TONER AND TWO-COMPONENT DEVELOPER

Abstract

The peak top molecular weight of the tetrahydrofuran-soluble component of the toner, as measured by gel permeation chromatography, is 4,000 or more and 6,500 or less. The tetrahydrofuran-insoluble component of the toner is 10% by weight or more and 30% by weight or less. When the endothermic peak temperature T1 in the heating process and the exothermic peak temperature T2 during the cooling process originating from the ester wax is measured using a differential scanning calorimeter, the value T1-T2 is 15° C. or more and 30° C. or less.

Claims

1. A toner including toner particles containing a polyester resin as a binder resin, and an ester wax as a mold release agent, wherein a peak top molecular weight of a tetrahydrofuran-soluble component of the toner, as measured by gel permeation chromatography, is 4,000 or more and 6,500 or less, a tetrahydrofuran-insoluble component of the toner is 10% by weight or more and 30% by weight or less with respect to 100% by weight of the toner, and given an endothermic peak temperature T1 in a heating process and an exothermic peak temperature T2 during a cooling process originating from the ester wax as measured using a differential scanning calorimeter, the value T1-T2 is 15° C. or more and 30° C. or less.

2. The toner according to claim 1, wherein given an outflow start temperature Ti and a softening temperature Tm measured by a flow tester, Ti is 85° C. or more and 95° C. or less, Tm is 120° C. or more and 140° C. or less, and the value Tm-Ti is 25° C. or more and 50° C. or less.

3. The toner according to claim 1, wherein the toner particles contain a styrene-acrylic resin, and a content of the styrene-acrylic resin is 1% by weight or more and 10% by weight or less with respect to 100% by weight of the toner particles.

4. The toner according to claim 1, wherein a content of the ester wax is 0.5% by weight or more and 5.0% by weight or less with respect to 100% by weight of the toner particles.

5. The toner according to claim 1, wherein an average dispersion diameter of the ester wax in the toner particles is 0.2 μm or more and 2.0 μm or less.

6. A two-component developer including the toner according to claim 1, and a carrier, wherein the carrier has a carrier core material, and a resin coating layer that coats the carrier core material, and given an SP value of a resin in the resin coating layer SP1, an SP value of the ester wax SP2, and an SP value of the binder resin SP3, SP1<SP2<SP3 and SP2-SP1>1.

Description

EXAMPLES

[0061] The present invention will be described below based on Examples and Comparative Examples. However, the present invention is not limited to these Examples. First, the measurements performed in the Examples and the like will be described.

Measurement Method of Peak Top Molecular Weight (Mp)

[0062] The peak top molecular weight (Mp) of the binder resin and the toner was measured by gel permeation chromatography (GPC) under the following conditions. Furthermore, for the measurement of the molecular weight, a sample solution obtained by dissolving the polyester resin in tetrahydrofuran (THF), and then filtering off the insoluble component using a glass filter was used. The peak top molecular weight refers to the molecular weight showing the maximum peak height in the chromatogram obtained by the GPC measurement. [0063] Device: HLC-8120 manufactured by Tosoh Corporation [0064] Columns: 2×TSK GEL GMH6 [manufactured by Toso Corporation] [0065] Measurement temperature: 40° C. [0066] Sample solution: 0.25 mass % THF (tetrahydrofuran) solution [0067] Solution injection amount: 100 μL [0068] Detection device: Refractive index detector [0069] Reference materials: Standard polystyrene (TSKstandard POLYSTYRENE) manufactured by Tosoh Corporation; 12 samples (molecular weights of 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, and 2,890,000)

Measurement Method of THF-Insoluble Component (Gel Component) Content in Toner

[0070] The content was calculated from the amount of the THF-insoluble component before and after the GPC measurement above.

Measurement Method of Endothermic Peak Temperature in Heating process and Exothermic Peak Temperature in Cooling Process

[0071] Using a differential scanning calorimeter (product name: DSC 220, manufactured by Seiko Electronics Industry Co., Ltd), a DSC curve was measured by heating 1 g of the sample to 150° C. at a heating rate of 10° C./min, holding the sample at 150° C. for 2 minutes, and then cooling the sample to 30° C. at a cooling rate of 10° C./min. The endothermic peak temperature in the heating process and the exothermic peak temperature in the cooling process were determined for the obtained DSC curve.

Measurement Method of Outflow Start Temperature and Softening Temperature of Toner

[0072] Using a flow characteristic evaluation device (manufactured by Shimadzu Corporation, flow tester, model number: CFT-100C), a load of 20 kgf/cm.sup.2 (9.8×10.sup.6 Pa) was applied to 1 g of the sample while heating from a start temperature of 40° C. at a heating rate of 6° C./min, causing the sample to flow out from a die (nozzle diameter 1 mm, length 1 mm). The temperature at which the material began to flow out was defined as the outflow start temperature “Ti”. The temperature at which half of the sample had flowed out was defined as the softening temperature “Tm”.

Measurement Method of Dispersion Diameter of Ester Wax

[0073] A sample was obtained by embedding the toner in an epoxy resin followed by surfacing using an ultramicrotome (manufactured by Reichert Inc., product name: Ultracut N). The dispersion state of the mold release agent (wax) in the obtained sample was observed using a scanning transmission electron microscope (manufactured by Hitachi High-Technologies Corporation, model number: S-4800). As a result of randomly extracting 200 to 300 wax portions from the obtained electron micrograph data and performing image analysis using image analysis software (product name: Azo-kun, manufactured by Asahi Kasei Engineering Corporation), the equivalent circle diameter (μm) of the wax was determined, and this was used as the dispersion diameter (μm) of the wax.

Calculation Method of SP Values

[0074] The SP values were calculated according to the method proposed by Fedors as described in “Polymer Engineering and Science, February, 1974, Vol. 14, No. 2, Robert F. Fedors. (pp. 147-154)”.

Evaluation Method of Fixing Performance (Low-Temperature Fixability and High-Temperature Fixability)

[0075] A fixed image was formed by the two-component developer using a commercially available copying machine (manufactured by Sharp Corp, model number: MX-5100FN) modified for evaluation purposes. First, a sample image including a solid image (a rectangle of 20 mm height and 50 mm width) was formed as an unfixed image on a sheet of recording paper (manufactured by Sharp Corporation, PPC paper, model number: SF-4AM3). At this time, the amount of toner adhered to the recording paper in the solid image was adjusted to 0.5 mg/cm.sup.2.

[0076] Next, a fixed image was prepared using a hard roller fixing device. The fixing process speed was set to 120 mm/sec, and the temperature of the fixing roller was raised from 110° C. in 5° C. increments to obtain a minimum temperature at which a low-temperature offset did not occur, and a maximum temperature at which a high-temperature offset did not occur.

[0077] The “low-temperature offset” and the “high-temperature offset” are defined as situations where the toner is not fixed to the recording paper at the time of fixing, but is attached to the recording paper after the fixing belt has made an entire loop while the toner is still attached to the fixing belt.

[0078] From the obtained results, the “low-temperature fixability” was judged according to the following criteria.

[0079] .circle-solid.: Excellent (minimum temperature was 105° C. or less)

[0080] ∘: Good (minimum temperature was 110° C. or more and less than 120° C.)

[0081] Δ: Fair (minimum temperature was 120° C. or more and less than 130° C.)

[0082] x: Poor (minimum temperature was 130° C. or more)

[0083] Furthermore, from the obtained results, the “high-temperature fixability” was judged according to the following criteria.

[0084] .circle-solid.: Excellent (maximum temperature was 195° C. or more)

[0085] ∘: Good (maximum temperature was 185° C. or more and less than 195° C.)

[0086] Δ: Fair (maximum temperature was 175° C. or more and less than 185° C.)

[0087] x: Poor (maximum temperature was less than 175° C.)

Evaluation Method of Gloss Unevenness

[0088] The image gloss values at the minimum fixable temperature at the time of the fixability evaluation, and at the minimum temperature+30° C. were measured using a gloss meter (manufactured by Nippon Denshoku Industries Co., Ltd., model number: VG2000). Then, a gloss A (“gloss at minimum temperature”−“gloss at minimum temperature+30”) was calculated.

[0089] From the obtained results, the “gloss unevenness” was judged according to the following criteria.

[0090] .circle-solid.: Excellent (gloss A was less than 5)

[0091] ∘: Good (gloss A was 5 or more and less than 8)

[0092] Δ: Fair (gloss A was 8 or more and less than 11)

[0093] x: Poor (gloss A was 11 or more)

Evaluation Method of Heat-Resistant Storage Stability

[0094] The heat-resistant storage stability was evaluated based on the presence or absence of aggregates after high-temperature storage. A 20 g sample of the external toner was sealed in a plastic container. After being left at 50° C. for 72 hours, the toner was taken out and sieved through a 230-mesh sieve. The weight of the toner remaining on the sieve was measured, and the residual amount, which is the ratio of this weight to the total weight of the toner, was calculated and then evaluated according to the following evaluation criteria. The lower the value of the residual amount, the less blocking that has been caused by the toner, which indicates that the toner particles have been sufficiently coated by the coating layer.

[0095] The evaluation criteria were as follows.

[0096] .circle-solid.: Excellent No aggregation. Residual amount was less than 0.5%.

[0097] ∘: Good Small amount of aggregation. Residual amount was 0.5% or more and less than 7%.

[0098] Δ: Fair Large amount of aggregation. Residual amount was 7% or more and less than 12%.

[0099] x: Poor Large amount of aggregation. Residual amount was 12% or more.

Evaluation Method of Burn-In Phenomenon

[0100] The prepared two-component developer and toner were respectively filled in a developing device and a toner cartridge of a color multifunction peripheral (product name: BP-20C25, manufactured by Sharp Corporation). Then, a continuous print test of 50,000 sheets was carried out at 30° C. in an 80% humidity environment such that square solid images (ID=1.45 to 1.50) with 1 cm sides were formed at three positions corresponding to the center and both ends of the axial direction of the developing roller.

[0101] The evaluation criteria of the burn-in phenomenon were as follows.

[0102] .circle-solid.: Excellent No decrease in concentration (ΔID (initial-50,000 sheets): less than 0.1), no toner fusion on surface of developing roller.

[0103] ∘: Good No decrease in concentration (ΔID: less than 0.1), but toner fusion observed on surface of developing roller.

[0104] Δ: Fair Small decrease in concentration (ΔID: 0.1 or more and less than 0.2), toner fusion on surface of developing roller.

[0105] x: Poor Large decrease in concentration (ΔID: 0.2 or more), toner fusion on surface of developing roller.

Evaluation Method of Charging Stability

[0106] The prepared two-component developer and toner mentioned above were respectively filled in a developing device and a toner cartridge of a color multifunction peripheral (product name: MX-2640, manufactured by Sharp Corporation). Then, a continuous print test of 50,000 sheets was carried out at 25° C. in an 50% humidity environment such that square solid images (ID=1.45 to 1.50) with 1 cm sides were formed at three positions corresponding to the center and both ends of the axial direction of the developing roller. The amount of charge (μC/g) in the two-component developer before and after the test was measured using a suction-type charge amount measurement device (manufactured by Trek Co., Ltd., model number: Model 210HS). The amount of charge was evaluated according to the following criteria using the absolute value of the difference between these values.

[0107] .circle-solid.: Excellent (difference in amount of charge was 3 μC/g or less)

[0108] ∘: Good (difference in amount of charge exceeded 3 μC/g and was 5 μC/g or less)

[0109] Δ: Fair (difference in amount of charge exceeded 5 μC/g and was 10 μC/g or less)

[0110] x: Poor (difference in amount of charge exceeded 10 μC/g)

Overall Evaluation Method for Toner and Two-Component Developer

[0111] An overall evaluation was performed according to the following criteria based on the evaluation results above.

[0112] .circle-solid.: Excellent: all evaluation criteria are .circle-solid.. Usable.

[0113] ∘: Good: One or more evaluation criteria are ∘. Usable.

[0114] Δ: Fair: One or more evaluation criteria are Δ. Usable.

[0115] x: Poor: One or more evaluation criteria are x. Unusable.

Example 1

Material Mixing/Kneading/Pulverization/Classification Processes

[0116] The components below were pre-mixed for 5 minutes using a Henschel mixer. Then, the mixture was melt-kneaded using a twin-screw extruder at a cylinder set temperature of 110° C., a barrel rotation speed of 300 rpm, and a raw material supply rate of 20 kg/hour, giving a melt-kneaded product. [0117] Binder resin (amorphous polyester resin (aromatic alcohol components: PO-BPA (propoxylated bisphenol A) and EO-BPA (ethoxylated bisphenol A), acid components: fumaric acid and mellitic anhydride)

[0118] Resin A: 42% by weight

[0119] Resin B: 42% by weight [0120] Colorant: Carbon black (manufactured by Cabot Corporation, product name: Regal 330) 6% by weight [0121] Mold release agent: Wax (1) (ester-based, Tm: 76° C.) 3% by weight [0122] Mold release agent dispersant: Styrene-acrylic copolymer resin (manufactured by Mitsui Chemicals, Inc., product name: SA800) 5% by weight [0123] Charge control agent: Salicylic acid compound (manufactured by Orient Chemical Industries Co., Ltd., product name: Bontron E-84) 2% by weight

[0124] The obtained melt-kneaded product was cooled with a cooling belt, and then coarsely pulverized using a cutting mill. Then, the product was finely pulverized using a jet crusher and further classified using a wind classifier to obtain toner particles having an average particle diameter of 6.5 μm.

External Process

[0125] To 100 parts by weight of the toner particles above was added 1.0 parts by weight of commercially available silica fine particles (product name: R976, manufactured by Nippon Aerosil Co., Ltd., average primary particle size 7 nm). The external toner was obtained by stirring the mixture for 2 minutes using an airflow mixer (manufactured by Mitsui Mining Co., Ltd., Henschel mixer) with a stirring blade set to a tip speed of 40 m/sec.

Carrier Production Process

[0126] To 12 parts by weight of toluene were dissolved 0.375 parts by weight of a coating resin (1) (silicone-based, product name: KR240, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.375 parts by weight of a coating resin (2) (product name: KR251, manufactured by Shin-Etsu Chemical Co., Ltd.). Then, 0.0375 parts by weight of conductive particles (product name: VULCAN XC-72, manufactured by Cabot Corporation) and 0.0225 parts by weight of a coupling agent (product name: AY43-059, manufactured by Toray Dow Corning Co., Ltd.) were added to the mixture, and these were dispersed to afford a coating resin liquid. The surface of 100 parts by weight of a ferrite carrier core material having a volume average diameter of 40 μm was coated by the dipping method using 12.8 parts by weight of the coating resin liquid. Then, the carrier was prepared by performing a curing process at a curing temperature of 200° C. and a curing time of 1 hour, followed by sieving through a sieve having a mesh size of 150 μm.

Production Method of Two-Component Developer

[0127] The obtained external toner and the prepared carrier were adjusted and mixed so that the concentration of the external toner was 7% by weight with respect to the total amount of the two-component developer, thereby affording a two-component developer having a toner concentration of 7% by weight.

Examples 2 to 19, Comparative Examples 1 to 8

[0128] Table 1 below shows a list of binder resins used in the Examples and the like. Table 2 shows a list of waxes used in the Examples and the like. Table 3 shows a list of carrier coating resins used in the Examples and the like. Except for combining these materials as shown in Table 4 and Table 5 below, the external toner and the two-component developer were obtained in the same manner as in Example 1.

TABLE-US-00001 TABLE 1 THF-soluble Sample Ti Tm component SP name Mp (° C.) (° C.) (% by weight) value Resin A 12,000 105 145 40 11.5 Resin B 5,400 80 95 0 11.5 Resin C 3,900 77 90 0 11.5 Resin D 3,400 75 85 0 11.5 Resin E 6,400 85 105 0 11.5 Resin F 8,000 90 110 0 11.5 *Resins A to F are all amorphous polyester resins (aromatic alcohol components: PO-BPA and EO-BPA, acid components: fumaric acid and mellitic anhydride)

TABLE-US-00002 TABLE 2 Transparent melting Sample point (° C.) SP name Wax type (Wax alone) Manufacturer Name value Wax (1) Ester 76 Nichiyu WE-15 8.9 Wax (2) Ester 82 Nichiyu WEP-5 8.9 Wax (3) Ester 79 Nichiyu WE-14 8.6 Wax (4) Ester 71 Nichiyu WE-12 8.6 Wax (5) Paraffin 75 Nippon Seiro HNP10 8.1 Wax (6) FT 90 Nippon Seiro FNP90 8.5 (Fischer- Tropsch) *SP value of wax (5) refers to the value in JP 6000660 B2, and the SP value of wax (6) refers to the value in JP6504761 B2

TABLE-US-00003 TABLE 3 Sample Resin SP name type Manufacturer Name value Coating Silicone Shin-Etsu Chemical KR-240 7.5 resin (1) Coating Silicone Shin-Etsu Chemical KR-251 7.5 resin (2) Coating Acrylic Mitsubishi Chemical DianaILR-1065 10.7 resin (3) *SP values are typical values for silicone and acrylic resins

TABLE-US-00004 TABLE 4 Toner DSC measurement Molecular weight peak THF-insoluble Endothermic peak Exothermic peak [Mp] (Resin type and component temperature temperature [T1] − [T2] ratio (% by weight)) (% by weight) Wax type [T1] (° C.) [T2] (° C.) (° C.) Example 1 5,500 (A:B = 42:42) 18 Wax (1) 79 60 19 Example 2 6,600 (A:B = 42:42) 18 Wax (2) 82 55 27 Example 3 5,500 (A:B = 42:42) 18 Wax (3) 80 65 15 Example 4 4,000 (A:C = 42:42) 18 Wax (1) 79 60 19 Example 5 6,500 (A:E = 42:42) 18 Wax (1) 79 60 19 Example 6 6,400 (A:B = 28:56) 10 Wax (1) 79 60 19 Example 7 6,000 (A:B = 56:28) 30 Wax (1) 79 60 19 Example 8 6,400 (A:E = 28:56) 10 Wax (1) 79 60 19 Example 9 4,700 (A:C = 56:28) 30 Wax (1) 79 60 19 Example 10 5,500 (A:B = 44:44) 18 Wax (1) 79 60 19 Example 11 5,500 (A:B = 39.5:39.5) 18 Wax (1) 79 60 19 Example 12 5,500 (A:B = 42:42) 18 Wax (1) 79 60 19 Example 13 5,500 (A:B = 37:37) 18 Wax (1) 79 60 19 Example 14 5,500 (A:B = 43:43) 18 Wax (1) 79 60 19 Example 15 5,500 (A:B = 43:43) 18 Wax (1) 79 60 19 Example 16 5,500 (A:B = 41:41) 18 Wax (1) 79 60 19 Example 17 5,500 (A:B = 42:42) 18 Wax (1) 79 60 19 Example 18 5,500 (A:B = 43:43) 18 Wax (3) 80 65 15 Example 19 5,500 (A:B = 42.5:42.5) 18 Wax (3) 80 65 15 Example 20 5,500 (A:B = 42:42) 18 Wax (1) 79 60 19 Example 21 5,500 (A:B = 42:42) 18 Wax (1) 79 60 19 Comparative Example 1 5,500 (A:B = 42:42) 18 Wax (4) 71 63 8 Comparative Example 2 5,500 (A:B = 42:42) 18 Wax (5) 77 70 7 Comparative Example 3 5,500 (A:B = 42:42) 18 Wax (6) 92 83 9 Comparative Example 4 5,200 (A:B = 14:70) 5 Wax (1) 79 60 19 Comparative Example 5 5,800 (A:B = 75:15) 35 Wax (1) 79 60 19 Comparative Example 6 3,500 (A:D = 42:42) 18 Wax (1) 79 60 19 Comparative Example 7 8,000 (A:F = 42:42) 18 Wax (1) 79 60 19 Comparative Example 8 7,000 (A:E:F = 42:21:21) 18 Wax (1) 79 60 19

TABLE-US-00005 TABLE 5 Flow tester measurement Styrene Wax Various SP values Outflow start Melting acrylic resin Content Dispersion Carrier resin Binder temperature temperature [Tm] − [Ti] (% by (% by diameter coating layer Wax resin [SP2] − [Ti] (° C.) [Tm] (° C.) (° C.) weight) weight) (μm) [SP1] [SP2] [SP3] [SP1] Example 1 88 125 37 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 2 88 125 37 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 3 88 125 37 5 3.0 0.7 7.5 8.6 11.5 1.1 Example 4 85 120 35 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 5 95 127 32 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 6 87 112 25 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 7 92 142 50 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 8 96 116 20 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 9 87 140 53 5 3.0 0.5 7.5 8.9 11.5 1.4 Example 10 88 125 37 1 3.0 0.7 7.5 8.9 11.5 1.4 Example 11 88 125 37 10 3.0 0.3 7.5 8.9 11.5 1.4 Example 12 88 125 37 0.5 3.0 0.8 7.5 8.9 11.5 1.4 Example 13 88 125 37 15 3.0 0.2 7.5 8.9 11.5 1.4 Example 14 88 125 37 5 0.5 0.2 7.5 8.9 11.5 1.4 Example 15 88 125 37 5 0.5 0.1 7.5 8.9 11.5 1.4 Example 16 88 125 37 5 5.0 0.8 7.5 8.9 11.5 1.4 Example 17 88 125 37 5 6.0 1.0 7.5 8.9 11.5 1.4 Example 18 88 125 37 1 5.0 2.0 7.5 8.6 11.5 1.1 Example 19 88 125 37 1 6.0 2.5 7.5 8.6 11.5 1.1 Example 20 88 125 37 5 3.0 0.5 7.9 8.9 11.5 1.0 Example 21 88 125 37 5 3.0 0.5 8.5 8.9 11.5 0.4 Comparative Example 1 88 125 37 5 3.0 1.5 7.5 8.6 11.5 1.1 Comparative Example 2 88 125 37 5 3.0 2.5 7.5 8.1 11.5 0.6 Comparative Example 3 88 125 37 5 3.0 2.0 7.5 8.5 11.5 1.0 Comparative Example 4 85 109 14 5 3.0 0.8 7.5 8.9 11.5 1.4 Comparative Example 5 95 142 47 5 3.0 0.4 7.5 8.9 11.5 1.4 Comparative Example 6 83 119 36 5 3.0 0.7 7.5 8.9 11.5 1.4 Comparative Example 7 98 130 32 5 3.0 0.4 7.5 8.9 11.5 1.4 Comparative Example 8 97 129 32 5 3.0 0.4 7.5 8.9 11.5 1.4

Example 20

[0129] In the production of the carrier, except for changing the coating resin to 0.325 parts by weight of a coating resin (1) (silicone-based resin, product name: KR240, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.325 parts by weight of a coating resin (2) (silicone-based resin, product name: KR251, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.100 parts by weight of a coating resin (3) (acrylic-based resin, product name: Dianal LR-1065, manufactured by Mitsubishi Chemical Corporation), the external toner and the two-component developer were obtained in the same manner as in Example 1.

Example 21

[0130] In the production of the carrier, except for changing the coating resin to 0.260 parts by weight of a coating resin (1) (silicone-based resin, product name: KR240, manufactured by Shin-Etsu Chemical Co., Ltd.), 0.260 parts by weight of a coating resin (2) (silicone-based resin, product name: KR251, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.230 parts by weight of a coating resin (3) (acrylic-based resin, product name: Dianal LR-1065, manufactured by Mitsubishi Chemical Corporation), the external toner and the two-component developer were obtained in the same manner as in Example 1.

[0131] A list of measurement results for the external toners and the two-component developers obtained in the Examples and the like is shown in Tables 4 and 5 above, and a list of evaluation results is shown in Table 6 below.

TABLE-US-00006 TABLE 6 Fixing performance evaluation Low-temperature High-temperature Gloss Heat-resistant Burn-in Charging Overall fixability fixability unevenness storage stability phenomenon stability evaluation Example 1 ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ ⊚ Example 2 ⊚ ⊚ ⊚ ◯ ⊚ ⊚ ◯ Example 3 ◯ ◯ ◯ ⊚ ◯ ◯ ◯ Example 4 ⊚ ◯ ⊚ ◯ ⊚ ⊚ ◯ Example 5 ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ Example 6 ⊚ Δ ◯ ◯ ⊚ ⊚ Δ Example 7 Δ ⊚ ⊚ ⊚ ⊚ ⊚ Δ Example 8 Δ ◯ ◯ ◯ ⊚ ⊚ Δ Example 9 ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ Example 10 ⊚ ⊚ ◯ ◯ ◯ ⊚ ◯ Example 11 ◯ ⊚ ⊚ ⊚ ⊚ ⊚ ◯ Example 12 ⊚ ⊚ ◯ ◯ ◯ ⊚ ◯ Example 13 Δ ⊚ ⊚ ⊚ ⊚ ⊚ Δ Example 14 ◯ ◯ ⊚ ◯ ⊚ ⊚ ◯ Example 15 Δ Δ ⊚ ◯ ⊚ ⊚ Δ Example 16 ⊚ ⊚ ◯ ◯ ◯ ◯ Δ Example 17 ⊚ ⊚ Δ Δ Δ ◯ Δ Example 18 ◯ ◯ Δ ◯ ◯ Δ Δ Example 19 ◯ ◯ Δ Δ Δ Δ Δ Example 20 ⊚ ⊚ ⊚ ⊚ ⊚ ◯ ◯ Example 21 ⊚ ⊚ ⊚ ⊚ ⊚ Δ Δ Comparative Example 1 Δ ◯ X ⊚ ◯ Δ X Comparative Example 2 X ◯ X ⊚ X X X Comparative Example 3 X ◯ X ⊚ X Δ X Comparative Example 4 ⊚ X Δ Δ ◯ ◯ X Comparative Example 5 X ⊚ ⊚ ⊚ ⊚ ⊚ X Comparative Example 6 ⊚ X ◯ Δ ◯ ◯ X Comparative Example 7 X ⊚ ⊚ ⊚ ⊚ ⊚ X Comparative Example 8 X ⊚ ⊚ ⊚ ⊚ ⊚ X

[0132] As is clear from Table 6, the toners and the two-component developers obtained in Examples 1 to 21, which include a polyester resin as the binder resin and an ester wax as the mold release agent, have an Mp of 4,000 or more and 6,500 or less, have a THF-insoluble component of 10% by weight or more and 30% by weight or less with respect to 100% by weight of the toner, and have a value T1-T2 of 15° C. or more and 30° C. or less, the evaluation of the low-temperature fixability and the high-temperature fixability were both excellent, and the evaluation of the gloss unevenness was also excellent.

[0133] In contrast, Comparative Examples 1 to 8, which did not satisfy these requirements, were inferior to the Examples because the evaluation of at least one of the low-temperature fixability, the high-temperature fixability, and the gloss unevenness was “x (poor)”.

Other Embodiments

[0134] The embodiment disclosed here is exemplary in all respects, and is not a basis for a limited interpretation. Therefore, the technical scope of the present invention is not only interpreted by the above embodiment, but is also defined based on the claims. Furthermore, the technical scope of the present invention includes all modifications within a meaning and scope equivalent to the claims.