阅读说明：本技术 调色剂 (Toner and image forming apparatus ) 是由 上仓健太 松井崇 青木健二 铃木正郎 岛野努 田川丽央 于 2019-06-12 设计创作，主要内容包括：本发明涉及一种调色剂。所述调色剂具有其中包含粘接剂树脂的调色剂核由壳层覆盖的调色剂颗粒,其中所述粘结剂树脂包含具有第一单体单元和第二单体单元的聚合物A；所述第一单元源自具有碳数为18至36的烷基的(甲基)丙烯酸酯；所述第一单体单元在所述聚合物中的含量为5.0至60.0mol％；所述第二单体单元的含量为20.0至95.0mol％；当所述第一单元的SP值表示为SP<Sub>11</Sub>且所述第二单元的SP值表示为SP<Sub>21</Sub>时,满足下式(1)；并且所述调色剂核在调色剂截面的外周的90％以上覆盖有高度均一性的壳；3.00≤(SP<Sub>21</Sub>-SP<Sub>11</Sub>)≤25.00...(1)。(The present invention relates to a toner. The toner has toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein the binder resin contains a polymer A having a first monomer unit and a second monomer unit; the first unit is derived from a (meth) acrylate having an alkyl group with a carbon number of 18 to 36; the content of the first monomer unit in the polymer is 5.0 to 60.0 mol%;the content of the second monomer unit is 20.0 to 95.0 mol%; when the SP value of the first unit is represented as SP 11 And the SP value of the second unit is denoted as SP 21 When the compound satisfies the following formula (1); and the toner core is covered with a highly uniform shell over 90% or more of the outer periphery of the toner cross section; less than or equal to 3.00 (SP) 21 ‑SP 11 )≤25.00...(1)。)

1. A toner characterized by comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer a having:

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;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the content of the first monomer unit in the polymer a is 5.0 mol% to 60.0 mol% with respect to the total moles of all monomer units in the polymer a;

the content of the second monomer unit in the polymer a is 20.0 mol% to 95.0 mol% with respect to the total moles of all monomer units in the polymer a;

when the SP value of the first monomer unit is represented as SP₁₁(J/cm³)^0.5And the SP value of the second monomer unit is represented as SP₂₁(J/cm³)^0.5When the above-mentioned composition satisfies the following formula (1),

3.00≤(SP₂₁-SP₁₁)≤25.00...(1)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), the shell layer is observed in 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer; and

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is represented as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

2. The toner according to claim 1, wherein the content of the second monomer unit in the polymer a is 40.0 mol% to 95.0 mol% with respect to the total number of moles of all monomer units in the polymer a.

3. A toner characterized by comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer a that is a polymer of a composition comprising a first polymerizable monomer, and a second polymerizable monomer different from the first polymerizable monomer;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the first polymerizable monomer is present in the composition in an amount of 5.0 to 60.0 mol% relative to the total moles of all polymerizable monomers in the composition;

the second polymerizable monomer is present in the composition in an amount of 20.0 to 95.0 mol% relative to the total moles of all polymerizable monomers in the composition;

when the SP value of the first polymerizable monomer is represented as SP₁₂(J/cm³)^0.5And the SP value of the second polymerizable monomer is represented by SP₂₂(J/cm³)^0.5When the above-mentioned compound satisfies the following formula (3),

0.60≤(SP₂₂-SP₁₂)≤15.00...(3)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), the shell layer is observed in 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer; and

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is represented as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

4. The toner according to claim 3, wherein the second polymerizable monomer is contained in the composition in an amount of 40.0 mol% to 95.0 mol% with respect to the total number of moles of all polymerizable monomers in the composition.

5. The toner according to claim 1 or 3, wherein the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having a linear alkyl group having a carbon number of 18 to 36.

6. The toner according to claim 1 or 3, wherein the polymer A has an acid value of 30mg KOH/g or less.

7. The toner according to claim 1 or 3, wherein the second polymerizable monomer is at least one selected from the group consisting of the following formula (A) and formula (B):

in the formula (A) mentioned above,

x represents a single bond or an alkylene group having 1 to 6 carbon atoms;

R¹is nitrile-C [ identical to ] N,

amido-C (═ O) NHR¹⁰，R¹⁰Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,

A hydroxyl group,

-COOR¹¹，R¹¹Is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms,

carbamate-NHCOOR¹²，R¹²Is an alkyl group having 1 to 4 carbon atoms,

ureido-NH-C (═ O) -N (R)¹³)₂，R¹³Each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms,

-COO(CH₂)₂NHCOOR¹⁴，R¹⁴Is an alkyl group having 1 to 4 carbon atoms, or

-COO(CH₂)₂-NH-C(＝O)-N(R¹⁵)₂，R¹⁵Each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and

R³is a hydrogen atom or a methyl group;

in the formula (B), the compound represented by the formula (B),

R²is an alkyl group having 1 to 4 carbon atoms, and

R³is a hydrogen atom or a methyl group.

8. The toner according to claim 7, wherein the second polymerizable monomer is at least one selected from the group consisting of the following formulae (a) and (B):

in the formula (A) mentioned above,

x represents a single bond or an alkylene group having 1 to 6 carbon atoms;

R¹is nitrile-C [ identical to ] N,

amido-C (═ O) NHR¹⁰，R¹⁰Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms,

A hydroxyl group,

-COOR¹¹，R¹¹Is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms,

-COO(CH₂)₂NHCOOR¹⁴，R¹⁴Is an alkyl group having 1 to 4 carbon atoms, or

-COO(CH₂)₂-NH-C(＝O)-N(R¹⁵)₂，R¹⁵Each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and

R³is a hydrogen atom or a methyl group;

in the formula (B), the compound represented by the formula (B),

R²is an alkyl group having 1 to 4 carbon atoms; and

R³is a hydrogen atom or a methyl group.

9. The toner according to claim 1 or 3, wherein the polymer A further comprises a third monomer unit derived from a third polymerizable monomer different from the first polymerizable monomer and different from the second polymerizable monomer, and

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.

10. The toner according to claim 1 or 3, wherein the toner contains a wax, and

satisfying the following formula (4) when the content of the wax is represented by W parts by mass, the content of the first monomer unit is represented by A parts by mass, and the content of the polymer A in the toner is represented by 100 parts by mass,

0.2×A≤W≤A...(4)。

11. the toner according to claim 1 or 3, wherein an endothermic amount of an endothermic peak associated with melting of the polymer A is 20J/g to 100J/g when the toner is measured by a differential scanning calorimeter.

12. The toner according to claim 1 or 3, wherein the polymer A has a charge decay constant of 100 or less.

13. The toner according to claim 1 or 3, wherein the amorphous resin constituting the shell layer is at least one selected from the group consisting of a polyester resin, a polyurethane resin, a melamine resin, a vinyl resin, and a urea resin.

14. The toner according to claim 1 or 3, wherein the shell layer is composed of one kind of amorphous resin.

15. The toner according to claim 1 or 3, wherein the shell layer has a thickness of 2nm to 100nm in an image of a cross section of the toner observed using a Transmission Electron Microscope (TEM).

16. The toner according to claim 1 or 3, wherein the polymer A is a vinyl polymer.

Technical Field

The present invention relates to a toner for developing an electrostatically charged image (electrostatic latent image) in an image forming method such as electrophotography and electrostatic printing.

Background

In recent years, the field of utilizing electrophotography has been extended to include commercial printing typified by package printing and advertisement printing, and this has been required to accommodate even higher speeds and higher image qualities than have hitherto been required for use in office environments.

In order to cope with the speeding-up, a technique is known in which a fixing temperature is lowered by using a crystalline resin in a binder resin of a toner. Known crystalline resins are a main chain crystalline resin in which the main chain is crystallized, and a side chain crystalline resin in which the side chain is crystallized. Crystalline polyesters are representative of the former, and long-chain acrylate polymers are representative of the latter. In particular, it is known that a side chain crystalline resin exhibits excellent low-temperature fixability due to its promoted increase in crystallinity, and has been widely studied.

Japanese patent application laid-open No. 2014-130243 discloses a toner exhibiting low-temperature fixing property as well as excellent image stacking property, sufficient charging performance, bending strength of a fixed image, and a wide fixing temperature range. This is achieved by covering the shell onto the core containing the side chain crystalline resin and by controlling the thermal characteristics of the toner.

Japanese patent application laid-open No. 2014-142632 discloses a toner exhibiting low-temperature fixability and enhanced image strength. This is achieved by controlling the thermal characteristics of the toner and by covering the shell to the core having a sea-island structure in which island portions of the amorphous resin are dispersed in sea portions of the side-chain crystalline resin.

Disclosure of Invention

On the other hand, in order to improve image quality, it is necessary to faithfully transfer the toner image formed on the drum onto an intermediate transfer member or paper. However, when a large amount of crystalline resin is used in the binder resin of the toner, it is difficult to obtain a toner exhibiting excellent transferability due to the influence of the charging property of the binder resin. It has been found that the toner in the above patent document may also suffer from poor transferability.

An object of the present invention is to obtain a toner exhibiting excellent low-temperature fixability and excellent transferability by improving transferability of a toner containing a side-chain crystalline resin in a binder resin.

A first aspect to solve the foregoing problems is a toner comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer a having:

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;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the content of the first monomer unit in the polymer a is 5.0 mol% to 60.0 mol% with respect to the total moles of all monomer units in the polymer a;

the content of the second monomer unit in the polymer a is 20.0 mol% to 95.0 mol% with respect to the total moles of all monomer units in the polymer a;

when the SP value of the first monomer unit is denoted as SP₁₁(J/cm³)^0.5And the SP value of the second monomer unit is represented as SP₂₁(J/cm³)^0.5When the above-mentioned composition satisfies the following formula (1),

3.00≤(SP₂₁-SP₁₁)≤25.00...(1)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), a shell layer is observed in 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer;

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is denoted as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

A second aspect to solve the above problems is a toner comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer a which is a polymer of a composition comprising a first polymerizable monomer, and a second polymerizable monomer different from the first polymerizable monomer;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the first polymerizable monomer is present in the composition in an amount of 5.0 to 60.0 mol% relative to the total moles of all polymerizable monomers in the composition;

the second polymerizable monomer is present in the composition in an amount of 20.0 to 95.0 mol% relative to the total moles of all polymerizable monomers in the composition;

the SP value of the first polymerizable monomer is denoted as SP₁₂(J/cm³)^0.5And the SP value of the second polymerizable monomer is represented by SP₂₂(J/cm³)^0.5Satisfying the following formula (3),

0.60≤(SP₂₂-SP₁₂)≤15.00...(3)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), a shell layer is observed in 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer; and

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is denoted as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

Therefore, the present invention can provide a toner exhibiting excellent low-temperature fixability and excellent transferability.

Further features of the present invention can be obtained from the following description of exemplary embodiments.

Detailed Description

In the present invention, unless otherwise specified, the expressions "from XX to YY" and "XX to YY" indicating numerical ranges mean the numerical ranges including the lower limit and the upper limit as endpoints.

In the present invention, "(meth) acrylate" means acrylate and/or methacrylate.

With respect to "monomeric units" in the present invention, one unit refers to one carbon-carbon bond segment (segment) in the backbone provided by the polymerization of vinyl monomers into polymers.

The vinyl monomer can be represented by the following formula (C).

[ wherein R_ARepresents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group), and R_BRepresents any substituent.]

"crystalline resin" means a resin showing a clear endothermic peak in measurement by a Differential Scanning Calorimeter (DSC).

The first aspect of the present invention is a toner comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer A having

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;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the content of the first monomer unit in the polymer a is 5.0 mol% to 60.0 mol% with respect to the total moles of all monomer units in the polymer a;

the content of the second monomer unit in the polymer a is 20.0 mol% to 95.0 mol% with respect to the total moles of all monomer units in the polymer a;

when the SP value of the first monomer unit is denoted as SP₁₁(J/cm³)^0.5And the SP value of the second monomer unit is represented as SP₂₁(J/cm³)^0.5When the above-mentioned composition satisfies the following formula (1),

3.00≤(SP₂₁-SP₁₁)≤25.00...(1)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), a shell layer is observed in 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer;

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is denoted as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

The second aspect of the present invention is a toner comprising toner particles in which a toner core containing a binder resin is covered with a shell layer, wherein

The binder resin comprises a polymer a which is a polymer of a composition comprising a first polymerizable monomer, and a second polymerizable monomer different from the first polymerizable monomer;

the first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36;

the first polymerizable monomer is present in the composition in an amount of 5.0 to 60.0 mol% relative to the total moles of all polymerizable monomers in the composition;

the second polymerizable monomer is present in the composition in an amount of 20.0 to 95.0 mol% relative to the total moles of all polymerizable monomers in the composition;

when the SP value of the first polymerizable monomer is denoted as SP₁₂(J/cm³)^0.5And the SP value of the second polymerizable monomer is represented by SP₂₂(J/cm³)^0.5When the above-mentioned compound satisfies the following formula (3),

0.60≤(SP₂₂-SP₁₂)≤15.00...(3)；

in an image of a toner cross section observed using a Transmission Electron Microscope (TEM), the shell layer is observed at 90% or more of the outer periphery of the toner cross section;

the shell layer is composed of at least one non-crystalline resin selected from the group consisting of a homopolymer, an alternating copolymer, and a random copolymer; and

when the shell layer is composed of two or more kinds of amorphous resins, the following formula (2) is satisfied, wherein

The resin having the highest SP value among the resins constituting the shell layer was designated as resin S1,

the resin having the lowest SP value among the resins constituting the shell layer was designated as resin S2,

the SP value of the resin S1 is denoted as SP_S1(J/cm³)^0.5And the SP value of the resin S2 is represented as SP_S2(J/cm³)^0.5，

SP_S1-SP_S2≤3.0...(2)。

The present inventors assume as follows a factor that can provide a toner having excellent low-temperature fixability and excellent transferability with respect to the above-described constitution.

A factor that makes it difficult to have low-temperature fixability that coexists with transferability in a toner containing a crystalline resin is that the crystalline resin has a lower resistance value than that of an amorphous resin. Taking the method using the intermediate transfer member as an example, when the resistance value is a low value, the charge carried by the toner is caused to leak due to the influence of the potential difference in the steps of conveying the toner using the potential difference, such as development and primary transfer. Therefore, in many cases, the toner does not hold a sufficient charge in the final secondary transfer step and the responsiveness to the transfer current decreases, which is associated with a decrease in transferability.

Even in a method without a secondary transfer step, the influence of charge leakage in the development step can be similarly associated with a decrease in transferability in the primary transfer step.

In order to improve charging properties, in the toner in the above-mentioned patent document, a core including a crystalline resin or a core of a sea-island structure including a crystalline resin and an amorphous resin is covered with a shell. Thereby improving charge retention during standing after charging. However, it has been found that it is insufficient for charge retention in steps such as development and primary transfer. The reason for this is that the crystalline portion of low resistance forms a simple continuous phase, and therefore the charge carried by the shell layer leaks through the crystalline portion.

Japanese patent application laid-open No. 2014-130243 also discloses a toner comprising a resin obtained by copolymerization of a long-chain alkyl acrylate as a monomer forming a crystalline site and acrylic acid as a highly polar monomer. However, since the amount of the highly polar monomer in the toner is small, the phase separation between the crystalline site and the highly polar site is insufficient. Therefore, the resistance of the resin as a whole is lowered, and it has been found that leakage in steps such as development and primary transfer cannot be suppressed similarly.

Based on the foregoing, it is considered that the following will be effective for suppressing charge leakage in steps such as development and primary transfer: the crystalline portion and the amorphous portion are phase-separated from each other, and a resin with which the crystalline portion does not form a simple continuous phase is used.

As a result of intensive studies, the present inventors have now found that excellent transferability is exhibited by a toner using the following polymer a: the polymer a has a specific ratio of both a monomer unit derived from a (meth) acrylate having an alkyl group with a carbon number of 18 to 36 and a monomer unit having an SP value sufficiently different from the foregoing monomer unit.

In the case of polymer a, since the difference between the SP values of these two monomer units is sufficiently large and since both monomer units are present in a sufficient amount, the two monomer units are incompatible with each other and can be present separately from each other. On the other hand, since two kinds of monomer units are present in the same molecule, a simple continuous phase cannot be formed by a crystalline site including a monomer unit derived from at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36.

Therefore, it is considered that the crystalline site and the amorphous site easily exhibit a microphase-separated structure of complex entanglement while undergoing phase separation. The present inventors speculate that the polymer a suppresses leakage because the low-resistance crystalline site and the high-resistance amorphous site exhibit a microphase-separated structure in which they are intricately entangled.

That is, the polymer a preferably has a crystalline site containing a first monomer unit derived from the first polymerizable monomer. Polymer a also preferably has an amorphous site comprising a second monomer unit derived from a second polymerizable monomer.

In addition, in order to obtain the polymer a, a (meth) acrylate having an alkyl group with a carbon number of 18 to 36 is preferably copolymerized with a monomer having an SP value sufficiently different from that of the (meth) acrylate. As a result, the monomers are not uniformly mixed with each other during the copolymerization, thereby promoting the generation of a block copolymer-like structure in which crystalline sites are separated from amorphous sites. By adopting the block copolymer-like structure, the crystallinity of the crystalline portion is enhanced and the formation of the microphase-separated structure is promoted.

Therefore, the toner including the polymer a has excellent transferability; however, the results of the study confirmed that merely having the polymer a as a binder resin did not provide sufficient improvement in transferability after long-term use. Therefore, the present inventors conducted studies for further improvement.

In this context, the present inventors have focused on the adhesion of the toner. The toner containing the polymer a provides excellent suppression of charge leakage; however, since the toner particle surface has a microphase-separated structure, the toner surface is considered to be non-uniform. The toner is generally obtained by adding, for example, inorganic fine powder as an external additive to the surface of toner particles, and the charging property of the toner surface is made uniform by its function. However, exposure of the resin to the toner particle surface increases and the influence of the charging uniformity of the toner particle surface becomes significant due to a change in the adhesion state of the external additive during long-term use.

When the toner particle surface has a nonuniform structure of crystalline sites and amorphous sites that are phase-separated, electric charges concentrate on highly polar amorphous sites during charging and thus electrostatic adhesion of the toner increases. In addition, exposure of the crystalline sites also increases the non-electrostatic adhesion, as the crystalline sites are closer to the adhesive body than the non-crystalline sites. The toner exhibiting high adhesion force will adhere to members such as the electrostatic latent image bearing member, and the intermediate transfer member in the transfer step, and as a result, the transferability will be reduced.

Accordingly, the present inventors have found that the aforementioned problems can be solved by covering a toner core having an uneven surface of the polymer a with a shell composed of an amorphous resin having a uniform composition and structure. The present invention has been completed as a result of this finding.

The first polymerizable monomer is at least one selected from the group consisting of (meth) acrylates having an alkyl group with a carbon number of 18 to 36.

The (meth) acrylate having an alkyl group with a carbon number of 18 to 36 may be exemplified by (meth) acrylates having a straight-chain alkyl group with a carbon number of 18 to 36 [ e.g., octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, heneicosyl (meth) acrylate, docosyl (meth) acrylate, ditetradecyl (meth) acrylate, hexacosyl (meth) acrylate, dioctadecyl (meth) acrylate, triacontyl (meth) acrylate, and triacontyl (meth) acrylate ], and (meth) acrylates having a branched-chain alkyl group with a carbon number of 18 to 36 [ e.g., 2-decyltetradecyl (meth) acrylate ].

More specifically, at least one selected from the group consisting of (meth) acrylates having a linear alkyl group having a carbon number of 18 to 36 is preferable from the viewpoint of transferability and low-temperature fixability of the toner; more preferably at least one selected from the group consisting of (meth) acrylates having a linear alkyl group having a carbon number of 18 to 30; and still more preferably at least one selected from the group consisting of linear octadecyl (meth) acrylate and linear behenyl (meth) acrylate.

In the first aspect, the content of the first monomer unit in the polymer a is 5.0 mol% to 60.0 mol% with respect to the total number of moles of all monomer units in the polymer a.

In a second aspect, polymer a is a polymer of a composition comprising a first polymerizable monomer and a second polymerizable monomer different from the first polymerizable monomer. The first polymerizable monomer is present in the composition in an amount of 5.0 to 60.0 mol% relative to the total moles of all polymerizable monomers in the composition.

When the content is within the above range, the crystallinity of the crystalline site in the polymer a increases and the phase separation thereof from the amorphous site is promoted. Therefore, a toner having excellent transferability and excellent low-temperature fixability can be obtained. The content is preferably 10.0 to 60.0 mol%, and more preferably 20.0 to 40.0 mol%.

On the other hand, when the content is less than 5.0 mol%, there are few crystalline sites and thus a toner having sufficient low-temperature fixability may not be obtained. In addition, since there are few crystalline sites, it is difficult to increase the crystallinity of the resin and the phase separation from the amorphous region is unclear. In contrast, when the content exceeds 60.0 mol%, a large number of crystalline sites are present and thus suppression of charge leakage is impaired, and a toner having sufficient transferability may not be obtained.

When the polymer A in the invention contains a plurality of monomer units satisfying the requirements of the aforementioned first monomer unit, a value provided by weighted averaging of the respective SP values of these monomer units is used for SP in the formula (1)₁₁The value of (c). For example, when the SP value is SP when the molar amount of Amol% relative to the total monomer units satisfying the requirements of the first monomer unit is included₁₁₁And contains a SP value of SP in a molar ratio of (100-A) mol% relative to the total monomer units satisfying the requirements of the first monomer unit₁₁₂The monomer unit B of (4), SP value (SP)₁₁) Is composed of

SP₁₁＝(SP₁₁₁×A+SP₁₁₂×(100-A))/100

The same calculation is performed when three or more monomer units satisfying the requirements of the first monomer unit are incorporated. SP, on the other hand₁₂Also means an average value similarly calculated using the molar ratio of each of the first polymerizable monomers.

In addition, when there are a plurality of first monomer units, then the content of the first monomer units is the sum of the contents of the individual monomer units. The same applies to the case where a plurality of first polymerizable monomers are present.

In the first aspect, the content of the second monomer unit in the polymer a is 20.0 mol% to 95.0 mol% with respect to the total number of moles of all the monomer units in the polymer a.

In the second aspect, the second polymerizable monomer is contained in the composition in an amount of 20.0 mol% to 95.0 mol% with respect to the total number of moles of all polymerizable monomers in the composition.

When the content is within the specified range, sufficient phase separation between the crystalline site and the amorphous site can be obtained, and a toner having excellent transferability can be obtained.

The content is preferably 40.0 to 95.0 mol% and more preferably 40.0 to 70.0 mol%.

On the other hand, when the content is less than 20.0 mol%, since compatibility between the crystalline site and the amorphous site is promoted, suppression of charge leakage is impaired. Therefore, a toner having sufficient transferability may not be obtained. In contrast, when the content exceeds 95.0 mol%, crystalline sites present are relatively few and thus a toner having sufficient low-temperature fixability may not be obtained. In addition, since the amount of crystalline sites is relatively small, it is difficult to increase the crystallinity of the resin and the melting point can be lowered.

In the first aspect, when the SP value of the first monomer unit is represented as SP₁₁(J/cm³)^0.5And the SP value of the second monomer unit is denoted as SP₂₁(J/cm³)^0.5Then, SP₁₁And SP₂₁Satisfies the following formula (1).

3.00≤(SP₂₁-SP₁₁)≤25.00...(1)

In the second aspect, for the polymer A, when the SP value of the first polymerizable monomer is represented by SP₁₂(J/cm³)^0.5And the SP value of the second polymerizable monomer is SP₂₂(J/cm³)^0.5Then, the following formula (3) is satisfied.

0.60≤(SP₂₂-SP₁₂)≤15.00...(3)

When the difference in SP value is within a specified range, sufficient phase separation between the crystalline site and the amorphous site can be brought about and a toner having excellent transferability can be obtained. SP₂₁-SP₁₁Preferably 4.00 or more and more preferably 5.00 or more. When SP₂₁-SP₁₁Within the specified range, the phase separation between the crystalline site and the amorphous site becomes more definite and the transferability is improved. SP₂₁-SP₁₁Preferably 20.00 or less and more preferably 15.00 or less. When SP₂₁-SP₁₁When within the specified range, development of compatibility between the crystalline site and the amorphous site at the time of fixing is promoted, and then a toner exhibiting sufficient low-temperature fixability can be obtained even in a more rapid fixing process.

Also, SP₂₂-SP₁₂Preferably 2.00 or more and more preferably 3.00 or more. SP₂₂-SP₁₂Also preferably 10.00 or less and more preferably 7.00 or less.

On the other hand, when the difference in SP value is less than the lower limit, phase separation between the crystalline site and the amorphous site becomes insufficient and a toner having sufficient transferability may not be obtained. When the difference in SP value exceeds the upper limit, the crystalline site is not compatible with the amorphous site even during fixing, and thus a toner having sufficient low-temperature fixability may not be obtained.

The method for calculating the SP value is described below. In the present invention, the second monomer unit is suitable for satisfying SP calculated by the method₁₁Related formula (1) having SP₂₁All of the monomer units of (a). Also, the second polymerizable monomer is suitable for satisfying SP calculated by the method₁₂Related formula (3) having SP₂₂All of the polymerizable monomers of (1).

That is, when the second polymerizable monomer is two or more polymerizable monomers, SP₂₁Represents the SP value of the monomer unit derived from each polymerizable monomer and SP₂₁-SP₁₁Is determined for the monomer unit derived from each second polymerizable monomer. Same SP₂₂Represents the SP value of each polymerizable monomer and SP₂₂-SP₁₂Is determined for each second polymerizable monomer.

The content of the second monomer unit is the sum of the contents of all the monomer units satisfying the conditions given above. The same applies to the case where a plurality of second polymerizable monomers are present.

When the specific polymerizable monomer satisfies formula (1) or formula (3), the polymerizable monomer provided below as an example may be used as the second polymerizable monomer.

A single second polymerizable monomer may be used, or two or more may be used in combination.

Examples of monomers having a nitrile group are acrylonitrile and methacrylonitrile.

Examples of the monomer having a hydroxyl group are 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

Examples of the monomer having an amido group are acrylamide, and monomers provided by a reaction between an amine having 1 to 30 carbon atoms and a carboxylic acid (e.g., acrylic acid, methacrylic acid) having 2 to 30 carbon atoms and containing an ethylenically unsaturated bond by a known method.

The monomer having a urethane group is prepared by reacting an alcohol having 2 to 22 carbon atoms and containing an ethylenically unsaturated bond (e.g., 2-hydroxyethyl methacrylate, vinyl alcohol, etc.) and an isocyanate having 1 to 30 carbon atoms [ e.g., a monoisocyanate compound (e.g., benzenesulfonyl isocyanate, p-toluenesulfonyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, butyl isocyanate, hexyl isocyanate, tert-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), an aliphatic diisocyanate compound (e.g., trimethylene diisocyanate, and the like), Tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1, 2-propylene diisocyanate, 1, 3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4, 4-trimethylhexamethylene diisocyanate), alicyclic diisocyanate compounds (e.g., 1, 3-cyclopentene diisocyanate, 1, 3-cyclohexane diisocyanate, 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate), or aromatic diisocyanate compounds (e.g., phenylene diisocyanate, 2, 4-toluene diisocyanate, hydrogenated xylylene diisocyanate, or hydrogenated xylylene diisocyanate), Monomers provided by a reaction between 2, 6-tolylene diisocyanate, 2 ' -diphenylmethane diisocyanate, 4 ' -toluidine diisocyanate (4,4 ' -toluidine diisocyanate), 4 ' -diphenylether diisocyanate, 4 ' -diphenyl diisocyanate, 1, 5-naphthalene diisocyanate, and xylylene diisocyanate) ] by a known method, and

by reacting an alcohol having 1 to 26 carbon atoms (e.g., methanol, ethanol, propanol, isopropanol, butanol, t-butanol, pentanol, heptanol, octanol, 2-ethylhexanol, nonanol, decanol, undecanol, lauryl alcohol, myristyl alcohol, pentadecanol, cetyl alcohol, heptadecanol, stearyl alcohol, isostearyl alcohol, trans-9-octadecenyl alcohol (elaidyl alcohol), oleyl alcohol, linolenyl alcohol, nonadecyl alcohol, heneicosyl alcohol, behenyl alcohol, and 13-docosadienyl alcohol (erucyl alcohol)) and an isocyanate having 2 to 30 carbon atoms and containing an ethylenic unsaturated bond [ e.g., 2-isocyanoethyl methacrylate, 2- (O- [ 1' -methylpropylideneamino ] carboxy-ethyl (meth) acrylate, 2- [ (3, 5-dimethylpyrazolyl) carbonylamino ] ethyl (meth) acrylate, And 1,1- (bis (meth) acryloyloxymethyl) ethyl isocyanate ] by known methods.

Examples of the monomer having a urea group are monomers provided by reacting an amine having 3 to 22 carbon atoms [ e.g., primary amines (n-butylamine, t-butylamine, propylamine, and isopropylamine), secondary amines (e.g., di-n-ethylamine, di-n-propylamine, and di-n-butylamine), aniline, and cyclohexylamine ] with an isocyanate having 2 to 30 carbon atoms and an ethylenically unsaturated bond by a known method.

Examples of the monomer having a carboxyl group are methacrylic acid, acrylic acid, and 2-carboxyethyl (meth) acrylate.

Of the foregoing, monomers having a nitrile group, an amide group, a urethane group, a hydroxyl group, or a urea group are preferably used. The monomer more preferably has an ethylenically unsaturated bond and at least one functional group selected from the group consisting of a nitrile group, an amide group, a urethane group, a hydroxyl group, and a urea group. These monomers are used to facilitate maintaining low resistance values of the polymer even at high humidity. Therefore, a toner having excellent transferability which is easily obtained even under high humidity is preferable.

Vinyl esters, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl pivalate, and vinyl caprylate, are also preferably used as the second polymerizable monomer. The vinyl ester is a non-conjugated monomer and has relatively low reactivity with the first polymerizable monomer as a conjugated monomer, and thus promotes phase separation between the first monomer unit and the second monomer unit. Thus promoting the production of toner having excellent transferability.

In addition, when a vinyl ester is used as the second polymerizable monomer, the reactivity contributes to phase separation in addition to the difference in SP value. Therefore, if SP₂₁-SP₁₁、SP₂₂-SP₁₂And the content of the first polymerizable monomer is within the range described in accordance with the present invention, even when these items are outside the preferred ranges, phase separation property equivalent to that within the preferred ranges can be obtained, and a toner having excellent transferability can be easily obtained.

The second polymerizable monomer preferably has an ethylenically unsaturated bond and more preferably has one ethylenically unsaturated bond.

In addition, the second polymerizable monomer is preferably at least one selected from the group consisting of the following formulas (a) and (B).

(wherein, X represents a single chain or an alkylene group having 1 to 6 carbon atoms.

R¹Is a nitrile group (-C ≡ N),

Amido (-C (═ O) NHR¹⁰(R¹⁰Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms))

A hydroxyl group,

-COOR¹¹(R¹¹Alkyl having 1 to 6 (preferably 1 to 4) carbon atoms or hydroxyalkyl having 1 to 6 (preferably 1 to 4) carbon atoms) to,

Carbamate group (-NHCOOR)¹²(R¹²Alkyl having 1 to 4 carbon atoms) to a base,

Ureido (-NH-C (═ O) -N (R)¹³)₂(R¹³Each independently a hydrogen atom or an alkyl group having 1 to 6 (preferably 1 to 4) carbon atoms,

-COO(CH₂)₂NHCOOR¹⁴(R¹⁴Is an alkyl group having 1 to 4 carbon atoms), or

-COO(CH₂)₂-NH-C(＝O)-N(R¹⁵)₂(R¹⁵Each independently a hydrogen atom or an alkyl group having 1 to 6 (preferably 1 to 4) carbon atoms.

R¹Preferably a nitrile group (-C.ident.N),

Amido (-C (═ O) NHR¹⁰(R¹⁰Is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms))

A hydroxyl group,

-COOR¹¹(R¹¹Alkyl having 1 to 6 (preferably 1 to 4) carbon atoms or hydroxyalkyl having 1 to 6 (preferably 1 to 4) carbon atoms) to,

Ureido (-NH-C (═ O) -N (R)¹³)₂(R¹³Each independently a hydrogen atom or an alkyl group having 1 to 6, preferably 1 to 4, carbon atoms) to a pharmaceutically acceptable carrier,

-COO(CH₂)₂NHCOOR¹⁴(R¹⁴Is an alkyl group having 1 to 4 carbon atoms), or

-COO(CH₂)₂-NH-C(＝O)-N(R¹⁵)₂(R¹⁵Each independently a hydrogen atom or an alkyl group having 1 to 6 (preferably 1 to 4) carbon atoms,

R²Is an alkyl group having 1 to 4 carbon atoms, and R³Each independently is a hydrogen atom or a methyl group. )

The polymer a is preferably a vinyl polymer. Vinyl polymers are, for example, polymers of monomers containing ethylenically unsaturated bonds. The ethylenically unsaturated bond represents a carbon-carbon double bond capable of radical polymerization, and may be exemplified by vinyl group, propenyl group, acryloyl group, methacryloyl group, and the like.

The acid value of the polymer A is preferably 30mg KOH/g or less and more preferably 20mg KOH/g or less. By having an acid value within the specified range, the low resistance value of the polymer is promoted to be maintained even under high humidity. Then, a toner exhibiting excellent transferability even under high humidity is easily obtained. The lower limit of the acid value is not particularly limited, but is preferably 0mgKOH/g or more. The acid value can be controlled by the kind and amount of the polymerizable monomer added.

Within the range of maintaining the aforementioned molar ratio of the first monomer unit derived from the first polymerizable monomer to the second monomer unit derived from the second polymerizable monomer, the polymer a may include a third monomer unit derived from a third polymerizable monomer which is not included in the aforementioned range of formula (1) or formula (3) (i.e., which is different from the first polymerizable monomer and the second polymerizable monomer).

A monomer that does not satisfy formula (1) or formula (3) among monomers from one of the above-described second polymerizable monomers may be used as the third polymerizable monomer.

The following monomers, which do not contain the aforementioned nitrile, amide, urethane, hydroxyl, urea or carboxyl groups, may also be used.

Examples are styrene and its derivatives, such as styrene and o-methylstyrene, and (meth) acrylic esters, such as methyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Among them, at least one selected from the group consisting of styrene, methyl methacrylate, and methyl acrylate is preferable.

These monomers do not contain a polar group and thus have a low SP value, making it difficult to satisfy formula (1) or formula (3). However, when it satisfies formula (1) or formula (3), it may be used as the second polymerizable monomer.

By satisfying the conditions given above, a polymer having a low resistance value while maintaining crystallinity can be obtained. Therefore, a toner exhibiting both excellent low-temperature fixability and excellent transferability can be obtained.

The charge decay constant can be used as an indicator of the resistance value. The charge decay constant of the polymer a is preferably 100 or less. In which charge leakage is impeded. This is advantageous for obtaining a toner having excellent transferability. The charge decay constant of the polymer a is more preferably 1 to 50. This range is more preferable because it enables suppression of excessive charging by charge delivery between toners while providing additional suppression of charge leakage. The charge decay constant of the polymer a can be controlled by the kind and the addition amount of the polymerizable monomer.

The endotherm of the absorption peak can be used as an indicator of crystallinity. The endothermic peak relating to the melting of the polymer a preferably has an endothermic amount of 20(J/g) to 100(J/g) from the viewpoint of low-temperature fixability. The endothermic amount is more preferably 30(J/g) to 80 (J/g). The endothermic amount can be controlled by the amount of the first monomer unit or the first polymerizable monomer added.

In an image of a toner cross section observed using a Transmission Electron Microscope (TEM), a shell layer is observed for 90% or more of the outer periphery of the toner cross section (hereinafter, the percentage of the shell layer observed on the outer periphery is also referred to as a coverage). In this case, in combination with satisfying the following conditions, the toner particle surface becomes sufficiently uniform and a toner having excellent transferability can be obtained. The shell layer is preferably observed at 95% or more of the outer periphery of the toner cross section. On the other hand, when the shell layer is observed only at less than 90% of the outer periphery of the toner cross section, the uniformity of the toner particle surface becomes insufficient and a toner having sufficient transferability may not be obtained.

The upper limit is not particularly limited, but the coverage is preferably 100% or less and more preferably 99.5% or less.

The coverage can be controlled by the amount and method of addition of the material forming the shell layer.

The shell layer is composed of at least one non-crystalline resin selected from the group consisting of homopolymers, alternating copolymers, and random copolymers. In this case, the surface of the toner particles becomes sufficiently uniform and a toner having excellent transferability can be obtained. Thus, homopolymers and alternating copolymers provide excellent homogeneity and are therefore preferred.

For the purposes of the present invention, and regardless of the particular type of polymer, homopolymer refers to a polymer composed only of monomeric units derived from a single monomer; alternating copolymers refer to polymers in which monomer units derived from two monomers are arranged alternately; and a random copolymer refers to a polymer in which monomer units derived from two or more monomers are arranged in a manner lacking regularity.

For example, the polymer obtained by polycondensation of a hydroxy acid is a homopolymer, while the resin obtained by polycondensation of a diol and a dicarboxylic acid is an alternating copolymer. When the reactivity of the monomers does not differ substantially from each other, the resin obtained by the simultaneous polycondensation of two diols and two dicarboxylic acids is a random copolymer.

Thermosetting resins having a network-like crosslinked structure can also be similarly classified when the aforementioned conditions are satisfied. For example, a silicone resin obtained by polycondensation of an alkylsilane is a homopolymer, while a melamine resin obtained by polycondensation of melamine and formaldehyde is an alternating copolymer.

On the other hand, when the shell layer is composed of a block copolymer or a graft copolymer or the like which does not conform to the foregoing, phase separation of each monomer unit easily occurs on the toner particle surface, and therefore the uniformity of the toner particle surface becomes insufficient, and a toner having sufficient transferability may not be obtained. In addition, when the shell layer is composed of a crystalline resin, then the shell layer eventually leaks electric charge and thus a toner having sufficient transferability may not be obtained.

The amorphous resin used for the shell layer should be a homopolymer, an alternating copolymer, or a random copolymer, but is not otherwise particularly limited, and the amorphous resins known so far may be used.

Specifically, examples of the thermoplastic resin are polyester resin, polyurethane resin, polyamide resin, and vinyl resin, and examples of the thermosetting resin are melamine resin and urea resin. At least one selected from the group consisting of polyester resins, polyurethane resins, melamine resins, vinyl resins, and urea resins is preferable because it provides excellent phase separation properties from the toner core and because it facilitates obtaining an alternating copolymer and facilitates the toner particle surface to become a uniform state.

The polyester resin can be obtained by reacting a polyvalent carboxylic acid having two or more members with a polyhydric alcohol.

The following compounds are examples of polycarboxylic acids: dibasic acids such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, and dodecenylsuccinic acid, anhydrides thereof, and lower alkyl esters thereof, and aliphatic unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, and citraconic acid, and 1,2, 4-benzenetricarboxylic acid and 1,2, 5-benzenetricarboxylic acid, anhydrides thereof, and lower alkyl esters thereof. One of these may be used alone or two or more may be used in combination.

The polyols may be exemplified by the following compounds:

alkylene glycols (ethylene glycol, 1, 2-propylene glycol, and 1, 3-propylene glycol), alkylene ether glycols (polyethylene glycol and polypropylene glycol), cycloaliphatic glycols (1, 4-cyclohexanedimethanol), bisphenols (bisphenol a), and alkylene oxide (ethylene oxide or propylene oxide) adducts on cycloaliphatic glycols and bisphenols.

The alkyl portion of the alkylene glycols and alkylene ether glycols may be straight-chain or branched. Further examples are glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol. One of these may be used alone, or two or more may be used in combination.

If necessary, a monobasic acid such as acetic acid or benzoic acid and a monobasic alcohol such as cyclohexanol or benzyl alcohol may also be used to adjust the acid value or hydroxyl value.

The method for producing the polyester resin is not particularly limited, but, for example, a transesterification method or a direct polycondensation method may be used alone or in combination.

The production of the polyester resin is preferably carried out at a polymerization temperature of 180 ℃ to 230 ℃; if necessary, the inside of the reaction system may be placed under reduced pressure; and the reaction is preferably carried out while removing water or alcohol produced by condensation. When the monomers are insoluble or incompatible at the reaction temperature, dissolution is induced by the addition of a high boiling solvent as a solubilizer. Then, the polycondensation reaction is carried out while distilling off the solubilizing agent. When a monomer having poor compatibility is present in the copolymerization reaction, it is preferable that the monomer having poor compatibility is preliminarily condensed with an acid or alcohol for polycondensation with the monomer, followed by polycondensation with the main component.

The following are examples of catalysts that may be used in the manufacture of polyesters: titanium catalysts such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, and titanium tetrabutoxide, and tin catalysts such as dibutyltin dichloride, dibutyltin oxide, and diphenyltin oxide.

The polyurethane resin is explained below. The polyurethane resin is a reaction product of a diol and a substance containing a diisocyanate group, and resins having various functionalities (functionalities) can be obtained by adjusting the diol and the diisocyanate.

The following are examples of the diisocyanate component: aromatic diisocyanates having 6 to 20 carbon atoms (the same applies below, except for the carbon atoms in the NCO group), aliphatic diisocyanates having 2 to 18 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms, as well as modifications of these diisocyanates (the modifications comprising urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretonimine groups, isocyanurate groups, or oxazolidone groups, hereinafter also referred to as "modified diisocyanates") and mixtures of two or more of the foregoing.

The following are examples of aromatic diisocyanates: m-and/or p-Xylylene Diisocyanate (XDI) and α, α, α ', α' -tetramethylxylylene diisocyanate.

The following are examples of aliphatic diisocyanates: ethylene diisocyanate, tetramethylene diisocyanate, Hexamethylene Diisocyanate (HDI), and dodecamethylene diisocyanate.

The following are examples of cycloaliphatic diisocyanates: isophorone diisocyanate (IPDI), dicyclohexylmethane-4, 4' -diisocyanate, cyclohexylene diisocyanate, and methylcyclohexylene diisocyanate.

Among the foregoing, aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms are preferable, and among them, XDI, IPDI, and HDI are particularly preferable.

In addition to the diisocyanate component, trifunctional or higher isocyanate compounds may be used.

For the diol component usable for the polyurethane resin, the same diols as those usable for the polyester resin as described above can be used.

The melamine resin is a condensation polymer of melamine and formaldehyde, and the monomer for forming the melamine resin is melamine. The urea resin is a polycondensate of urea and formaldehyde, and the monomer for forming the urea resin is urea. Melamine and urea can be modified as known.

The following describes a preferred range of using a thermoplastic resin as the non-crystalline resin, but is not limited thereto or thereby.

The glass transition temperature (Tg) of the amorphous resin is preferably 50 ℃ to 150 ℃. Within this range, transferability can be increased without impairing low-temperature fixability. More preferably from 60 ℃ to 130 ℃ and still more preferably from 65 ℃ to 120 ℃.

The weight average molecular weight of the non-crystalline resin is preferably 5,000 to 500,000. Within this range, transferability can be increased without impairing low-temperature fixability. More preferably 6,000 to 200,000, and still more preferably 7,000 to 100,000.

The content of the amorphous resin of the shell layer is preferably from 0.1 to 40.0 parts by mass with respect to 100 parts by mass of the binder resin. More preferably from 0.2 to 30.0 parts by mass, and still more preferably from 0.4 to 25.0 parts by mass.

When the shell layer is composed of two or more kinds of amorphous resins, the resin having the highest SP value among the resins constituting the shell layer is designated as resin S1, the resin having the lowest SP value among the resins constituting the shell layer is designated as resin S2, and the SP value of the resin S1 is designated as SP_S1(J/cm³)^0.5And the SP value of resin S2 is denoted as SP_S2(J/cm³)^0.5Then, SP_S1And SP_S2Satisfies the following formula (2).

SP_S1-SP_S2≤3.0...(2)

In this case, the toner particle surface is rendered sufficiently uniform and a toner having excellent transferability can be obtained. SP_S1-SP_S2Preferably 2.0 or less. The lower limit is not particularly limited, but is preferably 0 or more. The shell layer is more preferably composed of a single amorphous resin.

The thickness of the shell layer is preferably 2nm to 100 nm. When the thickness of the shell layer is within a specified range, charge leakage can be effectively suppressed without impairing low-temperature fixability. This thickness of the shell layer is preferably 5nm to 50 nm.

By making the polymer a in the present invention satisfy the contents of the first polymerizable monomer and the second polymerizable monomer in the aforementioned composition and satisfy formula (3), the polymer a having a block copolymer-like structure in which a crystalline site and a non-crystalline site are separated is easily provided. Therefore, the binder resin easily assumes a structure in which the crystalline site and the amorphous site undergo microphase separation. Thus, a toner having excellent low-temperature fixability and excellent transferability can be obtained.

Other materials used in the present invention are detailed below.

< Binder resin >

In addition to the polymer a, known resins such as vinyl resins, polyester resins, polyurethane resins, and epoxy resins can also be used for the binder resin in the toner particles.

The polyester resin and the polyurethane resin described in one of the above-mentioned noncrystalline resins can be used for the polyester resin and the polyurethane resin herein. In addition, the polymerizable monomer usable for the vinyl resin may be exemplified by polymerizable monomers usable for the first polymerizable monomer, the second polymerizable monomer, and the third polymerizable monomer as described above. A combination of two or more may be used as necessary.

The content of the polymer a in the binder resin is preferably 50.0 mass% or more. Making it 50.0 mass% or more promotes the maintenance of the quick fusing property of the toner and enhances the low-temperature fixing property. More preferably 80.0 to 100 mass%, while the binder resin is still more preferably polymer a.

< waxes >

The toner particles may comprise a wax.

The waxes may be exemplified by the following: esters between monohydric alcohols and monocarboxylic acids, such as behenyl behenate, stearyl stearate, and cetyl palmitate; esters between dicarboxylic acids and monoalcohols, such as behenyl sebacate; esters between dihydric and monocarboxylic acids, such as ethylene glycol distearate and hexylene glycol dibehenate; esters between trihydric and monocarboxylic acids, such as glyceryl tribehenate; esters between tetrahydric and monocarboxylic acids, such as pentaerythritol tetrastearate and pentaerythritol tetrapalmitate; esters between hexahydric alcohols and monocarboxylic acids, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate; synthetic ester waxes, for example, esters between a polyfunctional alcohol such as polyglyceryl dibehenate and a monocarboxylic acid; natural ester waxes such as carnauba wax and rice bran wax; petroleum-based hydrocarbon waxes such as paraffin wax, microcrystalline wax, and petrolatum, and derivatives thereof; hydrocarbon waxes and derivatives thereof provided by the fischer-tropsch process; polyolefin type hydrocarbon waxes such as polyethylene wax and polypropylene wax, and derivatives thereof; a higher aliphatic alcohol; fatty acids such as stearic acid and palmitic acid; and acid amide waxes, and the like.

For the content of the polymer a in the toner being 100 parts by mass, W parts by mass is used as the content of the wax and a parts by mass is used as the content of the first monomer unit, the wax content preferably satisfies the following formula (4).

0.2×A≤W≤A...(4)

Since the polymer a has high crystallinity and since it is covered with a shell, the toner according to the present invention exhibits high storability. However, in an environment where high and low temperatures repeatedly occur, for example, when stored in a place where the temperature difference between day and night is large, crystallinity may decrease, and therefore phase separation between a crystalline site and an amorphous site becomes unclear and the resistance value of the polymer a may decrease. In addition, the uniformity of the surface of the toner particles may be reduced because the crystalline sites are compatible with the shell layer. The transferability after storage may be reduced for these reasons.

When the wax amount W satisfies formula (4), the wax is compatible with a part of the crystalline sites in the toner, and a part exists in a precipitated state in the crystalline sites. Since the precipitated wax acts as a nucleating agent for crystalline sites, and since recrystallization of crystalline sites is promoted along with crystallization of compatible wax, high crystallinity can be maintained even after storage in an environment exhibiting a large temperature difference. As a result, the decrease in transferability after storage can be suppressed.

When a large amount of wax is added to a toner in which a non-crystalline binder resin is a main component, the phase-separated wax may exude to the surface after storage and/or use in a high-temperature environment because the difference in SP value between the wax and the binder resin is large. The non-electrostatic adhesion of the toner is increased under the influence of the exuded wax and the transferability may be lowered.

However, in the toner according to the present invention, due to the occurrence of phase separation between the low SP crystalline sites and the high SP amorphous sites in the polymer a, the low SP wax is trapped in the crystalline sites and thus bleeding of the wax to the toner particle surface is suppressed. Therefore, even when wax is added in a large amount, a decrease in transferability is suppressed.

The wax amount W more preferably satisfies the following formula (5).

0.2×A≤W≤0.8×A...(5)

By making the wax amount W satisfy formula (5), wax precipitation is more effectively suppressed, thereby promoting the obtainment of a toner having even better transferability. In addition, the crystalline portion can plasticize the amorphous portion more effectively during fixing, and then improve low-temperature fixability.

Further, since the wax deposition to the toner surface can be suppressed, W is more preferably 10.0 to 40.0.

Further, a hydrocarbon wax or an ester wax may be preferably used, and a hydrocarbon wax may be more preferably used because these waxes can function as excellent nucleating agents.

< polymerization initiator >

As the polymerization initiator for obtaining the polymer a, a publicly known polymerization initiator can be used without particular limitation.

The following are specific examples: such as hydrogen peroxide, acetyl peroxide, cumene peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetrahydronaphthalene hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-hydroperoxide, tert-butyl perforate, tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl permaleate, tert-butyl permethoxyacetate, tert-butyl per-N- (3-toluyl) palmitate, tert-butyl peroxy2-ethylhexanoate, Peroxide-based polymerization initiators such as t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2, 4-dichlorobenzoyl peroxide, and lauroyl peroxide; and

azo-and diazo-polymerization initiators represented by 2,2 '-azobis (2, 4-dimethylvaleronitrile), 2' -azobisisobutyronitrile, 1 '-azobis (cyclohexane 1-carbonitrile), 2' -azobis (4-methoxy-2, 4-dimethylvaleronitrile), and azobisisobutyronitrile.

< coloring agent >

The toner may include a colorant.

As the colorant, conventionally known magnetic bodies and pigments and dyes of respective colors of black, yellow, magenta, and cyan and other colors can be used without particular limitation.

For example, a black pigment specifically represented by carbon black may be used as the black colorant.

The yellow colorant may be specifically exemplified by yellow pigments or yellow dyes represented by, for example, monoazo compounds, disazo compounds, condensed azo compounds, isoindolinone compounds, benzimidazolone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds. Examples of more specific levels are c.i. pigment yellow 74, 93, 95, 109, 111, 128, 155, 174, 180, and 185 and c.i. solvent yellow 162.

The magenta colorant may be specifically exemplified by magenta pigments and magenta dyes, for example, azo compounds, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Examples of more specific levels are c.i. pigment red 2, 3,5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, and 269 and c.i. pigment violet 19.

The cyan colorant may be specifically exemplified by cyan pigments and cyan dyes, for example, ketophthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Examples of more specific levels are c.i. pigment blue 1, 7, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

The content of the colorant is preferably 1.0 part by mass to 20.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

The toner may also be made into a magnetic toner by incorporating a magnetic body. In this case, the magnetic substance may also be used as the colorant.

The magnetic body may be exemplified by iron oxides represented by magnetite, hematite, and ferrite; metals represented by iron, cobalt, and nickel; alloys of these metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, and vanadium; and mixtures thereof.

When a magnetic body is used, the content thereof is preferably 40.0 parts by mass to 150.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

< Charge control agent >

The toner may include a charge control agent.

As the charge control agent, heretofore known charge control agents can be used without particular limitation. Specific examples of the negatively charged charge control agent may be metal compounds of aromatic carboxylic acids such as salicylic acid, alkyl salicylic acid, dialkyl salicylic acid, naphthoic acid, and dicarboxylic acids, and polymers and copolymers of metal compounds having such aromatic carboxylic acids; polymers and copolymers having sulfonic acid groups, sulfonate groups, or sulfonate groups; metal salts and metal complexes of azo dyes and azo pigments; and boron compounds, silicon compounds, and calixarenes.

The positively charged charge control agent may be exemplified by quaternary ammonium salts and polymeric compounds having quaternary ammonium salts in side chain positions; a guanidine compound; a nigrosine compound; and an imidazole compound.

The polymer and copolymer having a sulfonate group or a sulfonate ester group may be exemplified by homopolymers of sulfonic acid group-containing vinyl monomers such as styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, and methacrylic sulfonic acid, and copolymers of these sulfonic acid group-containing vinyl monomers with the vinyl monomers described in one item of the binder resin.

The content of the charge control agent is preferably 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the binder resin.

< external additive >

The toner may contain external additives.

As the external additive, hitherto known external additives may be used without particular limitation. The following are specific examples: fine particles of base silica such as silica prepared by a wet process or silica prepared by a dry process; silica fine particles provided by surface-treating such base silica fine particles with a treating agent such as a silane coupling agent, a titanium coupling agent, and silicone oil; and resin fine particles such as vinylidene fluoride fine particles, and polytetrafluoroethylene fine particles.

The content of the external additive when incorporated is preferably 0.1 to 5.0 parts by mass with respect to 100.0 parts by mass of the toner particles.

The method for producing the toner will be described in detail below.

Heretofore known methods such as a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, or a pulverization method can be used as a toner production method; however, the method of manufacturing the toner is not limited to these. These methods can be broadly classified into a suspension polymerization method in which the production of a toner is performed simultaneously with the production of a polymer, and a dissolution suspension method, an emulsion aggregation method, and a pulverization method in which a toner is produced using a polymer produced separately.

Methods for obtaining the toner by the suspension polymerization method and by the emulsion aggregation method are described below as examples.

< method for producing toner by suspension polymerization >

(dispersing step)

The raw material dispersion liquid is prepared by combining any optional material with a polymerizable monomer composition including at least one first polymerizable monomer of (meth) acrylate having an alkyl group with a carbon number of 18 to 36, one or more second polymerizable monomers, and optionally a third polymerizable monomer, and melting, dissolving, or dispersing them using a disperser. The highly hydrophilic amorphous resin forming the shell by migrating to the toner particle surface layer during polymerization should be added to the raw material dispersion at this time in an appropriate amount according to the thickness of the desired shell layer.

Materials colorants, waxes, and charge control agents, solvents for adjusting viscosity, and other additives described in one section may optionally be added as desired. The solvent used for viscosity adjustment should be a solvent having low solubility in water and being capable of completely dissolving/dispersing the aforementioned materials, but a well-known solvent may be used unless otherwise particularly limited. Examples are toluene, xylene, and ethyl acetate. The disperser may be exemplified by a homogenizer, a ball mill, a colloid mill, and an ultrasonic disperser.

(granulation step)

The raw material dispersion liquid is introduced into a previously prepared aqueous medium and a disperser such as a high-speed stirrer or an ultrasonic disperser is used to prepare a suspension. The aqueous medium preferably contains a dispersion stabilizer for adjusting particle diameter and suppressing aggregation. The dispersion stabilizer is not particularly limited and hitherto known dispersion stabilizers can be used.

The following are examples of inorganic dispersion stabilizers: phosphates such as represented by tricalcium phosphate, calcium hydrogen phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; carbonates such as represented by calcium carbonate and magnesium carbonate; metal hydroxides such as represented by calcium hydroxide, magnesium hydroxide, and aluminum hydroxide; sulfates such as represented by calcium sulfate and barium sulfate; and calcium metasilicate, bentonite, silica, and alumina.

The following are examples of organic dispersion stabilizers: polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, the sodium salt of carboxymethyl cellulose, polyacrylic acid and its salts, and starch.

Inorganic charge stabilizers exhibit strong aggregation inhibition and are therefore preferred due to their high charge polarity and strong adsorption to the oil phase. In addition, hydroxyapatite, tricalcium phosphate, and calcium hydrogen phosphate are more preferable because they can be easily removed by adjusting pH.

(polymerization step)

The toner particles containing the polymer a are obtained by polymerizing the polymerizable monomer in the suspension.

The polymerization initiator may be mixed together with other additives during the preparation of the raw material dispersion or may be mixed into the raw material dispersion immediately before being suspended in the aqueous medium. In addition, it may also be added, dissolved in a polymerizable monomer or other solvent, as necessary, during the pelletization step or immediately after the pelletization step is completed, i.e., before the polymerization step is started. After obtaining a polymer by polymerization of a polymerizable monomer, if necessary, an aqueous dispersion of toner particles is obtained by applying a solvent removal process by heating or reduced pressure.

When a highly hydrophilic amorphous resin is added to the raw material dispersion, the amorphous resin migrates from the granulating step to the toner particle surface layer through the polymerization step to form a shell layer.

(filtration step, washing step, drying step, classification step, external addition step)

A filtration step of solid components obtained from the aqueous dispersion of toner particles by solid-liquid separation, and optionally a washing step, a drying step, and a classification step for adjusting particle size are performed to obtain toner particles. The toner particles are useful, for example, as toners. The toner can also be obtained by mixing an external additive such as an inorganic fine powder with toner particles using a mixer as needed to attach the external additive to the toner particles.

< method for producing toner by emulsion aggregation method >

(Polymer A production step)

Hitherto known methods such as solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, and dispersion polymerization can be used as the method for producing the polymer a, but are not limited thereto.

The method for obtaining the polymer a by solution polymerization is described below as an example.

The monomer solution is prepared by dissolving a polymerizable monomer composition including at least one first polymerizable monomer of (meth) acrylate having an alkyl group with a carbon number of 18 to 36, one or more second polymerizable monomers, and optionally a third polymerizable monomer in a solvent such as toluene. A polymerization initiator is added thereto, and then a polymer solution of the polymer a dissolved in a solvent such as toluene is obtained by polymerizing a polymerizable monomer. The polymer a is precipitated by mixing the polymer solution with a solvent (for example, methanol) in which the polymer a is insoluble. The precipitated polymer a was filtered and washed to obtain a polymer a.

(preparation step of resin Fine particle Dispersion)

The dispersion of the resin fine particles can be prepared by known methods, but there is no limitation to these methods. Examples are emulsion polymerization processes; a self-emulsification method; a phase inversion emulsification method in which a resin is emulsified by adding an aqueous medium to a resin solution dissolved in an organic solvent; and a forced emulsification method in which a resin is forcibly emulsified by performing a high-temperature treatment in an aqueous medium without using an organic solvent.

A method of preparing a resin fine particle dispersion using a phase inversion emulsification method is described below as an example.

The resin component containing the polymer a is dissolved in an organic solvent in which the resin component is dissolved, and a surfactant and/or an alkaline compound is added. If the resin component is a crystalline resin having a melting point, the dissolution should be performed by heating to above the melting point. Then, while stirring using, for example, a homogenizer, the aqueous medium is gradually added to precipitate the resin fine particles. Subsequently, the solvent is removed by heating or reduced pressure, thereby preparing an aqueous dispersion of resin fine particles.

The organic solvent used for dissolving the resin component containing the polymer a should be capable of dissolving the resin component containing the polymer a. Specific examples are toluene and xylene.

The surfactant used in the preparation step is not particularly limited, and the following are examples: anionic surfactants such as salts of sulfates, sulfonates, carboxylates, phosphates, and soaps; cationic surfactants such as amine salt type and quaternary ammonium salt type; and nonionic surfactants such as polyethylene glycol-based, ethylene oxide adduct-based on alkylphenol, and polyol-based surfactants. A single surfactant may be used or two or more may be used in combination.

The basic compound used in the preparation step can be exemplified by: inorganic bases such as sodium hydroxide and potassium hydroxide, such as ammonia, and organic bases such as diethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. One kind of the basic compound may be used alone or two or more kinds may be used in combination.

(preparation of colorant Dispersion)

The colorant dispersion liquid may be prepared using a known dispersion method, and a conventional dispersion method such as a homogenizer, a ball mill, a colloid mill, an ultrasonic disperser, and the like may be used without any limitation. The above surfactants are examples of surfactants that can be used for the dispersion.

(preparation of wax Dispersion)

The wax dispersion is prepared by dispersing a wax in combination with, for example, a surfactant and/or a basic compound in water, followed by heating to a temperature above the melting point of the wax while performing a dispersing treatment using a disperser or homogenizer which applies a strong shearing force. This process is carried out to produce a wax dispersion. The surfactant used for dispersion herein may be exemplified by the surfactants already described above. The basic compound used for dispersion herein can also be exemplified by the basic compounds already described above.

(aggregate particle formation step)

In the aggregated particle forming step, a mixture is first prepared by mixing a resin fine particle dispersion liquid, a colorant dispersion liquid, a wax dispersion liquid, and the like. Then, aggregation is induced by heating at a temperature lower than the melting point of the resin fine particles while adjusting the pH to an acidic region, and thus an aggregated particle dispersion is obtained by formation of aggregated particles containing the resin fine particles, the colorant particles, and the release agent particles.

(first fusing step)

In the first fusing step, while operating under stirring conditions following the aggregated particle forming step, the progress of aggregation is stopped by raising the pH of the aggregated particle dispersion, and a fused particle dispersion is obtained by heating to a temperature above the melting point of the aforementioned polymer.

(step of attaching fine particles of non-crystalline resin)

In the amorphous resin fine particle adhesion step, a dispersion of resin adhesion particles is obtained by adding an amorphous resin particle dispersion to the fused particle dispersion and inducing adhesion of the amorphous resin fine particles to the surface of the fused particles by lowering the pH. Here, the coating layer corresponds to a shell layer formed by performing the shell layer forming step described below. The amorphous resin fine particle dispersion liquid may be prepared according to the aforementioned resin fine particle dispersion liquid preparation step.

(second fusing step)

In the second fusing step, according to the first fusing step, the progress of aggregation is stopped by raising the pH of the resin-attached particle dispersion, and the fusing of the resin-attached aggregated particles is induced by heating to a temperature above the melting point of the polymer a to obtain toner particles having shell layers.

(filtration step, washing step, drying step, classification step, external addition step)

The toner particles are obtained by subsequently performing a filtration step of separating solid components of the toner particles by filtration, and performing an optional washing step, a drying step, and a classification step for adjusting particle size. The toner particles are useful, for example, as toners. The toner can also be obtained by mixing an external additive such as an inorganic fine powder and toner particles using a mixer as necessary to attach the external additive to the toner particles.

< other methods for Forming Shell layer >

The shell layer may be formed simultaneously with the toner particle production as described above, using a suspension polymerization method and an emulsion aggregation method. The shell layer can also be formed by the same method as the suspension polymerization method using the dissolution suspension method.

In other methods, the shell layer may be formed after the toner core is formed. Examples, a method of performing shell layer formation by performing an emulsion aggregation method on an aqueous dispersion of toner cores (hereinafter, toner core dispersion), and a method of performing shell layer formation on a toner core dispersion using a thermosetting resin precursor; however, it is not limited to these.

< formation of shell layer by emulsion aggregation method >

The shell layer may be formed by performing the same operation on the toner core dispersion as in the amorphous resin fine particle adhesion step and the second fusing step in the toner manufacturing method by the emulsion aggregation method described above.

Then, a filtering step of separating solid components of the toner particles by filtration, and an optional washing step, a drying step, and a classifying step for adjusting particle size are performed to obtain toner particles.

< formation of Shell layer Using thermosetting resin precursor >

The pH of the toner core dispersion is adjusted to about 4, followed by dissolving the shell-forming material in the aqueous dispersion containing the toner core. Subsequently, the shell layer forming material in the dispersion reacts to form a shell layer covering the surface of the toner core, and thus the toner particle dispersion is provided.

Here, the shell layer can be formed, for example, by the reaction of melamine, urea, and the reaction products of glyoxal/urea with precursors (methylol compounds) formed by their addition reaction with formaldehyde.

Then, a filtering step of separating solid components of the toner particles by filtration, and an optional washing step, a drying step, and a classifying step for adjusting particle size are performed to obtain toner particles.

The method for measuring the toner according to the present invention is described below.

< calculation method of the percentage of observed shell layer and thickness of shell layer >

The observed percentage (coverage) of the shell layer and the thickness of the shell layer of the toner can be determined by measuring the geometric structure of the cross section of the individual toner particle. The following is a specific method for determining the geometry of individual toner particle cross sections.

First, the toner is thoroughly dispersed in the photocurable epoxy resin, and then the epoxy resin is cured by exposure to ultraviolet radiation. The obtained cured product was sliced using a microtome equipped with a diamond blade to prepare a 100nm thick thin slice sample. The sample was stained with ruthenium tetroxide, and then a toner cross section was observed under an acceleration voltage of 120kV using a Transmission Electron Microscope (TEM) (product name: Tecnaitf20XT electron microscope, FEI Company) to obtain a TEM image. At this time, the toner particles for observation were selected to have a cross section having a major axis diameter of 0.9 to 1.1 times the number average particle diameter (D1) measured on the same toner using the following method for measuring the number average particle diameter (D1) of the toner particles.

In this particular observation method, the amorphous resin in the toner particles is strongly colored by ruthenium tetroxide. As a result, it can be observed by comparison that the shell region having the amorphous resin as a main component is dyed while the core region having the crystalline resin as a main component is not dyed. The observation magnification was 20,000X.

Based on the obtained TEM image, the length C1(nm) was determined in the individual toner particle section of the region where the shell layer was observed over the circumferential length of the individual toner particle; determining a length C2(nm) of a cross section of the individual toner particle at an outer periphery of the individual toner particle; and C1/C2 × 100 (%) is the coverage of the shell (percentage of shell observed).

In addition, the long axis of the individual toner particle is the longest segment passing through the geometric center of the cross section of the individual toner particle, and the length thereof is the long axis diameter r (nm). When the length between the two core/shell interfaces on the long axis is R (nm), the shell thickness is (R-R)/2 (nm).

The determination of the percentage of observed shell layers and the shell layer thickness was performed for 100 toner particles, and the arithmetic average values obtained were used.

< method for measuring the content of monomer units derived from various polymerizable monomers in Polymer A >

By passing¹H-NMR the content of monomer units derived from each polymerizable monomer in the polymer A was determined using the following conditions.

A measuring device: JNM-EX400FT-NMR apparatus (JEOL Ltd.)

Measuring frequency: 400MHz

Pulse conditions are as follows: 5.0 mus

Frequency range: 10,500Hz

And (4) accumulating times: 64

Measuring temperature: 30 deg.C

Sample preparation: by introducing 50mg of the measurement sample into a sample tube having an inner diameter of 5 mm; deuterated chloroform (CDCl) was added as solvent₃) (ii) a And dissolved in a thermostat at 40 ℃.

In the obtained¹In the H-NMR chart, from among peaks ascribed to the constituent components of the monomer unit derived from the first polymerizable monomer, a peak independent of peaks ascribed to the constituent components of the monomer unit derived from other sources is selected, and an integration value (integration value) S1 of the peak is calculated. Similarly, from among the peaks ascribed to the constituent components of the monomer unit derived from the second polymerizable monomer, a peak independent of the peaks ascribed to the constituent components of the monomer unit derived from other sources is selected, and the integrated value S2 of the peak is calculated.

When the third polymerizable monomer is used, from among peaks ascribed to the constituent components of the monomer unit derived from the third polymerizable monomer, a peak independent of peaks ascribed to the constituent components of the monomer unit derived from other sources is selected, and an integrated value S3 of the peak is calculated.

The content of the monomer unit derived from the first polymerizable monomer was determined using the integrated values of S1, S2, and S3 as follows. n1, n2, and n3 are the number of hydrogens in the constituent components of the target peak assigned to a particular fragment.

Content (mol%) of monomer unit derived from the first polymerizable monomer { (S1/n1)/((S1/n1) + (S2/n2) + (S3/n3)) } × 100

The content of the monomer unit derived from the second polymerizable monomer and the content of the monomer unit derived from the third polymerizable monomer were also determined as follows.

The content (mol%) of the monomer unit derived from the second polymerizable monomer unit { (S2/n2)/((S1/n1) + (S2/n2) + (S3/n3)) } × 100

The content (mol%) of the monomer unit derived from the third polymerizable monomer { (S3/n3)/((S1/n1) + (S2/n2) + (S3/n3)) } × 100

When a polymerizable monomer containing no hydrogen atom in constituent components other than vinyl groups is used for the polymer a,¹³c for using¹³C-NMR measurement of nuclei; the assay was performed in monopulse mode; and carry out the reaction with¹H-NMR was calculated in the same manner.

In addition, when the toner is manufactured by suspension polymerization, peaks of the release agent and other resins may overlap and no independent peak may be observed. Therefore, in some cases, the content of the monomer unit derived from each polymerizable monomer in the polymer a may not be calculated. In this case, polymer a 'was prepared by the same suspension polymerization without using a release agent and other resins, and then polymer a' was analyzed as polymer a.

< method for calculating SP value >

The SP is determined as follows according to the calculation method proposed by Fedors₁₂And SP₂₂。

For each polymerizable monomer, the molecular structure was determined from the table given in "Polym.Eng.Sci., 14(2),147-154 (1974)"The evaporation energy (Δ ei) (cal/mol) and the molar volume (Δ vi) (cm) of the atom or group of atoms of (1)³Mol) and (4.184 × Σ Δ ei/Σ Δ vi)^0.5For SP value (J/cm)³)^0.5。

For an atom or an atomic group in a molecular structure in a state provided by cleavage of a double bond in a polymerizable monomer due to polymerization, SP was determined by the same calculation method₁₂And SP₂₂。

SP was determined as follows_S1And SP_S2。

The SP value (SP) of the resin constituting the shell layer was calculated using the following formula (S1) and determined as follows_S): determining, for each repeating unit, the evaporation energy (Δ ei) and the molar volume (Δ vi) of the repeating unit constituting the resin; calculating the product of the molar ratios (j) of the specific repeating units in each resin; and the total evaporation energy of each repeat unit divided by the total molar volume.

Formula (S1): SP_S＝{(Σj×ΣΔei)/(Σj×ΣΔvi)}^1/2

In this manner, SP of each resin constituting the shell layer was calculated_S. The largest value in the group is denoted SP_S1And the smallest value is denoted as SP_S2。

The unit of SP value in the present invention is (J/m)³)^0.5However, it may use 1 (cal/cm)³)^0.5＝2.045×10³(J/m³)^0.5Conversion to (cal/cm)³)^0.5Units.

< method for measuring weight average molecular weight Mw of Polymer A >

The weight average molecular weight (Mw) of the THF-solubles in polymer A was determined using Gel Permeation Chromatography (GPC) as follows.

First, the sample was dissolved in Tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution was filtered using a "sample pretreatment cartridge" (Tosoh Corporation) solvent-resistant membrane filter having a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted to a THF-soluble component concentration of 0.8 mass%. The measurement was performed under the following conditions using the sample solution.

The device comprises the following steps: HLC8120GPC (detector: RI) (Tosoh Corporation)

Column: shodex KF-801, 802, 803, 804, 805, 806, and 807 7 pillars (Showa Denko Kabushiki Kaisha)

Eluent: tetrahydrofuran (THF)

Flow rate: 1.0mL/min

And (3) case temperature: 40.0 deg.C

Sample injection amount: 0.10mL

The molecular weight of the sample is determined using a molecular weight calibration curve constructed using polystyrene resin standards (e.g., trade names "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", Tosohcorporation).

< method for measuring endothermic amount of endothermic peak of toner >

The endothermic amount of the endothermic peak associated with melting of polymer a in the toner was measured using the following conditions and DSC Q1000(TA Instruments).

Temperature rise rate: 10 ℃/min

Measurement of the initial temperature: 20 deg.C

Measurement of termination temperature: 180 deg.C

The melting points of indium and zinc were used for temperature correction of the detection part of the instrument, and the heat of fusion of indium was used for heat correction.

Specifically, 5mg of the toner was accurately weighed and introduced into an aluminum pan, and differential scanning calorimetry was performed. An empty silver disc was used as a reference.

The endothermic amount of the endothermic peak associated with the melting of the polymer a in the first temperature raising process is regarded as the endothermic amount of the endothermic peak of the toner. For a toner containing polymer a and wax, when an endothermic peak relating to melting of polymer a and an endothermic peak relating to melting of wax overlap, the above measurement is performed solely on wax to determine the endothermic amount of the endothermic peak relating to melting of wax. The endothermic amount of the endothermic peak associated with the melting of polymer a is regarded as a value provided by subtracting the endothermic amount of the endothermic peak associated with the melting of the wax from the endothermic amount of the observed overlapping endothermic peak.

< method for measuring melting points of Polymer A and wax >

The melting point of polymer A and the melting point of the wax were determined in the present invention using the following conditions and DSC Q1000(TA Instruments).

Temperature rise rate: 10 ℃/min

Measurement of the initial temperature: 20 deg.C

Measurement of termination temperature: 180 deg.C

The melting points of indium and zinc were used for temperature correction of the detection part of the instrument, and the heat of fusion of indium was used for heat correction.

Specifically, 5mg of the toner was accurately weighed and introduced into an aluminum pan, and differential scanning calorimetry was performed. An empty silver disc was used as a reference.

The peak temperature of the maximum endothermic peak during the first temperature raising process is regarded as the melting point.

When a plurality of peaks are present, the peak having the largest endothermic amount is regarded as the largest endothermic peak.

< method for measuring Charge decay Rate coefficient (charge decay coefficient) of Polymer A >

The charge decay rate coefficient of Polymer A was measured using an NS-D100 electrostatic diffusivity analyzer (Nano Seeds Corporation).

First, approximately 100mg of polymer a was filled into a sample pan and scraped to provide a smooth, flat surface. The sample disk was exposed to X-rays from the X-ray charge eliminator for 30 seconds to remove the charge of polymer a. The discharged sample tray is mounted on the assay plate. While the metal plate is mounted as a reference for zero calibration of the surface voltmeter. The assay plate with the sample is kept in a 30 ℃/80% RH environment for at least one hour prior to assay.

The measurement conditions were set as follows.

Charging time: 0.1s

Measuring time: 1800s

Measurement interval: 1s

Discharge polarity: -

An electrode: exist of

The initial potential was set to-600V and the charge of the surface potential was started to be measured immediately after charging. The charge decay rate coefficient α was determined by substituting the obtained result into the following expression. The resulting charge decay rate coefficient α is taken as the charge decay constant.

V_t＝V₀exp(-αt^1/2)

V_t: surface potential (V) at time t

V₀: initial surface potential (V)

t: time after electrification(s)

α: coefficient of charge decay rate

< method for measuring acid value of Polymer A >

The acid value is the mass (mg) of potassium hydroxide required to neutralize the acid contained in 1g of the sample. In the present invention, the acid value of the polymer A is measured in accordance with JIS K0070-1992, specifically in accordance with the following procedure.

(1) Preparation of reagents

A phenolphthalein solution was obtained by dissolving 1.0g of phenolphthalein in 90mL of ethanol (95 vol%) and adding to 100mL by adding deionized water.

7g of special grade potassium hydroxide were dissolved in 5mL of water and added to 1L by adding ethanol (95 vol%). It is introduced into an alkali-resistant container to avoid contact with, for example, carbon dioxide or the like, and allowed to stand for 3 days, followed by filtration to obtain a potassium hydroxide solution. The resulting potassium hydroxide solution was stored in an alkaline-resistant container. The factor of the potassium hydroxide solution is determined by the amount of potassium hydroxide solution required for neutralization when 25ml of 0.1mol/L hydrochloric acid is introduced into an erlenmeyer flask, a few drops of phenolphthalein solution are added, and titration is performed using the potassium hydroxide solution. 0.1mol/L hydrochloric acid used was prepared in accordance with JIS K8001-.

(2) Process for producing a metal oxide

(A) Main test

A2.0 g sample of the pulverized polymer A was precisely weighed into a 200mL Erlenmeyer flask and dissolved for 5 hours or more by adding 100mL of a toluene/ethanol (2:1) mixed solution. A few drops of phenolphthalein solution were added as an indicator, and titration was performed using potassium hydroxide solution. The light pink color of the indicator lasting 30 seconds was taken as the titration endpoint.

(B) Blank test

The same titration as in the above procedure was performed, except that no sample was used, i.e., only the toluene/ethanol (2:1) mixed solution was used.

(3) The acid value was calculated by substituting the obtained result into the following formula.

A＝[(C-B)×f×5.61]/S

Here, a: acid number (mg KOH/g); b: the amount of potassium hydroxide solution added (mL) in the blank test; c: the amount of potassium hydroxide solution added (mL) in the main test; f: a factor for potassium hydroxide solution; and S: mass (g) of the sample.

< measurement of weight average particle diameter (D4) and number average particle diameter (D1) of toner >

Determination of the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner was performed as follows. The measuring instrument used was "Coulter Counter Multisizer 3" (registered trademark, Beckman Coulter, Inc.), an accurate particle size distribution measuring instrument operating on the basis of the orifice resistance method and equipped with a 100 μm orifice tube. The assay conditions were set and assay data were analyzed using an attached proprietary software, i.e., "Beckman Coulter Multisizer 3Version 3.51" (Beckman Coulter, Inc.). The measurement is performed with an effective number of measurement channels of 25,000 channels.

The aqueous electrolyte solution for the assay was prepared by dissolving sodium chloride of special grade in deionized water to provide a concentration of 1.0%, and "ISOTON II" (Beckman Coulter, Inc.) may be used, for example.

Before measurement and analysis, the dedicated software was configured as follows.

In the "modified standard operating method" (SOMME) "interface of the dedicated software, the total count of control modes is set to 50,000 particles; the number of measurements is set to one; and the value obtained using "standard particles 10.0 μm" (Beckman Coulter, Inc.) was set as the Kd value. The threshold and noise level are automatically set by pressing the "threshold/noise level determination button". In addition, the current was set to 1,600. mu.A; the gain is set to 2; the electrolyte is set to ISOTON II; and check "post-assay flush port tube".

In the interface of 'conversion setting of pulse to particle size' of special software, the element interval is set to logarithmic particle size; setting the particle size element to be a 256 particle size element; and the particle diameter range is set to 2 μm to 60 μm.

The specific procedure is as follows.

(1) 200.0mL of the aqueous electrolyte solution was introduced into a 250mL round-bottom beaker dedicated to Multisizer 3, and it was placed on a sample stage and stirred counterclockwise at 24 revolutions per second using a stirring rod. Dirt and air bubbles in the mouth tube are primarily removed through a special software 'mouth tube flushing' function.

(2) 30.0mL of the aqueous electrolyte solution was introduced into a 100mL flat bottom glass beaker. To this was added 0.3mL of a dispersant solution prepared by three-fold (mass) dilution of "continon N" (a 10% aqueous solution of a neutral pH7 detergent for cleaning precision measuring instruments, which includes a nonionic surfactant, an anionic surfactant, and an organic builder, from Wako Pure Chemical Industries, Ltd.) with deionized water.

(3) "Ultrasonic Dispersion System Tetra 150" (Nikkaki Bios co., Ltd.); it is an ultrasonic disperser with 120W electrical output and equipped with two oscillators (oscillation frequency 50kHz) phase-shifted by 180 °. 3.3L of deionized water was introduced into the water tank of the ultrasonic disperser and 2.0mL of Contaminon N was added to the water tank.

(4) Placing the beaker in (2) in a beaker fixing hole on an ultrasonic disperser and starting the ultrasonic disperser. The height position of the beaker is adjusted so as to maximize the resonance state of the liquid surface of the aqueous electrolyte solution in the beaker.

(5) When the aqueous electrolyte solution in the beaker provided according to (4) was irradiated with an ultraradio wave, 10mg of toner particles were added in small portions to the aqueous electrolyte solution and dispersed. The ultrasonic dispersion treatment was continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank was appropriately adjusted to 10 ℃ to 40 ℃.

(6) Using a pipette, the aqueous electrolyte solution prepared in (5) and including dispersed toner particles was dropped into a round bottom glass beaker provided in the sample stage as described in (1) and adjusted to provide a measured concentration of 5%. Then, measurement was performed until the number of particles measured reached 50,000.

(7) The measurement data were analyzed by dedicated software provided by the instrument and the weight average particle diameter (D4) and the number average particle diameter (D1) were calculated. The "average diameter" on the "analysis/volume statistics (arithmetic mean)" interface when set as graph/volume% using dedicated software is the weight average particle diameter (D4). The "average diameter" on the "analysis/number statistics (arithmetic mean)" interface when set as graph/number% using dedicated software is the number average particle diameter (D1).