TONER

Abstract

A toner comprising a toner particle comprising a toner core particle and a shell covering the toner core particle, wherein the shell comprises an organosilicon polymer, the shell encapsulates a domain of a release agent, and in cross-sectional observation of the toner particle by a transmission electron microscope, a ratio of domains of the release agent that are not in contact with the toner core particle to a total number of the observed domains of the release agent is 85% by number or more.

Claims

1. A toner comprising a toner particle, the toner particle comprising a toner core particle and a shell covering the toner core particle, wherein the shell comprises an organosilicon polymer, the shell encapsulates a domain of a release agent, and in cross-sectional observation of the toner particle by a transmission electron microscope, a ratio of domains of the release agent that are not in contact with the toner core particle to a total number of the observed domains of the release agent is 85% by number or more.

2. The toner according to claim 1, wherein the release agent is a hydrocarbon wax.

3. The toner according to claim 2, wherein with depth profile analysis of the toner particle using time-of-flight secondary ion mass spectrometry, a fragment ion peak corresponding to a structure represented by a formula (1) below is obtained within a range of a molecular weight of 400 to 600 in a region corresponding to the domain of the release agent: ##STR00003##

4. The toner according to claim 1, wherein in cross-sectional observation of the toner particle by a transmission electron microscope, an average value of a minimum distance D from a surface of the toner particle to the domain of the release agent is 5 to 50 nm.

5. The toner according to claim 1, wherein in cross-sectional observation of the toner particle by a transmission electron microscope, a ratio (S2/S1×100) of a total area S2 of the domains of the release agent to an area S1 occupied by the toner core particle is 0.05 to 5.5% by area.

6. The toner according to claim 1, wherein an area ratio of the organosilicon polymer on a surface of the toner particle is 35 to 75% by area.

7. The toner according to claim 1, wherein the organosilicon polymer is a condensation polymer of at least one compound selected from the group consisting of an organosilicon compound represented by a following formula (2), an organosilicon compound represented by a following formula (3), and an organosilicon compound represented by a following formula (4): ##STR00004## (In the formulas (2), (3) and (4), R.sup.a and R.sup.b are each independently an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 1 to 8 carbon atoms, or a phenyl group. R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each independently represent a halogen atom or an alkoxy group having 1 to 8 carbon atoms).

8. The toner according to claim 1, wherein the shell is the organosilicon polymer encapsulating the domains of the release agent.

Description

EXAMPLE

[0232] The present invention will be described in more detail hereinbelow with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, the “parts” and “%” used in the examples are based on mass.

[0233] Preparation of Organosilicon Compound Liquid 1

TABLE-US-00001 Ion-exchanged water 50.0 parts Methyltrimethoxysilane (organosilicon compound) 50.0 parts

[0234] The above materials were mixed, and the pH was adjusted to 4.0 with 1 mol/L hydrochloric acid. After that, the mixture was stirred for 1 h while being heated at 60° C. in a water bath to prepare an organosilicon compound liquid 1.

[0235] Preparation of Organosilicon Compound Liquids 2 to 4 Organosilicon compound liquids 2 to 4 were prepared in the same manner as the organosilicon compound liquid 1, except that the type of the organosilicon compound was changed as shown in Table 1 below.

TABLE-US-00002 TABLE 1 Organosilicon compound Organosilicon compound liquid 1 methyltrimethoxysilane Organosilicon compound liquid 2 phenyltriethoxysilane Organosilicon compound liquid 3 dimethyldimethoxysilane Organosilicon compound liquid 4 tetraethoxysilane

[0236] Preparation of Release Agent Particles 1 [0237] Release agent (HNP-9 (paraffin wax), melting point 75° C., Japanese wax) 20 parts [0238] Anionic surfactant (manufactured by DKS Co., Ltd.: NEOGEN RK) 1 part [0239] Ion-exchanged water 45 parts

[0240] The above materials were put into a mixing container equipped with a stirrer and then heated to 90° C. Next, the dispersion treatment was performed for 60 min by stirring at a rotor rotation speed of 19,000 rpm and a screen rotation speed of 18,000 rpm at a shear stirring portion with a rotor outer diameter of 3 cm and a clearance of 0.3 mm, while circulating to Clearmix W Motion CLM-2.2/3.7W (manufactured by M Technique Co., Ltd.).

[0241] After that, the dispersion liquid of release agent particles 1 was obtained by cooling to 40° C. under the conditions of a rotor rotation speed of 1000 rpm, a screen rotation speed of 0 rpm, and a cooling rate of 10° C./min.

[0242] The number-average particle diameter (D1) of the obtained release agent particles 1 was 90 nm.

[0243] Preparation of Release Agent Particles 2 to 7

[0244] Dispersion liquids of release agent particles 2 to 7 were prepared in the same manner as in the preparation of the release agent particles 1, except that the type of dispersoid used, the number of parts of the anionic surfactant, and the stirring conditions were changed as shown in Table 2 below.

[0245] Preparation of Resin Particles 8

[0246] A total of 150 parts of a 1.5% aqueous solution of NEOGEN RK (manufactured by DKS Co., Ltd.) was added to and dispersed in the oil phase obtained by mixing 78.0 parts of styrene and 22.0 parts of butyl acrylate.

[0247] An aqueous solution of 0.3 parts of potassium persulfate in 10.0 parts of ion-exchanged water was added while stirring slowly for another 10 min. After purging with nitrogen, emulsion polymerization was carried out at 70° C. for 6 h. After completion of the polymerization, the reaction solution was cooled to room temperature, and ion-exchanged water was added to obtain an aqueous dispersion of resin particles 8 having a solid fraction concentration of 12.5% by mass. The number average particle diameter (D1) of the resin particles 8 was 250 nm.

[0248] The resin particles 8 do not have releasability and are not release agent particles.

TABLE-US-00003 TABLE 2 Rotor Screen rotation rotation number-average Surfactant speed speed particle diameter Dispersoid (parts) (rpm) (rpm) (nm) Release agent particles 1 HNP-9 1 19000 18000 90 Release agent particles 2 HNP-9 1 17500 17500 130 Release agent particles 3 carnauba wax 1 17000 17000 180 Release agent particles 4 candelilla wax 1 15000 15000 320 Release agent particles 5 behenyl behenate 1 19000 18000 80 Release agent particles 6 EXCEREX 48070B 1 18000 18000 105 Release agent particles 7 EXCEREX 15341PA 3 19000 18000 45

[0249] EXCEREX 48070B and EXCEREX 15341PA are polyethylene waxes (manufactured by Mitsui Chemicals, Inc.).

[0250] Preparation of Release Agent-Encapsulated Particles 1 [0251] Release agent particles 1: 7.0 parts [0252] Organosilicon compound liquid 1: 4.0 parts [0253] Ion-exchanged water: 500 parts

[0254] The above materials were put into a mixing container equipped with a stirrer, the pH was adjusted to 9.6 with a 7.3% sodium hydrogen carbonate aqueous solution, and stirring was performed at room temperature for 5 h to obtain a dispersion liquid of the release agent-encapsulated particles 1.

[0255] Preparation of Release Agent-Encapsulated Particles 2 to 11

[0256] Dispersion liquids of release agent-encapsulated particles 2 to 11 were obtained in the same manner as in the preparation of the release agent-encapsulated particles 1, except that the amount of the organosilicon compound liquid 1 was changed as shown in Table 3 below.

[0257] Preparation of Release Agent-Encapsulated Particles 12 to 17 and Resin-Encapsulated Particles 18

[0258] Dispersion liquids of release agent-encapsulated particles 12 to 17 and resin-encapsulated particles 18 were obtained in the same manner as in the preparation of the release agent-encapsulated particles 1, except that the type of the release agent particles was changed as shown in Table 3 below.

TABLE-US-00004 TABLE 3 Release agent particles Organosilicon compound liquid Type Parts Type Parts Release agent-encapsulated particles 1 release agent particles 1 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 2 release agent particles 1 7.0 organosilicon compound liquid 1 0.1 Release agent-encapsulated particles 3 release agent particles 1 7.0 organosilicon compound liquid 1 0.2 Release agent-encapsulated particles 4 release agent particles 1 7.0 organosilicon compound liquid 1 0.3 Release agent-encapsulated particles 5 release agent particles 1 7.0 organosilicon compound liquid 1 0.4 Release agent-encapsulated particles 6 release agent particles 1 7.0 organosilicon compound liquid 1 0.5 Release agent-encapsulated particles 7 release agent particles 1 7.0 organosilicon compound liquid 1 0.6 Release agent-encapsulated particles 8 release agent particles 1 7.0 organosilicon compound liquid 1 0.8 Release agent-encapsulated particles 9 release agent particles 1 7.0 organosilicon compound liquid 1 1.6 Release agent-encapsulated particles 10 release agent particles 1 7.0 organosilicon compound liquid 1 6.0 Release agent-encapsulated particles 11 release agent particles 1 7.0 organosilicon compound liquid 1 8.0 Release agent-encapsulated particles 12 release agent particles 2 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 13 release agent particles 3 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 14 release agent particles 4 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 15 release agent particles 5 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 16 release agent particles 6 7.0 organosilicon compound liquid 1 4.0 Release agent-encapsulated particles 17 release agent particles 7 7.0 organosilicon compound liquid 1 4.0 Resin-encapsulated particles 18 resin particles 8 7.0 organosilicon compound liquid 1 4.0

[0259] Preparation of Toner Core Particles 1

[0260] A total of 14.0 parts of sodium phosphate (dodecahydrate, manufactured by Rasa Industries, Ltd.,) was added to 390.0 parts of ion-exchanged water in a reaction container, and the mixture was kept at 65° C. for 1.0 h while purging with nitrogen.

[0261] A calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was put into the container all at once, while stirring at 12,000 rpm by using a T. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), to prepare an aqueous medium containing a dispersion stabilizer. Furthermore, 10% hydrochloric acid was added to the aqueous medium in the reaction container to adjust the pH to 6.0, thereby preparing an aqueous medium 1.

[0262] Preparation of Polymerizable Monomer Composition

TABLE-US-00005 Styrene 60.0 parts C. I. Pigment Blue 15:3  6.5 parts

[0263] The above materials were put into an attritor (manufactured by Nippon Coke Kogyo Co., Ltd.), and further dispersed using zirconia particles with a diameter of 1.7 mm at 220 rpm for 5.0 h to prepare a pigment dispersion liquid.

[0264] Then, the following materials were added to the pigment dispersion liquid.

TABLE-US-00006 Styrene 10.0 parts n-Butyl acrylate 30.0 parts Polyester resin  5.0 parts
(Condensation product of terephthalic acid and 2 mol propylene oxide adduct of bisphenol A, weight-average molecular weight 10,000, acid value: 8.2 mg KOH/g)

[0265] The mixture was kept at 65° C. and uniformly dissolved and dispersed at 500 rpm using T. K. Homomixer to prepare a polymerizable monomer composition.

[0266] Granulation Step

[0267] While maintaining the temperature of the aqueous medium 1 at 70° C. and the rotation speed of the stirring device at 12,000 rpm, the polymerizable monomer composition was put into the aqueous medium 1, and 9.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. The mixture was granulated for 10 min while maintaining 12,000 rpm with a stirring device.

[0268] Polymerization Step

[0269] The high-speed stirring device was changed to a stirrer with a propeller stirring blade, polymerization was performed for 5.0 h while maintaining the temperature at 70° C. and stirring at 150 rpm, the temperature was then raised to 85° C. and heating was carried out for 2.0 h to conduct a polymerization reaction and obtain a dispersion liquid of toner core particles 1. The weight-average particle diameter (D4) of the toner core particles 1 was 6.7 m.

[0270] Preparation of Toner Core Particles 2

[0271] First, a pigment dispersion liquid was prepared in the same manner as in the method for preparing the toner core particles 1. Next, the following materials were added to the pigment dispersion, and then granulation and polymerization were carried out in the same manner as in the method for preparing the toner core particles 1 to obtain a dispersion liquid of toner core particles 2. The weight-average particle diameter (D4) of the toner core particles 2 was 6.8 m.

TABLE-US-00007 Styrene 10.0 parts n-Butyl acrylate 30.0 parts Polyester resin  5.0 parts
(Condensation product of terephthalic acid and 2 mol propylene oxide adduct of bisphenol A, weight-average molecular weight 10,000, acid value: 8.2 mg KOH/g) [0272] Release agent (HNP-9, melting point 75° C., manufactured by Nippon Seiro Co., Ltd.) 5.0 parts

[0273] Manufacturing Method of Toner 1

[0274] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0275] Toner core particles 1: 100 parts [0276] Release agent-encapsulated particles 1: 58 parts

[0277] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0278] Next, the pH of the mixed solution was adjusted to 5.6, then 2.8 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 9.6 by using a 7.3% sodium hydrogen carbonate aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0279] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, toner particles 1 were obtained by filtering, washing with water, and drying. These particles were designated as toner 1.

[0280] Manufacturing Method of Toners 2 to 19 and 22

[0281] Toners 2 to 19 and 22 were obtained in the same manner and in the manufacturing method of toner 1, except that the types and amounts of the organosilicon compound liquid and release agent-encapsulated particles were changed as shown in Table 4.

[0282] Manufacturing Method of Toner 20

[0283] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0284] Toner core particles 1: 100 parts [0285] Release agent-encapsulated particles 1: 58 parts

[0286] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0287] Next, the pH of the mixed solution was adjusted to 5.6, then 1.4 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 11.6 by using 1 mol/L sodium hydroxide aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0288] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, toner particles 20 were obtained by filtering, washing with water, and drying. These particles were designated as toner 20.

[0289] Manufacturing Method of Toner 21

[0290] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0291] Toner core particles 1: 100 parts [0292] Release agent-encapsulated particles 1: 58 parts

[0293] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0294] Next, the pH of the mixed solution was adjusted to 5.6, then 2.1 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 11.6 by using 1 mol/L sodium hydroxide aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0295] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, toner particles 21 were obtained by filtering, washing with water, and drying. These particles were designated as toner 21.

[0296] Manufacturing Method of Toner 23

[0297] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0298] Toner core particles 1: 100 parts [0299] Release agent-encapsulated particles 1: 58 parts

[0300] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0301] Next, the pH of the mixed solution was adjusted to 5.6, 2.6 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 9.6 by using a 7.3% sodium hydrogen carbonate aqueous solution and stirring was performed using a propeller stirrer blade. After 10 min, 1.5 parts of organosilicon compound liquid 1 was added and stirring was performed using the propeller stirrer blade.

[0302] After holding for 4 h, air-cooling was performed until the temperature reached 25° C. A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, toner particles 23 were obtained by filtering, washing with water, and drying. These particles were designated as toner 23.

[0303] Manufacturing Method of Toner 24

[0304] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0305] Toner core particles 1: 100 parts [0306] Release agent-encapsulated particles 1: 58 parts

[0307] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0308] Next, the pH of the mixed solution was adjusted to 5.6, then 3.0 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 2.5 by using 10% hydrochloric acid aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0309] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, toner particles 24 were obtained by filtering, washing with water, and drying. These particles were designated as toner 24.

TABLE-US-00008 TABLE 4 Release agent-encapsulated Organosilicon compound Toner core particles particles liquid No. Parts No. Parts No. Parts Toner 1 1 100 1 58 1 2.8 Toner 2 1 100 7 58 1 2.8 Toner 3 1 100 6 58 1 2.8 Toner 4 1 100 5 58 1 2.8 Toner 5 1 100 1 58 2 2.8 Toner 6 1 100 1 58 3 2.8 Toner 7 1 100 1 58 4 2.8 Toner 8 1 100 13 58 1 2.8 Toner 9 1 100 14 58 1 2.8 Toner 10 1 100 15 58 1 2.8 Toner 11 1 100 16 58 1 2.8 Toner 12 1 100 8 58 1 0.6 Toner 13 1 100 9 58 1 1.1 Toner 14 1 100 10 58 1 4.0 Toner 15 1 100 11 58 1 4.6 Toner 16 1 100 1 11 1 2.8 Toner 17 1 100 1 116 1 2.8 Toner 18 1 100 1 580 1 2.8 Toner 19 1 100 12 800 1 2.8 Toner 20 1 100 1 58 1 1.4 Toner 21 1 100 1 58 1 2.1 Toner 22 1 100 1 58 1 2.5 Toner 23 1 100 1 58 1 2.6 parts/1.5 parts Toner 24 1 100 17 58 1 3.0

[0310] Manufacturing Method of Comparative Toner 1

[0311] A total of 100 parts of toner core particles 2 were weighed into a reaction container and mixed using a propeller stirring blade.

[0312] Next, the pH of the mixed solution was adjusted to 5.6, then 2.8 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 9.6 by using a 7.3% sodium hydrogen carbonate aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0313] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, comparative toner 1 was obtained by filtering, washing with water, and drying.

[0314] Manufacturing Method of Comparative Toner 2

[0315] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0316] Resin-encapsulated particles 18: 58 parts [0317] Toner core particles 2: 100 parts

[0318] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0319] Next, the pH of the mixed solution was adjusted to 5.6, then 2.8 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 9.6 by using a 7.3% sodium hydrogen carbonate aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0320] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, comparative toner 2 was obtained by filtering, washing with water, and drying.

[0321] Manufacturing Method of Comparative Toner 3

[0322] A comparative toner 3 was obtained in the same manner as in the manufacturing method of the toner 1, except that the release agent-encapsulated particles 4 were used.

[0323] Manufacturing Method of Comparative Toner 4

[0324] A comparative toner 4 was obtained in the same manner as in the manufacturing method of the toner 1, except that the release agent-encapsulated particles 3 were used.

[0325] Manufacturing Method of Comparative Toner 5

[0326] A comparative toner 5 was obtained in the same manner as in the manufacturing method of the toner 1, except that the release agent-encapsulated particles 2 were used.

[0327] Manufacturing Method of Comparative Toner 6

[0328] The following samples were weighed into a reaction container and mixed using a propeller stirring blade. [0329] Release agent-encapsulated particles 1: 0.7 parts [0330] Toner core particles 1: 100 parts

[0331] Next, the temperature of the mixed liquid was raised to 55° C. and then kept for 1 h while mixing using the propeller stirring blade.

[0332] Next, the pH of the mixed solution was adjusted to 5.6, then 2.8 parts of the organosilicon compound solution 1 was added and stirred, the pH was adjusted to 9.6 by using a 7.3% sodium hydrogen carbonate aqueous solution, stirring using the propeller stirring blade was performed for 4 h, and then air-cooling was performed until the temperature reached 25° C.

[0333] A 10% hydrochloric acid aqueous solution was added to the obtained mixed solution to adjust the pH to 1.5, and after stirring for 2 h, comparative toner 6 was obtained by filtering, washing with water, and drying.

[0334] Physical Properties of Toners 1 to 24 and Comparative Toners 1 to 6

[0335] Tables 5-1 and 5-2 below shows the physical property values of the toners produced in Examples 1 to 24 and Comparative Examples 1 to 6.

TABLE-US-00009 TABLE 5-1 Domain Non-contact encapsulation rate The molecular weight Toner of release agent (%) of formula (1) Example 1 Toner 1 yes 100 503 Example 2 Toner 2 yes 96 503 Example 3 Toner 3 yes 90 503 Example 4 Toner 4 yes 85 503 Example 5 Toner 5 yes 100 503 Example 6 Toner 6 yes 100 503 Example 7 Toner 7 yes 100 503 Example 8 Toner 8 yes 100 No structure of formula (1) Example 9 Toner 9 yes 100 No structure of formula (1) Example 10 Toner 10 yes 100 No structure of formula (1) Example 11 Toner 11 yes 100 545 Example 12 Toner 12 yes 100 503 Example 13 Toner 13 yes 100 503 Example 14 Toner 14 yes 100 503 Example 15 Toner 15 yes 100 503 Example 16 Toner 16 yes 100 503 Example 17 Toner 17 yes 100 503 Example 18 Toner 18 yes 100 503 Example 19 Toner 19 yes 100 503 Example 20 Toner 20 yes 100 503 Example 21 Toner 21 yes 100 503 Example 22 Toner 22 yes 100 503 Example 23 Toner 23 yes 100 503 Example 24 Toner 24 yes 100 485 Comparative Comparative no Example 1 Toner 1 Comparative Comparative no 100 No structure of formula (1) Example 2 Toner 2 Comparative Comparative yes 80 503 Example 3 Toner 3 Comparative Comparative yes 70 503 Example 4 Toner 4 Comparative Comparative yes 50 503 Example 5 Toner 5 Comparative Comparative no 0 503 Example 6 Toner 6

TABLE-US-00010 TABLE 5-2 Average value of the minimum distance D Area % Coverage (nm) S2/S1 × 100 ratio Example 1 25 0.40%  58% Example 2 23 0.40%  61% Example 3 20 0.40%  57% Example 4 22 0.40%  59% Example 5 20 0.40%  65% Example 6 22 0.40%  63% Example 7 28 0.40%  65% Example 8 24 0.40%  61% Example 9 25 0.40%  57% Example 10 25 0.40%  58% Example 11 22 0.40%  62% Example 12 5 0.40%  52% Example 13 16 0.40%  55% Example 14 42 0.40%  61% Example 15 50 0.40%  65% Example 16 28 0.05%  58% Example 17 25 0.70%  58% Example 18 21 3.50%  60% Example 19 18 5.00%  62% Example 20 17 0.40%  35% Example 21 20 0.40%  41% Example 22 24 0.40%  50% Example 23 30 0.40%  75% Example 24 15 0.40% 100% Comparative  60% Example 1 Comparative 25 0.40%  61% Example 2 Comparative 22 0.40%  58% Example 3 Comparative 22 0.40%  62% Example 4 Comparative 22 0.40%  58% Example 5 Comparative 22 0.40%  60% Example 6

[0336] In the table, “Domain encapsulation” is indicated as “yes” when the release agent domains are encapsulated in the shell, and “no” when the domains are not encapsulated (in comparative toner 2, resin particles were encapsulated; in comparative toner 6, the release agent domains on the surface of the toner core particles were coated with the organosilicon polymer, but not encapsulated).

[0337] The % of non-contact rate is % by number. The molecular weight of formula (1) indicates the molecular weight of the fragment ion peak corresponding to the structure represented by formula (1) in TOF-SIMS. The coverage ratio is the area ratio (coverage ratio: % by area) occupied by the organosilicon polymer on the toner particle surface.

[0338] Toner Evaluation

[0339] The following evaluations were performed using toners 1 to 24 and comparative toners 1 to 6.

[0340] Evaluation of Fixing Performance

[0341] Low-temperature fixability is evaluated by evaluating the lowest fixing temperature at which visible image defects do not occur in the fixed image.

[0342] Examples of the main types of visible image defects that occur during low-temperature fixing include cold offset, which occurs when the toner does not melt, and blisters, which occur when the toner is not sufficiently melted and the adhesion between the fixing roller and the toner is high.

[0343] A blister is an image defect in which a part of the fixed image is peeled off by a fixing roller in the fixing step and is visually recognized as minute blank dots in the fixed image.

[0344] As for the temperature at which these image defects occur, cold offset occurs at a lower temperature, and blisters occur in a range of increased fixing temperature. The evaluation was performed in the following manner.

[0345] A color laser printer (HP Color LaserJet 3525dn, manufactured by HP) with the fixing unit removed was prepared, toner was removed from the black cartridge, cyan cartridge, and magenta cartridge, and 50 g of toner to be evaluated was filled instead in each cartridge.

[0346] Next, an unfixed toner image of 2.0 cm long and 15.0 cm wide (toner laid-on level: 1.2 mg/cm.sup.2) was formed using the filled toner on image-receiving paper (A4 size OceRedLabel paper (basic weight 80 g/m.sup.2) manufactured by Canon Inc.) in a portion that is 1.0 cm from the upper end in the paper-passing direction.

[0347] Next, the removed fixing unit was modified so that the fixing temperature and process speed could be adjusted, and the modified fixing unit was used to conduct a fixing test for unfixed images.

[0348] First, under a normal temperature and normal humidity environment (23° C., 60% RH), the process speed was set to 230 mm/s, the initial temperature was set to 155° C., and the set temperature was gradually increased by 5° C. At each temperature, the abovementioned unfixed image was fixed. Low-temperature fixability of the resulting fixed image was evaluated based on the following criteria, with the fixing temperature at which cold offset did not occur and the number of blister-derived blank dots was 2 or less being defined as the minimum fixing temperature. Table 6 shows the results. [0349] A: Minimum fixing temperature is 160° C. or less. [0350] B: Minimum fixing temperature is 165° C. or 170° C. [0351] C: Minimum fixing temperature is 175° C. or 180° C. [0352] D: Minimum fixing temperature is 185° C. or 190° C.

[0353] Evaluation of Releasability

[0354] In the above fixing test, the releasability was evaluated according to the following evaluation criteria.

[0355] High-temperature offset (H. O.) is a phenomenon in which a portion of the toner is fused to the fixing roller during high-temperature fixing. This phenomenon is likely to occur at a lower fixing temperature with a toner with lower releasability. The evaluation criteria are as follows. Table 6 shows the results. [0356] A: The maximum temperature at which high-temperature offset does not occur is the minimum fixing temperature plus 50° C. or more. [0357] B: The maximum temperature at which high-temperature offset does not occur is the minimum fixing temperature plus 40° C. or more and less than 50° C. [0358] C: The maximum temperature at which high-temperature offset does not occur is the minimum fixing temperature plus 30° C. or more and less than 40° C. [0359] D: The maximum temperature at which high temperature offset does not occur is the minimum fixing temperature plus less than 30° C.

[0360] Evaluation of Contamination of the Member

[0361] Toners 1 to 24 and comparative toners 1 to 6 were evaluated for contamination of the member by the following method.

[0362] First, a color laser printer (LBP-712Ci, manufactured by Canon Inc.) that was modified so that the process speed was 300 mm/sec was used. Next, the toner in the cyan cartridge was taken out, and 100 g each of toners 1 to 24 and comparative toners 1 to 6 were filled in this cartridge. After that, the following evaluations were performed.

[0363] The cartridge was mounted on the cyan station of the printer, and one image of a chart with a print percentage of 0.2% was output using A4 size plain paper office 70 (manufactured by Canon Marketing Japan, 70 g/m.sup.2) under normal temperature and normal humidity (temperature 23° C., humidity 60% RH). After that, the operation of outputting two sheets and stopping for 10 sec was repeated, the development blade and the development roller were visually observed every time 1,000 images were output while supplying the toner, and the presence or absence of toner fusion was confirmed. Using the output number of sheets at which resin fusion occurred as an index, contamination of the member was evaluated according to the following criteria. Table 6 shows the results. [0364] A: No fusion occurred on both the developing blade and the developing roller up to 16,000 sheets. [0365] B: Fusion occurred on the developing blade/developing roller after more than 10,000 sheets and up to 16,000 sheets. [0366] C: Fusion occurred on the developing blade/developing roller after more than 5000 sheets and up to 10,000 sheets. [0367] D: Fusion occurred on the developing blade/developing roller before 5000 sheets.

[0368] Evaluation of Toners 1-24 and Comparative Toners 1-6

[0369] Table 6 shows the evaluation results of the toners produced in Examples 1-24 and Comparative Examples 1-6.

TABLE-US-00011 TABLE 6 Contamination of the Member Releasability Fixing Performance Example 1 Toner 1 A 16000 sheets A 55° C. A 155° C. Example 2 Toner 2 A 16000 sheets A 50° C. A 160° C. Example 3 Toner 3 A 16000 sheets B 45° C. A 160° C. Example 4 Toner 4 A 16000 sheets B 40° C. A 160° C. Example 5 Toner 5 B 15000 sheets A 55° C. A 155° C. Example 6 Toner 6 B 13000 sheets A 55° C. A 155° C. Example 7 Toner 7 A 16000 sheets A 55° C. B 165° C. Example 8 Toner 8 A 16000 sheets B 40° C. A 160° C. Example 9 Toner 9 A 16000 sheets B 40° C. A 160° C. Example 10 Toner 10 A 16000 sheets B 45° C. A 160° C. Example 11 Toner 11 A 16000 sheets A 55° C. A 155° C. Example 12 Toner 12 B 15000 sheets A 55° C. A 155° C. Example 13 Toner 13 A 16000 sheets A 55° C. A 155° C. Example 14 Toner 14 A 16000 sheets A 55° C. B 165° C. Example 15 Toner 15 A 16000 sheets A 55° C. B 170° C. Example 16 Toner 16 A 16000 sheets B 45° C. A 160° C. Example 17 Toner 17 A 16000 sheets A 50° C. A 160° C. Example 18 Toner 18 B 15000 sheets A 55° C. A 155° C. Example 19 Toner 19 B 14000 sheets A 55° C. A 155° C. Example 20 Toner 20 B 14000 sheets A 55° C. A 155° C. Example 21 Toner 21 B 15000 sheets A 55° C. A 155° C. Example 22 Toner 22 A 16000 sheets A 55° C. A 155° C. Example 23 Toner 23 A 16000 sheets A 50° C. A 160° C. Example 24 Toner 24 A 16000 sheets B 45° C. B 165° C. Comparative Comparative A 16000 sheets C 35° C. C 175° C. Example 1 Toner 1 Comparative Comparative B 15000 sheets C 35° C. C 175° C. Example 2 Toner 2 Comparative Comparative A 16000 sheets C 35° C. B 170° C. Example 3 Toner 3 Comparative Comparative A 16000 sheets C 30° C. C 175° C. Example 4 Toner 4 Comparative Comparative A 16000 sheets C 30° C. C 180° C. Example 5 Toner 5 Comparative Comparative B 15000 sheets D 25° C. D 185° C. Example 6 Toner 6

[0370] 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. This application claims the benefit of Japanese Patent Application No. 2022-088586, filed May 31, 2022 which is hereby incorporated by reference herein in its entirety.