller than the area of the contact area between the surface of the carrier particle and the surface of the toner particle, then The interactions between the polar parts present in the coating resin on the surface of the carrier and the non-polar parts present on the surface of the toner particles and the non-polar parts present in the coating resin on the surface of the carrier particles are improved. Therefore, it is considered that the size of the block of the coating resin on the surface of the carrier particle is preferably smaller than the area of the contact portion between the surface of the carrier particle and the surface of the toner particle.

In the first embodiment, the polymer A includes a first monomer unit derived from a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. The SP value of the first monomer unit is SP ₁₁ (J/cm ³ ) ^0.5 , and the SP value of the second monomer unit is SP ₂₁ (J/cm ³ ). When it is set to ^0.5 , the following formula (1) is satisfied.
In the second embodiment, the SP value of the first polymerizable monomer is SP ₁₂ (J/cm ³ ) ^0.5 , and the SP value of the second polymerizable monomer is SP ₂₂ (J/cm 3 ). cm ³ ) ^0.5 , the following formula (5) is satisfied.
3.00≦(SP ₂₁ −SP ₁₁ )≦25.00 (1)
0.60≦(SP ₂₂ −SP ₁₂ )≦15.00 (5)

By satisfying the above SP value difference, the polymer A easily forms a structure similar to a block copolymer, and the melting point is maintained. As a result, in addition to the above-mentioned improvement in the charge rise speed of the developer and the ability to maintain the charge in a high temperature and high humidity environment, low temperature fixability is achieved. This mechanism is speculated as follows.
The first monomer unit is incorporated into polymer A, and the first monomer units aggregate to form a structure similar to a block copolymer, but in normal cases, other monomer units are incorporated. If present, blocking will be inhibited, making it difficult for the polymer to exhibit blocking properties. This tendency becomes remarkable when the first monomer unit and the other monomer unit are randomly bonded within one molecule of the polymer.
On the other hand, in the present invention, by using a polymerizable monomer in which SP ₂₂ -SP ₁₂ falls within the range of formula (5) above, the first polymerizable monomer and the second polymerizable monomer are combined during polymerization. It is thought that the molecules do not bind randomly, but rather can bind sequentially to some extent. As a result, in Polymer A, the first monomer units are able to aggregate with each other, and even if other monomer units are incorporated, it is possible to increase crystallinity, and it is thought that the melting point can also be maintained. .
It is preferable that the polymer A has a crystalline site containing a first monomer unit derived from a first polymerizable monomer. Moreover, it is preferable that the polymer A has an amorphous site containing a second monomer unit derived from the second polymerizable monomer.
The lower limit of SP ₂₁ -SP ₁₁ is preferably 4.00 or more, more preferably 5.00 or more. The upper limit of SP ₂₁ -SP ₁₁ is preferably 20.00 or less, more preferably 15.00 or less.
On the other hand, the lower limit of SP ₂₂ -SP ₁₂ is preferably 2.00 or more, more preferably 3.00 or more. The upper limit of SP ₂₂ -SP ₁₂ is preferably 10.00 or less, more preferably 7.00 or less.

In addition, it is thought that by having the SP value difference within the above range, the first monomer unit and the second monomer unit in Polymer A can form a clear phase separation state without being compatible with each other, and the crystallinity can be improved. It is believed that the melting point is maintained without decreasing.
When the SP value difference is smaller than the above lower limit, the crystallinity of the polymer A decreases, resulting in a decrease in charge retention in a high-temperature, high-humidity environment. In addition, if the SP value difference is larger than the above upper limit, the crystallinity of polymer A will become too high, resulting in non-uniformity of polar parts and non-polar parts at the contact area between carrier particles and toner particles, and developer The rise of charging becomes slow.

In addition, in the present invention, if there are multiple types of monomer units satisfying the requirements of the first monomer unit in the polymer A, the value of SP ₁₁ in formula (1) is the weighted average of the SP values of each monomer unit. value. For example, the first monomer unit contains monomer unit A with an SP value of SP ₁₁₁ in A mol% based on the number of moles of the entire monomer unit that satisfies the requirements for the first monomer unit, and monomer unit B with an SP value of SP ₁₁₂ . The SP value (SP ₁₁ ) when containing (100-A) mol% based on the number of moles of the entire monomer unit that satisfies the requirements is:
SP ₁₁ = (SP ₁₁₁ × A + SP ₁₁₂ × (100-A)) / 100
It is. The same calculation is performed when three or more monomer units that meet the requirements for the first monomer unit are included. On the other hand, SP ₁₂ similarly represents an average value calculated from the molar ratio of each first polymerizable monomer.
Further, in the present invention, the second monomer unit corresponds to all monomer units satisfying SP ₂₁ that satisfies formula (1) with respect to SP ₁₁ calculated by the above method. Similarly, the second polymerizable monomer corresponds to all polymerizable monomers having SP ₂₂ that satisfies formula (5) with respect to SP ₁₂ calculated by the above method.
That is, when the second polymerizable monomer is two or more types of polymerizable monomers, SP ₂₁ represents the SP value of the monomer unit derived from each polymerizable monomer, and SP ₂₁ -SP _1
1 is determined for each monomer unit derived from the second polymerizable monomer. Similarly, SP ₂₂ represents the SP value of each polymerizable monomer, and SP ₂₂ -SP ₁₂ is determined for each second polymerizable monomer.

Preferably, polymer A is a vinyl polymer. Examples of vinyl polymers include polymers of monomers containing ethylenically unsaturated bonds. The ethylenically unsaturated bond refers to a carbon-carbon double bond that can undergo radical polymerization, and includes, for example, a vinyl group, a propenyl group, an acryloyl group, a methacryloyl group, and the like.

The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a), and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . When, the following formulas (3) and (4) are satisfied.
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4)

By satisfying the above formulas (3) and (4), the monomer unit (a) corresponds to the second monomer unit of the polymer A, and the monomer unit (b) corresponds to the first monomer unit of the polymer A. ) interacts with each other to improve charge build-up and charge maintenance under high temperature and high humidity environments.
When SP(a) is larger than 22.00 (J/cm ³ ) ^0.5 , the size of the block of the coating resin on the surface of the carrier particle becomes larger than the area of the contact portion between the surface of the carrier particle and the surface of the toner particle. The charging rise speed decreases. Similarly, when SP(b) is smaller than 19.00 (J/cm ³ ) ^0.5 , the size of the block of coating resin on the surface of the carrier particle becomes larger than the area of the contact area between the surface of the carrier particle and the surface of the toner particle. Therefore, the charging rise speed decreases.
Furthermore, when SP(a) is smaller than 20.30 (J/cm ³ ) ^0.5 , the polarity of the polar group becomes weak, so that the polarity of the polar moiety present on the toner particle surface and the polarity present in the coating resin on the carrier surface is Since the interaction between the non-polar part present on the surface of the toner particle and the non-polar part present in the coating resin on the surface of the carrier particle is not sufficiently expressed, the charging rise speed of the developer decreases.
Similarly, when SP(b) is larger than 20.20 (J/cm ³ ) ^0.5 , the nonpolarity of the nonpolar group becomes weak, so that the polar parts present on the toner particle surface and the coating resin on the carrier surface are Since the interaction between the existing polar part, the non-polar part existing on the surface of the toner particles, and the non-polar part existing in the coating resin on the surface of the carrier particle is not sufficiently expressed, the charging rise speed of the developer decreases. do.
SP(a) is preferably 20.30 (J/cm ³ ) ^0.5 to 21.50 (J/cm ³ ) ^0.5 , more preferably 20.30 (J/cm ³ ) ^{0 .5} to 20.50 (J/cm ³ ) ^0.5 .
Further, SP(b) is preferably 19.50 (J/cm ³ ) ^0.5 to 20.20 (J/cm ³ ) ^0.5 , more preferably 20.00 (J/cm ^{3 )} ) ^0.5 to 20.20 (J/cm ³ ) ^0.5 .

The binder resin contains a first monomer unit derived from a first polymerizable monomer that is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms. It is characterized by containing a polymer A having the following properties.
Since the first monomer unit is a (meth)acrylic acid ester having an alkyl group having 18 to 36 carbon atoms, the binder resin has crystallinity and low-temperature fixability is improved.
If the number of carbon atoms is less than 18, the crystallinity of the polymer A will be significantly reduced, resulting in poor charge retention in a high temperature, high humidity environment. Furthermore, when the number of carbon atoms is greater than 36, the crystallinity of the polymer A is too high, and the charging rise speed of the developer decreases.

Further, in the first embodiment, the content of the first monomer unit in the polymer A is 5.0 mol% to 60.0 mol% based on the total number of moles of all monomer units in the polymer A. It is characterized by being
Further, in the second embodiment, the polymer A is a polymer of a composition containing a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. It is a combination. The content of the first polymerizable monomer in the composition is 5.0 mol% to 60.0 mol% based on the total number of moles of all polymerizable monomers in the composition. .
When the content ratio of the first polymerizable monomer or the first monomer unit is within the above range, low-temperature fixability, charge build-up in a low-humidity environment, and charge maintenance property in a high-temperature and high-humidity environment are improved. Becomes good. If the content is less than 5.0 mol %, not only low-temperature fixability will be deteriorated, but also charge retention in a high-temperature, high-humidity environment will be deteriorated due to a decrease in crystallinity.
On the other hand, if the content exceeds 60.0 mol %, the non-polar portion with a low SP value occupies a large portion of the polymer A, resulting in a decrease in the rate of charging rise. The preferred range is 10.0 mol% to 60.0 mol%, and the more preferred range is 20.0 mol% to 40.0 mol%.

The first polymerizable monomer forming the first monomer unit is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms.
Examples of the (meth)acrylic ester having an alkyl group having 18 to 36 carbon atoms include (meth)acrylic ester having a linear alkyl group having 18 to 36 carbon atoms [stearyl (meth)acrylate, (meth)acrylic ester, ) nonadecyl acrylate, eicosyl (meth)acrylate, heneicosanyl (meth)acrylate, behenyl (meth)acrylate, lignoceryl (meth)acrylate, ceryl (meth)acrylate, octacosa (meth)acrylate, (meth) [myricyl acrylate, dotriacontane (meth)acrylate, etc.] and (meth)acrylic acid esters having a branched alkyl group having 18 to 36 carbon atoms [2-decyltetradecyl (meth)acrylate, etc.].

Among these, from the viewpoint of the charge maintenance property of the toner in a high-temperature, high-humidity environment and the charge build-up speed, it is preferably selected from the group consisting of (meth)acrylic acid esters having a linear alkyl group having 18 to 36 carbon atoms. more preferably at least one selected from the group consisting of (meth)acrylic acid esters having a straight-chain alkyl group having 18 to 30 carbon atoms; even more preferably a straight-chain is at least one selected from the group consisting of stearyl (meth)acrylate and behenyl (meth)acrylate.
The first polymerizable monomer may be used alone or in combination of two or more.
Here, the SP value is an abbreviation for solubility parameter, and is a value that is an index of solubility. The calculation method will be described later.
The unit of SP value in the present invention is (J/m ³ ) ^0.5 , but 1 (cal/cm ³ ) ^0.5 = 2.045×10 ³ (J/m ³ ) ^0.5 ( cal/cm ³ ) can be converted into a unit of ^0.5 .

The binder resin contains polymer A. Polymer A includes a first monomer unit derived from a first polymerizable monomer, and a second monomer derived from a second polymerizable monomer different from the first polymerizable monomer. unit, and the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms.
By having the first monomer unit, the polymer A becomes a resin exhibiting crystallinity.
In the first embodiment, the content of the second monomer unit in the polymer A is 20.0 mol% to 95.0 mol% based on the total number of moles of all monomer units in the polymer A. It is characterized by
Further, in the second embodiment, the polymer A is a polymer of a composition containing a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. It is a combination. The content of the second polymerizable monomer in the composition is 20.0 mol% to 95.0 mol% based on the total number of moles of all polymerizable monomers in the composition. .
From the viewpoint of charging buildup in a low humidity environment, the above content ratio is preferably 40.0 mol% to 95.0 mol%, more preferably 40.0 mol% to 70.0 mol%.

As the second polymerizable monomer forming the second monomer unit, for example, among the following, polymerizable monomers satisfying formulas (1) and (2) or formulas (5) and (6) are used. be able to. The second polymerizable monomer may be used alone or in combination of two or more.
A monomer having a nitrile group; for example, acrylonitrile, methacrylonitrile, etc.
Monomers having a hydroxy group; for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, etc.
A monomer having an amide group; for example, acrylamide, an amine having 1 to 30 carbon atoms, and a carboxylic acid having 2 to 30 carbon atoms having an ethylenically unsaturated bond (acrylic acid, methacrylic acid, etc.) are reacted by a known method. monomer.
Monomers having urethane groups: For example, alcohols having 2 to 22 carbon atoms and having ethylenically unsaturated bonds (2-hydroxyethyl methacrylate, vinyl alcohol, etc.) and isocyanates having 1 to 30 carbon atoms [monoisocyanate compounds] (benzenesulfonyl isocyanate, tosyl isocyanate, phenyl isocyanate, p-chlorophenylisocyanate, butyl isocyanate, hexyl isocyanate, t-butyl isocyanate, cyclohexyl isocyanate, octyl isocyanate, 2-ethylhexyl isocyanate, dodecyl isocyanate, adamantyl isocyanate, 2,6-dimethylphenyl isocyanate, 3,5-dimethylphenyl isocyanate and 2,6-dipropylphenyl isocyanate), aliphatic diisocyanate compounds (trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1 , 3-butylene diisocyanate, dodecamethylene diisocyanate and 2,4,4-trimethylhexamethylene diisocyanate, etc.), alicyclic diisocyanate compounds (1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, etc.), and aromatic diisocyanate compounds (phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, etc.) -Tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, etc.), and alcohols having 1 to 26 carbon atoms (methanol, ethanol, propanol, isopropyl alcohol, butanol, t-butyl alcohol, pentanol, Heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecyl alcohol, lauryl alcohol, dodecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetanol, heptadecanol, stearyl alcohol, isostearyl alcohol, elaidyl alcohol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol, nonadecyl alcohol, heneicosanol, behenyl alcohol, erucyl alcohol, etc.) and isocyanates with 2 to 30 carbon atoms having an ethylenically unsaturated bond [2-isocyanatoethyl (meth) Acrylate, 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (meth)acrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate and 1,1- (bis(meth)acryloyloxymethyl)ethyl isocyanate, etc.) by a known method.

Monomers having urea groups: For example, amines having 3 to 22 carbon atoms [primary amines (n-butylamine, t-butylamine, propylamine, isopropylamine, etc.), secondary amines (di-n-ethylamine, di-n-propylamine, di-n-propylamine, etc.), (n-butylamine, etc.), aniline, cycloxylamine, etc.] with an isocyanate having 2 to 30 carbon atoms and having an ethylenically unsaturated bond, by a known method.
Monomers having a carboxyl group; for example, methacrylic acid, acrylic acid, 2-carboxyethyl (meth)acrylate.
Among these, it is preferable to use monomers having a nitrile group, an amide group, a urethane group, a hydroxy group, or a urea group. More preferably, it is a monomer having at least one functional group selected from the group consisting of a nitrile group, an amide group, a urethane group, a hydroxy group, and a urea group and an ethylenically unsaturated bond. These monomers are preferable from the viewpoint of charge retention under a high temperature and high humidity environment. Among these, nitrile groups are particularly preferred from the viewpoint of low-temperature fixability.

As the second polymerizable monomer, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, pivalic acid Vinyl esters such as vinyl and vinyl octylate are also preferably used.
Vinyl esters are non-conjugated monomers that tend to maintain appropriate reactivity with the first polymerizable monomer, so they can easily improve the crystallinity of Polymer A, improve low-temperature fixability, and improve high-temperature and high-humidity environments. This makes it easier to achieve both the lower charge retention properties.
The second polymerizable monomer preferably has an ethylenically unsaturated bond, more preferably one ethylenically unsaturated bond.
Moreover, it is preferable that the second polymerizable monomer is at least one selected from the group consisting of the following formulas (A) and (B).

In the formulas (A) and (B), X represents a single bond or an alkylene group having 1 to 6 carbon atoms.
R ¹ is a nitrile group (-C≡N),
Amide group (-C(=O)NHR ¹⁰ (R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)),
hydroxy group,
-COOR ¹¹ (R ¹¹ is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4) or a hydroxyalkyl group having 1 to 6 carbon atoms (preferably 1 to 4)),
Urethane group (-NHCOOR ¹² (R ¹² is an alkyl group having 1 to 4 carbon atoms)),
Urea group (-NH-C(=O)-N(R ¹³ ) ₂ (R ¹³ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4))),
-COO(CH ₂ ) ₂ NHCOOR ¹⁴ (R ¹⁴ is an alkyl group having 1 to 4 carbon atoms), or -COO(CH ₂ ) ₂ -NH-C(=O)-N(R ¹⁵ ) ₂ (R ¹⁵ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms)
, R ² is an alkyl group having 1 to 4 carbon atoms, and R ³ is each independently a hydrogen atom or a methyl group.
Preferably, R ¹ is a nitrile group (-C≡N),
Amide group (-C(=O)NHR ¹⁰ (R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms)),
hydroxy group,
-COOR ¹¹ (R ¹¹ is an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4) or a hydroxyalkyl group having 1 to 6 carbon atoms (preferably 1 to 4)),
-COO(CH ₂ ) ₂ NHCOOR ¹⁴ (R ¹⁴ is an alkyl group having 1 to 4 carbon atoms), or -COO(CH ₂ ) ₂ -NH-C(=O)-N(R ¹⁵ ) ₂ (R ¹⁵ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms)
, R ² is an alkyl group having 1 to 4 carbon atoms, and R ³ is each independently a hydrogen atom or a methyl group.

In the first embodiment, the polymer A is characterized by having a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer. When the SP value of the second monomer unit is SP ₂₁ , it is characterized by satisfying the following formula (2). It is preferable that the following formula (2)' is satisfied, and it is more preferable that the following formula (2)'' is satisfied.
21.00≦SP ₂₁ ...(2)
21.00≦SP ₂₁ ≦40.00...(2)'
25.00≦SP ₂₁ ≦30.00...(2)''
Further, in the second embodiment, when the SP value of the second polymerizable monomer is SP ₂₂ (J/cm ³ ) ^0.5 , the following formula (6) is satisfied. It is preferable that the following formula (6)' is satisfied, and it is more preferable that the following formula (6)'' is satisfied.
18.30≦SP ₂₂ ...(6)
18.30≦SP ₂₂ ≦30.00...(6)'
21.00≦SP ₂₂ ≦23.00...(6)''
When SP ₂₁ and SP ₂₂ are within the above ranges, charge is more likely to move from the polar portion of the coating resin on the surface of the carrier particles to the surface of the toner particles, so that the charging rise speed of the developer is improved.

The acid value Av of the polymer A is preferably 30.0 mgKOH/g or less, more preferably 20.0 mgKOH/g or less. The lower limit is not particularly limited, but is preferably 0 mgKOH/g or more. When the acid value is 30.0 mgKOH/g or less, crystallization of the polymer A is hardly inhibited and the melting point is maintained well.

Further, the weight average molecular weight (Mw) of the tetrahydrofuran (THF) soluble portion of the polymer A measured by gel permeation chromatography (GPC) is preferably 10,000 or more and 200,000 or less, and preferably 20,000 or more and 150,000 or less. It is more preferable that there be. When Mw is within the above range, elasticity near room temperature can be easily maintained.

Further, the melting point Tp of the polymer A is preferably 50°C or more and 80°C or less, more preferably 53°C or more and 70°C or less. When the melting point is 50° C. or higher, the charge maintenance property under a high temperature and high humidity environment is good, and when the melting point is 80° C. or less, the low temperature fixing property is good.

Polymer A contains the above-mentioned components within a range that does not impair the molar ratio of the first monomer unit derived from the first polymerizable monomer described above and the second monomer unit derived from the second polymerizable monomer. A third polymerizable monomer that is not included in any of the ranges of formula (1) or (5) (that is, different from the first polymerizable monomer and the second polymerizable monomer) It may contain monomer units derived from.
As the third polymerizable monomer, among the monomers listed in the section of the second polymerizable monomer, monomers that do not satisfy formula (1) or formula (5) may be used. can.
Examples of the third polymerizable monomer include styrene, styrene and its derivatives such as o-methylstyrene, n-butyl (meth)acrylate, t-butyl (meth)acrylate, and (meth)acrylic acid. Examples include (meth)acrylic acid esters such as -2-ethylhexyl.
The third polymerizable monomer is preferably at least one selected from the group consisting of styrene, methyl methacrylate, and methyl acrylate in order to improve the storage stability of the toner.

From the viewpoint of making it easier to obtain the effects of the present invention, the content of polymer A is preferably 50% by mass or more based on the total mass of the binder resin. It is more preferably 80% by mass to 100% by mass, and it is even more preferred that the binder resin is Polymer A.
Further, it is preferable that the polymer A be present on the surface of the toner particles because the effects of the present invention can be easily obtained.

The binder resin may contain a resin other than the polymer A, if necessary, for purposes such as improving pigment dispersibility.
Examples of resins other than Polymer A used for the binder resin include the following resins.
Monopolymers of styrene and its substituted products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene - Acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Styrenic copolymers such as copolymers, styrene-vinyl methyl ketone copolymers, styrene-acrylonitrile-indene copolymers; polyvinyl chloride, phenolic resins, natural resin-modified phenolic resins, natural resin-modified maleic acid resins, acrylics Examples include resins, methacrylic resins, polyvinyl acetate, silicone resins, polyester resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumaron-indene resins, and petroleum-based resins.
Among these, styrene copolymers and polyester resins are preferred. Further, it is preferably amorphous.

The glass transition temperature of the coating resin of the magnetic carrier is preferably 40° C. to 100° C. from the viewpoint of charge maintenance properties and charge build-up speed in a high temperature and high humidity environment. More preferably the temperature is 50°C to 90°C.
In polymer B, the content of monomer unit (a) is 10.0 mol% to 90.0 mol% based on the total number of moles of all monomer units in polymer B. It is preferable from the viewpoint of the ratio of parts. More preferably, it is 30.0 mol% to 70.0 mol%.
For the same reason, the content of monomer unit (b) is preferably 10.0 mol% to 90.0 mol%, based on the total number of moles of all monomer units in polymer B, and 30. More preferably, it is 0 mol% to 70.0 mol%.

Examples of the polymerizable monomer (a) include methyl methacrylate, methyl acrylate, and vinyl acetate. Preferably, it is at least one selected from the group consisting of alkyl esters of (meth)acrylic acid having an alkyl group having 1 to 4 carbon atoms. From the viewpoint of charging rise speed, it is more preferable that methyl methacrylate is included. These monomers may be used alone or in combination of two or more.
Examples of the polymerizable monomer (b) include cyclohexyl methacrylate, cyclodecyl methacrylate, and butyl methacrylate. Preferably, it is at least one selected from the group consisting of cycloalkyl esters of (meth)acrylic acid having a cycloalkyl group having 3 to 8 carbon atoms. From the viewpoint of charge build-up speed, it is more preferable to include cyclohexyl methacrylate. These monomers may be used alone or in combination of two or more.

Further, it is preferable that the content of the polymer B is 50% by mass or more based on the total mass of the coating resin from the viewpoint of charging rise speed and charge maintenance property under a high temperature and high humidity environment. More preferably, it is 70% by mass to 100% by mass.
Further, the ratio of the total number of moles of the second monomer unit to the total number of moles of all monomer units in polymer A is E, and the ratio of the total number of moles of the second monomer unit to the total number of moles of all monomer units in polymer B is When the ratio of moles is F, it is preferable that the following formula (9) is satisfied.
0.20≦E/F≦7.00 (9)
E/F is more preferably 0.40 to 3.50. Within the above range, charging rises quickly.

Further, the magnetic core is not particularly limited, and for example, the following can be used.
Iron powder with an oxidized surface, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, rare earths, their alloy particles, and their oxide particles , a magnetic material such as ferrite or magnetite, or a magnetic material-dispersed resin carrier (so-called resin carrier) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state. Here, good results are usually obtained when the carrier mixing ratio is preferably 2% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 13% by mass or less in terms of toner concentration in the two-component developer. .
Further, the charging time constant of the two-component developer is preferably 10 seconds to 500 seconds, more preferably 10 seconds to 400 seconds. Within the above range, density changes are less likely to occur when images with different image printing ratio densities are output. The charging time constant can be controlled by the type of binder resin of the toner particles, the type of coating resin of the carrier particles, and the like. How to determine the charging time constant will be described later.

Further, the magnetic core is a porous magnetic core,
A resin-filled magnetic core particle in which the porous magnetic core has a filled resin present in the pores of the porous magnetic core,
In the pore size distribution of the porous magnetic core,
The peak pore diameter at which the differential pore volume is maximum in the range of 0.1 μm or more and 3.0 μm or less is 0.20 μm or more and 0.70 μm or less,
The pore volume, which is the integral value of the differential pore volume in the range of 0.1 μm or more and 3.0 μm or less, is 20 mm ³ /g or more and 57 mm ³ /g or less,
The magnetic carrier has a region R1 and a region R2 defined as follows:
The mass-based proportions of the composition derived from the resin component are respectively JR1 and JR2,
Let the mass-based ratios of the composition derived from the porous magnetic core be FR1 and FR2, respectively,
Furthermore, when JR1/FR1 is MR1 and JR2/FR2 is MR2, MR1 and MR2 are
0.20≦MR2/MR1≦0.90
It is preferable that the following relationship is satisfied.

Here, the definition of region R1 will be explained based on FIG. 1. In the cross-sectional image of the magnetic carrier, two straight lines that pass through the center of gravity of the cross-section of the magnetic carrier and are parallel to the line segment that is the maximum length of the resin-filled magnetic core particles and are 2.5 μm apart from the line segment are designated as A and B. shall be. A straight line C passing through the intersection of the line segment and the contour line of the resin-filled magnetic core particle and perpendicular to the line segment, and a straight line C that is parallel to the straight line C and 5.0 μm from the straight line C toward the center of the magnetic carrier. Assume a distant straight line D.
A region surrounded by the outline of the resin-filled magnetic core particle between straight lines A and B and straight lines A, B, and D and in contact with straight line C is designated as R1.
Further, the region R2 is a region surrounded by straight lines A, B, and D, and a straight line E that is parallel to the straight line D and is 5.0 μm away from the straight line D toward the center of the magnetic carrier.
This indicates that the resin ratio near the coating resin on the surface of the resin-filled magnetic core particle is higher than the resin ratio inside. With this configuration, it is possible to improve the charging rise speed.

The ratio (MR1) of the composition derived from the resin near the surface layer of the resin-filled magnetic core particle to the composition derived from the porous magnetic core is the ratio of the composition derived from the resin in the inner part to the porous magnetic core. It is characterized in that it is larger than the ratio (MR2) to the composition ratio from the origin. In other words, it shows that the resin component in the surface layer is larger than that in the inner part.
When MR2/MR1 is in the range of 0.20 to 0.90, interaction between the polar parts of the toner particle surface and the carrier particle surface or the non-polar parts each occurs moderately, so that the charge buildup of the developer is reduced. Increases speed.
Note that MR2/MR1 can be controlled by the amount and viscosity of the resin to be filled. The control method will also be explained in the magnetic carrier manufacturing method described later. MR2/MR1 is preferably 0.25≦MR2/MR1≦0.85, and more preferably 0.30≦MR2/MR1≦0.75.

When the magnetic carrier is a magnetic carrier having a resin-filled magnetic core particle containing a filling resin in the pores of a porous magnetic core, and a resin coating layer existing on the surface of the resin-filled magnetic core particle, the carrier particle Since the frequency of charge transfer from the surface to the toner particle surface increases, the charging rise speed of the developer increases.
In the pore size distribution of the porous magnetic core, the pore volume, which is the integral value of the differential pore volume in the range of 0.1 μm or more and 3.0 μm or less, is 20.0 mm ³ /g or more and 57.0 mm ³ /g or less. It is preferable that When the pore volume is 20.0 mm ³ /g or more, the frequency at which charges move from the surface of the carrier particles to the surface of the toner particles increases due to the microscopic deviation of the center of gravity, so that the charging rise speed of the developer increases. . The pore volume is more preferably 25.0 mm ³ /g or more and 55.0 mm ³ /g or less. The pore volume can be controlled by the firing temperature and firing time of the porous magnetic core. For example, the pore volume can be reduced by increasing the firing temperature.

In the pore size distribution of the porous magnetic core, the peak pore size at which the differential pore volume is maximum in the range of 0.1 μm or more and 3.0 μm or less is preferably 0.20 μm or more and 0.70 μm or less. When the pore diameter is within the above range, interaction between the polar portions or non-polar portions of the toner particle surface and the carrier particle surface occurs appropriately, so that the charging rise speed of the developer is improved.

The peak pore diameter is preferably 0.25 μm or more and 0.65 μm or less. The peak pore diameter can be controlled by the particle size of the calcined ferrite finely ground product, the firing temperature and firing time of the porous magnetic core. For example, the peak pore diameter can be reduced by reducing the particle size of the finely pulverized calcined ferrite product.

Further, the magnetic core is a magnetic material-dispersed resin carrier core material,
The magnetic substance dispersed resin carrier core material contains magnetic particles A whose primary particles have a number average particle diameter of ra (μm), and magnetic particles B whose primary particles have a number average particle diameter of rb (μm),
The ra and rb satisfy the relationship ra≧rb,
The magnetic particles A contain an oxide of at least one non-ferrous metal element selected from the group consisting of manganese element, aluminum element, magnesium element, titanium element, and nickel element, and iron oxide,
In the measurement of the magnetic carrier by X-ray fluorescence diffraction, when the total content of the non-ferrous metal elements is M1 (mass%) and the content of iron elements is F1 (mass%), the ratio of M1 to F1 is The value (M1/F1) is 0.010 or more and 0.100 or less,
In the measurement of the magnetic carrier by X-ray photoelectron spectroscopy, when the total content of the nonferrous metal element is M2 (mass%) and the content of the iron element is F2 (mass%), the ratio of M2 to F2 The value (M2/F2) is preferably 1.0 or more and 10.0 or less.

In measurement of magnetic carriers by X-ray fluorescence diffraction, when the total content of nonferrous metal elements is M1 (mass%) and the content of iron elements is F1 (mass%), the value of the ratio of M1 to F1 ( M1/F1) is preferably 0.010 or more and 0.100 or less, more preferably 0.020 or more and 0.090 or less.
This indicates the ratio of components other than iron oxide components present inside the magnetic material dispersed resin carrier core material. When M1/F1 is within the above range, the charging rise speed of the developer is improved. M1/F1 can be controlled by the ratio of magnetic particles A and magnetic particles B. For example, M1/F1 can be increased by increasing the ratio of magnetic particles A.

In the measurement of magnetic carriers by X-ray photoelectron spectroscopy, when the total content of nonferrous metal elements is M2 (mass%) and the content of iron elements is F2 (mass%), the value of the ratio of M2 to F2 ( M2/F2) is preferably 1.0 or more and 10.0 or less, more preferably 1.5 or more and 8.5 or less, and even more preferably 1.8 or more and 6.0 or less.
This indicates the ratio of components other than iron oxide components present in the surface layer of the magnetic material-dispersed resin carrier core material. When M2/F2 is 1.0 or more, the density of the image output after high-density output becomes more stable. On the other hand, if it is 10.0 or less, the density of the image output after low density output becomes stable.
M2/F2 can be controlled by the coating amount of the non-ferrous metal element of the magnetic particles A, which will be described later. For example, M2/F2 can be increased by increasing the coating amount of the non-ferrous metal element component of the magnetic particles A.

The fact that (M1/F1) and (M2/F2) are within the above ranges indicates that the non-ferrous metal elements are unevenly distributed in the surface layer of the magnetic material dispersed resin carrier. This improves the charging start-up speed of the developer.
In the measurement of M1 and M2, the nonferrous metal element is preferably at least one selected from the group consisting of manganese element, aluminum element, magnesium element, titanium element, and nickel element. By selecting the above as the non-ferrous metal element component, charge retention and charge relaxation properties can be easily controlled. As a result, the electrostatic adhesion between the toner and the magnetic carrier and the fluidity of the developer are stabilized, and the agitation and transportability of the developer is improved, which is expected to improve charge retention in high-temperature, high-humidity environments. It will be done.

<Colorant>
A coloring agent may be used in the toner. As the coloring agent, the following may be mentioned.
Examples of the black colorant include carbon black, which is colored black using a yellow colorant, a magenta colorant, and a cyan colorant. Although a pigment may be used alone as a coloring agent, it is more preferable to use a dye and a pigment together to improve the clarity from the viewpoint of the image quality of a full-color image.
Examples of pigments for magenta toner include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; I. Pigment Violet 19; C. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.
Examples of dyes for magenta toner include the following. C. I. Solvent red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. I. Dispersed Red 9; C. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C. I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of pigments for cyan toner include the following. C. I. Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, 17; C.I. I. Bat Blue 6;C. I. Acid Blue 45, a copper phthalocyanine pigment with 1 to 5 phthalimidomethyl groups substituted on the phthalocyanine skeleton.
As a dye for cyan toner, C.I. I. There is Solvent Blue 70.
Examples of pigments for yellow toner include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C. I. Bat yellow 1, 3, 20.
As the dye for yellow toner, C. I. There is Solvent Yellow 162.
The content of the colorant is preferably 0.1 parts by mass or more and 30 parts by mass or less based on 100 parts by mass of the binder resin.

<Wax>
Wax may be used as the toner. Examples of wax include the following:
Hydrocarbon waxes such as microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxides of hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof; Waxes that are partially or completely deoxidized from fatty acid esters such as deoxidized carnauba wax.
Furthermore, the following may be mentioned. Saturated straight chain fatty acids such as palmitic acid, stearic acid, montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, valinaric acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol, seryl alcohol , saturated alcohols such as mericyl alcohol; polyhydric alcohols such as sorbitol; fatty acids such as palmitic acid, stearic acid, behenic acid, montanic acid, and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol. esters with alcohols such as , ceryl alcohol, and mericyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, and ethylene bislauric acid amide. acid amide, saturated fatty acid bisamides such as hexamethylene bis-stearamide; ethylene bis-oleic acid amide, hexamethylene bis-oleic acid amide, N,N' dioleyl adipate amide, N, N' dioleyl sebacic acid amide; unsaturated fatty acid amides such as m-xylene bisstearamide, aromatic bisamides such as N,N' distearyl isophthalic acid amide; calcium stearate, calcium laurate, zinc stearate, magnesium stearate Aliphatic metal salts (generally called metal soaps); Waxes made by grafting aliphatic hydrocarbon waxes with vinyl monomers such as styrene and acrylic acid; Fatty acids such as behenic acid monoglyceride Partial esterification product of polyhydric alcohol; methyl ester compound with hydroxyl group obtained by hydrogenation of vegetable oil.
The wax content is preferably 2.0 parts by mass to 30.0 parts by mass based on 100 parts by mass of the binder resin.

<Charge control agent>
The toner can also contain a charge control agent if necessary. As the charge control agent contained in the toner, any known charge control agent can be used, but a metal compound of an aromatic carboxylic acid is particularly preferable because it is colorless, has a high charging speed of the toner, and can stably maintain a constant charge amount.
Examples of negative charge control agents include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer-type compounds with sulfonic acid or carboxylic acid in the side chain, and sulfonate or sulfonic acid ester compounds in the side chain. Examples include polymeric compounds, polymeric compounds having carboxylates or carboxylic acid esters in their side chains, boron compounds, urea compounds, silicon compounds, and calixarene. The charge control agent may be added internally or externally to the toner particles.
The amount of the charge control agent added is preferably 0.2 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the binder resin.

<Inorganic fine particles>
The toner may contain inorganic fine particles as necessary.
The inorganic fine particles may be added internally to the toner particles or may be mixed with the toner particles as an external additive. As the external additive, inorganic fine particles such as silica are preferred.
The inorganic fine particles are preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.
As an external additive for improving fluidity, inorganic fine particles with a specific surface area of 50 m ² /g or more and 400 m ² /g or less are preferable, and for durability stability, a specific surface area of 10 m ² /g or more and 50 m ^{2 /} g is preferred. It is preferable that the particles be inorganic fine particles having a particle size of 100 g or less. In order to achieve both improved fluidity and durability stability, inorganic fine particles having a specific surface area within the above range may be used in combination.

<Manufacturing method>
The method for producing toner particles is not particularly limited, and conventionally known production methods such as a suspension polymerization method, an emulsion aggregation method, a melt-kneading method, and a dissolution/suspension method can be employed.
The obtained toner particles may be used as a toner as they are. A toner may be obtained by mixing toner particles with inorganic fine particles and, if necessary, other external additives. Mixing of toner particles and external additives such as inorganic fine particles can be carried out using a double con mixer, V-type mixer, drum-type mixer, super mixer, Henschel mixer, Nauta mixer, Mechano Hybrid (manufactured by Nippon Coke Industries Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.). A mixing device such as one manufactured by a company (manufactured by a company) can be used.
The external additive is preferably used in an amount of 0.1 parts by mass or more and 10.0 parts by mass or less based on 100 parts by mass of toner particles.
Methods for measuring various physical properties of toner and raw materials will be described below.

(Analysis method)
<Method for measuring the content ratio of monomer units derived from various polymerizable monomers in polymer A and polymer B>
The content ratio of monomer units derived from various polymerizable monomers in Polymer A and Polymer B is measured by ¹ H-NMR under the following conditions.
Measuring device: FT NMR device JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0μs
Frequency range: 10500Hz
Total number of times: 64 times Measurement temperature: 30℃
Sample: Prepared by placing 50 mg of the measurement sample into a sample tube with an inner diameter of 5 mm, adding deuterium chloroform (CDCl ₃ ) as a solvent, and dissolving this in a constant temperature bath at 40°C.
From the obtained ¹ H-NMR chart, among the peaks attributed to the constituent elements of the monomer unit derived from the first polymerizable monomer, the peaks attributed to the constituent elements of the monomer unit derived from other selects an independent peak and calculates the integral value _S1 of this peak. Similarly, from among the peaks attributed to the constituent elements of the monomer unit derived from the second polymerizable monomer, a peak that is independent of the peaks attributed to the constituent elements of the monomer unit derived from other sources is selected. , calculate the integral value _S2 of this peak.
Furthermore, if a third polymerizable monomer is used, from the peak attributed to the components of the monomer unit derived from the third polymerizable monomer, the components of the monomer unit derived from other A peak independent of the peak attributed to is selected, and the integral value _S3 of this peak is calculated.
The content ratio of the monomer unit derived from the first polymerizable monomer is determined as follows using the above integral values S ₁ , S ₂ and S ₃ . Note that n ₁ , n _{2 , and} n ₃ are the numbers of hydrogens in the constituent elements to which the focused peaks are assigned for each site.
Content ratio (mol%) of monomer units derived from the first polymerizable monomer =
{(S ₁ /n ₁ )/((S ₁ /n ₁ )+(S ₂ /n ₂ )+(S ₃ /n ₃ ))}×100
Similarly, the proportion of monomer units derived from the second polymerizable monomer and the third polymerizable monomer is determined as follows.
Content ratio (mol%) of monomer units derived from the second polymerizable monomer =
{(S ₂ /n ₂ )/((S ₁ /n ₁ )+(S ₂ /n ₂ )+(S ₃ /n ₃ ))}×100
Content ratio (mol%) of monomer units derived from the third polymerizable monomer =
{(S ₃ /n ₃ )/((S ₁ /n ₁ )+(S ₂ /n ₂ )+(S ₃ /n ₃ ))}×100
In addition, if a polymerizable monomer containing no hydrogen atom as a constituent other than the vinyl group is used in Polymer A, use ¹³ C-NMR to measure the atomic nucleus as ¹³ C, and use single pulse mode. Measurements are made using 1 H-NMR, and calculations are made in the same manner using ¹ H-NMR.
Furthermore, when the toner is manufactured by suspension polymerization, the peaks of the release agent and other resins overlap, and independent peaks may not be observed. As a result, the content ratio of monomer units derived from various polymerizable monomers in the polymer A may not be calculated. In that case, polymer A' can be produced by performing similar suspension polymerization without using a mold release agent or other resin, and can be analyzed by regarding polymer A' as polymer A.
Polymer B can also be calculated in the same manner as polymer A.

<Method for measuring glass transition temperature and melting point of polymer A and coating resin>
The glass transition temperature and melting peak temperature are measured according to ASTM D3418-82 using a differential scanning calorimeter "Q2000" (manufactured by TA Instruments).
The temperature correction of the device detection part uses the melting points of indium and zinc, and the heat of fusion of indium is used to correct the amount of heat.
Specifically, approximately 3 mg of a sample is accurately weighed, placed in an aluminum pan, and measured under the following conditions using an empty aluminum pan as a reference.
Temperature increase rate: 10℃/min
Measurement start temperature: 30℃
Measurement end temperature: 180℃
Measurement is carried out within the measurement range of 30 to 180°C at a temperature increase rate of 10°C/min. The temperature is raised once to 180°C, held for 10 minutes, then lowered to 30°C, and then raised again. In this second temperature raising process, a change in specific heat is obtained in the temperature range of 30°C to 100°C. At this time, the intersection of the midpoint line between the baseline before and after the specific heat change and the differential heat curve is defined as the glass transition temperature (Tg) of the binder resin.
Furthermore, the temperature at which the maximum endothermic peak of the temperature-endothermic curve in the temperature range of 60° C. to 90° C. occurs is defined as the melting peak temperature (Tp) of the melting point of the polymer.

<Separation of polymer and binder resin from toner>
DSC measurement can be performed after separating the polymer and binder resin from the toner by utilizing the difference in solubility in a solvent.

<How to calculate SP value>
SP ₁₂ , SP ₂₂ , SP(a), and SP(b) are determined as follows according to the calculation method proposed by Fedors.
For each polymerizable monomer, the evaporation energy (Δei ) (cal/mol) and molar volume (Δvi) (cm ³ /mol), and set (4.184×ΣΔei/ΣΔvi) ^0.5 as the SP value (J/cm ³ ) ^0.5 .
Note that SP ₁₁ and SP ₂₁ are calculated using the same calculation method as above for atoms or atomic groups of the molecular structure in which the double bond of the polymerizable monomer is cleaved by polymerization.

<Measurement of molecular weight of THF soluble content of resin in toner particles>
The molecular weight (Mw) of the THF-soluble portion of Polymer A is measured by gel permeation chromatography (GPC) as follows.
First, the sample is dissolved in tetrahydrofuran (THF) for 24 hours at room temperature. Then, the obtained solution is filtered through a solvent-resistant membrane filter "Maishori Disk" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. Note that the sample solution is adjusted so that the concentration of components soluble in THF is approximately 0.8% by mass. Using this sample solution, measurements are performed under the following conditions.
Equipment: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: 7 series of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko)
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0ml/min
Oven temperature: 40.0℃
Sample injection amount: 0.10ml
When calculating the molecular weight of the sample, use standard polystyrene resin (for example, trade name "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F- 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500'', manufactured by Tosoh Corporation).

<Method for measuring acid value>
The acid value Av is the number of mg of potassium hydroxide required to neutralize the acid contained in 1 g of sample. The acid value of Polymer A in the present invention is measured according to JIS K 0070-1992, and specifically, it is measured according to the following procedure.
(1) Preparation of reagents Dissolve 1.0 g of phenolphthalein in 90 mL of ethyl alcohol (95% by volume) and add ion exchange water to make 100 mL to obtain a phenolphthalein solution.
Dissolve 7 g of special grade potassium hydroxide in 5 mL of water, and add ethyl alcohol (95% by volume) to make 1 L. After leaving it in an alkali-resistant container for 3 days to avoid contact with carbon dioxide gas, filter it to obtain a potassium hydroxide solution. The obtained potassium hydroxide solution is stored in an alkali-resistant container. The factor of the potassium hydroxide solution was determined by placing 25 mL of 0.1 mol/L hydrochloric acid in an Erlenmeyer flask, adding a few drops of the phenolphthalein solution, and titrating with the potassium hydroxide solution. Determine from the amount of potassium solution. The 0.1 mol/L hydrochloric acid prepared according to JIS K 8001-1998 is used.
(2) Operation (A) Main test Accurately weigh 2.0 g of the crushed sample of Polymer A into a 200 ml Erlenmeyer flask, add 100 ml of a mixed solution of toluene/ethanol (2:1), and dissolve over 5 hours. . Next, several drops of the phenolphthalein solution are added as an indicator, and titration is carried out using the potassium hydroxide solution. The end point of the titration is when the indicator remains pale red for about 30 seconds.
(B) Blank test Perform titration in the same manner as above, except that no sample is used (that is, only a mixed solution of toluene/ethanol (2:1) is used).
(3) Substitute the obtained results into the following formula to calculate the acid value.
A=[(CB)×f×5.61]/S
Here, A: acid value (mgKOH/g), B: amount of potassium hydroxide solution added in blank test (mL), C: amount of potassium hydroxide solution added in main test (mL), f: potassium hydroxide Solution factor, S: Mass of sample (g).

(Weight average particle diameter of toner particles (D4))
The weight average particle diameter (D4) of the toner particles was measured using a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 100 μm aperture tube using the pore electrical resistance method. Using the included dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) for setting conditions and analyzing measured data, measurements were taken with 25,000 effective measurement channels, and the measured data was Analyze and calculate.
The electrolytic aqueous solution used in the measurement can be one in which special grade sodium chloride is dissolved in ion-exchanged water to have a concentration of about 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter).
Note that before performing measurement and analysis, the dedicated software is set as follows.
In the "Change standard measurement method (SOM) screen" of the dedicated software, set the total count in control mode to 50,000 particles, set the number of measurements to 1, and set the Kd value to "standard particle 10.0 μm" (Beckman Coulter). Set the value obtained using By pressing the threshold/noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the aperture tube flush after measurement.
On the "Pulse to particle size conversion setting screen" of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) Approximately 200 ml of the above electrolyte aqueous solution is placed in a 250 ml round-bottom glass beaker exclusively for Multisizer 3, set on a sample stand, and stirred with a stirrer rod counterclockwise at 24 revolutions/second. Then, use the dedicated software's ``Aperture Tube Flush'' function to remove dirt and air bubbles from inside the aperture tube.
(2) Pour about 30 ml of the above electrolytic aqueous solution into a 100 ml glass flat-bottomed beaker, and add "Contaminon N" as a dispersant (precision measurement of pH 7 consisting of nonionic surfactant, anionic surfactant, and organic builder). Approximately 0.3 ml of a diluted solution prepared by diluting a 10% by mass aqueous solution of a neutral detergent for cleaning utensils (manufactured by Wako Pure Chemical Industries, Ltd.) by 3 times by mass with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with their phases shifted by 180 degrees, and are placed in the water tank of an ultrasonic dispersion device "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is poured into the water tank, and approximately 2 ml of the contaminon N is added to the water tank.
(4) Set the beaker of (2) above in the beaker fixing hole of the ultrasonic disperser, and operate the ultrasonic disperser. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic aqueous solution in the beaker is maximized.
(5) While the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion treatment is continued for another 60 seconds. In addition, in the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10° C. or more and 40° C. or less.
(6) Using a pipette, drop the electrolytic aqueous solution of (5) in which toner is dispersed into the round-bottomed beaker of (1) placed in the sample stand, and adjust the measured concentration to approximately 5%. . Then, the measurement is continued until the number of particles to be measured reaches 50,000.
(7) Analyze the measurement data using the dedicated software attached to the device and calculate the weight average particle diameter (D4). Note that when the dedicated software is set to graph/volume %, the "average diameter" on the analysis/volume statistics (arithmetic mean) screen is the weight average particle diameter (D4).

<Measurement of pore diameter and pore volume of porous magnetic core>
The pore size distribution of the porous magnetic core is measured by mercury intrusion method.
The measurement principle is as follows.
In this measurement, the pressure applied to mercury is changed and the amount of mercury that has entered the pores is measured. The conditions under which mercury can penetrate into the pores can be expressed as PD=-4σ cos θ from the balance of forces, where θ and σ are the pressure P, the pore diameter D, the contact angle of mercury, and the surface tension, respectively. If the contact angle and surface tension are constants, then the pressure P and the pore diameter D into which mercury can enter are inversely proportional. For this reason, the horizontal axis P of the PV curve obtained by measuring the pressure P and the amount of infiltrated liquid V at that time by changing the pressure is directly replaced with the pore diameter from this formula to calculate the pore distribution. There is.
As a measuring device, Autopore IV9520 manufactured by Shimadzu Corporation is used to perform measurements under the following conditions and procedures.
Measurement conditions Measurement environment 20℃
Measuring cell Sample volume: 5 cm ³ , Injection volume: 1.1 cm ³ , Purpose: For powder Measuring range: 2.0 psia (13.8 kPa) or more, 59989.6 psia (413.7 kPa) or less Measurement steps: 80 steps
(Steps are carved at equal intervals when the pore diameter is taken as a logarithm.)
Press-in parameters Exhaust pressure 50μmHg
Exhaust time 5.0min
Mercury injection pressure 2.0 psia (13.8 kPa)
Equilibrium time 5secs
High pressure parameters Equilibrium time 5secs
Mercury parameters Advancing contact angle 130.0 degrees
Receding contact angle 130.0 degrees
Surface tension 485.0mN/m (485.0dynes/cm)
Mercury density 13.5335g/mL
Measurement procedure (1) Weigh approximately 1.0 g of the porous magnetic core and place it in a sample cell.
Enter the weight value.
(2) Measure the range of 2.0 psia (13.8 kPa) or more and 45.8 psia (315.6 kPa) or less at the low pressure part.
(3) Measurement in the range of 45.9 psia (316.3 kPa) or more and 59989.6 psia (413.6 kPa) or less at the high pressure part.
(4) Calculate the pore size distribution from the mercury injection pressure and mercury injection amount.
(2), (3), and (4) are automatically performed using the software attached to the device.
From the pore size distribution measured as described above, the peak pore size at which the differential pore volume is maximum in the pore size range of 0.1 μm or more and 3.0 μm or less is read.
Further, the pore volume is calculated by integrating the differential pore volume in the pore diameter range of 0.1 μm or more and 3.0 μm or less using the attached software, and is defined as the pore volume.

<Separation of the resin coating layer from the magnetic carrier and separation of the coating resin (polymer B) in the resin coating layer>
As a method for separating the coating resin from the magnetic carrier, there is a method in which the magnetic carrier is placed in a cup and the coating resin is eluted using toluene.
The eluted resin is fractionated using the following equipment.
[Device configuration]
LC-908 (manufactured by Japan Analysis Industry Co., Ltd.)
JRS-86 (Company; repeat injector)
JAR-2 (Company; auto sampler)
FC-201 (Gilson; Fra cushion collector)
[Column configuration]
JAIGEL-1H to 5H (20φ x 600mm: preparative column) (manufactured by Japan Analytical Industry Co., Ltd.)
[Measurement condition]
Temperature: 40℃
Solvent: THF
Flow rate: 5ml/min.
Detector: RI
Based on the molecular weight distribution of the coating resin, the elution time at which the peak molecular weight (Mp) is reached for each type of coating resin (polymer B and other resins as necessary) is measured in advance using the resin composition specified by the method below. Then, before and after that, each resin component is separated. Thereafter, the solvent is removed and dried to obtain each type of coating resin.
The resin composition is determined for each resin contained in the coating resin by identifying atomic groups from the absorption wave number using a Fourier transform infrared spectrometer (Spectrum One: manufactured by PerkinElmer).

<Measurement of MR1 and MR2 of magnetic carrier cross section>
1. Cutting out a cross section A focused ion beam processing and observation device (FIB), FB-2100 (manufactured by Hitachi High-Technologies), is used to process the cross section of the magnetic carrier. A sample is prepared by applying carbon paste onto the FIB sample stage (metal mesh), fixing a small amount of magnetic carrier onto it so that each particle exists independently, and depositing platinum as a conductive film. The sample is set in an FIB apparatus, and rough processing (beam current 39 nA) is performed using an acceleration voltage of 40 kV and a Ga ion source, followed by finishing processing (beam current 7 nA) to cut out a cross section of the carrier that is the sample.
The cross section of the magnetic carrier selected as the measurement sample is a magnetic carrier that satisfies D50×0.9≦H≦D50×1.1, where H is the length of the line segment that is the maximum length of the carrier particle cross section. Prepare 100 cross-sectional samples within this range.
2. Analysis of components derived from the porous magnetic core and resin components of the magnetic carrier Using a scanning electron microscope (manufactured by Hitachi, Ltd., S4700), the elements of the magnetic components and resin components of the cross-sectional sample of the magnetic carrier were analyzed using a scanning electron microscope (manufactured by Hitachi, Ltd., S4700). Analysis is performed using an elemental analysis means (energy dispersive X-ray analyzer manufactured by EDAX) attached to the electron microscope.
At an observation magnification of 10,000 times or more, observation is performed on a region composed only of magnetic components at an accelerating voltage of 20 kV and an acquisition time of 100 seconds to identify elements in the components derived from the porous magnetic core. Similarly, the elements in the resin component are also specified.
The components derived from the porous magnetic core are the elements specified above, but as for oxygen, it is contained in both the component derived from the porous magnetic core and the resin component, and it is difficult to specify the content ratio. Therefore, it is excluded from the components derived from the porous magnetic core. In other words, the components derived from the porous magnetic core in the present invention are metal elements in the ferrite that constitutes the porous magnetic core.
The resin component is the element specified above. Oxygen is contained in both the magnetic component and the resin component, and it is difficult to specify the content ratio, so oxygen is excluded from the resin component. Furthermore, since hydrogen cannot be identified with the energy dispersive X-ray analyzer used in the present invention, hydrogen is also excluded from the resin components. That is, in the present invention, when an acrylic resin composed of carbon, hydrogen, and oxygen is used, the element that becomes the resin component is only carbon. In the case of silicone resin, carbon and silicon are used.

3. Measurement of metal component abundance rate and resin abundance rate in cross section The cross section of the magnetic carrier is observed at 2000 times magnification using a scanning electron microscope.
In the obtained cross-sectional image, two straight lines that pass through the center of gravity of the magnetic carrier cross section and are parallel to the line segment that is the maximum length of the resin-filled magnetic core particles and are 2.5 μm apart from the line segment are designated as A and B. do. A straight line C passing through the intersection of the line segment and the contour line of the resin-filled magnetic core particle and perpendicular to the line segment; Assume a straight line D separated by .0 μm.
The region surrounded by the contour line of the resin-filled magnetic core particle between the straight lines A and B and the straight lines A, B, and D and in contact with the straight line C is designated as R1.
By dividing the regions in this way, measurements can be made under conditions that minimize the influence of the coating resin component.
Further, a region surrounded by the straight lines A, B, and D and a straight line E that is parallel to the straight line D and is 5.0 μm away from the straight line D toward the center of the magnetic carrier is designated as R2.
For each region R1 and R2, the mass ratio (mass %) of the element is measured using an elemental analysis means at an accelerating voltage of 20 kV and an acquisition time of 100 seconds.
For example, in the case of a magnetic carrier in which the components of the magnetic core particles are Mn-Mg-Sr ferrite, filled with silicone resin, and coated with acrylic resin, the elements of the metal components are iron, manganese, magnesium, and strontium. , the elements of the resin component are carbon and silicon. At this time, the total mass ratio of the mass ratios (mass%) of carbon and silicon elements in the R1 region is JR1, and the total mass ratio of the mass ratios (mass%) of iron, manganese, magnesium, and strontium elements is FR1. Become. Further, the total mass ratio of the mass ratios (mass %) of carbon and silicon elements in the R2 region is JR2, and the total mass ratio of the mass ratios (mass %) of iron, manganese, magnesium, and strontium elements is FR2.

<Measurement of the amount of coating resin on the magnetic carrier>
For example, when the filled resin is not dissolved in toluene and a thermoplastic resin is used as the coating resin, the amount of the coating resin can be measured from the magnetic carrier by the following method.
A: After accurately weighing a 100 ml beaker (measured value 1), add about 5 g of the sample to be measured, and accurately weigh the total mass of the sample and beaker (measured value 2).
B Put about 50ml of toluene into a beaker and shake for 5 minutes using an ultrasonic shaker.
C. After the shaking is finished, let stand for several minutes, stir the sample in the beaker by tracing the bottom of the beaker 20 times with a neodymium magnet, and then drain only the toluene solution in which the coating resin has been dissolved as waste liquid.
D While holding the sample in the beaker from the outside with a neodymium magnet, pour about 50 ml of toluene into the beaker again and repeat the above operations B and C 10 times.
E Change the solvent to chloroform and perform the above operations B and C once more.
F Put the whole beaker into a vacuum dryer and dry and remove the solvent (use a vacuum dryer equipped with a solvent trap, perform the drying at a temperature of 50° C., a degree of vacuum of -0.093 MPa or less, and a drying time of 12 hours).
G Take out the beaker from the vacuum dryer, leave it to cool for about 20 minutes, and then accurately weigh the mass (measurement value 3).
H From the measured values obtained as described above, the amount of coated resin (% by mass) is calculated according to the following formula.
Amount of coating resin = (Initial sample mass - Sample mass after dissolving coating resin) / Sample mass x 100
In the above formula, the sample mass is determined by calculating (measured value 2 - measured value 1), and the sample mass after dissolving the coating resin is calculated by (measured value 3 - measured value 1).

<Method for measuring number average particle diameter of magnetic material>
The number average particle diameter of magnetic particles A and magnetic particles B in the magnetic material-dispersed resin carrier core material is measured by the following procedure.
A cross section of the magnetic material-dispersed resin carrier core material cut with a microtome or the like is observed with a scanning electron microscope (50,000 times magnification), and 100 particles having a particle diameter of 50 nm or more are randomly extracted. The long axis particle diameter of each extracted particle is calculated from the image, and the average value of the 100 particle diameters is defined as the number average particle diameter.
Note that when the magnetic particles B do not contain manganese element, aluminum element, magnesium element, titanium element, or nickel element, magnetic particles A and B can be distinguished from each other in the cross section by the following method.
Using a scanning electron microscope (manufactured by Hitachi, Ltd., S4700 (trade name)), the elements of the magnetic component and resin component of the cross section of the magnetic material-dispersed resin carrier core material were measured using the elements attached to the scanning electron microscope. Analyze using analysis means (energy dispersive X-ray analyzer manufactured by EDAX).
Elemental analysis of one magnetic particle is performed while adjusting the magnification, and particles in which elemental iron and elemental manganese, aluminum, magnesium, titanium, or nickel are detected are defined as magnetic particles A. Particles containing only iron element or iron element and elements other than manganese element, aluminum element, magnesium element, titanium element, and nickel element are defined as magnetic particles B, and particles in which iron element is not detected are defined as non-magnetic particles. It is defined as

<Measurement method of F1 and M1 using fluorescent X-ray diffraction method>
F1 and M1 of the magnetic carrier are measured using a sample before being coated with resin. Alternatively, the resin coating layer of the coated magnetic carrier may be dissolved in chloroform and then dried.
Elements from Na to U in the magnetic material-dispersed resin carrier core material are directly measured in a He atmosphere using a wavelength-dispersive X-ray fluorescence spectrometer Axios advanced (manufactured by Spectris). Although a resin component is present in the magnetic material-dispersed resin carrier core material, since the element detected by fluorescent X-ray analysis is a metal, the ratio of F1 and M1 in the magnetic carrier is essentially the same. is required.
For the sample, use the liquid sample cup attached to the device, cover the bottom with a PP (polypropylene) film, add a sufficient amount (10 g) of the sample, form a layer of uniform thickness on the bottom, and close the lid. Measured under the condition that the output is 2.4kW.
The analysis uses the FP (fundamental parameter) method. At this time, it is assumed that all the detected elements are oxides, and their total mass is 100% by mass. F1 for the total mass using the software UniQuant5 (ver. 5.49) (manufactured by Spectris),
The content (mass%) of M1 is determined as an oxide equivalent value.

<Measurement method of F2 and M2 by XPS>
Paste the magnetic carrier on the indium foil. At that time, the particles are applied uniformly so that the indium foil portion is not exposed. The measurement conditions for the XPS analysis are as follows.
Equipment: PHI5000VERSAPROBE II (ULVAC-PHI Co., Ltd.)
Irradiation line: Al Kd line output: 25W 15kV
Pass Energy: 29.35eV
Step size: 0.125eV
XPS peaks: Ti _2P , Al _2P , Mg _2P , Mn _2p , Ni _2p , Fe _2p
The element % calculated from each peak is converted into mass %, and F2 and M2 are defined as F2 and M2.

<Time constant of charging of developer>
The charging time constant of the developer was calculated by the following method.
First, 90 g of the specified magnetic carrier and 10 g of toner were placed in a plastic bottle with a lid, and shaken in a shaker (YS-LD, manufactured by Yayoi Co., Ltd.) for a specified period of time at a speed of 4 reciprocations per second. A developer consisting of toner and carrier is charged. The times defined here are 60 seconds, 120 seconds, 300 seconds, 600 seconds, 1200 seconds, 1800 seconds, and 2400 seconds.
Next, the amount of triboelectric charge is measured using the apparatus for measuring the amount of triboelectric charge shown in FIG. Approximately 0.5 to 1.5 g of the developer described above is placed in a metal measuring container 2 with a 500 mesh screen 3 at the bottom, and a metal lid 4 is placed. The mass of the entire measurement container at this time is weighed and is defined as W1 (g). Next, in the suction device 1 (at least the portion in contact with the measurement container 2 is an insulator), suction is performed from the suction port 7, and the air volume control valve 6 is adjusted to set the pressure of the vacuum gauge 5 to 250 mmAq. In this state, suction is performed for 2 minutes to remove the toner. The potential of the electrometer 9 at this time is assumed to be V (volt). Here, the capacitance of the capacitor 8 is assumed to be C (mF). Moreover, the mass of the entire measurement container after suction is weighed and is defined as W2 (g). The amount of triboelectric charge (mC/kg) of this sample is calculated from the following formula.
Triboelectric charge amount of sample q(t)=(mC/kg)=C×V/(W1-W2)
From the obtained results, we can calculate the change in the amount of charge of the developer by
q(t)=A {1-exp(-t/tg)}
When approximated,
The value of tg is calculated as the charging time constant. (A: constant, t: shaking time)

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited only to these Examples. In the following formulations, parts are by weight unless otherwise specified.

<Production example of polymer 1>
・Solvent: Toluene 100.0 parts ・Monomer composition 100.0 parts (The monomer composition is a mixture of the following behenyl acrylate, methacrylonitrile, and styrene in the ratio shown below)
・Behenyl acrylate (first monomer) 67.0 parts (28.9 mol%)
・Methacrylonitrile (second monomer) 22.0 parts (53.8 mol%)
・Styrene (third monomer) 11.0 parts (17.3 mol%)
・Polymerization initiator t-butyl peroxypivalate (manufactured by NOF Corporation: Perbutyl PV) 0.5 parts The above materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen introduction tube under a nitrogen atmosphere. I put it in. While stirring the inside of the reaction vessel at 200 rpm, the reaction vessel was heated to 70°C to carry out a polymerization reaction for 12 hours to obtain a solution in which the polymer of the monomer composition was dissolved in toluene. Subsequently, the temperature of the solution was lowered to 25° C., and then the solution was poured into 1000.0 parts of methanol with stirring to precipitate methanol-insoluble components. The resulting methanol-insoluble matter was filtered off, further washed with methanol, and then vacuum-dried at 40° C. for 24 hours to obtain Polymer 1. Polymer 1 had a weight average molecular weight of 68,400, a melting point of 62° C., and an acid value of 0.0 mgKOH/g.
When the above polymer A1 was analyzed by NMR, it contained 28.9 mol% of monomer units derived from behenyl acrylate, 53.8% of monomer units derived from methacrylonitrile, and 17.3 mol% of monomer units derived from styrene. It was The SP value of the monomer and the monomer unit derived from the monomer was calculated.

<Preparation of monomer having urethane group>
50.0 parts of methanol was charged into the reaction vessel. Thereafter, 5.0 parts of Karenz MOI [2-isocyanatoethyl methacrylate] (Showa Denko KK) was added dropwise at 40° C. while stirring. After the dropwise addition was completed, stirring was performed for 2 hours while maintaining the temperature at 40°C. Thereafter, unreacted methanol was removed using an evaporator to prepare a monomer having a urethane group.

<Preparation of monomer having urea group>
50.0 parts of dibutylamine was charged into a reaction vessel. Thereafter, 5.0 parts of Karenz MOI [2-isocyanatoethyl methacrylate] was added dropwise at room temperature while stirring. After the dropwise addition was completed, stirring was performed for 2 hours. Thereafter, unreacted dibutylamine was removed using an evaporator to prepare a monomer having a urea group.

<Production examples of polymers 2 to 26>
Polymers 2 to 26 were obtained by carrying out the reaction in the same manner as in the production example of Polymer 1, except that the respective monomers and parts by mass were changed as shown in Table 1. The physical properties are shown in Tables 2 to 4.

表中の略号は以下の通り。
ＢＥＡ：ベヘニルアクリレート
ＳＡ：ステアリルアクリレート
ＭＹＡ：ミリシルアクリレート
ＯＡ：オクタコサアクリレート
ＨＡ：ヘキサデシルアクリレート
ＭＮ：メタクリロニトリル
ＡＮ：アクリロニトリル
ＨＰＭＡ：メタクリル酸２ヒドロキシプロピル
ＡＭ：アクリルアミド
ＵＴ：ウレタン基を有する単量体
ＵＲ：ウレア基を有する単量体
ＡＡ：アクリル酸
ＶＡ：酢酸ビニル
ＭＡ：アクリル酸メチル
Ｓｔ：スチレン
ＭＭ：メタクリル酸メチル

The abbreviations in the table are as follows.
BEA: Behenyl acrylate SA: Stearyl acrylate MYA: Myricyl acrylate OA: Octacosa acrylate HA: Hexadecyl acrylate MN: Methacrylonitrile AN: Acrylonitrile HPMA: 2-hydroxypropyl methacrylate AM: Acrylamide UT: Monomer with urethane group UR: Monomer having urea group AA: Acrylic acid VA: Vinyl acetate MA: Methyl acrylate St: Styrene MM: Methyl methacrylate

<Synthesis example of amorphous resin 1 that is not polymer A>
After 50 parts of xylene was charged into an autoclave and the autoclave was purged with nitrogen, the temperature was raised to 185° C. in a closed state while stirring. A mixed solution of 95 parts of styrene, 5 parts of n-butyl acrylate, 5 parts of di-t-butyl peroxide, and 20 parts of xylene was continuously added dropwise for 3 hours to polymerize while controlling the temperature inside the autoclave at 185°C. Ta. The polymerization was further maintained at the same temperature for 1 hour, and the solvent was removed to obtain amorphous resin 1, which is not polymer A. The weight average molecular weight (Mw) of the obtained resin was 3500, the softening point (Tm) was 96°C, and the glass transition temperature (Tg) was 58°C.

<Production example of polymer fine particle 1 dispersion>
- Toluene (manufactured by Wako Pure Chemical Industries, Ltd.) 300 parts - Polymer 1 100 parts The above materials were weighed, mixed, and dissolved at 90°C.
Separately, 5.0 parts of sodium dodecylbenzenesulfonate and 10.0 parts of sodium laurate were added to 700 parts of ion-exchanged water and dissolved by heating at 90°C. Next, the toluene solution and the aqueous solution were mixed together, and an ultra-high speed stirring device T. K. Stirring was performed at 7000 rpm using Robomix (manufactured by Primix). Further, the mixture was emulsified at a pressure of 200 MPa using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo). Thereafter, toluene was removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain an aqueous dispersion of polymer fine particles 1 with a concentration of 20% by mass (polymer fine particle 1 dispersion).
The 50% particle diameter (D50) of the polymer fine particles 1 based on the volume distribution was measured using a dynamic light scattering particle size analyzer Nanotrack UPA-EX150 (manufactured by Nikkiso) and found to be 0.40 μm.

<Production example of polymer fine particles 2 to 26 dispersion>
Emulsification was carried out in the same manner as in the production example of Polymer Fine Particles 1 dispersion, except that the respective polymers were changed as shown in Table 5, to obtain Polymer Fine Particles 2 to 26 dispersions. The physical properties are shown in Table 5.

<Example of manufacturing a dispersion of amorphous resin fine particles 1 that is not polymer A>
・Tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) 300 parts ・Amorphous resin 1 that is not polymer A 100 parts ・Anionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku) 0.5 parts The above materials are weighed, mixed, and dissolved. I let it happen.
Next, 20.0 parts of 1 mol/L aqueous ammonia was added, and a T. K. Stirring was performed at 4000 rpm using Robomix (manufactured by Primix). Further, 700 parts of ion-exchanged water was added at a rate of 8 parts/min to precipitate fine particles of amorphous resin 1. Thereafter, tetrahydrofuran was removed using an evaporator, and the concentration was adjusted with ion-exchanged water to obtain an aqueous dispersion of Amorphous Resin 1 microparticles at a concentration of 20% by mass (Amorphous Resin 1 microparticle dispersion).
The 50% particle diameter (D50) of the fine particles of the amorphous resin 1 based on the volume distribution was 0.13 μm.

<Example of production of mold release agent (aliphatic hydrocarbon compound) fine particle dispersion>
・Aliphatic hydrocarbon compound HNP-51 (manufactured by Nippon Seiro) 100 parts ・Anionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku) 5 parts ・Ion exchange water 395 parts Weigh the above materials and mix with a stirring device. After putting it into a container, it was heated to 90° C. and circulated through Clearmix W Motion (manufactured by M Techniques) to perform a dispersion treatment for 60 minutes. The conditions for the distributed processing were as follows.
・Rotor outer diameter 3cm
・Clearance 0.3mm
・Rotor rotation speed 19000r/min
・Screen rotation speed 19000r/min
After the dispersion treatment, the release agent (aliphatic hydrocarbon compound) fine particles are cooled to 40°C under the following cooling treatment conditions: rotor rotation speed 1000 r/min, screen rotation speed 0 r/min, and cooling rate 10°C/min. An aqueous dispersion (a mold release agent (aliphatic hydrocarbon compound) fine particle dispersion) having a concentration of 20% by mass was obtained.
The 50% particle size (D50) of the mold release agent (aliphatic hydrocarbon compound) fine particles based on the volume distribution was measured using a dynamic light scattering particle size analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso), and it was found to be 0. It was 15 μm.

<Production of colorant fine particle dispersion>
・Coloring agent 50.0 parts (Cyan pigment Dainichiseika: Pigment Blue 15:3)
・Anionic surfactant Neogen RK (manufactured by Daiichi Kogyo Seiyaku) 7.5 parts ・Ion exchange water 442.5 parts Weigh and mix the above materials, dissolve them, and use a high-pressure impact dispersion machine Nanomizer (manufactured by Yoshida Kikai Kogyo). The mixture was dispersed for about 1 hour to obtain an aqueous dispersion of colorant fine particles having a concentration of 10% by mass (colorant fine particle dispersion).
The 50% particle diameter (D50) of the colorant fine particles based on the volume distribution was measured using a dynamic light scattering particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso) and found to be 0.20 μm.

<Production example of toner particles 1>
- Polymer fine particle 1 dispersion liquid 500 parts - Mold release agent (aliphatic hydrocarbon compound fine particle dispersion liquid) 50 parts - Colorant fine particle dispersion liquid 80 parts - Ion exchange water 160 parts Each of the above materials was placed in a round stainless steel flask. Added and mixed. Subsequently, the mixture was dispersed for 10 minutes at 5000 r/min using a homogenizer Ultra Turrax T50 (manufactured by IKA). After adding a 1.0% nitric acid aqueous solution and adjusting the pH to 3.0, the mixture was heated to 58°C using a stirring blade in a heating water bath while adjusting the rotation speed as appropriate to stir the mixture. heated to. The volume average particle size of the formed aggregated particles was appropriately confirmed using Coulter Multisizer III, and when aggregated particles with a weight average particle size (D4) of about 6.00 μm were formed, 5% sodium hydroxide was added. The pH was brought to 9.0 using an aqueous solution. Thereafter, the mixture was heated to 75° C. while stirring was continued. The aggregated particles were then fused by holding at 75° C. for 1 hour.
Thereafter, the temperature was cooled to 50° C. and maintained for 3 hours to promote crystallization of the polymer.
Thereafter, it was cooled to 25 degrees, filtered and separated into solid and liquid, and then washed with ion-exchanged water. After washing, the toner particles 1 having a weight average particle diameter (D4) of about 6.1 μm were obtained by drying using a vacuum dryer.

<Production example of toner particles 2>
- Monomer composition 100.0 parts (The monomer composition is a mixture of behenyl acrylate, methacrylonitrile, and styrene shown below in the proportions shown below.)
Behenyl acrylate 67.0 parts (28.9 mol%)
Methacrylonitrile 22.0 parts (53.8 mol%)
Styrene 11.0 parts (17.3 mol%)
・Colorant Pigment Blue 15:3 6.5 parts ・Aluminum di-t-butylsalicylate 1.0 parts ・Paraffin wax 10.0 parts (Nippon Seirosha: HNP-51)
- A mixture consisting of 100.0 parts of toluene was prepared. The above mixture was put into an attritor (manufactured by Nippon Coke Co., Ltd.) and dispersed using zirconia beads with a diameter of 5 mm at 200 rpm for 2 hours to obtain a raw material dispersion.
Meanwhile, 735.0 parts of ion-exchanged water and 16.0 parts of trisodium phosphate (decahydrate) were added to a container equipped with a high-speed stirring device Homomixer (manufactured by Primix) and a thermometer, and the mixture was stirred at 12,000 rpm. At the same time, the temperature was raised to 60°C. A calcium chloride aqueous solution containing 9.0 parts of calcium chloride (dihydrate) dissolved in 65.0 parts of ion-exchanged water was added thereto, and the mixture was stirred at 12,000 rpm for 30 minutes while maintaining the temperature at 60°C. 10% hydrochloric acid was added thereto to adjust the pH to 6.0 to obtain an aqueous medium containing a dispersion stabilizer.
Subsequently, the raw material dispersion was transferred to a container equipped with a stirring device and a thermometer, and the temperature was raised to 60° C. while stirring at 100 rpm. Thereto, 8.0 parts of t-butyl peroxypivalate (Perbutyl PV, manufactured by NOF Corporation) was added as a polymerization initiator, and the mixture was stirred at 100 rpm for 5 minutes while maintaining the temperature at 60°C. The mixture was poured into an aqueous medium being stirred at 12,000 rpm. While maintaining the temperature at 60° C., stirring was continued for 20 minutes at 12,000 rpm using the above-mentioned high-speed stirring device to obtain a granulated liquid.
The above granulation liquid was transferred to a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen introduction tube, and the temperature was raised to 70° C. while stirring at 150 rpm under a nitrogen atmosphere. The polymerization reaction was carried out at 150 rpm for 10 hours while maintaining the temperature at 70°C. Thereafter, the reflux condenser was removed from the reaction vessel, and the reaction solution was heated to 95° C., and then stirred at 150 rpm for 5 hours while maintaining 95° C. to remove toluene and obtain a toner particle dispersion.
The resulting toner particle dispersion was cooled to 20° C. while stirring at 150 rpm, and dilute hydrochloric acid was added to the dispersion while stirring until the pH reached 1.5 to dissolve the dispersion stabilizer. The solid content was filtered off, thoroughly washed with ion-exchanged water, and then vacuum-dried at 40° C. for 24 hours to obtain toner particles 2.

<Production example of toner particles 3>
[Preparation of fine particle dispersion 1]
In a reaction vessel equipped with a stirring rod and a thermometer, 683.0 parts of water, 11.0 parts of sodium salt of methacrylic acid EO adduct sulfate ester (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), and 130.0 parts of styrene were added. , 138.0 parts of methacrylic acid, 184.0 parts of n-butyl acrylate, and 1.0 part of ammonium persulfate were added, and the mixture was stirred at 400 rpm for 15 minutes to obtain a white suspension. The system was heated to an internal temperature of 75° C. and reacted for 5 hours. Furthermore, 30.0 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75° C. for 5 hours to obtain a vinyl polymer fine particle dispersion 1. The volume average particle diameter of the fine particle dispersion 1 was 0.15 μm.

[Preparation of colorant dispersion 1]
C. I. Pigment Blue 15:3 100.0 parts Ethyl acetate 150.0 parts Glass beads (1 mm) 200.0 parts The above materials were put into a heat-resistant glass container, dispersed for 5 hours in a paint shaker, and then glassed with a nylon mesh. The beads were removed to obtain Colorant Dispersion 1.

[Preparation of wax dispersion 1]
Paraffin wax (manufactured by Nippon Seiro Co., Ltd.: HNP-51) 20.0 parts Ethyl acetate 80.0 parts The above mixture was placed in a sealable reaction vessel, and heated and stirred at 80°C. Then, the system was cooled to 25° C. over 3 hours while being gently stirred at 50 rpm to obtain a milky white liquid.
This solution was put into a heat-resistant container along with 30.0 parts of glass beads with a diameter of 1 mm, and dispersed for 3 hours using a paint shaker (manufactured by Toyo Seiki).The glass beads were removed using a nylon mesh to obtain wax dispersion 1. Ta.

[Preparation of oil phase 1]
Polymer (A1) 100.0 parts Ethyl acetate 85.0 parts The above materials were placed in a beaker and stirred for 1 minute at 3000 rpm using a disper (manufactured by Tokushu Kika Co., Ltd.).
Wax dispersion 1 (solid content 20%) 50.0 parts Colorant dispersion 1 (solid content 40%) 12.5 parts Ethyl acetate 5.0 parts Further, put the above materials in a beaker, and put Disper (manufactured by Tokushu Kika Co., Ltd.) ) and stirred at 6000 rpm for 3 minutes to prepare oil phase 1.

[Preparation of aqueous phase 1]
Fine particle dispersion liquid 1 15.0 parts Sodium dodecyl diphenyl ether disulfonate aqueous solution (Eleminol MON7, manufactured by Sanyo Chemical Industries, Ltd.) 30.0 parts Ion-exchanged water 955.0 parts Place the above materials in a beaker and disper (manufactured by Tokushu Kika Co., Ltd.) The mixture was stirred for 3 minutes at 3000 rpm to prepare aqueous phase 1.

[Manufacture of toner particles 3]
Oil phase 1 was added to water phase 1 and dispersed for 10 minutes at a rotation speed of 10,000 rpm using a TK homo mixer (manufactured by Tokushu Kika Co., Ltd.). Thereafter, the solvent was removed for 30 minutes at 30° C. and under a reduced pressure of 50 mmHg. Next, filtration was performed, and the operations of filtration and redispersion into ion-exchanged water were repeated until the conductivity of the slurry reached 100 μS, thereby removing the surfactant and obtaining a filter cake.
After vacuum drying the filter cake, toner particles 3 were obtained by performing air classification.

<Production example of toner particles 4>
- Polymer 1 100 parts - Aliphatic hydrocarbon compound HNP-51 (manufactured by Nippon Seiro) 10 parts - C.I. I. Pigment Blue 15:3 6.5 parts 3,5-di-t-butylsalicylic acid aluminum compound 0.5 parts After mixing at 20 s ⁻¹ and a rotation time of 5 min, the mixture was kneaded at a discharge temperature of 135° C. using a twin-screw kneader (PCM-30 model, manufactured by Ikegai Co., Ltd.) set at a temperature of 120° C. The obtained kneaded material was cooled at a cooling rate of 15° C./min, and coarsely ground to 1 mm or less using a hammer mill to obtain a coarsely ground material.
The obtained coarse material was pulverized using a mechanical pulverizer (T-250, manufactured by Freund Turbo Co., Ltd.). Further, classification was performed using Faculty F-300 (manufactured by Hosokawa Micron) to obtain toner particles 4. The operating conditions were a classification rotor rotation speed of 130 s ⁻¹ and a dispersion rotor rotation speed of 120 s ⁻¹ .

<Production example of toner 1>
・Toner particles 1 100 parts ・Large-sized silica particles surface-treated with hexamethyldisilazane with an average particle size of 130 nm
3 parts/Small silica particles surface-treated with hexamethyldisilazane with an average particle size of 20 nm
1 part Each of the above materials was mixed using a Henschel mixer model FM-10C (manufactured by Mitsui Miike Kakoki) at a rotation speed of 30 s ^-1 and a rotation time of 10 min to obtain Toner 1. The weight average particle diameter (D4) of Toner 1 was 6.07 μm.

<Production example of toner particles 2 to 31>
Toner particles 5 to 31 were obtained in the same manner as in the production example of toner particles 1, except that the formulation of polymer 1 was changed as shown in Table 8. For toner particles 24 and 25, a dispersion of polymer fine particles 1 and a fine particle dispersion of amorphous resin 1 were mixed in amounts shown in Table 6.
<Production example of toners 2 to 31>
Toners 2 to 31 were produced in the same manner as in the production example of Toner 1 except that the toner particles were changed to those listed in Table 6.

<Example of manufacturing magnetic carrier>
<Manufacturing example of magnetic core 1>
Process 1 (weighing/mixing process)
Fe ₂ O ₃ 69.3% by mass
MnCO ₃ 27.5% by mass
Mg(OH) ₂ 1.7% by mass
SrCO ₃ 1.5% by mass
The above ferrite raw material was weighed, 20 parts of water was added to 80 parts of the ferrite raw material, and then wet-mixed for 3 hours in a ball mill using zirconia having a diameter (φ) of 10 mm to prepare a slurry. The solid content concentration of the slurry was 80% by mass.
Process 2 (temporary firing process)
After drying the mixed slurry with a spray dryer (manufactured by Okawara Kakoki Co., Ltd.), it was fired in a batch electric furnace at a temperature of 1070°C for 3.0 hours in a nitrogen atmosphere (oxygen concentration 1.0% by volume), and then calcined. Ferrite was produced.
Process 3 (Crushing process)
After the calcined ferrite was crushed to about 0.5 mm using a crusher, water was added to prepare a slurry. The solid content concentration of the slurry was set to 70% by mass. The mixture was ground for 3.5 hours in a wet ball mill using 1/8 inch stainless steel beads to obtain a slurry. Further, this slurry was pulverized for 4 hours in a wet bead mill using zirconia with a diameter of 1 mm to obtain a calcined ferrite slurry having a volume-based 50% particle diameter (D50) of 1.1 μm.
Process 4 (granulation process)
After adding 1.0 part of ammonium polycarboxylate as a dispersant and 1.5 parts of polyvinyl alcohol as a binder to 100 parts of the above calcined ferrite slurry, they were granulated into spherical particles using a spray dryer (manufactured by Okawara Kakoki Co., Ltd.). , dried. After adjusting the particle size of the obtained granules, they were heated at 720° C. for 2 hours using a rotary electric furnace to remove organic substances such as dispersants and binders.
Process 5 (baking process)
The time from room temperature to the firing temperature (1100°C) was 1.7 hours in a nitrogen atmosphere (oxygen concentration 1.0% by volume), and the temperature was maintained at 1180°C for 4.5 hours for firing. Thereafter, the temperature was lowered to 60°C over 8 hours, returned to the atmosphere from the nitrogen atmosphere, and taken out at a temperature of 40°C or lower.
Process 6 (sorting process)
After crushing the aggregated particles, sieving with a sieve with an opening of 150 μm to remove coarse particles, performing wind classification to remove fine particles, and further removing low magnetic force components by magnetic beneficiation to obtain the pre-magnetic core 1. Obtained. The obtained pre-magnetic core 1 was porous and had holes. The premagnetic core 1 had a D50 of 41.3 μm, a magnetization amount of 60 Am ² /kg, a peak pore diameter of 0.45 μm, and a pore volume of 45 mm ³ /g.

(Manufacture of filled resin composition 1)
・Methyl silicone oligomer (KR-400: manufactured by Shin-Etsu Silicone Co., Ltd.): 95.0 parts ・γ-Aminopropyltriethoxysilane (KBM-903: manufactured by Shin-Etsu Silicone Co., Ltd.)
: 5.0 parts Filled resin composition 1 was obtained by mixing the above materials.

(Filling process)
100 parts of the pre-magnetic core 1 was placed in a stirring container of a mixing stirrer (all-purpose stirrer NDMV type manufactured by Dalton), the temperature was maintained at 60°C, and 7 parts of the pre-magnetic core 1 was added under normal pressure. It was dropped onto core 1.
After the dropwise addition was completed, stirring was continued while adjusting the time, the temperature was raised to 70° C., and the particles of the pre-magnetic core 1 were filled with the resin composition.
After cooling, the resin-filled magnetic core obtained was transferred to a mixer (drum mixer UD-AT type manufactured by Sugiyama Heavy Industries, Ltd.) having a spiral blade in a rotatable mixing container, and heated at 2°C/min under a nitrogen atmosphere. The temperature was raised to the curing temperature of 140° C. while stirring at a heating rate of . Thereafter, heating and stirring were continued at 140° C. for a curing time of 50 minutes.
Thereafter, it was cooled to room temperature, and the resin-filled and hardened ferrite particles were taken out, and non-magnetic materials were removed using a magnetic separator. Furthermore, coarse particles were removed using a vibrating sieve to obtain a resin-filled magnetic core 1. The resin-filled magnetic core 1 had a D50 of 41.3 μm and a magnetization amount of 60 Am ² /kg.

<Manufacturing example of magnetic core 2>
<Production example of amorphous magnetic particles a>
Fe ₃ O ₄ was mixed and ground in a wet ball mill for 10 hours. 1 part of polyvinyl alcohol was added, and the mixture was granulated and dried using a spray dryer. Firing was performed in an electric furnace at 900° C. for 10 hours in a nitrogen atmosphere with an oxygen concentration of 0.0% by volume.
The obtained magnetic material was ground in a dry ball mill for 5 hours. It was classified using an air classifier (Elbo Jet Lab EJ-L3, manufactured by Nippon Steel Mining Co., Ltd.), and fine powder and coarse powder were simultaneously classified and removed to obtain amorphous magnetic particles a having a number average particle diameter of 1.7 μm.

<Preparation of magnetic particles A>
To 100 L of slurry containing 90 g/L of the amorphous magnetic particles a whose number average particle diameter was adjusted to 1.7 μm, a sodium hydroxide solution was added at a temperature of 90°C to adjust the pH to 8.5. 30 L of an aqueous manganese sulfate solution and an aqueous sodium hydroxide solution were added over 190 minutes while simultaneously adjusting the pH to 8.5±0.2. Next, after aging for 60 minutes, dilute sulfuric acid was added to adjust the pH to 7.0, followed by filtration, washing with water, and drying to obtain amorphous magnetic particles A surface-treated with Mn.
Furthermore, the obtained amorphous magnetic particles A and a silane coupling agent (3-(2-aminoethylamino)propyltrimethoxysilane) (0.2 parts per 100 parts of the amorphous magnetic particles A) were added. , introduced into the container.
Then, the mixture was surface-treated by high-speed mixing and stirring at 100° C. for 1 hour in the container to obtain magnetic particles A for a magnetic core 2 of a magnetic material dispersion type. The number average particle diameter ra of the magnetic particles A was 1.7 μm.

<Production example of amorphous magnetic particles B>
Fe ₃ O ₄ was mixed and ground in a wet ball mill for 10 hours. 1 part of polyvinyl alcohol was added, and the mixture was granulated and dried using a spray dryer. Firing was performed in an electric furnace at 900° C. for 10 hours in a nitrogen atmosphere with an oxygen concentration of 0.0% by volume.
The obtained magnetic material was ground in a dry ball mill for 10 hours. Classification was performed using an air classifier (Elbo Jet Lab EJ-L3, manufactured by Nippon Steel Mining Co., Ltd.), and fine powder and coarse powder were simultaneously classified and removed to obtain amorphous magnetic particles B with a number average particle diameter rb of 0.3 μm. .

<Preparation of magnetic particles B>
The obtained amorphous magnetic particles B and a silane coupling agent (3-glycidoxypropylmethyldimethoxysilane) (1.2 parts per 100 parts of amorphous magnetic particles B) were introduced into a container. . Then, the mixture was surface-treated by high-speed mixing and stirring at 100° C. for 1 hour in the container, to obtain magnetic particles B for the magnetic core 2 of the magnetic material dispersion type.

(Dispersion process)
- Phenol 10.0 parts - Formaldehyde solution (formaldehyde 37% by mass aqueous solution) 15.0 parts - Magnetic particles A 10.0 parts - Magnetic particles B 90.0 parts - 25% by mass aqueous ammonia 3.5 parts - Water 15. 0 parts The above materials were introduced into a reaction vessel, brought to a temperature of 40°C, and mixed well. Thereafter, the mixture was heated to 85° C. with stirring at an average temperature increase rate of 1.5° C./min, maintained at 85° C., and subjected to a polymerization reaction for 3 hours to be cured. The circumferential speed of the stirring blade at this time was 1.96 m/sec.
After the polymerization reaction, the mixture was cooled to 30° C. and water was added. The precipitate obtained by removing the supernatant liquid was washed with water and further air-dried. The obtained air-dried product was dried at 180° C. for 5 hours under reduced pressure (5 mmHg or less) to obtain a magnetic core 2 of a magnetic material dispersion type. The D50 of the magnetic material-dispersed magnetic core 2 was 43.1 μm, and the amount of magnetization was 62 Am ² /kg. Moreover, M1/F1 was 0.041, and M2/F2 was 3.0.

<Manufacturing example of magnetic core 3>
As the magnetic core 3, commercially available ferrite particles EF-35 (manufactured by Powder Tech) were used. The magnetic core 3 had a D50 of 42.0 μm and a magnetization amount of 61 Am ² /kg.

<Production example of coating resin polymer 101 solution>
Cyclohexyl methacrylate: 37.3 parts Methyl methacrylate: 62.7 parts The above materials were added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a grinding type stirring device, and then 100 parts of toluene. , 100 parts of methyl ethyl ketone, and 2.4 parts of azobisisovaleronitrile were added and kept at 80° C. for 10 hours under a nitrogen stream to obtain a solution of polymer 101 (solid content: 35% by mass).

<Production example of coating resin polymer 102-115 solution>
In the production example of the coating resin polymer 101 solution, the reaction was carried out in the same manner except that the respective monomers and mass parts were changed as shown in Table 7, and solutions of polymers 102 to 115 were obtained. Table 7 shows the SP values of the monomer units of Polymers 101 to 115.

表７中の略号は以下の通り。
ＭＭＡ：メチルメタクリレート
ＣＨＭＡ：シクロヘキシルメタクリレート
ＣＤＭＡ：シクロデシルメタクリレート
ＶＡ：酢酸ビニル
ＭＡ：メチルアクリレート
ＢＭＡ：ブチルメタクリレート
ＨＭＡ：ヘキシルメタクリレート
ＡＡ：アクリル酸

The abbreviations in Table 7 are as follows.
MMA: Methyl methacrylate CHMA: Cyclohexyl methacrylate CDMA: Cyclodecyl methacrylate VA: Vinyl acetate MA: Methyl acrylate BMA: Butyl methacrylate HMA: Hexyl methacrylate AA: Acrylic acid

<Manufacturing example of magnetic carrier 1>
A coating resin polymer solution was diluted with toluene so that the resin component was 5% by mass, and a sufficiently stirred resin solution was prepared. Thereafter, a coating resin amount of 2.0% by mass as solid content of the resin component based on 100 parts of magnetic core particles was placed in a planetary motion mixer (Nauta mixer VN type manufactured by Hosokawa Micron) maintained at a temperature of 60°C. The resin solution was added so that As for the charging method, 1/2 amount of resin solution was charged, and solvent removal and coating operations were performed for 30 minutes. Next, 1/2 the amount of the resin solution was added, and the solvent removal and coating operations were performed for 40 minutes.
Thereafter, the magnetic carrier coated with the coating resin composition was transferred to a mixer (drum mixer UD-AT type manufactured by Sugiyama Heavy Industries, Ltd.) having a spiral blade in a rotatable mixing container. While stirring the mixing container at 10 revolutions per minute, heat treatment was performed at a temperature of 120° C. for 2 hours in a nitrogen atmosphere. The obtained magnetic carrier was separated into low-magnetic products by magnetic separation, passed through a sieve with an opening of 150 μm, and then classified using an air classifier to obtain Magnetic Carrier 1.

<Production examples of magnetic carriers 2 to 19>
Magnetic carriers 2 to 19 were obtained by carrying out the reaction in the same manner as in the production example of magnetic carrier 1, except that the respective polymers, other resins, and parts were changed as shown in Table 8. Table 8 shows the MR2/MR1 and glass transition temperature of the coating resin.

<Production example of two-component developer 1>
8.0 parts of Toner 1 was added to 92.0 parts of Magnetic Carrier 1 and mixed using a V-type mixer (V-20, manufactured by Seishin Enterprises) to obtain Two-Component Developer 1.

<Production examples of two-component developers 2 to 46>
Two-component developers 2 to 46 were produced in the same manner as in the production example of two-component developer 1, except that the toner and carrier were changed as shown in Table 9. Table 9 shows the E/F value and charging time constant.

<Evaluation of two-component developer>
The evaluation method for two-component developers 1 to 46 will be explained. In addition, two-component developers 1 to 7, 10 and 13 to 36 were evaluated as examples, and two-component developers 8, 9, 11, 12 and 37 were evaluated as reference examples.
evaluated. Further, two-component developers 38 to 46 were evaluated as comparative examples.

<Evaluation of charging rise>
The charging rise was evaluated by measuring density changes when images with different image printing ratio densities were output. After outputting an image with a low image ratio to bring the toner in the developing machine into a saturated state, an image with a high image ratio is output. Then, a change in density occurs due to a difference in charge between the saturated toner in the developing machine and the toner newly supplied into the developing machine. Toner that is charged quickly becomes saturated immediately after being supplied into the developing machine, resulting in less change in density. On the other hand, toner whose charge rises slowly takes time to reach saturation after it is supplied into the developing machine, resulting in a decrease in the amount of charge of the entire toner and a change in density.
Using a full color copying machine imagePress C800 manufactured by Canon as an image forming apparatus, the above two-component developer was put into the cyan developing device of the image forming apparatus, and the above toner was put into a cyan toner container, and the evaluation described below was performed. .
The main point of modification was that the mechanism for discharging excess magnetic carrier inside the developing device from the developing device was removed. Plain paper GF-C081 (A4, basis weight 81.4 g/m ² , sold by Canon Marketing Japan Inc.) was used as the evaluation paper.
Adjustments were made so that the amount of toner applied on the paper in the FFh image (solid image) was 0.45 mg/cm ² . FFh is a value that represents 256 gradations in hexadecimal notation, where 00h is the 1st gradation (white area) of 256 gradations, and FF is the 256th gradation (solid area) of 256 gradations. .
First, an image output test was conducted on 1000 sheets at an image ratio of 1%. During the continuous feeding of 1000 sheets, the sheets were fed under the same development conditions and transfer conditions (without calibration) as for the first sheet.
Thereafter, an image output test was conducted on 1000 sheets at an image ratio of 80%. During the continuous feeding of 1000 sheets, the sheets were fed under the same development conditions and transfer conditions (without calibration) as for the first sheet.
The image density of the 1000th sheet printed at an image ratio of 1% was taken as the initial density, and the density of the 1000th sheet printed at an image ratio of 80% was measured and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 10.
The above tests were conducted under a normal temperature and normal humidity environment (N/N; temperature 23°C, relative humidity 50% RH) and a normal temperature and low humidity environment (N/L; temperature 23°C, relative humidity 5% RH).

(1) Measurement of image density change Using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite), measure the initial density and the density of the 1,000th image printed at an image ratio of 80%. It was measured and ranked based on the following criteria. The evaluation results are shown in Table 8. A rating of D or higher was judged to indicate that the effects of the present invention were achieved.
(concentration difference)
A: Less than 0.02 B: 0.02 or more and less than 0.04 C: 0.04 or more and less than 0.06 D: 0.06 or more and less than 0.10 E: 0.10 or more

[Charge retention under high temperature and high humidity environment]
The amount of triboelectric charge of the toner was calculated by sucking and collecting the toner on the electrostatic latent image carrier using a metal cylindrical tube and a cylindrical filter.
Specifically, the amount of triboelectric charge of the toner on the electrostatic latent image carrier was measured using a Faraday-Cage. A Faraday cage is a coaxial double cylinder, with an inner cylinder and an outer cylinder insulated. If a charged body with a charge amount Q is placed in this inner cylinder, it will be the same as if a metal cylinder with a charge amount Q exists due to electrostatic induction. The amount of induced charge is measured with an electrometer (Kesley 6517A manufactured by Kesley), and the amount of charge Q (mC) divided by the mass of toner in the inner cylinder M (kg) (Q/M) is calculated as the triboelectrification of the toner. Quantity.
Toner triboelectric charge amount (mC/kg) = Q/M
First, the evaluation image is formed on the electrostatic latent image carrier, and before being transferred to the intermediate transfer member, the rotation of the electrostatic latent image carrier is stopped, and the toner on the electrostatic latent image carrier is transferred to the metal. It was collected by suction using a cylindrical tube and a cylindrical filter, and the [initial Q/M] was measured.
Subsequently, after leaving the developing device inside the evaluation machine for two weeks in a high temperature and high humidity environment (H/H; temperature 30°C, relative humidity 80% RH), the same operation as before leaving was performed, and the The amount of charge Q/M (mC/kg) per unit mass on the electrostatic latent image carrier was measured. The above-mentioned initial Q/M per unit mass on the electrostatic latent image bearing member is taken as 100%, and the maintenance rate of Q/M per unit mass on the electrostatic latent image bearing member after standing ([after standing Q/M]/[Initial Q/M]×100) was calculated and judged based on the following criteria. A rating of D or higher was judged to indicate that the effects of the present invention were achieved.
(Evaluation criteria)
A: Retention rate is 95% or more B: Retention rate is 90% or more and less than 95% C: Retention rate is 85% or more and less than 90% D: Retention rate is 80% or more and less than 85% E: Retention rate is less than 80%

<Low temperature fixability evaluation of toner>
Paper: GFC-081 (81.0g/m ² )
(Sold by Canon Marketing Japan Inc.)
Amount of toner on paper: 0.50mg/ ^cm2
(Adjusted by DC voltage VDC of developer carrier, charging voltage VD of electrostatic latent image carrier, and laser power)
Evaluation image: Place a 2cm x 5cm image in the center of the above A4 paper Test environment: Low temperature and low humidity environment: Temperature 15°C/Relative humidity 10%RH (hereinafter referred to as "L/L")
Fixing temperature: 130℃
Process speed: 377mm/sec
The above evaluation image was output and low temperature fixability was evaluated. The value of image density reduction rate was used as an evaluation index of low temperature fixability. The image density reduction rate was determined by first measuring the image density at the center using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite). Next, a load of 4.9 kPa (50 g/cm ² ) was applied to the area where the image density was measured, and the fixed image was rubbed (5 times back and forth) with Silbon paper, and the image density was measured again. Then, the reduction rate of image density before and after rubbing was calculated using the following formula. The reduction rate of the obtained image density was evaluated according to the following evaluation criteria. A rating of D or higher was judged to indicate that the effects of the present invention were achieved.
Decrease rate of image density = (Image density before friction - Image density after friction) / Image density before friction x 100
(Evaluation criteria)
A: Decrease rate of image density less than 3.0% B: Decrease rate of image density 3.0% or more and less than 5.0% C: Decrease rate of image density 5.0% or more and less than 15.0% D: Image density Reduction rate of 10.0% or more and less than 15.0% E: Reduction rate of image density of 15.0% or more The evaluation results of two-component developers 1 to 46 are shown in Table 10.

1: Suction machine, 2: Measuring container, 3: Screen, 4: Lid, 5: Vacuum gauge, 6: Air volume control valve, 7: Suction port, 8: Condenser, 9: Electrometer

Claims (18)

A two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
The binder resin includes a first monomer unit derived from a first polymerizable monomer and a second monomer unit derived from a second polymerizable monomer different from the first polymerizable monomer. Contains a polymer A having a monomer unit,
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content ratio of the first monomer unit in the polymer A is based on the total number of moles of all monomer units in the polymer A, 10 . 0 mol% to 60.0 mol%,
The content ratio of the second monomer unit in the polymer A is 20.0 mol% to 95.0 mol% based on the total number of moles of all monomer units in the polymer A,
When the SP value of the first monomer unit is SP ₁₁ (J/cm ³ ) ^0.5 and the SP value of the second monomer unit is SP ₂₁ (J/cm ³ ) ^0.5 , the following formula Satisfy (1) to (2),
3.00≦(SP ₂₁ −SP ₁₁ )≦25.00 (1)
21.00≦SP ₂₁ ...(2)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a) and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The content of the monomer unit (a) in the polymer B is 10.0 mol% to 70.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The content of the monomer unit (b) in the polymer B is 30.0 mol% to 90.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . A two-component developer characterized by satisfying the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4) A two-component developer having a toner having toner particles containing a binder resin and a magnetic carrier,
A polymer A in which the binder resin is a polymer of a composition containing a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. Contains
The first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having an alkyl group having 18 to 36 carbon atoms,
The content ratio of the first polymerizable monomer in the composition is based on the total number of moles of all polymerizable monomers in the composition, 10 . 0 mol% to 60.0 mol%,
The content of the second polymerizable monomer in the composition is 20.0 mol% to 95.0 mol% based on the total number of moles of all polymerizable monomers in the composition. can be,
The SP value of the first polymerizable monomer is SP ₁₂ (J/cm ³ ) ^0.5 , and the SP value of the second polymerizable monomer is SP ₂₂ (J/cm ³ ) ^0.5 . Then, the following formulas (5) to (6) are satisfied,
0.60≦(SP ₂₂ −SP ₁₂ )≦15.00 (5)
18.30≦SP ₂₂ ...(6)
The magnetic carrier has a magnetic core and a coating resin on the surface of the magnetic core,
The coating resin includes a monomer unit (a) derived from a polymerizable monomer (a) and a monomer unit (b) derived from a polymerizable monomer (b) different from the polymerizable monomer (a). ) containing a polymer B having
The content of the monomer unit (a) in the polymer B is 10.0 mol% to 70.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The content of the monomer unit (b) in the polymer B is 30.0 mol% to 90.0 mol%, based on the total number of moles of all monomer units in the polymer B,
The SP value of the monomer unit (a) was set to SP(a) (J/cm ³ ) ^0.5 , and the SP value of the monomer unit (b) was set to SP(b) (J/cm ³ ) ^0.5 . A two-component developer characterized by satisfying the following formulas (3) and (4).
20.30≦SP(a)≦22.00 (3)
19.00≦SP(b)≦20.20...(4) Claim 1: The content of the second monomer unit in the polymer A is 40.0 mol% to 95.0 mol%, based on the total number of moles of all monomer units in the polymer A. The two-component developer described in . The ratio of the total number of moles of the second monomer unit to the total number of moles of the polymer A is E,
The two-component developer according to claim 1 or 3, which satisfies the following formula (9), where F is a ratio of the total number of moles of the monomer unit (a) to the total number of moles of the polymer B.
0.20≦E/F≦7.00 (9) The content of the second polymerizable monomer in the composition is 40.0 mol% to 95.0 mol% based on the total number of moles of all polymerizable monomers in the composition. The two-component developer according to claim 2. Any one of claims 1 to 5, wherein the first polymerizable monomer is at least one selected from the group consisting of (meth)acrylic esters having a linear alkyl group having 18 to 36 carbon atoms. The two-component developer according to item 1. The two-component developer according to any one of claims 1 to 6, wherein the second polymerizable monomer is at least one selected from the group consisting of the following formulas (A) and (B).

(In formula (A), X represents a single bond or an alkylene group having 1 to 6 carbon atoms,
R ¹ is -C≡N,
-C(=O)NHR ¹⁰ (R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms),
hydroxy group,
-COOR ¹¹ (R ¹¹ is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms),
-NHCOOR ¹² (R ¹² is an alkyl group having 1 to 4 carbon atoms),
-NH-C(=O)-N(R ¹³ ) ₂ (R ¹³ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms),
-COO(CH ₂ ) ₂ NHCOOR ¹⁴ (R ¹⁴ is an alkyl group having 1 to 4 carbon atoms), or -COO(CH ₂ ) ₂ -NH-C(=O)-N(R ¹⁵ ) ₂ (R ¹⁵ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)
and R ³ is a hydrogen atom or a methyl group. )
(In formula (B), R ² is an alkyl group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or a methyl group.) The two-component developer according to any one of claims 1 to 7, wherein the second polymerizable monomer is at least one selected from the group consisting of the following formulas (A) and (B).

(In formula (A), X represents a single bond or an alkylene group having 1 to 6 carbon atoms,
R ¹ is -C≡N,
-C(=O)NHR ¹⁰ (R ¹⁰ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms),
hydroxy group,
-COOR ¹¹ (R ¹¹ is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms),
-COO(CH ₂ ) ₂ NHCOOR ¹⁴ (R ¹⁴ is an alkyl group having 1 to 4 carbon atoms), or -COO(CH ₂ ) ₂ -NH-C(=O)-N(R ¹⁵ ) ₂ (R ¹⁵ is each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms)
and R ³ is a hydrogen atom or a methyl group. )
(In formula (B), R ² is an alkyl group having 1 to 4 carbon atoms, and R ³ is a hydrogen atom or a methyl group.) The polymer A further contains a third monomer unit derived from a third polymerizable monomer different from the first polymerizable monomer and the second polymerizable monomer, According to any one of claims 1 to 8, the third monomer unit is a monomer unit derived from at least one polymerizable monomer selected from the group consisting of styrene, methyl methacrylate, and methyl acrylate. Two-component developer. The two-component developer according to any one of claims 1 to 9, wherein the content of the polymer A is 50% by mass or more based on the total mass of the binder resin. The two-component developer according to any one of claims 1 to 10, wherein the coating resin has a glass transition temperature of 40°C to 100°C. Any one of claims 1 to 11, wherein the polymerizable monomer (a) is at least one selected from the group consisting of alkyl esters of (meth)acrylic acid having an alkyl group having 1 to 4 carbon atoms. The two-component developer according to item 1. 13. The polymerizable monomer (b) is at least one selected from the group consisting of cycloalkyl esters of (meth)acrylic acid having a cycloalkyl group having 3 to 8 carbon atoms. The two-component developer according to any one of the items. The two-component developer according to any one of claims 1 to 13 , wherein the content of the polymer B is 50% by mass or more based on the total mass of the coating resin. The two-component developer according to any one of claims 1 to 14 , wherein the two-component developer has a charging time constant of 10 seconds to 500 seconds. The two-component developer according to any one of claims 1 to 15 , wherein the polymer A is a vinyl polymer. The magnetic core is a porous magnetic core,
A resin-filled magnetic core particle in which the porous magnetic core has a filled resin present in the pores of the porous magnetic core,
In the pore size distribution of the porous magnetic core,
The peak pore diameter at which the differential pore volume is maximum in the range of 0.1 μm or more and 3.0 μm or less is 0.20 μm or more and 0.70 μm or less,
The pore volume, which is the integral value of the differential pore volume in the range of 0.1 μm or more and 3.0 μm or less, is 20 mm ³ /g or more and 57 mm ³ /g or less,
The magnetic carrier has a region R1 and a region R2 defined as follows:
The mass-based proportions of the composition derived from the resin component are respectively JR1 and JR2,
Let the mass-based ratios of the composition derived from the porous magnetic core be FR1 and FR2, respectively,
Furthermore, when JR1/FR1 is MR1 and JR2/FR2 is MR2, MR1 and MR2 are
0.20≦MR2/MR1≦0.90
The two-component developer according to any one of claims 1 to 16 , which satisfies the following relationship.
(Region R1 is defined by drawing a line segment passing through the center of gravity of the cross section and having the maximum length of the resin-filled magnetic core particles in the cross-sectional image of the magnetic carrier, being parallel to the line segment, and 2. Let two straight lines 5 μm apart be straight lines A and B,
A straight line passing through the intersection of the line segment and the outline of the resin-filled magnetic core particle and perpendicular to the line segment is defined as a straight line C,
When a straight line D is parallel to the straight line C and is 5.0 μm away from the straight line C toward the center of the magnetic carrier,
This region is surrounded by the outline of the resin-filled magnetic core particle and the straight lines A, B, and D, and is in contact with the straight line C.
Region R2 is parallel to the straight lines A, B, D and the straight line D,
This is a region surrounded by a straight line E that is 5.0 μm away from the straight line D toward the center of the magnetic carrier. ) The magnetic core is a magnetic material-dispersed resin carrier core material,
The magnetic substance-dispersed resin carrier core material contains magnetic particles A whose primary particles have a number average particle diameter of ra (μm), and magnetic particles B whose primary particles have a number average particle diameter of rb (μm),
The ra and rb satisfy the relationship ra≧rb,
The magnetic particles A contain an oxide of at least one non-ferrous metal element selected from the group consisting of manganese element, aluminum element, magnesium element, titanium element, and nickel element, and iron oxide,
In the measurement of the magnetic carrier by X-ray fluorescence diffraction, when the total content of the nonferrous metal element is M1 (mass%) and the content of iron element is F1 (mass%), the ratio of M1 to F1 is The value (M1/F1) is 0.010 or more and 0.100 or less,
In the measurement of the magnetic carrier by X-ray photoelectron spectroscopy, when the total content of the nonferrous metal element is M2 (mass%) and the content of the iron element is F2 (mass%), the ratio of M2 to F2 The two-component developer according to any one of claims 1 to 16 , wherein the value (M2/F2) is 1.0 or more and 10.0 or less.

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