Toner and method for producing toner

Abstract

The present invention relates to a toner and a method for producing a toner. A toner includes toner particles having a resin component containing a crystalline resin and a non-crystalline resin, wherein the resin component contains a tetrahydrofuran-insoluble component, and the content of the tetrahydrofuran-insoluble component is 5.0% to 80.0% by mass relative to the content of the resin component, wherein the maximum endothermic peak temperature of the tetrahydrofuran-insoluble component is 55.0°C to 80.0°C, and the maximum endothermic peak of the tetrahydrofuran-insoluble component has an endothermic quantity of 10.0 to 80.0 J / g, and the toner particles have a structure including a matrix containing the crystalline resin and domains containing the non-crystalline resin.

Description

Technical Field

[0001] The present disclosure relates to a toner for an electrophotographic image forming apparatus. Background Art

[0002] In recent years, there has been an increasing demand for energy conservation in electrophotographic image forming apparatuses. As a measure for energy conservation, toners having excellent low-temperature fixability are required to reduce the amount of heat required to fix the toners.

[0003] In order to improve the low-temperature fixing property of toner, a method of using a crystalline resin in the toner has been studied. Amorphous resins, which are commonly used as binder resins for toners, do not show a clear endothermic peak in differential scanning calorimetry (DSC) measurements. Crystalline resins do show endothermic peaks in DSC measurements. Crystalline resins have a regular arrangement of long-chain alkyl groups between or within molecules and therefore have the property of hardly softening until the melting point is reached. Due to this property, crystalline resins melt rapidly at their melting point, i.e., melt sharply, resulting in a rapid decrease in viscosity.

[0004] For this reason, crystalline resins have attracted attention as materials that have excellent rapid melting properties and improve the low-temperature fixing properties of toners. Known examples of crystalline resins include crystalline vinyl resins. Crystalline vinyl resins are vinyl polymers that include monomer units containing long-chain alkyl groups. That is, crystalline vinyl resins have a main chain (skeleton) and long-chain alkyl groups serving as side chains. The long-chain alkyl groups in the side chains are regularly arranged and crystallized, thereby exhibiting the crystallinity of the crystalline vinyl resin.

[0005] Toners with a high crystalline resin content have poor high-temperature elasticity and are prone to high-temperature offset. Methods of introducing crystalline resins and non-crystalline resins into toners to achieve sufficient high-temperature elasticity are known.

[0006] International Publication No. WO2019 / 073731 reports a toner containing a cross-linked polyester and a crystalline vinyl resin to improve low-temperature fixability and high-temperature offset resistance.

[0007] The present inventors have examined the toner described in WO2019 / 073731 and found that the toner's developing performance tends to deteriorate when outputting images in a low-temperature, low-humidity environment. Specifically, it was found that the non-image area in the fixed image is easily contaminated. Summary of the Invention

[0008] At least one aspect of the present disclosure is directed to providing a toner that excels in low-temperature fixability and high-temperature offset resistance and excels in developing performance in a low-temperature and low-humidity environment.

[0009] According to one aspect of the present disclosure, there is provided a toner including toner particles, the toner particles comprising a resin component containing a crystalline resin and a non-crystalline resin, wherein the resin component contains a tetrahydrofuran-insoluble component, and the content of the tetrahydrofuran-insoluble component is 5.0% by mass to 80.0% by mass relative to the content of the resin component, wherein when a maximum endothermic peak temperature in a differential scanning calorimetry measurement (DSC measurement) of the tetrahydrofuran-insoluble component is defined as Tm [° C.] and when a maximum endothermic peak temperature determined by the DSC measurement of the tetrahydrofuran-insoluble component is defined as Tm [° C.], the toner particles are provided. When the endothermic value of the peak is defined as H(I) [J / g], Tm [°C] satisfies the formula (1): 55.0 ≤ Tm ≤ 80.0···(1), and H(I) [J / g] satisfies the formula (2): 10.0 ≤ H(I) ≤ 80.0···(2), and when a cross section of 100 toner particles is observed, each cross section has a domain-matrix structure including a matrix containing a crystalline resin and domains each containing a non-crystalline resin, and among the 100 particles, the number of particles in which the major diameters of all the domains are 1.0 μm or less is 20 or more. According to one aspect of the present disclosure, a toner that excels in low-temperature fixability and high-temperature offset resistance and excels in developing performance in a low-temperature, low-humidity environment can be provided.

[0010] Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Schematic cross-sectional view of a toner particle according to an embodiment of the present disclosure for the purpose of explaining a presumed mechanism providing the effects of the present disclosure. DETAILED DESCRIPTION

[0012] Unless otherwise stated, the expressions “XX or more and YY or less” and “XX to YY” refer to numerical ranges including the lower limit and the upper limit as endpoints.

[0013] The term "(meth)acrylate" refers to acrylate and / or methacrylate. The term "(meth)acrylic" refers to acrylic and / or methacrylic.

[0014] When a numerical range is described in segments, the upper limit and lower limit of each numerical range can be freely combined.

[0015] Monomeric unit is the part (unit) contained in polymer (polymeric material), and refers to the reaction form of monomer (polymerizable monomer).For example, the segment of a carbon-carbon bond in the main chain of the polymer formed by the polymerization of vinyl monomer is regarded as a monomeric unit.Vinyl monomer can be represented by the following formula (Z).Vinyl monomer unit is the constituent unit of polymer and is formed by the reaction of the monomer represented by the following formula (Z).Vinyl monomer undergoes polymerization reaction to form vinyl polymer.Monomeric unit can also be simply referred to as "unit".

[0016]

[0017] In formula (Z), R Z1 is a hydrogen atom or an alkyl group, and R Z2 is an arbitrary substituent.

[0018] The crystalline resin is a resin that shows a clear endothermic peak in differential scanning calorimetry (DSC) measurement when used as a measurement sample in the form of a resin, toner particles, or toner.

[0019] The term "THF" refers to tetrahydrofuran.

[0020] In cross-sectional observation of toner particles, the portion containing a crystalline resin refers to a portion having a grayscale of 127 or less when a change in brightness from black to white is defined as grayscale 0 to grayscale 255 in image analysis of a cross-sectional image of a toner particle stained with ruthenium staining as described below. Similarly, the portion containing an amorphous resin refers to a portion having a grayscale of 128 or greater. When a binarization process is performed in which a portion having a grayscale of 127 or less is black and a portion having a grayscale of 128 or greater is white, a portion mainly composed of a crystalline resin appears black, and a portion mainly composed of an amorphous resin appears white.

[0021] The present inventors have conducted intensive studies and have found that a toner having the above-mentioned constitutional features can have excellent low-temperature fixing ability and excellent developing performance. The presumed mechanism and constitutional features will be described in detail below.

[0022] Mechanism showing the effect of the present disclosure

[0023] The present inventors presume that the mechanism providing the effects of the present disclosure is as follows.

[0024] The toner contains a resin component containing a tetrahydrofuran (hereinafter, tetrahydrofuran is also referred to as "THF") insoluble component and thus has excellent high-temperature offset resistance. This is because a THF-insoluble resin generally has excellent high-temperature elasticity.

[0025] When the THF insoluble content satisfies the above formula (1) and formula (2), the resin component contained in the toner is easily plasticized at low temperatures, thereby achieving both excellent high-temperature offset resistance and excellent low-temperature fixing ability.

[0026] The fact that a matrix containing a crystalline resin was observed in cross-sectional observation of toner particles indicates that the physical properties of the toner tend to depend on the crystalline resin, and therefore the toner has excellent low-temperature fixing ability. The fact that domains containing a non-crystalline resin were observed indicates that the toner has excellent high-temperature elasticity provided by the non-crystalline resin without impairing the low-temperature fixing ability provided by the crystalline resin, thereby achieving both low-temperature fixing ability and high-temperature offset resistance.

[0027] When a cross section of 100 toner particles is observed and the number of toner particles in which all domains have a major diameter of 1.0 μm or less is 20 or more, toner particles free of coarsened domains are readily obtained. This results in a toner with minimal broadening of the charge distribution of the toner as a whole and excellent developing performance.

[0028] THF insoluble components

[0029] When the maximum endothermic peak temperature in differential scanning calorimetry (DSC) measurement of the tetrahydrofuran-insoluble component contained in the toner is defined as Tm [°C] and the endothermic quantity of the maximum endothermic peak is defined as H(I) [J / g], Tm [°C] satisfies the above formula (1), and H(I) [J / g] satisfies the above formula (2).

[0030] The THF-insoluble component in the resin component is a resin that generally has better high-temperature elasticity than a THF-soluble resin and thus improves the high-temperature offset resistance of the toner. An example of the THF-insoluble component in the resin component is a resin having a cross-linked structure.

[0031] The fact that the THF-insoluble component in the resin component satisfies the above formulas (1) and (2) indicates that the resin component contains a crystalline resin having excellent high-temperature elasticity. When the THF-insoluble component satisfies formula (1), the THF-insoluble component melts at a temperature near Tm, and the resin contained in the toner is thus easily plasticized. This easily results in a toner having excellent low-temperature fixability and high-temperature offset resistance.

[0032] When Tm is 55.0°C or higher, the melting start temperature of the THF-insoluble component is not too low, and the fixing temperature of the toner is easily maintained appropriately. Tm is preferably 58.0°C or higher, more preferably 60.0°C or higher. When Tm is 80.0°C or lower, the melting start temperature of the THF-insoluble component is not too high, and the resin contained in the toner is easily plasticized at low temperatures. This easily leads to a toner with excellent low-temperature fixing properties. Tm is preferably 77.0°C or lower, more preferably 67.0°C or lower. Tm can be controlled by, for example, the composition of the THF-insoluble component and the amount of crystalline components in the THF-insoluble component.

[0033] The fact that the above-mentioned H(I) is 10.0 J / g or more indicates that the crystalline part of the THF-insoluble component absorbs heat, and the resin component contained in the toner is therefore easily plasticized. H(I) is preferably 11.5 J / g or more, more preferably 13.0 J / g or more, and even more preferably 16.5 J / g or more. When H(I) is 80.0 J / g or less, the amount of heat absorbed is not too large. Therefore, the crystalline part of the THF-insoluble component does not excessively plasticize, and the resin component contained in the toner is not easily excessively plasticized. It is easy to properly maintain the elasticity of the toner during fixing, thereby easily providing a toner with excellent high-temperature defacement resistance. H(I) is preferably 65.0 J / g or less, more preferably 50.0 J / g or less, and even more preferably 40.0 J / g or less.

[0034] The THF-insoluble component satisfying the above formula (1) and formula (2) can be introduced into the toner by mixing raw materials containing the THF-insoluble component to prepare a resin component. Alternatively, the THF-insoluble component can be introduced into the toner by using a free radical initiator to induce a crosslinking reaction between the resins when mixing a crystalline resin and a non-crystalline resin to prepare the resin component.

[0035] When the endothermic amount of the maximum endothermic peak of the toner determined by DSC measurement is defined as H(T) [J / g], H(I) [J / g] and H(T) [J / g] preferably satisfy the following formula (3).

[0036] 3.0%≤H(I) / H(T)≤20.0%···(3)

[0037] H(T) refers to the endothermic quantity of the endothermic peak that contributes most to the melting of the toner. When the endothermic quantity of the THF-insoluble component (H(I)) is within the above range relative to the endothermic quantity of the endothermic peak that contributes most to the melting of the toner, the melting of the THF-insoluble component seems to contribute to the melting of the toner in an appropriate proportion. This easily leads to a toner having excellent resistance to high-temperature defacement. The reason is that THF-insoluble resins generally maintain a certain degree of elasticity even above Tm, making it easy for the toner to maintain appropriate elasticity during fixing. Therefore, H(I) / H(T) is preferably 3.0% or more, more preferably 4.0% or more. H(I) / H(T) is preferably 20.0% or less, more preferably 15.0% or less, and even more preferably 12.0% or less.

[0038] H(I) and H(I) / H(T) can be controlled by, for example, adjusting the amount of crystalline resin used when preparing the resin component and the degree of crosslinking between the crystalline resin and the amorphous resin. The degree of crosslinking can be controlled by, for example, adjusting the amount of polymerization initiator added when preparing the resin component (binder resin) and the amount of carbon-carbon double bonds contained in the amorphous resin when preparing the resin component.

[0039] The content of the THF insoluble component is 5.0% to 80.0% by mass relative to the content of the resin component. A THF insoluble component content of 5.0% by mass or more easily results in a toner having excellent low-temperature fixability and high-temperature offset resistance. The THF insoluble component content is preferably 20.0% by mass or more, more preferably 30.0% by mass or more. That is, the THF insoluble component content can be in the range of 30.0% to 80.0% by mass. When the THF insoluble component content in the resin component is 80.0% by mass or less, the elasticity of the toner is not too large and is easily and appropriately maintained. The THF insoluble component content is preferably 70.0% by mass or less, more preferably 67.0% by mass or less.

[0040] The THF-insoluble content in the resin component can be controlled by, for example, adjusting the degree of crosslinking between the crystalline resin and the amorphous resin and the composition and molecular weight of the resin before crosslinking. The degree of crosslinking can be controlled by, for example, adjusting the amount of polymerization initiator added when preparing the resin component and the amount of carbon-carbon double bonds contained in the amorphous resin when preparing the resin component.

[0041] Domain-matrix structure

[0042] When observing the cross-section of 100 toner particles, each cross-section has a domain-matrix structure comprising a matrix containing a crystalline resin and domains each containing an amorphous resin. To form toner particles having such a domain-matrix structure, the resin component can be prepared by mixing a crystalline resin and an amorphous resin.

[0043] The above domain-matrix structure can be formed by controlling the amount ratio and viscosity ratio of the crystalline resin and the amorphous resin used in the production of toner particles. The above domain-matrix structure appears to be easily formed when a crystalline resin and an amorphous resin that is not easily mixed with the crystalline resin are used in the resin mixing process. Examples of amorphous resins that are not easily mixed with the crystalline resin include cross-linked amorphous resins.

[0044] Among 100 toner particles, the number of particles in which all domains have a major diameter of 1.0 μm or less is 20 or more, preferably 40 or more, more preferably 60 or more, even more preferably 80 or more. The upper limit is not particularly limited and may be 100 or less.

[0045] The present inventors have found that the toner controlled as described above is less likely to have coarsened domains in each toner particle and can have excellent developing performance. The present inventors presume the reason is as follows.

[0046] Toner particles that do not contain coarsened domains are more likely to have a uniform charge throughout the toner particles. A relatively large number of toner particles with a uniform charge tends to result in a sharper charge distribution for the toner as a whole, making it less likely that toner particles will have a charge outside the range suitable for development. Such toner is less likely to adhere to non-image areas in a fixed image and is easily developed only in image areas. Consequently, it is easier to produce a toner with excellent development performance.

[0047] Also, it is conceivable that due to the filler effect, the high-temperature elasticity of the toner is likely to be sufficiently exhibited and the toner is likely to have excellent high-temperature elasticity.

[0048] As an example of a method for achieving the number of toner particles having a major diameter of 1.0 μm or less for all observed domains within the above range, a cross-linked resin in which a high polarity site of a crystalline resin is cross-linked with an amorphous resin is included in an embodiment of the present disclosure. Figure 1 The mechanism presumed by the present inventors is described.

[0049] Each crosslinked resin molecule 4, which is the crosslinked resin, is formed by crosslinking a high-polarity site of a crystalline resin with a non-crystalline resin. It therefore has a non-crystalline portion 5 derived from the non-crystalline resin and a crystalline portion 6, which is a low-polarity site of the crystalline resin. In the toner particles 1, the non-crystalline portion 5 of the crosslinked resin molecule 4 is likely located near the domain 3, while the crystalline portion 6 is likely located in the region where the matrix 2 is present. It is speculated that each domain 3 is likely to be covered with the crystalline portion 6. The present inventors speculate that the presence of the low-polarity crystalline portion 6 on the surface of the domain 3 tends to induce repulsion with other domains and inhibit the aggregation of the domains. Furthermore, the crosslinked resin molecule 4 contains the crystalline portion 6 and therefore appears to plasticize the surrounding resin. Furthermore, the crosslinked resin exhibits high elasticity at high temperatures. Therefore, it appears that a toner with excellent low-temperature fixability and high-temperature offset resistance is likely to be obtained.

[0050] The present inventors have considered that the above cross-linked resin can be introduced by making the compositions of the crystalline resin and the non-crystalline resin used for production satisfy the following formulas (5), (6) and (7).

[0051] When observing the cross-section of 100 toner particles, the number of particles in which all domains have a major axis of 5.0 μm or more is preferably 0. That is, preferably, no domains having a major axis of 5.0 μm or more are observed.

[0052] Resin component

[0053] The resin component includes a crystalline resin and a non-crystalline resin. When the resin component includes a crystalline resin, a toner having excellent low-temperature fixability is easily obtained. The presence of the non-crystalline resin makes it easier to produce a toner having excellent high-temperature offset resistance.

[0054] The resin component according to an embodiment of the present disclosure may be a binder resin. In other words, the toner according to an embodiment of the present disclosure may include toner particles containing a binder resin containing a crystalline resin and a non-crystalline resin, wherein the binder resin contains a tetrahydrofuran-insoluble component and the content of the tetrahydrofuran-insoluble component is 5.0% by mass to 80.0% by mass or less relative to the content of the binder resin.

[0055] Vinyl polymer A and monomer unit A1

[0056] The crystalline resin may be a vinyl polymer A comprising a monomer unit A1 represented by the following formula (A). When the toner comprises the vinyl polymer A, a toner having excellent low-temperature fixability is easily obtained. This is probably because each of the R 2The long-chain alkyl groups represented by are easily aggregated, and thus a resin component having excellent crystallinity is easily obtained. The vinyl polymer A may be a THF-soluble resin.

[0057]

[0058] In formula (A), R 1 is H or CH3, and R 2 is an alkyl group having 18 to 36 carbon atoms.

[0059] Regarding the vinyl polymer A containing monomer unit A1, a (meth)acrylate containing an alkyl group having 18 to 36 carbon atoms can be introduced as a monomer unit of the vinyl polymer A by vinyl polymerization of a (meth)acrylate used as a polymerizable monomer (hereinafter, also referred to as a "first polymerizable monomer").

[0060] The first polymerizable monomer is a (meth)acrylate containing a chain hydrocarbon group having 18 to 36 carbon atoms.

[0061] Examples of the chain hydrocarbon group having 18 to 36 carbon atoms include chain unsaturated hydrocarbon groups each having 18 to 36 carbon atoms and chain saturated hydrocarbon groups each having 18 to 36 carbon atoms (hereinafter, the chain saturated hydrocarbon group is also referred to as an "alkyl group"). Examples of the (meth)acrylate containing a chain hydrocarbon group having 18 to 36 carbon atoms include (meth)acrylates each containing an alkyl group having 18 to 36 carbon atoms.

[0062] Examples of the (meth)acrylates each containing an alkyl group having 18 to 36 carbon atoms include (meth)acrylates each containing a linear alkyl group having 18 to 36 carbon atoms, such as octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, heneicosyl (meth)acrylate, behenyl (meth)acrylate, tetracosyl (meth)acrylate, hexacosyl (meth)acrylate, nonacoustic (meth)acrylate, myristyl (meth)acrylate, and triacontyl (meth)acrylate, and (meth)acrylate each containing a branched alkyl group having 18 to 36 carbon atoms, such as 2-decyltetradecyl (meth)acrylate.

[0063] Among them, from the viewpoint of achieving satisfactory low-temperature fixability and satisfactory high-temperature offset resistance of the toner, (meth)acrylates each containing a linear alkyl group having 18 to 36 carbon atoms are preferred. (Meth)acrylates each containing a linear alkyl group having 18 to 34 carbon atoms are more preferred. (Meth)acrylates each containing a linear alkyl group having 18 to 30 carbon atoms are even more preferred. At least one selected from the group consisting of stearyl (meth)acrylate and behenyl (meth)acrylate is even more preferred.

[0064] In the above formula (A), R 2 is an alkyl group having 18 to 36 carbon atoms, preferably an alkyl group having 18 to 34 carbon atoms, more preferably an alkyl group having 18 to 30 carbon atoms, and even more preferably an alkyl group having 18 to 22 carbon atoms. 2 It can be a straight chain alkyl group. 1 It may be a hydrogen atom.

[0065] One kind of the first polymerizable monomer may be used alone, or two or more kinds thereof may be used in combination. One kind of the monomer unit A1 may be used alone, or two or more kinds thereof may be used in combination.

[0066] Taking into account the low-temperature fixing and developing properties of the toner, the content of monomer unit A1 can be 30.0% by mass to 99.9% by mass relative to the content of vinyl polymer A. When the content of monomer unit A1 in vinyl polymer A is 30.0% by mass or more, a crystalline portion caused by the aggregation of monomer unit A1 is easily formed, thereby easily obtaining a vinyl polymer A with improved crystallinity. The presence of vinyl polymer A in the toner easily improves the crystallinity of the matrix so that the low-polarity crystalline portion is easily aggregated on the surface layer of the domain, thereby easily suppressing the aggregation of the domains with each other. This easily leads to a toner with excellent developing properties. Therefore, the content of monomer unit A1 in vinyl polymer A is preferably 30.0% by mass or more, more preferably 40.0% by mass or more, and even more preferably 45.0% by mass or more. When the content of monomer unit A1 in vinyl polymer A is 99.9% by mass or less, vinyl polymer A will not have too low polarity. Therefore, it is likely to properly maintain the appropriate SP associated with the improvement of dispersibility described below. A Therefore, the content of the monomer unit A1 in the vinyl polymer A is preferably 99.9% by mass or less, more preferably 85.0% by mass or less, and even more preferably 75.0% by mass or less.

[0067] When the vinyl polymer A contains two or more monomer units A1, the content of the monomer units A1 in the vinyl polymer A is the total of the contents thereof.

[0068] The amount of the vinyl polymer A used for preparing the resin component by mixing the resins may be 40.0 parts by mass or more based on 100.0 parts by mass of the total of the mixed resins.

[0069] Monomer unit A2

[0070] The vinyl polymer A further comprises monomer unit A2. When the SP value of monomer unit A1 is defined as SP A1 (J / cm 3 ) 0.5 When the SP value of monomer unit A2 is defined as SP A2 (J / cm 3 ) 0.5 When SP A1 and SP A2 The following formula (4) can be satisfied.

[0071] 3.0≤SP A2 -SP A1 ≤25.0···(4).

[0072] The SP value is an abbreviation of the solubility parameter value and is used as an indicator of solubility. The calculation method will be described below.

[0073] The unit of SP value in this disclosure is (J / cm 3 ) 0.5 And it can also be achieved by using 1(cal / cm 3 ) 0.5 =2.045×10 3 (J / m 3 ) 0.5 Converted and expressed as (cal / cm 3 ) 0.5 .

[0074] When the above formula (4) is satisfied, the polarity of monomer unit A2 is sufficiently higher than that of the low-polarity monomer unit A1. Therefore, these monomer units are easily aggregated by type. This easily produces a crystalline portion resulting from the aggregation of monomer unit A1, making it easier to obtain a toner with excellent low-temperature fixability.

[0075] SP A2 -SP A1 It is preferably 4.0 or more, more preferably 5.0 or more, because the above effects are more significant. A2 -SP A1It can be 25.0 or less. In this case, the compatibility between the crystalline resin and the non-crystalline resin is easily improved during fixing, so that the toner has sufficient low-temperature fixability even in a relatively high-speed fixing process. In addition, the vinyl polymer A with variations in composition, such as a vinyl polymer A with a particularly large amount of monomer units A1 or A2, is less likely to appear. This easily leads to a toner with more uniform properties. Therefore, SP A2 -SP A1 It is preferably 25.0 or less, more preferably 20.0 or less, even more preferably 15.0 or less.

[0076] The monomer unit A2 can be introduced by vinyl polymerization of a corresponding vinyl monomer used as a polymerizable monomer as a monomer unit of the vinyl polymer A. Hereinafter, the polymerizable monomer is also referred to as a "second polymerizable monomer," and details thereof will be described below.

[0077] The vinyl monomer unit satisfying formula (4) corresponds to monomer unit A2. One monomer unit A2 may be used alone, or two or more thereof may be used in combination. One second polymerizable monomer may be used alone, or two or more thereof may be used in combination.

[0078] When the SP value of the vinyl polymer A is defined as SP A (J / cm 3 ) 0.5 When the SP value of the non-crystalline resin used for the preparation of the resin component is defined as SP P (J / cm 3 ) 0.5 When , the formula (5) and the formula (6) can be satisfied. Hereinafter, the non-crystalline resin used for the preparation of the resin component is also referred to as "non-crystalline resin P").

[0079] 0<|SP P -SP A |≤10.0···(5)

[0080] |SP P -SP A |>|SP P -SP A2 |···(6)

[0081] 6.0≤|SP P -SP A |≤10.0···(7)

[0082] When the above formula (5) is satisfied, the polarity difference between the vinyl polymer A and the non-crystalline resin P will not be too large, and the affinity between the vinyl polymer A and the non-crystalline resin P is easily and appropriately maintained. Therefore, the cross-linking reaction between the vinyl polymer A and the non-crystalline resin is easily and appropriately carried out. The presence of the cross-linking resin as described above inhibits the domains from aggregating together. Therefore, it is less likely that the domains will be coarsened. This easily leads to a toner with excellent developing properties. Since the affinity is appropriately maintained, it is less likely that toner particles containing a particularly large amount of vinyl polymer A will be formed. The proportion of these resins in the toner particles is less likely to vary from particle to particle. The properties of the resulting toner are also less likely to vary. For the above reasons, it is preferred to satisfy the above formula (5), and it is more preferred to satisfy the above formula (7).

[0083] When the above formula (6) is satisfied, the domain containing the non-crystalline resin is less likely to be coarsened. This easily leads to a toner having excellent developing performance. The present inventors presume that the mechanism providing this effect is as follows.

[0084] When the above formula (6) is satisfied, the amorphous resin P appears to have a higher affinity for the monomer unit A2 having a high SP value than for a monomer unit having a low SP value such as the monomer unit A1. For this reason, in the crosslinking reaction between the vinyl polymer A and the amorphous resin P, it is presumed that a crosslinked resin is easily formed near the monomer unit A2. Therefore, as Figure 1 As shown in , the amorphous portion derived from the amorphous resin P in the cross-linked resin is likely close to the domains, while the crystalline portion of the vinyl polymer A, formed from monomer units having a low SP value, is likely oriented toward the matrix. The repulsive force acting between the crystalline portion of the cross-linked resin and other domains appears to easily hinder domain aggregation. This appears to inhibit the formation of coarsened domains formed by domain aggregation.

[0085] The content of the monomer unit A2 may be 1.0% to 70.0% by mass relative to the content of the vinyl polymer A. When the content of the monomer unit A2 is within the above range, it is easy to appropriately control the above SP A , and it is easy to satisfy the above equations (5), (6) and (7).

[0086] When the content of monomer units A2 in the vinyl polymer A is 1.0% by mass or greater, the elasticity of the vinyl polymer A is less likely to deteriorate, and the high-temperature offset resistance of the toner is less likely to deteriorate. Furthermore, a crystalline portion resulting from the aggregation of monomer units A1 is more likely to form, which can easily result in a toner with excellent low-temperature fixability. Therefore, the content of monomer units A2 in the vinyl polymer A is preferably 1.0% by mass or greater, more preferably 10.0% by mass or greater, and even more preferably 20.0% by mass or greater. When the content of monomer units A2 in the vinyl polymer A is 70.0% by mass or less, the crystallinity of the vinyl polymer A is less likely to deteriorate. This can easily result in a toner with excellent low-temperature fixability. Therefore, the content of monomer units A2 in the vinyl polymer A is preferably 70.0% by mass or less, more preferably 60.0% by mass or less, even more preferably 50.0% by mass or less, and even more preferably 40.0% by mass or less.

[0087] When the vinyl polymer A contains two or more monomer units A2, the monomer unit A2 content of the vinyl polymer A is the sum of their contents. One monomer unit A2 may be used alone, or two or more thereof may be used in combination. One second polymerizable monomer may be used alone, or two or more thereof may be used in combination.

[0088] Examples of the second polymerizable monomer include the following polymerizable monomers:

[0089] Monomers containing cyano groups, such as acrylonitrile and methacrylonitrile;

[0090] Monomers containing hydroxyl groups, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate;

[0091] Monomers containing amide bonds, such as acrylamide and monomers each formed by the reaction of an amine having 1 to 30 carbon atoms with a carboxylic acid having 3 to 30 carbon atoms containing an ethylenically unsaturated bond, such as acrylic acid or methacrylic acid;

[0092] Monomers containing urea bonds, such as monomers each formed by the reaction of an amine having 3 to 22 carbon atoms, such as a primary amine (e.g., n-butylamine, tert-butylamine, propylamine, or isopropylamine), a secondary amine (e.g., diethylamine, di-n-propylamine, or di-n-butylamine), aniline, or cyclohexylamine, with an isocyanate having 3 to 30 carbon atoms containing an ethylenically unsaturated bond; and

[0093] Carboxyl group-containing monomers, such as methacrylic acid, acrylic acid, and 2-carboxyethyl (meth)acrylate.

[0094] Among them, monomers each containing a cyano group, a hydroxyl group, an amide bond, or a urea bond can be used. The second polymerizable monomer can be a monomer containing at least one functional group selected from the group consisting of a cyano group, a hydroxyl group, an amide bond, and a urea bond, and an ethylenically unsaturated bond.

[0095] Vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl octanoate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl pivalate, and vinyl octanoate can also be used as the second polymerizable monomer. Vinyl esters are non-conjugated monomers and tend to maintain moderate reactivity with the first polymerizable monomer. Therefore, in the vinyl polymer A, monomer units A1 tend to aggregate easily. In other words, the aggregation of monomer units A1 easily forms a crystalline portion, which easily leads to a toner having excellent low-temperature fixability.

[0096] The monomer unit A2 may be at least one monomer unit selected from the group consisting of a monomer unit represented by the following formula (A21) and a monomer unit represented by the following formula (A22).

[0097]

[0098]

[0099] In formulae (A21) and (A22), X is a single bond or an alkylene group having 1 to 6 carbon atoms, and R 4 Cyano (-C≡N), -C(=O)NHR 7 (where R 7 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms), a hydroxyl group, -COOR 8 (where R 8 is an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, or a hydroxyalkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms), -NHCOOR 9 (where R 9 is an alkyl group having 1 to 4 carbon atoms), -NH-C(=O)-NH(R 10 )2(where each R 10 is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms), -COO(CH2)2NHCOOR 11 (where R 11 is an alkyl group having 1 to 4 carbon atoms), or -COO(CH2)2-NH-C(=O)-NH(R 12 )2(each R 12 are independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms), R 6is an alkyl group having 1 to 4 carbon atoms, and R 3 and R 5 Each is independently a hydrogen atom or CH3.

[0100] Monomer unit A3

[0101] The vinyl polymer A may contain monomer units A3 that are not included in the monomer units A1 or A2 to such an extent that the content of the monomer units A1 and the content of the monomer units A2 are not impaired.

[0102] The monomer unit A3 can be introduced as a monomer unit of the polymer by vinyl polymerization of a monomer corresponding to the monomer unit A3. Hereinafter, this monomer is referred to as a "third polymerizable monomer," and specific examples thereof will be described below.

[0103] As the third polymerizable monomer, among the polymerizable monomers listed in the section of the second polymerizable monomer, a polymerizable monomer that does not satisfy the above formula (4) can be used.

[0104] The following polymerizable monomers having no cyano group, amide bond, urethane bond, hydroxyl group, urea bond, or carboxyl group can also be used.

[0105] Examples thereof include styrene and derivatives thereof such as styrene and o-methylstyrene, and (meth)acrylates such as n-butyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0106] When they satisfy the above formula (4), they can be used as the second polymerizable monomer.

[0107] Wherein, monomeric unit A3 can be at least one monomeric unit selected from the group consisting of a monomeric unit represented by the following formula (A31) and a monomeric unit represented by the following formula (A32). These monomeric units can be introduced by adding corresponding monomers during the copolymerization reaction for preparing the vinyl polymer A. Wherein, monomeric unit A3 can be a monomeric unit represented by the following formula (A31) in view of low-temperature fixing property, high-temperature offset resistance and the crushing property of the resin component.

[0108]

[0109] In formula (A32), R 13 The content of the monomer unit A3 relative to the content of the vinyl polymer A may be 1.0% by mass or more and 60.0% by mass or less.

[0110] When the content of monomeric unit A3 in vinyl polymer A is 1.0% by mass or more, the elasticity of the toner is easily improved. This easily leads to a toner with excellent high-temperature stain resistance and durability. Therefore, the content of monomeric unit A3 in vinyl polymer A is preferably 1.0% by mass or more, more preferably 5.0% by mass or more. When the content of monomeric unit A3 in vinyl polymer A is 60.0% by mass or less, the crystallinity of vinyl polymer A is unlikely to deteriorate. Therefore, the content of monomeric unit A3 in vinyl polymer A is preferably 60.0% by mass or less, more preferably 40.0% by mass or less, even more preferably 30.0% by mass or less.

[0111] One monomer unit A3 may be used alone or in combination of two or more thereof. One third polymerizable monomer may be used alone or in combination of two or more thereof. The vinyl polymer A may contain other monomer units in addition to monomer units A1, A2 or A3.

[0112] Other embodiments of vinyl polymer A

[0113] The content of THF soluble vinyl polymer A can be 20.0 mass % to 95.0 mass % relative to the content of resin component. The fact that the content of THF soluble vinyl polymer A is more than 20.0 mass % shows that the resin component contains enough THF soluble vinyl polymer A. Therefore, it is easy to keep the appropriate elasticity of toner, thus easily cause the toner with excellent low temperature fixability. Therefore, the content of THF soluble vinyl polymer A in the resin component is preferably more than 20.0 mass %, more preferably more than 30.0 mass %, even more preferably more than 40.0 mass %. The fact that the content of THF soluble vinyl polymer A in the resin component is below 95.0 mass % is not easy to make the toner elasticity deficiency. Therefore, the content of THF soluble vinyl polymer A in the resin component is preferably below 95.0 mass %, more preferably below 80.0 mass %, even more preferably below 70.0 mass %, even more preferably below 60.0 mass %.

[0114] The weight average molecular weight (Mw) of the vinyl polymer A is preferably from 10,000 to 200,000, more preferably from 20,000 to 100,000, and even more preferably from 40,000 to 80,000.

[0115] One type of vinyl polymer A may be used alone, or two or more types thereof may be used in combination.

[0116] Amorphous resin P

[0117] The non-crystalline resin (non-crystalline resin P) used in the production of the resin component may contain a carbon-carbon double bond from the viewpoint of promoting a cross-linking reaction with the vinyl polymer A. Furthermore, the non-crystalline resin P may be contained in the toner.

[0118] The weight average molecular weight (Mw) of the non-crystalline resin P is preferably 2,000 to 40,000, more preferably 10,000 to 35,000, even more preferably 15,000 to 30,000.

[0119] One kind of the non-crystalline resin P may be used alone, or two or more kinds thereof may be used in combination.

[0120] Non-crystalline polyester P

[0121] The non-crystalline resin P may be a non-crystalline polyester. Hereinafter, the non-crystalline polyester of the present disclosure is also referred to as "non-crystalline polyester P." Polyester is a condensation product of an alcohol component and a carboxylic acid component.

[0122] There are no particular limitations on the method for producing the non-crystalline polyester P. A polycondensation reaction of an alcohol component and a carboxylic acid component can be performed to produce a non-crystalline polyester P that is a polycondensate of the corresponding alcohol component and the carboxylic acid component. One alcohol component can be used alone, or two or more thereof can be used in combination. One carboxylic acid component can be used alone, or two or more thereof can be used in combination.

[0123] The non-crystalline polyester P may be a polyester containing at least one of an unsaturated carboxylic acid component and an unsaturated alcohol component as a constituent component.

[0124] In addition to the unsaturated carboxylic acid component or the unsaturated alcohol component, the non-crystalline polyester P may contain a constituent component having a polycondensation structure of a saturated alcohol component and / or a saturated carboxylic acid component. One saturated alcohol component may be used alone, or two or more thereof may be used in combination. One saturated carboxylic acid component may be used alone, or two or more thereof may be used in combination.

[0125] The non-linear non-crystalline polyester P can be produced, for example, by polycondensing an unsaturated carboxylic acid component and / or an unsaturated alcohol component with a trivalent or higher polyol component as a saturated alcohol component serving as an alcohol component. Similarly, the non-linear non-crystalline polyester P can also be produced by polycondensing an unsaturated carboxylic acid component and / or an unsaturated alcohol component with a trivalent or higher carboxylic acid component.

[0126] During the polycondensation reaction of the alcohol component and the carboxylic acid component, the polycondensation reaction is preferably carried out in an inert gas atmosphere such as a nitrogen atmosphere at a reaction temperature of 150°C to 280°C, more preferably 160°C to 250°C, and even more preferably 170°C to 235°C. When the polycondensation reaction is carried out at a reaction temperature within the above range, the components can be fully reacted. From the perspective of ensuring that the polycondensation reaction proceeds reliably, the reaction time is preferably 30 minutes to 40 hours, more preferably 2 hours to 40 hours.

[0127] During the production of the non-crystalline polyester P (during the polycondensation reaction), an esterification catalyst may be used.

[0128] Examples of the esterification catalyst include: tin-containing catalysts such as dibutyltin oxide; antimony dioxide; titanium-containing catalysts such as titanium alkoxide, potassium titanium oxalate, titanium terephthalate, titanium alkoxyterephthalate, dihydroxybis(triethanolamine)titanium, monohydroxytris(triethanolamine)titanium, titanylbis(triethanolamine), intramolecular condensation products thereof, tributoxytitanium terephthalate, triisopropoxytitanium terephthalate, and diisopropoxytitanium diterephthalate; zirconium-containing catalysts such as zirconyl acetate; and zinc acetate.

[0129] Among them, a titanium-containing catalyst can be used. In order to increase the reaction rate at the end of the reaction, reducing the pressure is also effective.

[0130] For the purpose of providing good polymerization stability, a stabilizer may also be added. Examples of the stabilizer include hydroquinone, methylhydroquinone, and hindered phenol compounds.

[0131] Examples of the alcohol component of the non-crystalline polyester P include unsaturated alcohol components and saturated alcohol components. Among them, alcohols having 1 to 30 carbon atoms can be used. Aliphatic alcohol components having 1 to 6 carbon atoms can be used for the alcohol component of the non-crystalline polyester P.

[0132] Among the above-mentioned aliphatic alcohol components having 1 to 6 carbon atoms, polyols having 2 to 6 carbon atoms can be used in consideration of low-temperature fixing property, high-temperature offset resistance and developing performance. Alkylene glycols having 2 to 6 carbon atoms can be used. Ethylene glycol can be used. That is, the non-crystalline polyester P can have a polycondensation structure of a polyol having 2 to 6 carbon atoms. The non-crystalline polyester P can have a polycondensation structure of an alkylene glycol having 2 to 6 carbon atoms. The non-crystalline polyester P can have a polycondensation structure of ethylene glycol. Examples of polyols having 2 to 6 carbon atoms include ethylene glycol, propylene glycol, pentaerythritol and neopentyl glycol. When the non-crystalline polyester P has such a structure, the SP is appropriately controlled. PTherefore, the formulas (5), (6) and (7) are easily satisfied, which easily leads to a toner having excellent developing performance.

[0133] The content of the polycondensation structure of the aliphatic alcohol component having 1 to 6 carbon atoms may be 10.0% by mass or more relative to the content of the non-crystalline polyester P. When the content of the polycondensation structure is 10.0% by mass or more, the SP is appropriately controlled. P Therefore, the above formulae (5), (6) and (7) are easily satisfied. Therefore, the content of the polycondensation structure is preferably 10.0% by mass or more, more preferably 20.0% by mass or more, and even more preferably 30.0% by mass or more.

[0134] The content of the polycondensation structure of the aliphatic alcohol component having 1 to 6 carbon atoms relative to the total content of the polycondensation structure of the alcohol component contained in the non-crystalline polyester P is preferably 15.0 mass % or more, more preferably 25.0 mass % or more, even more preferably 40.0 mass % or more.

[0135] Examples of the aliphatic alcohol component having 1 to 6 carbon atoms include, as unsaturated aliphatic alcohols, unsaturated monohydric alcohols having 3 to 6 carbon atoms such as 2-propylene-1-ol, unsaturated diols having 4 to 6 carbon atoms; and, as saturated aliphatic alcohols, alkanols having 1 to 6 carbon atoms such as methanol, ethanol and isopropanol, alkylene glycols having 2 to 6 carbon atoms such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol and 1,6-hexanediol, and polyhydric alcohols having 3 to 8 valences or more.

[0136] Examples of the carboxylic acid component of the non-crystalline polyester P include unsaturated carboxylic acids and saturated carboxylic acids. Examples of the unsaturated carboxylic acids include unsaturated monocarboxylic acids, unsaturated dicarboxylic acids, unsaturated polycarboxylic acids, and anhydrides and lower alkyl esters of these acids.

[0137] Examples of the unsaturated monocarboxylic acid include unsaturated monocarboxylic acids having 3 to 80 carbon atoms, such as acrylic acid, methacrylic acid, propiolic acid, 2-butenoic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, angelic acid, tiglic acid, 4-pentenoic acid, 2-ethyl-2-butenoic acid, 10-undecenoic acid, 2,4-hexadienoic acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, erucic acid, and nervonic acid.

[0138] Examples of the unsaturated dicarboxylic acid include unsaturated dicarboxylic acids having 4 to 50 carbon atoms, such as alkenylsuccinic acid, for example, dodecenylsuccinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, and glutaconic acid.

[0139] Examples of the unsaturated polycarboxylic acid include vinyl polymers of unsaturated carboxylic acids (having a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 450 to 10,000).

[0140] Among the unsaturated carboxylic acids mentioned above, acrylic acid, methacrylic acid, alkenyl succinic acids such as dodecenyl succinic acid, maleic acid, fumaric acid, and combinations thereof can be used from the viewpoint of achieving both good low-temperature fixability and good high-temperature offset resistance. Acrylic acid, methacrylic acid, maleic acid, fumaric acid, and combinations thereof can also be used. The unsaturated carboxylic acid may also be an anhydride or a lower alkyl ester of these acids.

[0141] Examples of the above-mentioned saturated carboxylic acids include: aliphatic monocarboxylic acids having 2 to 50 carbon atoms, such as stearic acid and behenic acid; aromatic monocarboxylic acids having 7 to 37 carbon atoms, such as benzoic acid; aliphatic dicarboxylic acids having 2 to 50 carbon atoms, such as oxalic acid, malonic acid, succinic acid, adipic acid, azelaic acid and sebacic acid; aromatic dicarboxylic acids having 8 to 86 carbon atoms, such as phthalic acid, isophthalic acid, terephthalic acid and naphthalene dicarboxylic acid; aromatic polycarboxylic acids having 9 to 20 carbon atoms, such as trimellitic acid and pyromellitic acid; and aliphatic tricarboxylic acids having 6 to 36 carbon atoms, such as hexanetricarboxylic acid.

[0142] The above-mentioned saturated carboxylic acids may also be anhydrides and lower alkyl (1 to 4 carbon atoms) esters of these carboxylic acids such as methyl ester, ethyl ester and isopropyl ester.

[0143] Among the above-mentioned saturated carboxylic acids, aromatic carboxylic acids having 7 to 87 carbon atoms, alkanedicarboxylic acids having 2 to 50 carbon atoms, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms can be used. The use of the above-mentioned saturated carboxylic acids easily results in a toner having excellent low-temperature fixing and high-temperature offset resistance. In view of low-temperature fixing, high-temperature offset resistance, and chargeability, benzoic acid, adipic acid, alkyl succinic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, and combinations thereof can be used. Adipic acid, terephthalic acid, trimellitic acid, and combinations thereof can be used. Anhydrides and lower alkyl esters of these acids can also be used.

[0144] Carbon-carbon double bond content

[0145] The content of carbon-carbon double bonds (double bond equivalent) in the non-crystalline resin P is preferably 0.02 mmol / g or more and 0.80 mmol / g or less, and more preferably 0.20 mmol / g or more and 0.70 mmol / g or less.

[0146] Within the above range, the crosslinking reaction between the crystalline resin and the amorphous resin tends to proceed appropriately, and a THF-insoluble component satisfying the above formulas (1) and (2) can be easily contained in the toner. A resin in which the crystalline resin and the amorphous resin are crosslinked is easily contained, thereby easily suppressing domain aggregation. This easily results in a toner having excellent developing performance.

[0147] Weight average molecular weight (Mw) of non-crystalline polyester P

[0148] The weight average molecular weight (Mw) of the non-crystalline polyester P is preferably 2,000 or more and 40,000 or less, more preferably 10,000 or more and 35,000 or less, and even more preferably 15,000 or more and 30,000 or less. When the weight average molecular weight (Mw) of the non-crystalline polyester P is within the above range, the size of the domains in the domain-matrix structure is not excessively large, and the inclusion of coarsened domains is unlikely. One type of non-crystalline polyester P may be used alone, or two or more types thereof may be used in combination.

[0149] Cross-linking reaction between crystalline resin A and amorphous resin P

[0150] The THF-insoluble component may include a resin formed by a crosslinking reaction between a crystalline resin A and a non-crystalline resin P. That is, the THF-insoluble component may include a resin in which a crystalline resin and a non-crystalline resin are bonded together. The THF-insoluble component may have a structure in which the crystalline resin and the non-crystalline resin are at least partially bonded together. Hereinafter, the resin in which the crystalline resin A and the non-crystalline resin P are bonded together will be referred to as "crosslinked resin L."

[0151] Examples of the method for combining the crystalline resin A and the non-crystalline resin P include a method of applying a radical initiator to a mixture of the crystalline resin A and the non-crystalline resin P that has been dissolved or melted, and a method of using a cross-linking agent containing a functional group that reacts with both the crystalline resin A and the non-crystalline resin P.

[0152] Non-limiting examples of the free radical initiator used in the crosslinking method using a free radical initiator include inorganic peroxides, organic peroxides and azo compounds. These free radical reaction initiators can also be used in combination.

[0153] When both the crystalline resin A and the non-crystalline resin P have carbon-carbon double bonds, the carbon-carbon double bonds appear to be broken by the radical initiator, resulting in crosslinking of the crystalline resin A and the non-crystalline resin P.

[0154] Examples of the crosslinking agent containing a functional group that reacts with both the crystalline resin A and the non-crystalline resin P include, but are not particularly limited to, a crosslinking agent containing an epoxy group, a crosslinking agent containing an isocyanate group, a crosslinking agent containing an oxazoline group, a crosslinking agent containing a carbodiimide group, a crosslinking agent containing a hydrazine group, and a crosslinking agent containing an aziridine group. In the crosslinking method using a crosslinking agent containing a functional group that reacts with both the crystalline resin A and the non-crystalline resin P, both the crystalline resin A and the non-crystalline resin P need to contain a functional group that reacts with the crosslinking agent.

[0155] A resin in which the crystalline resin A and the non-crystalline resin P are crosslinked and at least partially bonded together by the above-described method, that is, a crosslinked resin L in which the crystalline resin A and the non-crystalline resin P are crosslinked, can be used for toner production. In the case of toner production by a melt-kneading method, a raw material mixture containing the crystalline resin A and the non-crystalline resin P can be melt-kneaded in the presence of the above-described free radical initiator or crosslinking agent to produce toner particles containing a resin in which the crystalline resin A and the non-crystalline resin P are bonded together.

[0156] The content of the cross-linked resin L can be controlled by the composition and molecular weight of the crystalline resin A and the non-crystalline resin P in the production of the resin component and the degree of bonding between the crystalline resin A and the non-crystalline resin P. The degree of bonding can be controlled, for example, by the type and amount of the above-mentioned free radical reaction initiator added and the amount of carbon-carbon double bonds contained in the non-crystalline resin P in the production of the resin component.

[0157] For example, the crosslinked resin L may be a resin produced by melt-kneading a non-crystalline polyester resin containing carbon-carbon double bonds as the non-crystalline resin P and a vinyl polymer A as the crystalline resin A while adding a radical reaction initiator to perform a crosslinking reaction.

[0158] When the cross-linked resin L is produced using the crystalline resin A and the non-crystalline resin P, the crystalline resin A and the non-crystalline resin P are at least partially combined together to form the cross-linked resin L.

[0159] Examples of the radical reaction initiator used in the crosslinking reaction include, but are not particularly limited to, inorganic peroxides, organic peroxides, and azo compounds. These radical reaction initiators may also be used in combination.

[0160] Examples of the inorganic peroxide include, but are not particularly limited to, hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

[0161] Examples of the organic peroxide include, but are not particularly limited to, benzoyl peroxide, di-tert-butyl peroxide, tert-butylcumyl peroxide, dicumyl peroxide, α,α-bis(tert-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, di-tert-hexyl peroxide, 2,5-dimethyl-2,5-di-tert-butyl peroxyhexanoate, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluoyl peroxide, tert-butyl peroxyisobutyrate, tert-butyl peroxyneodecanoate, cumyl peroxyneodecanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxybenzoate, tert-butyl peroxyisopropylmonocarbonate, and tert-butyl peroxyacetate.

[0162] Examples of the azo compounds and diazo compounds include, but are not particularly limited to, 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis(cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

[0163] Wherein, organic peroxide can be used because they have high initiator efficiency and do not produce toxic byproducts such as cyanide.Because the cross-linking reaction is carried out effectively and the amount of initiator is small, the reaction initiator with high hydrogen abstraction ability can be used.Its example includes free radical reaction initiator such as tert-butyl peroxyisopropyl monocarbonate, benzoyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, dicumyl peroxide, α, α-bis (tert-butyl peroxide) diisopropylbenzene, 2,5-dimethyl-2,5-bis (tert-butyl peroxide) hexane and di-tert-hexyl peroxide.

[0164] The mixing ratio of the vinyl polymer A and the non-crystalline polyester P when mixed (mass of the polymer A used when mixed / mass of the non-crystalline polyester used when mixed) is preferably (40 / 60) to (95 / 5), more preferably (50 / 50) to (80 / 20). Within this range, the crosslinking reaction between the vinyl polymer A and the non-crystalline polyester P tends to proceed appropriately, thereby easily resulting in a toner having excellent low-temperature fixing ability, high-temperature offset resistance, and developing performance. When the above mixing ratio is outside the range of (50 / 50) to (80 / 20), the amount of the radical initiator added may be 2.0 parts by mass or more based on 100.0 parts by mass of the total of the vinyl polymer A and the non-crystalline polyester P used when mixed. This is because when the amount of the radical initiator added is less than 2.0 parts by mass, in some cases, the crosslinking reaction between the vinyl polymer A and the non-crystalline polyester P does not proceed sufficiently, and the above formulas (1) and (2) are not satisfied.

[0165] Two-component developer

[0166] The toner may be used as a one-component developer. The toner may also be a two-component developer including the toner according to an embodiment of the present disclosure and a magnetic carrier.

[0167] Examples of magnetic carriers include iron powder having an oxidized surface, unoxidized iron powder, particles of metals such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium and rare earth metals, alloy particles thereof, oxide particles thereof, magnetic materials such as ferrite, and magnetic material-dispersed resin carriers (referred to as resin carriers) each containing a magnetic material and a binder resin for maintaining the magnetic material in a dispersed state.

[0168] When the toner is mixed with a magnetic carrier and used as a two-component developer, the amount of the carrier contained is preferably 2% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 13% by mass or less, based on the total mass of the two-component developer. Within the above range, good results are generally provided.

[0169] Various additives

[0170] In addition to the resin component (binder resin), the toner may contain one or more additives selected from a colorant, a release agent, a charge control agent, a fluidizing agent, and other additives as needed. Materials other than the resin component used for the toner will be described below.

[0171] release agent

[0172] The toner may contain a releasing agent to provide good releasability during fixing. Examples of the releasing agent include polyolefin copolymers, such as polyolefin wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax and other aliphatic hydrocarbon waxes, and ester waxes.

[0173] The molecular weight of the release agent may be 1,000 or greater. Release agents with a molecular weight of 1,000 or greater appear to be less compatible with the crystalline portion of the vinyl polymer A. This allows the release agent to readily seep onto the surface of the toner particles during fixing, thereby readily improving releasability. The crystalline portion is less compatible with the release agent, and thus, its crystallinity is less likely to be impaired.

[0174] The molecular weight of the release agent refers to the peak molecular weight (Mp) measured by gel permeation chromatography (GPC). The measurement method will be described below.

[0175] The molecular weight of the release agent may be 1,500 or more. From the viewpoint of achieving good releasability, the upper limit of the molecular weight of the release agent is preferably, but not particularly limited to, 10,000 or less, more preferably 5,000 or less.

[0176] There is no particular limitation on the releasing agent as long as its molecular weight is 1,000 or more.

[0177] Examples thereof include aliphatic hydrocarbon-based waxes such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, low-molecular-weight olefin copolymers and Fischer-Tropsch waxes, as well as oxidation products thereof and acid addition products thereof.

[0178] Ester wax mainly composed of fatty acid esters can also be used. In view of molecular weight, the ester wax is preferably a trifunctional or higher functional ester wax, more preferably a tetrafunctional or higher functional ester wax.

[0179] For example, trifunctional or higher ester waxes are produced by condensation of trifunctional or higher acids with long-chain linear saturated alcohols or by condensation of trifunctional or higher alcohols with long-chain linear saturated fatty acids.

[0180] The following are non-limiting examples of trifunctional or higher alcohols that can be used in the ester wax. These ester waxes can also be used in combination as a mixture.

[0181] Examples thereof include glycerol, trimethylolpropane, erythritol, pentaerythritol, and sorbitol. Examples of condensation products thereof include condensation products of glycerol, i.e., polyglycerols such as diglycerol, triglycerol, tetraglycerol, hexaglycerol, and decaglycerol; condensation products of trimethylolpropane such as di(trimethylolpropane) and tri(trimethylolpropane); and condensation products of pentaerythritol such as di(pentaerythritol) and tri(pentaerythritol).

[0182] Among them, compounds having a branched structure can be used. Pentaerythritol and dipentaerythritol can be used. In particular, dipentaerythritol can be used.

[0183] Long-chain linear saturated fatty acids represented by the following general formula can be used: n H 2n+1 COOH, wherein n is 5 or more and 28 or less.

[0184] Non-limiting examples of long-chain straight-chain saturated fatty acids include caproic acid, caprylic acid, octyl acid, nonanoic acid, capric acid, dodecanoic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, and behenic acid. From the perspective of the melting point of the wax, myristic acid, palmitic acid, stearic acid, and behenic acid can be used. These can also be used in combination as a mixture.

[0185] Non-limiting examples of trifunctional or higher acids include trimellitic acid and butanetetracarboxylic acid. These can also be used in combination as a mixture.

[0186] Long-chain linear saturated alcohols represented by the following general formula can be used: n H2n+1 OH, wherein n is 5 or more and 28 or less.

[0187] Non-limiting examples of long-chain straight-chain saturated alcohols include octanol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, and behenyl alcohol. From the perspective of the melting point of the wax, myristyl alcohol, palmityl alcohol, stearyl alcohol, and behenyl alcohol can be used. These can also be used in combination as a mixture.

[0188] As the release agent, one having a softening point of 50° C. to 170° C. as measured by a flow tester can be used. Examples thereof include polyolefin wax, natural wax, aliphatic alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and mixtures thereof.

[0189] Examples of polyolefin waxes include: (co)polymers of olefins such as ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene and mixtures thereof, including those obtained by (co)polymerization and thermally degradable polyolefins; olefin (co)polymers oxidized with oxygen and / or ozone; maleic acid-modified olefin (co)polymers, for example, olefin (co)polymers modified with maleic acid and its derivatives such as maleic anhydride, monomethyl maleate, monoethyl maleate and monobutyl maleate; copolymers of olefins, unsaturated carboxylic acids such as (meth)acrylic acid, itaconic acid and maleic anhydride and / or unsaturated carboxylic acid alkyl esters such as alkyl (meth)acrylates (wherein the alkyl group has 1 to 18 carbon atoms) and alkyl maleates (wherein the alkyl group has 1 to 18 carbon atoms); and sazol wax.

[0190] Examples of natural waxes include carnauba wax, montan wax, paraffin wax, and rice wax. Examples of aliphatic alcohols having 30 to 50 carbon atoms include triacontanol. Examples of fatty acids having 30 to 50 carbon atoms include triacontanic acid.

[0191] The release agent may contain an aliphatic hydrocarbon wax. The release agent may be an aliphatic hydrocarbon wax. The aliphatic hydrocarbon wax has low polarity and therefore tends to bleed out from the polymer A during fixing.

[0192] The content of the release agent in the toner is preferably 1.0% by mass to 30.0% by mass. A release agent content of 1.0% by mass or more can result in a toner with good releasability. Therefore, the content of the release agent is preferably 1.0% by mass or more, more preferably 2.0% by mass or more. A release agent content of 30.0% by mass or less is less likely to result in the release agent being exposed on the surface of the toner particles. Therefore, the content of the release agent is preferably 30.0% by mass or less, more preferably 25.0% by mass or less.

[0193] The melting point of the release agent may be 80°C or higher and 120°C or lower. A melting point of 80°C or higher makes it less likely that the release agent will be exposed on the surface of the toner particles. Therefore, the melting point of the release agent is preferably 80°C or higher, more preferably 85°C or higher. A melting point of 120°C or lower allows the release agent to melt appropriately during fixing. This tends to result in a toner having excellent low-temperature fixing ability and high-temperature offset resistance. Therefore, the melting point of the release agent is preferably 120°C or lower, more preferably 110°C or lower.

[0194] One kind of releasing agent may be used alone, or two or more kinds thereof may be used in combination.

[0195] magnetic materials

[0196] Examples of the magnetic material are described below.

[0197] Examples include iron oxides such as magnetite, hematite, and ferrite; metals such as iron, cobalt, and nickel; alloys of the above metals with metals such as aluminum, cobalt, copper, lead, magnesium, tin, zinc, antimony, bismuth, calcium, manganese, titanium, tungsten, and vanadium; and mixtures thereof.

[0198] Colorants

[0199] Examples of the colorant are described below.

[0200] Examples of black colorants include carbon black, black colorants prepared using yellow colorants, magenta colorants, and cyan colorants. As colorants, pigments can be used alone, or dyes and pigments can be used in combination. In consideration of the image quality of the full-color image, dyes and pigments can be used in combination.

[0201] Examples of magenta toner pigments include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57 :1, 58, 60, 63, 64, 68, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269 and 282; CI Pigment Violet 19; and CI Vat Red 1, 2, 10, 13, 15, 23, 29 and 35.

[0202] Examples of the dye for magenta toner include oil-soluble dyes such as CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109 and 121, CI Disperse Red 9, CI Solvent Violet 8, 13, 14, 21 and 27, and CI Disperse Violet 1; and basic dyes such as CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39 and 40, and CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27 and 28.

[0203] Examples of the pigment for cyan toner include CI Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, and 17; CI Vat Blue 6; CI Acid Blue 45; and copper phthalocyanine pigments each having a phthalocyanine skeleton substituted with 1 to 5 phthalimidomethyl groups.

[0204] An example of a cyan toner dye is CI Solvent Blue 70. Examples of yellow toner pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, and 185; and CI Vat Yellow 1, 3, and 20.

[0205] An example of the dye for yellow toner is CI Solvent Yellow 162.

[0206] These colorants may be used alone, in combination as a mixture, or in the form of a solid solution.

[0207] Charge control agent

[0208] A charge control agent may be included to stabilize the chargeability of the toner. The charge control agent may be an organometallic complex or a chelate. Examples include monoazo metal complexes, acetylacetone metal complexes, metal complexes of aromatic hydroxycarboxylic acids, metal complexes of aromatic dicarboxylic acids, and metal salts thereof. The charge control agent may be added internally or externally to the toner.

[0209] Inorganic fine particles

[0210] The toner may contain inorganic fine particles as needed. The inorganic fine particles may be internally added to the toner particles or may be mixed with the toner as an external additive. Examples of inorganic particles include fine particles such as silica fine particles, titanium oxide fine particles, aluminum oxide fine particles, and composite oxide fine particles thereof. Among the inorganic particles, silica fine particles and titanium oxide fine particles can be used to improve fluidity and charge uniformity.

[0211] The inorganic particles may be hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.

[0212] The amount of the external additive may be 0.1 parts by mass or more and 10.0 parts by mass or less based on 100 parts by mass of the toner particles.The toner particles and the external additive may be mixed using a known mixer such as a Henschel mixer.

[0213] Fluidizing agent

[0214] A fluidizing agent may be included to adjust the fluidity of the toner. Examples of the fluidizing agent include colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.

[0215] Method for producing toner

[0216] There is no particular limitation on the method for producing the toner according to the embodiment of the present disclosure. Examples of the production method that can be adopted include a pulverization method, a suspension polymerization method, a dissolution suspension method, an emulsification aggregation method, and a dispersion polymerization method. In view of the developing performance and the high-temperature deterioration resistance, a pulverization method that can further improve the dispersibility can be adopted. That is, the method for producing the toner according to the embodiment of the present disclosure can include the steps of melt-kneading a mixture containing a crystalline resin, a non-crystalline resin, and a free radical initiator to provide a kneaded product and pulverizing the kneaded product to provide a pulverized product.

[0217] In view of the developing performance, high-temperature offset resistance, and low-temperature fixing property as described above, a method for producing a toner according to an embodiment of the present disclosure may include the steps of melt-kneading a mixture of a crystalline vinyl polymer A, a non-crystalline resin P containing a carbon-carbon double bond, and a radical initiator to provide a kneaded product and pulverizing the kneaded product to provide a pulverized product, wherein the vinyl polymer A includes a monomer unit A1 represented by the above formula (A), and the vinyl polymer A further includes a monomer unit A2, and when the SP value of the vinyl polymer A is defined as SP A (J / cm 3 ) 0.5 When the SP value of the non-crystalline resin P is defined as SP P (J / cm 3 ) 0.5When the SP value of monomer unit A1 is defined as SP A1 (J / cm 3 ) 0.5 When the SP value of monomer unit A2 is defined as SP A2 (J / cm 3 ) 0.5 When SP A1 and SP A2 Satisfying the above formula (4), SP A and SP P Satisfies the above formula (5), and SP A2 、SP A and SP P Satisfies the above formula (6).

[0218] The toner is produced by a pulverization method as described below. Toner particles are prepared by the following steps.

[0219] (i) The resin component of the toner and, if necessary, a colorant, a magnetic material, wax, and other additives are thoroughly mixed together using a mixer such as a Henschel mixer or a ball mill.

[0220] (ii) The obtained mixture is melt-kneaded using a heat kneading machine such as a twin-screw extruder, a heating roll, a kneader or an extruder to make the resins compatible with each other.

[0221] (iii) The resulting mixture is cooled to solidify, pulverized and classified.

[0222] To control the shape and surface properties of the toner particles, a surface treatment step may be included in which the toner particles are passed through a surface treatment device that continuously applies mechanical impact force to the pulverized and classified toner particles. The surface shape of the toner particles and the adhesion of the toner particles can be controlled by controlling the treatment time in the surface treatment step.

[0223] As necessary, a desired external additive may be sufficiently mixed with the obtained toner particles using a mixer such as a Henschel mixer to produce a toner.

[0224] Examples of mixers include a Henschel mixer (available from Nippon Coke & Engineering Co., Ltd.); a super mixer (available from Kawata Mfg. Co., Ltd.); a Ribocone (available from Okawara Mfg. Co., Ltd.); a Nauta mixer, a Turbulizer, and a Cyclomix (available from Hosokawa Micron Corporation); a screw pin mixer (available from Pacific Machinery & Engineering Co., Ltd.); and Mixer (available from Matsubo Corporation).

[0225] Examples of mixing machines include KRC kneader (available from Kurimoto Ltd.); Buss Ko-kneader (available from Buss AG); TEM type extruder (available from Toshiba Machine Co., Ltd.); TEX twin-screw extruder (available from The Japan Steel Works, Ltd.); PCM extruder (available from Ikegai Corp.); three-roll mill, mixing roll mill and kneader (available from Inoue Mfg., Inc.); Kneadex (available from Mitsui Mining Co., Ltd.); MS type pressure kneader and Kneader-Ruder (available from Nihon Spindle Manufacturing Co., Ltd.); and Banbury mixer (available from Kobe Steel, Ltd.).

[0226] Examples of pulverizers include Counter Jet Mill, Micron Jet, and Innomizer (available from Hosokawa Micron Corporation); IDS-type grinder and PJM jet mill (available from Nippon Pneumatic Mfg. Co., Ltd.); Cross Jet Mill (available from Kurimoto Ltd.); Ulmax (available from Nisso Engineering Co., Ltd.); SK-Jet-O-Mill (available from Seishin Enterprise Co., Ltd.); Kryptron (available from Kawasaki Heavy Industries, Ltd.); Turbo Mill (available from Turbo Kogyo Co., Ltd.); and Super Rotor (available from Nisshin Engineering Inc.).

[0227] Examples of classifiers include Classiel, micron classifier, and Speidc classifier (available from Seishin Enterprise Co., Ltd.); Turbine classifier (available from Nisshin Engineering Inc.); Micron separator, Turboplex (ATP), and TSP separator (available from Hosokawa Micron Corporation); Elbow-Jet (available from Nittetsu Mining Co., Ltd.); Dispersion separator (available from Nippon Pneumatic Mfg. Co., Ltd.); and YM Micro Cut (available from Yaskawa & Co., Ltd.).

[0228] Examples of surface treatment devices include Faculty (available from Hosokawa Micron Corporation), Mechano Fusion (available from Hosokawa Micron Corporation), Nobilta (available from Hosokawa Micron Corporation), Hybridizer (available from Nara Machinery Co., Ltd.), Innomizer (available from Hosokawa Micron Corporation), Theta Composer (available from Tokuju Corporation), and Mechano Grinder (available from Okada Seiko Co., Ltd.).

[0229] Examples of sieving machines for sieving coarse particles include Ultrasonic (available from Koei Sangyo Co., Ltd.); Resona sieve and Gyro sieve (available from Tokuju Corporation); Vibrasonic system (available from Dalton Corporation); Soniclean (available from Sintokogio, Ltd.); Turbine sifter (available from TurboKogyo Co., Ltd.); micron sieve (available from Makino Mfg. Co., Ltd.); and circular vibrating screen.

[0230] Various measurement methods

[0231] Various measurement methods and the like will be described below.

[0232] The cross section of the toner particles was observed using a transmission electron microscope (TEM) and the major diameter and number of domains were measured. Law

[0233] The domain-matrix structure was observed after ruthenium staining of a cross section of the toner particle.

[0234] The toner was spread as a single layer on a cover glass (square cover glass No. 1, Matsunami Glass Ind., Ltd.). An Os film (5 nm) and a naphthalene film (20 nm) were formed as a protective film on the toner using an osmium plasma coater (Filgen Inc., OPC80T). Filled with D800 light-curing resin (JEOL Ltd). The above-mentioned cover glass is gently placed on the top of the tube so that the toner is in contact with the D800 light-curing resin. In this state, the resin is cured by irradiation with light, and then the cover glass and the tube are removed. This forms a cylindrical resin with toner particles embedded in the upper surface. An ultrasonic ultramicrotome (Leica Microsystems, UC7) is used to cut the length of the radius of the toner particles (4.0 μm when the weight-average particle size (D4) is 8.0 μm) from the upper surface of the cylindrical resin at a cutting speed of 0.6 mm / s to expose the cross section of the toner particles. The resin is cut into a thin flaky sample with a thickness of 250 nm to prepare a cross section of the toner particles. The cross section of the center portion of the toner particles can be obtained by cutting in this way.

[0235] The obtained flaky sample was stained with a vacuum electron staining apparatus (Filgen Inc., VSC4R1H) in an atmosphere of RuO 4 gas at a pressure of 500 Pa for 15 minutes, and subjected to STEM observation with a TEM (JEOL Ltd., JEM-2800).

[0236] The probe size in STEM observation is 1 nm, and the image size is 1,024 × 1,024 pixels.

[0237] The obtained bright field image was binarized using the image processing software Image-Pro Plus (Media Cybernetics Inc.) This binarization process was performed so that when the brightness change from black to white is defined as 0 to 255 grayscales, the portion with a grayscale of 127 or less is black and the portion with a grayscale of 128 or more is white.

[0238] In cross-sectional observation of the toner particles, the portion containing the crystalline resin appears black when subjected to the above-described binarization process, and the portion containing the amorphous resin appears white when subjected to the above-described binarization process.

[0239] From the binarized image obtained by STEM observation, it was determined whether a domain-matrix structure was observed in the cross section of each toner particle. In addition, it was determined whether the domain contained a crystalline resin or an amorphous resin and whether the matrix contained a crystalline resin or an amorphous resin.

[0240] Toner particles to be observed for the major diameter of the measurement domain are selected as follows. From a cross-sectional image of the toner particles, the cross-sectional area of ​​each toner particle is determined, and the diameter of a circle having an area equal to the cross-sectional area (equivalent circle diameter) is determined. Toner particles for which the absolute difference between the equivalent circle diameter and the weight-average particle diameter (D4) of the toner particles is 1.0 μm or less are selected for observation. Cross-sectional observation of the toner particles is continued until the number of toner particles for which the absolute difference between the diameter of a circle having an area equal to the cross-sectional area of ​​each toner particle and the weight-average particle diameter (D4) of the toner particles is 100 or less.

[0241] Measure the major diameters of all domains observed in a cross-section of a selected toner particle. When the domains are composed of an amorphous resin, they are observed as white areas. Select the domain with the longest diameter. The longest diameter of a domain is referred to as the major diameter of the domain. Perform this measurement on 100 selected toner particles. Count the number of toner particles with a major diameter of 1.0 μm or less.

[0242] Principle of Ruthenium Staining

[0243] When a cross-section of a toner particle is stained with ruthenium, the crystalline resin component is stained more strongly than the amorphous resin component. This results in clearer contrast and facilitates observation of the toner particle cross-section. This is because RuO₄ has a strong oxidizing ability and oxidizes the long-chain alkyl and alkylene groups that enhance crystallinity. Consequently, the crystalline resin component is stained more strongly than the amorphous resin component.

[0244] The higher the crystallinity of the resin component, the more ruthenium atoms are present. The greater the number of ruthenium atoms present, the more they interfere with the transmission of the electron beam. Therefore, the resin component with higher crystallinity is observed to be more strongly stained in the electron microscope image. In contrast, the amorphous resin component is observed to be weakly stained or not stained. This indicates that the strongly stained portion is the portion containing the crystalline resin, and the weakly stained or not stained portion is the portion containing the amorphous resin.

[0245] Method for analyzing matrix and domains in cross-sectional observation of toner particles

[0246] First, a sheet as a reference sample for the amount present was prepared.

[0247] Crystalline resin A was fully dispersed in a visible light-curable resin (Aronix LCR series, D800), and the mixture was then cured by irradiation with short-wavelength light. The resulting cured product was sliced ​​using an ultramicrotome equipped with a diamond knife to prepare a 250 nm thick flaky sample. A flaky sample of amorphous resin P was similarly prepared.

[0248] Crystalline resin A and amorphous resin P were mixed at mass ratios of 0 / 100, 30 / 70, 70 / 30, and 100 / 0. Each of the resulting mixtures was melt-kneaded to prepare a kneaded product. These were also dispersed in a visible light-curable resin in the same manner, cured, and then cut to prepare a sheet-like sample.

[0249] Cross sections of these reference samples were observed using a transmission electron microscope (JEOL Ltd., JEM-2800 electron microscope, TEM-EDX), and element mapping was performed using EDX. The mapped elements were carbon, oxygen, and nitrogen.

[0250] The mapping conditions are given below.

[0251] Accelerating voltage: 200 kV

[0252] Electron beam irradiation size: 1.5nm

[0253] Live time limit: 600 seconds

[0254] Stagnation time: 20 to 30 seconds

[0255] Mapping resolution: 256×256

[0256] Based on the (average) spectral intensity of each element (in a 10 nm square area), (oxygen intensity / carbon intensity) and (nitrogen intensity / carbon intensity) were calculated. A calibration curve was then created for the mass ratio of crystalline resin A to amorphous resin P. When the monomer unit of crystalline resin A contains nitrogen atoms, the calibration curve of (nitrogen intensity / carbon intensity) was used for quantification.

[0257] Next, the toner particle samples were analyzed.

[0258] The toner particles were fully dispersed in a visible light curable resin (Aronix LCR Series D800), and the mixture was then cured by irradiation with short-wavelength light. The resulting cured product was cut using an ultramicrotome equipped with a diamond knife to prepare 250 nm thick flaky samples. The cut samples were observed using a transmission electron microscope (JEOL Ltd., JEM-2800) (TEM-EDX). Cross-sectional images of the toner particles were obtained, and elemental mapping was performed using EDX. The mapped elements were carbon, oxygen, and nitrogen.

[0259] The cross-sections of the toner particles to be observed were selected as follows. From the cross-sectional images of the toner particles, the cross-sectional area of ​​each toner particle was determined, and the diameter of a circle having an area equal to the cross-sectional area (equivalent circle diameter) was determined. Only cross-sectional images of toner particles were observed in which the absolute value of the difference between the equivalent circle diameter and the weight-average particle size (D4) of the toner particles was 1.0 μm or less.

[0260] For the domains and matrix identified in the observed image, (oxygen intensity / carbon intensity) and / or (nitrogen intensity / carbon intensity) are calculated based on the (average) spectral intensity of each element within a 10 nm square. The ratio of crystalline resin A to amorphous resin P can be calculated by comparing the calculated results with the calibration curve described above.

[0261] Method for measuring the ratio of various monomer units in a resin

[0262] The ratio of various monomer units in the resin is determined by 1 H-NMR is measured under the following conditions.

[0263] Measuring instrument: FT-NMR instrument

[0264] JNM-EX400 (available from JEOL Ltd.)

[0265] Measurement frequency: 400MHz

[0266] Pulse condition: 5.0μs

[0267] Frequency range: 10,500Hz

[0268] Number of points: 64 times

[0269] Measurement temperature: 30℃

[0270] Sample: 50 mg of the measurement sample was placed in a sample tube with an inner diameter of 5 mm, and then deuterated chloroform (CDCl3) was added as a solvent. The mixture was maintained in a thermostat at 40°C to dissolve the measurement sample, thereby preparing the sample. As an example of measurement, the ratio of each monomer unit in vinyl polymer A was calculated as follows.

[0271] In income 1 In the H-NMR graph, among the peaks attributable to monomer unit A1, a peak that is independent of the peaks attributable to other monomer units is selected. The integral value S1 of this peak is calculated. Similarly, among the peaks attributable to monomer unit A2, a peak that is independent of the peaks attributable to other monomer units is selected. The integral value S2 of this peak is calculated.

[0272] When monomer unit A3 is introduced, a peak independent of peaks attributable to monomer unit A3 is selected from the peaks attributable to the other monomer units, and the integrated value S3 of the peak is calculated.

[0273] The monomer unit A1 content is determined using the above-mentioned integrated values ​​S1, S2, and S3 as follows: Note that n1, n2, and n3 are each the number of hydrogen atoms in the portion attributable to the target peak for each unit.

[0274] Monomer unit A1 content (mol%) = {(S1 / n1) / ((S1 / n1)+(S2 / n2)+(S3 / n3))}×100

[0275] Similarly, the monomer unit A2 content and the monomer unit A3 content are found as follows.

[0276] Monomer unit A2 content (mol%) = {(S2 / n2) / ((S1 / n1)+(S2 / n2)+(S3 / n3))}×100

[0277] Monomer unit A3 content (mol%) = {(S3 / n3) / ((S1 / n1)+(S2 / n2)+(S3 / n3))}×100

[0278] When a polymerizable monomer containing no hydrogen atoms in the portion other than the vinyl group is used in the vinyl polymer A, 13 C-NMR, and the measurement nucleus is 13 C. Measured in single pulse mode and with 1 H-NMR was calculated similarly.

[0279] When using toner or toner particles as a measurement sample, due to the overlap of the peaks of the release agent and other resins, the independent peaks of the various monomer units in the vinyl polymer A are sometimes not observed. In some cases, the ratio of the various monomer units in the vinyl polymer A cannot be calculated. In such a case, vinyl polymer A' is produced by performing the same suspension polymerization without using the release agent or other resins. Then, vinyl polymer A' can be regarded as vinyl polymer A and analyzed.

[0280] When measuring a resin such as the non-crystalline polyester P, the ratio of each monomer unit is also calculated using the above-mentioned measuring instrument and conditions.

[0281] Method for measuring the content of THF-insoluble components in resin components

[0282] First, 1.5 g of the toner as a measurement sample (0.7 g if the measurement sample is only the resin component) (W1[g]) is accurately weighed, placed in a cylindrical filter paper (trade name: No.86R, size 28×100 mm, available from Advantec Toyo Kaisha, Ltd.) that has been accurately weighed in advance, and placed in a Soxhlet extractor.

[0283] The extraction was performed for 18 hours using 200 mL of THF as a solvent at a reflux rate of approximately 5 minutes for the solvent extraction cycle. After the extraction was complete, the cylindrical filter paper was removed, air-dried, and then vacuum-dried at 40° C. for 8 hours, with the THF-insoluble component removed. The mass of the cylindrical filter paper containing the extraction residue was weighed. The mass of the extraction residue (W2 [g]) was then calculated by subtracting the mass of the cylindrical filter paper from the mass of the extraction residue.

[0284] When the THF-soluble component is recovered, the THF-soluble component can be recovered by sufficiently removing THF from a solution of the soluble component in THF using an evaporator.

[0285] Next, the mass of the components other than the resin component (W3 [g]) is found by the following procedure: In this procedure, when the measurement sample contains only the resin component, W3 is set to 0 g.

[0286] About 2 g of toner (W a [g]) accurately weighed into a pre-weighed 30 mL magnetic crucible.

[0287] The magnetic crucible was placed in an electric furnace, heated at about 900°C for about 3 hours, allowed to stand in the furnace, and allowed to cool at room temperature in a desiccator for more than 1 hour. The mass of the crucible containing the incineration ash was weighed. The incineration ash (W) was calculated by subtracting the mass of the crucible from it. b [g]).

[0288] The mass of the incineration ash (W3[g]) in the sample W1[g] is calculated by formula (8):

[0289] W3=W1×(W b / W a )···(8).

[0290] In this case, the THF-insoluble content of the resin component in the toner can be obtained from formula (9):

[0291] THF-insoluble content of the resin component (mass %) = {(W2-W3) / (W1-W3)} x 100···(9).

[0292] Quantitative method for the content of carbon-carbon double bonds

[0293] An example of a method for quantifying the amount of carbon-carbon double bonds (double bond equivalent) in polyester having carbon-carbon double bonds is a method of measuring and quantifying protons or carbons in carbon-carbon double bonds by a nuclear magnetic resonance (NMR) instrument.

[0294] Sample preparation

[0295] In an NMR sample tube, 100 mg of sample, 10 mg of sodium trimethylsilylpropanesulfonate as an internal standard, and 10 mg of Cr(AcAc) 3 as a relaxation reagent are placed. Then, 0.45 mL of a deuterated solvent such as deuterated pyridine is added to fully dissolve the sample.

[0296] Measurement conditions

[0297] Instrument: Bruker BioSpin AVANCE III HD400

[0298] Measurement core: 13 C

[0299] Measurement frequency: 125.77MHz

[0300] Sample rotation frequency: 6kHz

[0301] Number of points: 24,000

[0302] Measuring temperature: room temperature

[0303] Analysis and calculation

[0304] The total amount of double bonds (mmol / g) was calculated from the area ratio of the carbon peaks of double bonds derived from the unsaturated carboxylic acid component and the unsaturated alcohol component to the carbon peak of the methyl group of the internal standard substance.

[0305] For example, for unsaturated carboxylic acid components such as maleic acid or fumaric acid, the double bond content (mmol / g) is calculated from the area ratio of the double bond carbon peak (164.6 ppm) to the carbon peak of the methyl portion of the internal standard (0 ppm).

[0306] Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn) of resin

[0307] The molecular weight distribution (weight average molecular weight (Mw) and number average molecular weight (Mn)) of the resin was measured by gel permeation chromatography (GPC) as described below.

[0308] Each sample was dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The resulting solution was filtered through a "MySyori Disc" solvent-resistant membrane filter (available from Tosoh Corporation) with a pore size of 0.2 μm to prepare a sample solution. The sample solution was adjusted so that the concentration of the THF-soluble component was 0.8% by mass. The measurement was performed using this sample solution under the following conditions.

[0309] Instrument: HLC-8120GPC (detector: RI) (available from Tosoh Corporation)

[0310] Column: Shodex KF-7 column series of 801, 802, 803, 804, 805, 806, and 807 (available from ShowaDenko KK)

[0311] Eluent: tetrahydrofuran (THF)

[0312] Flow rate: 1.0 mL / min

[0313] Oven temperature: 40.0℃

[0314] Sample injection volume: 0.10mL

[0315] In calculating the molecular weight of the sample, a molecular weight calibration curve prepared using standard polystyrene resins such as those available from Tosoh Corporation under the 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, and A-500" is utilized.

[0316] Measurement of maximum endothermic peak temperature (Tm, melting point) and endothermic heat

[0317] The heat absorption of the sample was measured using DSC Q1000 (available from TA Instruments) under the following conditions.

[0318] Heating rate: 10℃ / min

[0319] Measurement start temperature: 20°C

[0320] Measurement end temperature: 200℃

[0321] The instrument's detection cell temperature is calibrated using the melting points of indium and zinc, and the heat of fusion of indium is used to calibrate the heat.

[0322] Specifically, approximately 5 mg of a sample was accurately weighed, placed in an aluminum pan, and subjected to differential scanning calorimetry, using an empty silver pan as a reference.

[0323] In the measurement, the temperature was once raised to 200°C (first temperature rise process), then lowered to 20°C, and then raised again (second temperature rise process). The peak temperature (Tm, melting point) of the maximum endothermic peak in the temperature range of 20°C to 200°C was determined from the DSC curve obtained in the second temperature rise process. The maximum endothermic peak is the peak with the largest amount of heat absorbed per unit temperature within the temperature range of 20°C to 200°C. The amount of heat absorbed of the maximum endothermic peak represents the integrated value of the maximum endothermic peak.

[0324] The reason for not performing the above measurement during the first temperature increase is that resins produced through a production process that includes a heat treatment step may exhibit behavior attributed to the heat treatment during the first temperature increase in DSC measurement, such as an endothermic peak due to resin relaxation. If this behavior overlaps with the original behavior of the sample, accurate measurement may be difficult.

[0325] However, it is known that the first temperature increase process homogenizes the behavior of the sample, and in the second temperature increase process after the temperature of the sample is lowered, the behavior caused by the heat treatment disappears or decreases. Therefore, in the present disclosure, the above-mentioned measurement is performed during the second temperature increase process to measure the original behavior of the sample.

[0326] In the present disclosure, H(I) (J / g) and H(T) (J / g) are determined by the following formulas (11) and (12).

[0327] H(I) (J / g) = {(integral value of the above endothermic peak of the THF-insoluble component used as a sample) × W2 / (W2-W3)} × 100···(11)

[0328] H(T)(J / g)=(integrated value of the maximum endothermic peak of the toner used as a sample)×W1 / (W1-W3)×100···(12)

[0329] When using a THF-insoluble component as a sample, the inorganic fine particles and the magnetic material are separated from the toner particles by the method for separating inorganic particles described below, and then the toner particles are subjected to Soxhlet extraction as described above. In this way, the THF-insoluble component to be used as a sample can be recovered from the toner particles.

[0330] Method used to calculate SP value

[0331] As described below, the SP value of the polymerizable monomer, the SP value of the monomer unit, and the SP value of the resin were determined according to the calculation method proposed by Fedors.

[0332] For the calculation object, the evaporation energy (Δei) (cal / mol) and molar volume (Δvi) (cm2) of the atoms or atomic groups (monomer units) of the molecular structure are obtained from the table described in "Polym. Eng. Sci., 14(2), 147-154(1974)". 3 / mol). From (4.184×ΣΔei / ΣΔvi) 0.5 Calculate the SP value (J / cm 3 ) 0.5 .

[0333] SP is calculated by the same calculation method as above for atoms or atomic groups in the molecular structure in which the double bonds of the polymerizable monomer are broken by polymerization. A1 and SP A2 .

[0334] SP is calculated by dividing the vaporization energy of the monomer unit by the molar volume A1 and SP A2 .

[0335] SP A It is calculated as follows: First, for each monomer unit, the evaporation energy (Δei) and molar volume (Δvi) of each monomer unit derived from the constituent polymerizable monomers are calculated. The product of the evaporation energy (Δei) of each monomer unit in the vinyl polymer A and the molar ratio (j) is calculated. The product of the molar volume (Δvi) of each monomer unit in the vinyl polymer A and the molar ratio (j) is calculated. Then, the sum of the evaporation energies of each monomer unit is divided by the sum of the molar volumes of each monomer unit. That is, SP is calculated by the following formula: A .

[0336] SP A ={4.184×(Σj×ΣΔei) / (Σj×ΣΔvi)} 0.5

[0337] With SP A SP is calculated in the same way P, provided that unsaturated components added during the polymerization reaction in the production of non-crystalline polyesters are excluded from the calculation formula.

[0338] Example

[0339] Although the present disclosure will be specifically described below by way of examples, the present disclosure is not limited thereto. Unless otherwise specified, the term "part(s)" means "part(s) by mass".

[0340] Production Example of Polymer A-1

[0341] In a nitrogen atmosphere, the following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube.

[0342] Toluene: 100.0 parts

[0343] Behenyl acrylate (first polymerizable monomer): 67.0 parts (25.3 mol%)

[0344] Acrylonitrile (second polymerizable monomer): 22.0 parts (59.5 mol%)

[0345] Styrene (third polymerizable monomer): 11.0 parts (15.2 mol%)

[0346] Tert-butyl peroxypivalate (available from NOF Corporation as Perbutyl PV): 0.5 parts

[0347] The polymerization reaction was carried out by heating the mixture to 70°C for 12 hours under stirring at 200 rpm in a reaction vessel, thereby preparing a solution of a polymer of the polymerizable monomer composition dissolved in toluene. Subsequently, the solution was cooled to 25°C and then poured into 1000.0 parts of methanol under stirring to precipitate methanol-insoluble matter. The obtained methanol-insoluble matter was removed by filtration, washed with methanol and vacuum dried at 40°C for 24 hours to obtain polymer A-1. The weight average molecular weight (Mw) of polymer A-1 was 30,000, and the SP calculated by the above method was 1.0447. A The polymer A-1 is a crystalline resin showing a clear endothermic peak in DSC measurement. Table 1 shows the physical properties of the polymer A-1.

[0348] Production Examples of Polymers A-2 to A-5

[0349] Polymers A-2 to A-5 were prepared in the same manner as Polymer A-1, except that the amount of the polymerizable monomer was changed as shown in Table 1. Each of Polymers A-2 to A-5 is a crystalline resin that exhibits a clear endothermic peak in DSC measurement. Table 1 shows the physical properties of Polymers A-2 to A-5.

[0350] Table 1

[0351]

[0352] The abbreviations in Table 1 are as follows.

[0353] BEA: Behenyl Acrylate

[0354] AN: Acrylonitrile

[0355] MA: Methacrylic acid

[0356] St:Styrene

[0357] SP in Table 1 A1 、SP A2 and SP A The unit is (J / cm 3 ) 0.5 The Mw values ​​in Table 1 were measured using the above method.

[0358] Production Example of Amorphous Resin P-1

[0359] In a nitrogen atmosphere, the following materials were placed in a reaction vessel equipped with a reflux condenser, a stirrer, a thermometer, and a nitrogen inlet tube.

[0360] Ethylene glycol: 50.0 parts

[0361] Terephthalic acid: 50.0 parts

[0362] Bis(triethanolamine)diisopropoxytitanium: 2.5 parts

[0363] The above materials were reacted at 230°C for 2 hours under a nitrogen stream while removing the generated water. The reaction was then continued under a reduced pressure of 2.5 kPa for 5 hours, after which the temperature was lowered to 180°C. One part of tert-butylcatechol was added as a polymerization inhibitor, followed by 10.0 parts of fumaric acid. The mixture was reacted under a reduced pressure of 0.5 to 2.5 kPa for 8 hours, after which it was removed to obtain amorphous resin P-1. Table 2 shows the physical properties of amorphous resin P-1.

[0364] Production Examples of Amorphous Resins P-2 to P-9

[0365] Amorphous resins P-2 to P-9 were prepared in the same manner as for the amorphous resin P-1, except that the amount of the polymerizable monomer was changed as shown in Table 2. Table 2 shows the physical properties of the amorphous resins P-2 to P-9.

[0366] Table 2

[0367]

[0368] The abbreviations in Table 2 are as follows.

[0369] EG: ethylene glycol

[0370] PeE: Pentaerythritol

[0371] NPG: Neopentyl Glycol

[0372] BPA-EO: Bisphenol A-ethylene oxide adduct (average number of ethylene oxide addition moles: 2.0)

[0373] BPA-PO: Bisphenol A-propylene oxide adduct (average number of added moles of propylene oxide: 2.0)

[0374] TPA: terephthalic acid

[0375] ADA: adipic acid

[0376] FuA: Fumaric acid

[0377] The Mw and double bond equivalent in Table 2 were measured by the above-mentioned measurement method, and SP was calculated by the above-mentioned calculation method. P .

[0378] Production Example of Binder Resin C-1

[0379] First, 60 parts of polymer A-1 and 40 parts of amorphous resin P-1 were mixed together and fed to a twin-screw mixer (Kurimoto Ltd., S5KRC kneader) at a feed rate of 40 kg / hour. Simultaneously, 3.0 parts of tert-butyl peroxyisopropyl monocarbonate were fed at a feed rate of 0.4 kg / hour as a free radical reaction initiator. The mixture was reacted by mixing and extruding at 100 rpm at 160°C for 5 minutes. Furthermore, the mixture was mixed with nitrogen flowing from a vent to remove the organic solvent. The product obtained by mixing was cooled to obtain binder resin C-1.

[0380] Production Examples of Binder Resins C-2 to C-11, C-14, C-16, C-17, C-19 to C-21

[0381] Binder resins C-2 to C-11, C-14, C-16, C-17, C-19 to C-21 were prepared in the same manner as binder resin C-1, except that polymer A and non-crystalline resin P used were changed as shown in Table 3.

[0382] Table 3

[0383]

[0384] The SP in Table 3 is calculated using the above calculation method. P and SP A . 1)|SP P -SP A2 |(J / cm 3 ) 0.5 The value of SP A2 The SP values ​​of acrylonitrile shown in Table 1 are shown. 2) |SP P -SP A2 |(J / cm 3 ) 0.5 The value of SP A2 These are the SP values ​​of methacrylic acid shown in Table 1.

[0385] Production Example of Toner 1

[0386] Binder resin C-1: 100 parts by mass

[0387] Carbon black (NIPex 35, available from Orion Engineered Carbons): 5.0 parts by mass

[0388] Release agent (Excerex 15341PA, available from Mitsui Chemicals, Inc.): 5.0 parts by mass

[0389] The above materials were premixed in a Henschel mixer and then melt-kneaded using a twin-screw extruder (trade name: PCM-30, available from Ikegai Corp.) at a temperature such that the temperature of the melt at the discharge port was 150°C. The resulting kneaded product was cooled, coarsely pulverized using a hammer mill, and then finely pulverized using a pulverizer (trade name: Turbomold T250, available from Turbo Kogyo Co., Ltd.). The resulting finely pulverized powder was classified using a multi-stage classifier utilizing the Coanda effect to provide toner particles 1 having a weight-average particle size (D4) of 7.2 μm.

[0390] 1.0 part by mass of hydrophobic silica fine powder surface-treated with hexamethyldisilazane (number average primary particle size: 10 nm) was added to 100.0 parts by mass of Toner Particles 1. The mixture was mixed at 3,200 rpm for 2 minutes using a Henschel mixer to provide Toner 1. Table 4 shows the physical properties of Toner 1.

[0391] Production Examples of Toners 2 to 11, Toner 14, Toner 16, Toner 17, and Toners 19 to 21

[0392] Toners 2 to 11, 14, 16, 17, 19 to 21 were produced in the same manner as Toner 1, except that the type of binder resin C-1 used was changed as shown in Table 4. Table 4 shows the physical properties of the obtained Toners 2 to 11, 14, 16, 17, 19 to 21.

[0393] In the cross-sectional observation of the colorant particles, among colorants 1 to 11, colorant 14, colorant 16, colorant 17, and colorant 19 to colorant 21, colorant particles including domains with a major diameter of 5.0 μm or more were observed only in colorant 20 and were not observed in the other toners.

[0394] Table 4

[0395]

[0396] The physical properties of the toner in Table 4 were measured by the above-described measuring methods. The polymer A content in the resin component is a value calculated as a percentage of the mass of the polymer A soluble in THF based on the mass of the resin component.

[0397] Example 1

[0398] Toner 1 was evaluated as follows. Table 5 shows the evaluation results.

[0399] Evaluation of low-temperature fixability of toner

[0400] For the evaluation of low-temperature fixability, a color laser printer (trade name: HP Color LaserJet3525dn, available from HP) was modified and used as an image forming apparatus, and white paper (Office Planner: 64 g / m 2 , available from CANON KABUSHIKI KAISHA) was used as evaluation paper. The image forming apparatus was modified so that the fixing temperature and the process speed could be changed and the fixing unit was detachable.

[0401] The fixing unit was removed from the image forming apparatus. The toner was removed from the black cartridge. The cartridge was filled with 100 g of Toner 1.

[0402] An image forming apparatus was used to form an image on the evaluation paper at a position 1.0 cm from the upper end of the paper along the paper feeding direction, each having a length of 2.0 cm, a width of 15.0 cm, and a toner load of 0.9 mg / cm 2 unfixed toner image.

[0403] The unfixed image was fixed using an external fixing device configured to operate even outside the laser beam printer. In a normal temperature and humidity environment (23°C, 60% RH), the processing speed of the external fixing device was set to 410 mm / s. The initial temperature was set at 100°C, and the set temperature was subsequently increased by 5°C. The above-mentioned unfixed image was fixed at various temperatures. For each of the obtained fixed images, the lowest fixing temperature at which low-temperature deterioration did not occur was confirmed. The value of this lowest fixing temperature was used to evaluate the low-temperature fixing property of the toner. A toner showing a lowest fixing temperature lower than 135°C was determined to be a toner providing the advantageous effects of the present disclosure. Table 5 shows the evaluation results.

[0404] The term "low-temperature offset" refers to visible image defects caused by the fact that the fixing temperature is not high enough to melt the toner.

[0405] Evaluation of high-temperature offset resistance of toner

[0406] As described below, the high-temperature offset resistance of Toner 1 was evaluated using the same image forming apparatus and evaluation paper used in the evaluation of the toner's low-temperature fixability described above. The evaluation method was as follows: the toner was fixed at a temperature that easily causes high-temperature offset of the toner. The difference in reflection density between the location where the high-temperature offset occurred and the reflection density of a white background portion on which no toner was placed was measured.

[0407] Using the above-mentioned image forming apparatus, a sheet with a length of 100 mm, a width of 100 mm, and a toner load of 0.3 mg / cm was formed on an evaluation paper having a 5 mm margin at the leading end using the toner 1. 2 Unfixed image.

[0408] In this evaluation, an external fixing device configured to operate even outside the laser beam printer was also used to fix the unfixed image. In a normal temperature and humidity environment (23°C, 50% RH), fixing was performed using an external fixing device set to a processing speed of 410 mm / s and a fixing temperature of 200°C to provide a fixed image. The reflection density at the position where the colorant stain occurred in the obtained fixed image was measured. The reflection density was measured using a Macbeth densitometer, which is a reflection densitometer using an SPI color filter (available from Macbeth). The absolute value of the difference between the reflection density of the white background portion on which no toner was placed and the reflection density of the position where the stain occurred was defined as the stain concentration. This value was used to evaluate the high-temperature stain resistance of the toner. A toner showing a stain concentration of less than 0.15 was determined to be a toner that provides the advantageous effects of the present disclosure. Table 5 shows the evaluation results.

[0409] Evaluation of toner development performance

[0410] Using the same image forming apparatus and evaluation paper used in the above-mentioned evaluation of the low-temperature fixability of the toner, a horizontal line pattern with a print rate of 1% was formed on two sheets of paper for each job. The apparatus was set so that the apparatus would stop once between jobs and then start the next job. Under this setting, a total of 20,000 sheets were output. Afterwards, a white image evaluation paper with a print rate of 0% was output. The white image evaluation paper was then evaluated according to the following criteria. This was used to evaluate the developing performance of Toner 1. The evaluation was conducted in a low-temperature, low-humidity environment (temperature: 15°C, humidity: 10% RH), where the toner tends to be overcharged and the non-image area is easily contaminated.

[0411] For the measurement of the white image evaluation paper, a reflectometer capable of measuring reflection density (TC-6DS reflectometer, available from Tokyo Denshoku Co., Ltd.) was used. The minimum reflection density of the entire white image evaluation paper after output was designated as Ds, and the average reflection density of the white image evaluation paper before output was designated as Dr. (Dr-Ds) was used as an index to evaluate the developing performance. Dr is the average reflection density of five points measured at the four corners and the center of the evaluation paper.

[0412] Therefore, the smaller the value of (Dr-Ds), the better the developing performance of the toner. Toners showing a value of (Dr-Ds) of less than 2.5 were judged to be toners that provide the advantageous effects of the present disclosure. Table 5 shows the evaluation results.

[0413] Examples 2 to 11, 14, 16 and 17

[0414] Toners 2 to 11, 14, 16, and 17 were evaluated in the same manner as in Example 1. Table 5 shows the evaluation results.

[0415] Comparative Examples 2 to 4

[0416] Toners 19 to 21 were evaluated in the same manner as in Example 1. Table 5 shows the evaluation results.

[0417] Table 5

[0418]

[0419] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner comprising toner particles, the toner particles comprising a resin component containing a crystalline resin and a non-crystalline resin, It is characterized in that The resin component contains a tetrahydrofuran-insoluble component, and The content of the tetrahydrofuran-insoluble component is 5.0% by mass to 80.0% by mass relative to the content of the resin component. The crystalline resin includes a vinyl polymer A containing a monomer unit A1 represented by formula (A): In formula (A), R 1 is H or CH3, and R 2 is an alkyl group having 18 to 36 carbon atoms, The vinyl polymer A further contains monomer unit A2, The monomer unit A2 is at least one monomer unit selected from the group consisting of a monomer unit represented by the following formula (A21) and a monomer unit represented by the following formula (A22): In formula (A21) and formula (A22), X is a single bond or an alkylene group having 1 to 6 carbon atoms, R 4 is cyano -C≡N; -C(=O)NHR 7 , where R 7 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a hydroxyl group; -COOR 8 , where R 8 is an alkyl group having 1 to 6 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms; -NHCOOR 9 , where R 9 is an alkyl group having 1 to 4 carbon atoms; -NH-C(=O)-NH(R 10 )2, where each R 10 are independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; -COO(CH2)2NHCOOR 11 , where R 11 is an alkyl group having 1 to 4 carbon atoms; or -COO(CH2)2-NH-C(=O)-NH(R 12 )2, where each R 12 are independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R 6 is an alkyl group having 1 to 4 carbon atoms, and R 3 and R 5 are each independently a hydrogen atom or CH3, The vinyl polymer A further contains monomer unit A3, The monomer unit A3 is at least one monomer unit selected from the group consisting of a monomer unit represented by formula (A31) and a monomer unit represented by formula (A32): In formula (A32), R 13 is H or CH3, The tetrahydrofuran-insoluble component comprises a cross-linked resin in which a crystalline resin and a non-crystalline resin are combined together; The non-crystalline resin includes a non-crystalline polyester P which is a polycondensate of an alcohol component and a carboxylic acid component; wherein when the maximum endothermic peak temperature in differential scanning calorimetry (DSC) measurement of the tetrahydrofuran-insoluble component is defined as Tm in ° C., and when the endothermic quantity of the maximum endothermic peak determined by DSC measurement of the tetrahydrofuran-insoluble component is defined as H(I) in J / g, Tm in °C satisfies formula (1): 55.0≤Tm≤80.0···(1), and H(I) in J / g satisfies formula (2): 10.0≤H(I)≤80.0···(2), and When observing the cross section of 100 particles of the toner particles, Each of the cross sections has a domain-matrix structure including a matrix containing the crystalline resin and domains each containing the amorphous resin, and Among the 100 particles, the number of particles in which the major diameters of all domains are 1.0 μm or less is 20 or more.

2. The toner according to claim 1, wherein when the endothermic amount of the maximum endothermic peak determined by DSC measurement of the toner is defined as H(T) in J / g, H(I) in J / g and H(T) in J / g satisfy formula (3): 3.0%≤H(I) / H(T)≤20.0%···(3).

3. The toner according to claim 1, The content of the monomer unit A1 relative to the content of the vinyl polymer A is 30.0% by mass to 99.9% by mass.

4. The toner according to claim 1, Wherein, when the SP value of the monomer unit A1 calculated by the Fedors method is defined as SP A1 (J / cm 3 ) 0.5 When the SP value of the monomer unit A2 calculated by the Fedors method is defined as SP A2 (J / cm 3 ) 0.5 hour, SP A1 and SP A2 Satisfying formula (4): 3.0≤SP A2 -SP A1 ≤25.0···(4)。 5. The toner according to claim 1 or 4, The content of the monomer unit A2 relative to the content of the vinyl polymer A is 1.0% by mass to 70.0% by mass.

6. The toner according to any one of claims 1 to 4, The content of the tetrahydrofuran-insoluble component is 30.0% by mass to 80.0% by mass relative to the content of the resin component.

7. A method for producing a toner according to any one of claims 1 to 6, comprising the steps of: melt-kneading a mixture of a crystalline vinyl polymer A, a non-crystalline resin P containing a carbon-carbon double bond, and a radical initiator to provide a kneaded product; and pulverizing the kneaded product to provide a pulverized product, It is characterized in that The vinyl polymer A contains a monomer unit A1 represented by the following formula (A): The vinyl polymer A further contains monomer unit A2, When the SP value of the vinyl polymer A calculated by the Fedors method is defined as SP A (J / cm 3 ) 0.5 hour, When the SP value of the non-crystalline resin P calculated by the Fedors method is defined as SP P (J / cm 3 ) 0.5 hour, When the SP value of the monomer unit A1 calculated by the Fedors method is defined as SP A1 (J / cm 3 ) 0.5 When, and When the SP value of the monomer unit A2 calculated by the Fedors method is defined as SP A2 (J / cm 3 ) 0.5 hour, SP A1 and SP A2 Satisfying formula (4): 3.0≤SP A2 -SP A1 ≤25.0···(4), SP A and SP P Satisfying formula (5): 0<|SP P -SP A |≤10.0···(5), and SP A2 、SP A and SP P Satisfying formula (6): |SP P -SP A |>|SP P -SP A2 |···(6), In formula (A), R 1 is H or CH3, and R 2 is an alkyl group having 18 to 36 carbon atoms.

8. The method according to claim 7, Among them SP A and SP P Satisfying formula (7): 6.0≤|SP P -SP A |≤10.0···(7)。 9. The method according to claim 7, wherein the non-crystalline resin P is a non-crystalline polyester P, The non-crystalline polyester P has a polycondensation structure of an alcohol component and a polycondensation structure of a carboxylic acid component, and As the alcohol component, a polyhydric alcohol having 2 to 6 carbon atoms is included.

10. The method according to claim 9, The content of the polycondensation structure of the polyol relative to the content of the non-crystalline polyester P is 10.0% by mass or more.

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