Toner, toner cartridge, image forming apparatus

Abstract

A toner, a toner cartridge, and an image forming apparatus are provided, all exhibiting excellent heating roller life, resistance to low-temperature offset, and resistance to high-temperature offset. The toner cartridge contains the toner. The toner of one embodiment contains a colorant, an amorphous polyester resin A, and an amorphous polyester resin B. The Mw of the amorphous polyester resin A... A 0.9×10 4 ~1.5×10 4 Mw of non-crystalline polyester resin B B 4.0×10 4 ~11.0×10 4 The Mn content of non-crystalline polyester resin A A 3.0×10 3 ~4.0×10 3 Mw A / Mn A The Mn content is 3.1–4.0. (This refers to the Mn content of amorphous polyester resin B.) B 2.2×10 3 ~3.5×10 3 Mw B / Mn B The content of amorphous polyester resin A is 50-60% by mass. The content of amorphous polyester resin B is 20-30% by mass.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to toner, a toner cartridge, and an image forming apparatus. BACKGROUND

[0002] Toner containing a polyester resin is known. Toner containing a polyester resin can be applied to an image forming apparatus equipped with a fixing device. The fixing device, for example, heats the polyester resin of the toner by a pair of heating rollers to fix a toner image on a medium such as paper.

[0003] Toner containing a crystalline polyester resin is excellent in low-temperature fixing property because it melts rapidly due to the heat of the fixing device (for example, Patent Literature 1). However, it is known that in an image forming apparatus equipped with a fixing device, a phenomenon in which a toner image directly contacts a heating roller or a belt, that is, offset, occurs (Patent Literature 2). Since toner containing a crystalline polyester resin is excellent in low-temperature fixing property, offset is likely to occur at a high temperature. Therefore, toner containing a crystalline polyester resin has room for improvement in high-temperature offset resistance.

[0004] In addition, the heating roller of the fixing device is maintained at a relatively high fixing temperature for a long time when an image is formed. Therefore, a contact member such as a peeling claw or a thermistor, which contacts the heating roller, is also maintained at a temperature close to the fixing temperature.

[0005] Since the crystalline polyester resin is excellent in low-temperature fixing property, it is likely to adhere to the contact member. The crystalline polyester resin adhering to the contact member changes in melting property due to a heat history accompanying switching of a power source of the image forming apparatus between ON and OFF.

[0006] The crystalline polyester resin subjected to the heat history increases in viscosity at the fixing temperature and starts to solidify before being subjected to the heat history. Therefore, the crystalline polyester resin subjected to the heat history is likely to damage the surface of the heating roller even at the fixing temperature. As a result, when an image is formed, image defects such as a striped image occur. Therefore, toner containing a crystalline polyester resin has room for improvement in that it is not likely to damage the surface of the heating roller, that is, in the service life of the heating roller.

[0007] As toner suitable for an image forming apparatus, toner containing a non-crystalline polyester resin is known (for example, Patent Literature 3).

[0008] In an image forming apparatus equipped with a fixing device, a medium having a width narrower than that of the heating roller is sometimes used, although this also depends on the operating conditions of the image forming apparatus. The surface temperature of the heating roller is relatively lowered in the portion in contact with the medium having a narrow width at the time of heat fixing. On the other hand, both ends of the heating roller are maintained at a temperature close to the fixing temperature. As a result, a temperature distribution can occur in the width direction on the surface of the heating roller.

[0009] Therefore, there is also a demand for toner that is less likely to cause offset even under relatively low temperature conditions, i.e., low temperature offset resistance. However, according to the present inventors' studies, the low temperature offset resistance of the toner particles containing an amorphous resin described in Patent Document 3 is insufficient. SUMMARY

[0010] The present application addresses the problem of providing toner having excellent heating roller service life, low temperature offset resistance, and high temperature offset resistance, a toner cartridge containing the toner, and an image forming apparatus.

[0011] The toner of the embodiment has a colorant, an amorphous polyester resin A, and an amorphous polyester resin B. The mass average molecular weight: Mw of the amorphous polyester resin A is 0.9 x 10 A 4 ~ 1.5 x 10 4 The mass average molecular weight: Mw of the amorphous polyester resin B is 4.0 x 10 B 4 ~ 11.0 x 10 4 .

[0012] The number average molecular weight: Mn of the amorphous polyester resin A is 3.0 x 10 A 3 ~ 4.0 x 10 3 The molecular weight distribution: Mw / Mn of the amorphous polyester resin A is 3.1 ~ 4.0. A A

[0013] The number average molecular weight: Mn of the amorphous polyester resin B is 2.2 x 10 B 3 ~ 3.5 x 10 3 The molecular weight distribution: Mw / Mn of the amorphous polyester resin B is 11.4 ~ 50. B B

[0014] The content of the amorphous polyester resin A is 50 ~ 60 mass% relative to the total amount of the toner, 100 mass%. The content of the amorphous polyester resin B is 20 ~ 30 mass% relative to the total amount of the toner, 100 mass%. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a diagram showing one example of the outline structure of the image forming apparatus of the embodiment.

[0016] Figure 2 is a diagram showing one example of the fixing device configuration of the image forming apparatus of the embodiment.

[0017] SYMBOL EXPLANATION​​​​​​​​

[0018] 1a, photosensitive drum; 2a, charging device; 3a, exposure device; 4a, first developer; 5, heat source; 7, intermediate transfer belt; 8a, primary transfer roller; 9, secondary transfer roller; 10, support roller; 11, heating roller; 12, pressure roller; 14a, primary transfer power source; 15, secondary transfer power source; 16a, cleaning device; 17A, first image forming unit; 18, thermistor; 19, temperature control device; 20, image forming device; 21, fixing device. DETAILED DESCRIPTION

[0019] The toner of the embodiment is described below.

[0020] The toner of the embodiment contains a colorant, a non-crystalline polyester resin A, and a non-crystalline polyester resin B. The toner of the embodiment preferably contains, in addition to the colorant, the non-crystalline polyester resin A, and the non-crystalline polyester resin B, a crystalline polyester resin C.

[0021] The toner of the embodiment can contain other resins than the non-crystalline polyester resin A, the non-crystalline polyester resin B, and the crystalline polyester resin C, as long as the effects of the present application are not impaired. The toner of the embodiment can contain an additive as an arbitrary component.

[0022] The colorant is described.

[0023] The colorant is not particularly limited, and examples thereof include carbon black, cyan, yellow, magenta pigments, dyes, and the like.

[0024] As the carbon black, aniline black, lamp black, acetylene black, furnace black, thermal carbon black, tank black, and Ketjen black can be given.

[0025] As the pigments and dyes, for example, fast yellow G, benzidine yellow, chrome yellow, quinoline yellow, Indian fast orange, eriegenet red, fast rubine FB, permanent bordeaux FRR, pigment orange R, lithol red 2G, lake light red C, rhodamine FB, rhodamine B rose madder, du Pont oil red, phthalocyanine blue, pigment blue, aniline blue, calcium blue, ultramarine blue, brilliant green B, phthalocyanine green, oxalic malachite green, methylene blue, rose Bengal, quinacridone, and the like can be given.

[0026] In addition, as the colorant, for example, C.I. Pigment Black 1, 6, 7, C.I. Pigment Yellow 1, 12, 14, 17, 34, 74, 83, 97, 155, 180, 185, C.I. Pigment Orange 48, 49, C.I. Pigment Red 5, 12, 31, 48, 48:1, 48:2, 48:3, 1, 81:4, 122, 146, 150, 177, 185, 202, 206, 207, 209, 238, 269, C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 75, 76, 79, C.I. Pigment Green 1, 7, 8, 36, 42, C.I. Pigment Violet 1, 19, 42, C.I. Acid Red 52, and the like represented by color index numbers can be given. However, the colorant is not limited to these examples.

[0027] The colorant can be used alone or in combination of two or more.

[0028] The non-crystalline polyester resin A will be described.

[0029] The weight average molecular weight (Mw) of the non-crystalline polyester resin A A is 0.9 x 10 4 ~ 1.5 x 10 4 , preferably 1.1 x 10 4 ~ 1.4 x 10 4 . Since the Mw A is equal to or greater than the lower limit value, the toner has excellent high-temperature offset resistance. In addition, since the Mw A is equal to or less than the upper limit value, the toner has excellent low-temperature offset resistance and heating roller life.

[0030] The weight average molecular weight (Mw) of the non-crystalline polyester resin A A can be measured by GPC (gel permeation chromatography) ("Alliance HPLC" manufactured by Waters Corporation) under the following conditions.

[0031] • Column: TSK PWXL + G4000PWXL + G2500PWXL (all manufactured by Tosoh Corporation)

[0032] • Column temperature: 40°C

[0033] • Detector: RI or UV (210 nm)

[0034] • Eluent: 0.2 mol / L phosphate buffer / acetonitrile = 9 / 1

[0035] • Flow rate: 1.0 mL / min

[0036] • Injection amount: 0.1 mL

[0037] The molecular weight of the sample was calculated based on a standard curve prepared in advance using polyethylene glycol as a standard substance.

[0038] The number average molecular weight of the amorphous polyester resin A: Mn A is 3.0 x 10 3 ~ 4.0 x 10 3 , preferably 3.2 x 10 3 ~ 3.8 x 10 3 . Since the Mn A is more than the lower limit value, the toner has excellent high-temperature offset resistance. In addition, since the Mn A is less than the upper limit value, the toner has excellent low-temperature offset resistance and heating roller life.

[0039] The number average molecular weight of the amorphous polyester resin A: Mn A can be measured by GPC (gel permeation chromatography) ("Alliance HPLC" manufactured by Waters Corporation) under the following conditions.

[0040] • Column: TSK PWXL + G4000PWXL + G2500PWXL (all manufactured by Tosoh Corporation)

[0041] • Column temperature: 40°C

[0042] • Detector: RI or UV (210 nm)

[0043] • Eluent: 0.2 mol / L phosphate buffer / acetonitrile = 9 / 1

[0044] • Flow rate: 1.0 mL / min

[0045] • Injection amount: 0.1 mL

[0046] The molecular weight of the sample was calculated based on a standard curve prepared in advance using polyethylene glycol as a standard substance.

[0047] The molecular weight distribution of the amorphous polyester resin A: Mw A / Mn A is 3.1 ~ 4.0, preferably 3.2 ~ 3.7.

[0048] Since the Mw A / Mn A is more than the lower limit value, the toner has excellent low-temperature offset resistance and high-temperature offset resistance. In addition, since the Mw A / Mn AThe upper limit value is 50°C or less, and therefore the toner has excellent low-temperature offset resistance and high-temperature offset resistance.

[0049] The non-crystalline polyester resin A has a molecular weight distribution of Mw A / Mn A The value of Mw A , Mn A may be calculated.

[0050] The glass transition temperature of the non-crystalline polyester resin A is preferably 50 to 70°C, and more preferably 55 to 65°C. When the glass transition temperature of the non-crystalline polyester resin A is the lower limit value or more, the toner has excellent storage properties. When the glass transition temperature of the non-crystalline polyester resin A is the upper limit value or less, the toner has excellent fixing properties.

[0051] The glass transition temperature of the non-crystalline polyester resin A can be measured by differential scanning calorimetry.

[0052] As the non-crystalline polyester resin A, a polycondensate of a dihydric or more alcohol and a dihydric or more carboxylic acid is selected from among various non-crystalline polyester resins, and the non-crystalline polyester resin A has a value of Mw A , Mn A , Mw A / Mn A in a predetermined numerical range.

[0053] As the non-crystalline polyester resin A, a polycondensate of a dihydric or more alcohol and a dihydric or more carboxylic acid can be exemplified.

[0054] As the dihydric or more carboxylic acid, a dihydric or more carboxylic acid, an anhydride of a dihydric or more carboxylic acid, an ester of a dihydric or more carboxylic acid, or the like can be exemplified. As the ester of a dihydric or more carboxylic acid, a lower alkyl (1 to 12 carbon atoms) ester of a dihydric or more carboxylic acid can be exemplified.

[0055] As the dihydric alcohol, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,4-butylenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, bisphenol A, hydrogenated bisphenol A, an alkylene oxide adduct of bisphenol A, or the like can be exemplified. Among these, the dihydric alcohol is not limited to these examples.

[0056] As the alkylene oxide adduct of bisphenol A, a compound in which 1 to 10 moles of an alkylene oxide having 2 to 3 carbon atoms are added to bisphenol A can be given. As the alkylene oxide adduct of bisphenol A, polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (3.3)-2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (2.0)-polyoxyethylene (2.0)-2,2-bis(4-hydroxyphenyl)propane, polyoxypropylene (6)-2,2-bis(4-hydroxyphenyl)propane, and the like can be given.

[0057] As the dihydric alcohol, an alkylene oxide adduct of bisphenol A is preferred. The dihydric alcohol can be used alone as any one of them or in combination with two or more of them.

[0058] As the trihydric or higher alcohol, for example, sorbitol, 1,2,3,6-tetrahydroxyhexane, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylglycerol, 2-methyl-1,2,4-butanetriol, trimethylol ethane, trimethylol propane, 1,3,5-trimethylolbenzene, and the like can be given. Among them, the trihydric or higher alcohol is not limited to these examples.

[0059] As the trihydric or higher alcohol, sorbitol, 1,4-sorbitan, pentaerythritol, glycerol, and trimethylol propane are preferred. The trihydric or higher alcohol can be used alone as any one of them or in combination with two or more of them.

[0060] As the dihydric carboxylic acid, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, succinic acid substituted with an alkyl group or an alkenyl group, and the like can be given. Among them, the dihydric carboxylic acid is not limited to these examples.

[0061] As the succinic acid substituted with an alkyl group or an alkenyl group, succinic acid substituted with an alkyl group or an alkenyl group having 2 to 20 carbon atoms can be given. For example, n-dodecenyl succinic acid, n-dodecyl succinic acid, and the like can be given. In addition, an anhydride of the above dihydric carboxylic acid or an ester of the dihydric carboxylic acid can be used.

[0062] As the dihydric carboxylic acid, maleic acid, fumaric acid, terephthalic acid, and succinic acid substituted with an alkenyl group having 2 to 20 carbon atoms are preferred. The dihydric carboxylic acid can be used alone as any one of them or in combination with two or more of them.

[0063] As the carboxylic acid of three or more valences, for example, 1,2,4-benzene tricarboxylic acid, 2,5,7-naphthalene tricarboxylic acid, 1,2,4-naphthalene tricarboxylic acid, 1,2,4-butane tricarboxylic acid, 1,2,5-hexane tricarboxylic acid, 1,3-dicarbonyl-2-methyl-2-methylene carboxylic propane, 1,2,4-cyclohexane tricarboxylic acid, tetra(methylene carboxylic) methane, 1,2,7,8-octane tetracarboxylic acid, pyromellitic acid, Empol trimellitic acid, an acid anhydride thereof, or an ester thereof, and the like can be given. Among them, the carboxylic acid of three or more valences is not limited to these examples.

[0064] As the carboxylic acid of three or more valences, 1,2,4-benzene tricarboxylic acid (trimellitic acid), an acid anhydride thereof, or a lower alkyl (carbon number 1 to 12) ester thereof is preferable.

[0065] The carboxylic acid of three or more valences can be used alone as any one of them or in combination with two or more of them.

[0066] The amorphous polyester resin can be sulfonated. For example, a metal salt or an alkali salt of a basic sulfonated polyester resin, and the like can be given.

[0067] When the dihydric or more alcohol and the dihydric or more carboxylic acid are subjected to polycondensation, a catalyst generally used can be used to promote the reaction. As the catalyst, for example, dibutyl tin oxide, a titanium compound, dialkoxy tin (II), tin (II) oxide, tin (II) fatty acid, tin (II) dioctanoate, tin (II) distearate, and the like can be given.

[0068] The amorphous polyester resin B will be described.

[0069] The weight average molecular weight (Mw) of the amorphous polyester resin B is 4.0 x 104to 11.0 x 104. B 4 4 4 4 B Since the Mw is the lower limit value or more, the toner has excellent high-temperature offset resistance. In addition, since the Mw is the upper limit value or less, the toner has excellent low-temperature offset resistance and heating roller life. B

[0070] The weight average molecular weight (Mw) of the amorphous polyester resin B is 4.0 x 104to 11.0 x 104. B It can be measured by GPC (gel permeation chromatography) (Waters Corporation, "Alliance HPLC") under the following conditions.

[0071] • Column: TSK PWXL + G4000PWXL + G2500PWXL (all manufactured by Tosoh Corporation)

[0072] ​​​​​​• Column temperature: 40°C

[0073] • Detector: RI or UV (210 nm)

[0074] • Eluent: 0.2 mol / L phosphate buffer / acetonitrile = 9 / 1

[0075] • Flow rate: 1.0 mL / min

[0076] • Injection amount: 0.1 mL

[0077] The molecular weight of the sample was calculated based on a standard curve prepared in advance using polyethylene glycol as a standard substance.

[0078] The number average molecular weight of the amorphous polyester resin B: MnB was 2.2 x 10 3 ~ 3.5 x 10 3 , preferably 2.5 x 10 3 ~ 3.1 x 10 3 .

[0079] Since Mn B is more than the lower limit value, the toner has excellent high-temperature offset resistance. In addition, since Mn B is less than the upper limit value, the toner has excellent low-temperature offset resistance, heating roller service life.

[0080] The number average molecular weight of the amorphous polyester resin B: Mn B can be measured by GPC (gel permeation chromatography) (manufactured by Waters Corporation "Alliance HPLC") under the following conditions.

[0081] • Column: TSK PWXL + G4000PWXL + G2500PWXL (all manufactured by Tosoh Corporation)

[0082] • Column temperature: 40°C

[0083] • Detector: RI or UV (210 nm)

[0084] • Eluent: 0.2 mol / L phosphate buffer / acetonitrile = 9 / 1

[0085] • Flow rate: 1.0 mL / min

[0086] • Injection amount: 0.1 mL

[0087] The molecular weight of the sample was calculated based on a standard curve prepared in advance using polyethylene glycol as a standard substance.

[0088] The non-crystalline polyester resin B has a molecular weight distribution (MwB / MnB) of 11.4 to 50, preferably 14.5 to 36.

[0089] Since Mw B / Mn B is the lower limit value or more, the toner has excellent low-temperature offset resistance and high-temperature offset resistance. In addition, since Mw B / Mn B is the upper limit value or less, the toner has excellent low-temperature offset resistance and high-temperature offset resistance.

[0090] The non-crystalline polyester resin B has a molecular weight distribution (Mw B / Mn B can be calculated from the values of Mw B , Mn B .

[0091] The non-crystalline polyester resin B has a glass transition temperature of preferably 45 to 65°C, more preferably 52 to 60°C. When the glass transition temperature of the non-crystalline polyester resin B is the lower limit value or more, the toner has excellent storage properties. When the glass transition temperature of the non-crystalline polyester resin B is the upper limit value or less, the toner has excellent fixing properties.

[0092] The glass transition temperature of the non-crystalline polyester resin B can be measured by a differential scanning calorimetry method.

[0093] As specific examples of the non-crystalline polyester resin B, the same content as that described in the specific examples of the non-crystalline polyester resin A is given. From the non-crystalline polyester resins exemplified as the specific examples of the non-crystalline polyester resin A, a non-crystalline polyester resin having Mw B , Mn B , Mw B / Mn B in a predetermined numerical range is selected.

[0094] The crystalline polyester resin C is described.

[0095] In the case where the toner contains the crystalline polyester resin C, the toner has excellent low-temperature fixing properties. In the embodiments, the crystalline polyester resin refers to a polyester resin having a ratio of softening point to melting temperature (softening point / melting temperature) of 0.8 to 1.2. The non-crystalline polyester resin refers to a polyester resin having a ratio of softening point to melting temperature of less than 0.8 or more than 1.2.

[0096] As the crystalline polyester resin C, for example, a polycondensate of a dihydric or more alcohol and a dihydric or more carboxylic acid can be given.

[0097] As the dihydric or more alcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-butylenediol, polyoxypropylene, polyoxyethylene, glycerol, pentaerythritol, trimethylolpropane, and the like can be given. As the dihydric or more alcohol, 1,4-butanediol and 1,6-hexanediol are preferred.

[0098] As the dihydric or more carboxylic acid, adipic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, phthalic acid, isophthalic acid, terephthalic acid, sebacic acid, azelaic acid, succinic acid substituted with an alkyl group or an alkenyl group, cyclohexanedicarboxylic acid, trimellitic acid, pyromellitic acid, anhydride thereof, or ester thereof, and the like can be given. As the succinic acid substituted with an alkyl group or an alkenyl group, succinic acid substituted with an alkyl group or an alkenyl group having 2 to 20 carbon atoms can be given, for example, n-dodecenyl succinic acid, n-dodecyl succinic acid, and the like can be given. Among these, fumaric acid is preferred. Among these, the crystalline polyester resin C is not limited to these examples. The crystalline polyester resin C can be used alone as any one of them, or two or more of them can be used in combination

[0099] Weight average molecular weight of the crystalline polyester resin C: Mw c Preferably, 7.0 x 10 3 ~ 12.0 x 10 3 More preferably, 8.5 x 10 3 ~ 11.0 x 10 3 When Mw c is more than the lower limit value, the high temperature fixing property of the toner is more excellent. In addition, when Mw c is less than the upper limit value, the stability during storage and the low temperature offset resistance of the toner are excellent.

[0100] Number average molecular weight of the crystalline polyester resin C: Mn c Preferably, 7.0 x 10 3 ~ 12.0 x 10 3 More preferably, 8.5 x 10 3 ~ 11.0 x 10 3 When Mn c is more than the lower limit value, the low temperature fixing property of the toner is more excellent. In addition, when Mn c is less than the upper limit value, the stability during storage and the low temperature offset resistance of the toner are excellent.

[0101] Molecular weight distribution of the crystalline polyester resin C: Mw C / Mn C Preferably, 7.0 x 10 3 ~ 12.0 x 10 3 More preferably, 8.5 x 10 3~ 11.0 x 10 3 When Mw C / Mn C is the lower limit value or more, the toner has more excellent low-temperature offset resistance and high-temperature offset resistance. In addition, when Mw C / Mn C is the upper limit value or less, the toner has excellent low-temperature offset resistance and high-temperature offset resistance.

[0102] The other resin will be described.

[0103] The toner of the embodiment can also contain other resins than the non-crystalline polyester resin A, the non-crystalline polyester resin B, and the crystalline polyester resin C, as long as the effects of the present application are obtained. In this case, the other resins function as the binder resin.

[0104] As the other resin, various resins used as the binder resin of the toner of styrene-based resins, ethylene-based resins, acrylic-based resins, phenolic-based resins, epoxy-based resins, allyl phthalate-based resins, polyamide-based resins, maleic acid-based resins, and the like can be given. Among them, the other resin is not limited to these examples. The other resin can be used alone as any one of them or two or more of them can be used in combination.

[0105] The other resin is obtained by polymerizing, alone or in a plurality of kinds, a vinyl polymerizable monomer, for example, aromatic vinyl monomers such as styrene, methylstyrene, methoxystyrene, phenylstyrene, chlorostyrene, and the like; ester monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and the like; carboxylic acid-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, and the like; amine monomers such as amino acrylate, acrylamide, methacrylamide, vinylpyridine, vinylpyrrolidone, and the like; and derivatives of these and the like.

[0106] The other resin is also obtained by polycondensation of a polymerizable monomer of a polycondensation type composed of an alcohol component and a carboxylic acid component. At the time of polymerization of the polymerizable monomer, various aids used at the time of polymerization of the binder resin, such as a chain transfer agent, a crosslinking agent, a polymerization initiator, a surfactant, a coagulant, a pH adjuster, an antifoaming agent, and the like, can be used.

[0107] The toner of the embodiment can also contain an additive other than the colorant, the non-crystalline polyester resin A, the non-crystalline polyester resin B, and the crystalline polyester resin C.

[0108] As the additive, various additives such as a charge control agent, a release agent, an antioxidant, and the like can be given. Among them, the additive is not limited to these examples. The additive can be used alone as any one of them or two or more of them can be used in combination.

[0109] From the viewpoint of more excellent preservability of the toner, an ester wax is preferred as the release agent. The ester wax can be synthesized, for example, by an esterification reaction of a long-chain alkyl carboxylic acid and a long-chain alkyl alcohol. As the long-chain alkyl carboxylic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and the like can be given. As the long-chain alkyl alcohol, palmitol, stearyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol, cerotyl alcohol, montanyl alcohol, and the like can be given.

[0110] The composition of the toner is described.

[0111] The content of the non-crystalline polyester resin A is 50 to 60% by mass, preferably 52 to 58% by mass, relative to 100% by mass of the total amount of the toner. Since the content of the non-crystalline polyester resin A is the lower limit value or more, the toner has excellent low-temperature fixing property, low-temperature offset resistance, and heating roller life. In addition, since the content of the non-crystalline polyester resin A is the upper limit value or less, the toner has excellent high-temperature offset resistance.

[0112] The content of the non-crystalline polyester resin B is 20 to 30% by mass, preferably 23 to 28% by mass, relative to 100% by mass of the total amount of the toner. Since the content of the non-crystalline polyester resin B is the lower limit value or more, the toner has excellent high-temperature offset resistance. In addition, since the content of the non-crystalline polyester resin B is the upper limit value or less, the toner has excellent low-temperature fixing property, low-temperature offset resistance, and heating roller life.

[0113] The content of the colorant is preferably 3 to 10% by mass, more preferably 4 to 8% by mass. When the content of the colorant is the lower limit value or more, the color reproducibility of the toner is excellent. In addition, when the content of the colorant is the upper limit value or less, the dispersibility of the colorant is excellent, and the low-temperature fixing property of the toner is excellent.

[0114] If the toner contains the crystalline polyester C, the content of the crystalline polyester resin C is preferably 3 to 20% by mass, more preferably 5 to 15% by mass, relative to 100% by mass of the total amount of the toner. When the content of the crystalline polyester resin C is the lower limit value or more, the low-temperature fixing property of the toner is more excellent. In addition, when the content of the crystalline polyester resin C is the upper limit value or less, the low-temperature offset resistance and the high-temperature offset resistance of the toner are more excellent.

[0115] The method for producing the toner is described.

[0116] The toner of the embodiment can be produced, for example, by a kneading pulverization method, a chemical method. The toner produced by the kneading pulverization method, the chemical method, or the like can be used directly as the toner, or can be mixed with external additives as needed to be used as the toner.

[0117] The kneading pulverization method is described.

[0118] As the kneading pulverization method, for example, a production method including a mixing step, a kneading step, and a pulverization step can be given. The kneading pulverization method can further include a classification step.

[0119] • Mixing step: a step of mixing a colorant, the non-crystalline polyester resin A, the non-crystalline polyester resin B, and the like to obtain a mixture.

[0120] • Kneading step: a step of melt-kneading the mixture to obtain a kneaded product.

[0121] • Pulverization step: a step of pulverizing the kneaded product to obtain a pulverized product.

[0122] • Classification step: a step of classifying the pulverized product.

[0123] In the mixing step, raw materials of the toner are mixed to form a mixture. The mixing machine used in the mixing step is not particularly limited. In the mixing step, the crystalline polyester C, other resins, additives can be used as needed.

[0124] In the kneading step, the mixture formed in the mixing step is melt-kneaded to form a kneaded product. The kneader used in the kneading step is not particularly limited.

[0125] In the pulverization step, the kneaded product formed in the kneading step is pulverized to form a pulverized product. As the pulverizer used in the pulverization step, various pulverizers such as a hammer-type pulverizer can be used. In addition, the pulverized product obtained with the pulverizer can be further finely pulverized. Various pulverizers can be used as the pulverizer for further finely pulverizing the pulverized product. The pulverized product obtained in the pulverization step can be directly used as the toner, or can be used as the toner after the classification step as needed.

[0126] In the classification step, the pulverized product obtained in the pulverization step is classified. The classifier used in the classification step is not particularly limited.

[0127] The chemical method will be described.

[0128] In the chemical method, a colorant, a non-crystalline polyester resin A, a non-crystalline polyester resin B, and the like are mixed to form a mixture. Then, the mixture is melt-kneaded to form a kneaded product. Then, the kneaded product is pulverized to form a coarse granular intermediate particle. Then, the intermediate particle is mixed with an aqueous medium to prepare a mixed solution. Then, the mixed solution is subjected to mechanical shearing to form a fine particle dispersion liquid. Finally, fine particles are agglomerated in the fine particle dispersion liquid to form a toner.

[0129] The external additive will be described.

[0130] The external additive is added because the toner has excellent fluidity, chargeability, and stability during storage. As the external additive, particles composed of inorganic oxides can be given. As the inorganic oxides, for example, silicon dioxide, titanium dioxide, aluminum oxide, strontium titanate, tin oxide, and the like can be given. In addition, from the viewpoint of improving stability, the particles composed of inorganic oxides can be surface-treated with a hydrophobic agent. The external additive can be used alone as any one of them or in combination with two or more of them.

[0131] The volume average particle diameter of the particle group of the particles composed of inorganic oxides is not particularly limited. For example, a range of 8 to 200 nm is preferable. When the volume average particle diameter of the particle group of the particles composed of inorganic oxides is less than the lower limit value, there is a risk that the toner deteriorates the transfer efficiency to a transfer belt or paper. When the volume average particle diameter of the particle group of the particles exceeds the upper limit value, there is a risk that a photoreceptor is damaged.

[0132] The amount of addition of the external additive is not particularly limited, but is preferably in a range of 0.2 to 8.0% by mass of the entire mass of the toner. In the toner, resin fine particles of 1 μm or less can be added in addition to the particles composed of inorganic oxides.

[0133] The method of adding the external additive will be described.

[0134] The external additive is mixed with the toner, for example, by a mixer. As the mixer, the same mixer as used in the mixing process in the kneading pulverization method can be given.

[0135] The external additive can also be sieved by a sieving device as needed, for example, into coarse particles and the like. The sieving device is not particularly limited, and various sieving devices can be used.

[0136] Next, the toner cartridge of the embodiment will be described.

[0137] The toner cartridge of the embodiment contains the toner of the above-described embodiment. For example, the toner cartridge has a container in which the toner of the embodiment is contained. The container is not particularly limited, and various containers applicable to an image forming apparatus can be used.

[0138] The toner of the embodiment can be used as a single-component developer or as a two-component developer in combination with a carrier.

[0139] Next, the image forming apparatus of the embodiment will be described with reference to the drawings.

[0140] In the image forming apparatus of the embodiment, the toner of the above-described embodiment is contained in an apparatus main body. As the apparatus main body, a general electrophotographic apparatus can be used.

[0141] Figure 1 is a diagram showing one example of a brief structure of an image forming apparatus of an embodiment.

[0142] The image forming apparatus 20 has an apparatus main body that includes the intermediate transfer belt 7, the first image forming unit 17A and the second image forming unit 17B provided in this order on the intermediate transfer belt 7, and the fixing device 21 provided downstream thereof. The first image forming unit 17A is provided downstream of the second image forming unit 17B along a direction of travel X of the intermediate transfer belt 7, i.e., along a direction of travel in an image forming process. The fixing device 21 is provided downstream of the first image forming unit 17A.

[0143] The first image forming unit 17A has the photosensitive drum la, the cleaning device 16a, the charging device 2a, the exposure device 3a, the first developer 4a, and the primary transfer roller 8a. The cleaning device 16a, the charging device 2a, the exposure device 3a, and the first developer 4a are provided in this order along a direction of rotation of the photosensitive drum la. The primary transfer roller 8a is provided opposite the photosensitive drum la with the intermediate transfer belt 7 interposed therebetween.

[0144] The second image forming unit 17B has the photosensitive drum lb, the cleaning device 16b, the charging device 2b, the exposure device 3b, the second developer 4b, and the primary transfer roller 8b. The cleaning device 16b, the charging device 2b, the exposure device 3b, and the second developer 4b are provided in this order along a direction of rotation of the photosensitive drum lb. The primary transfer roller 8b is provided opposite the photosensitive drum lb with the intermediate transfer belt 7 interposed therebetween.

[0145] Inside the first developer 4a, the second developer 4b contains the toner of the above-described embodiment. The toner can be supplied from a toner cartridge not shown.

[0146] The primary transfer roller 8a is connected to the primary transfer power source 14a. The primary transfer roller 8b is connected to the primary transfer power source 14b.

[0147] Downstream of the first image forming unit 17A, the secondary transfer roller 9 and the support roller 10 are arranged opposite each other with the intermediate transfer belt 7 interposed therebetween. The secondary transfer roller 9 is connected to the secondary transfer power source 15.

[0148] The fixing device 21 has the heating roller 11 and the pressure roller 12 arranged opposite each other. The heat source 5 is inserted into a central portion of a roller of the heating roller 11. The heat source 5 is a heat source of the heating roller 11. By being heated and pressed by the heating roller 11 and the pressure roller 12, the toner image is fixed to paper.

[0149] Figure 2 is a diagram showing one example of a configuration of the fixing device 21. As Figure 2As shown, the heating roller 11 is in contact with the thermistor 18. The thermistor 18 is electrically connected to the temperature control device 19. Therefore, the fixing device 21 is able to monitor the temperature of the heating roller 11 using the thermistor 18, and control within a certain temperature range using the temperature control device 19.

[0150] By the image forming device 20, for example, image formation is performed as follows.

[0151] First, the charging device 2b uniformly charges the photosensitive drum lb. Then, exposure is performed by the exposure device 3b, and an electrostatic latent image is formed. Then, development is performed using the toner of the embodiment supplied from the developer 4b, and a second toner image is obtained.

[0152] Next, the charging device 2a uniformly charges the photosensitive drum la. Then, exposure is performed by the exposure device 3a according to the first image information (the second toner image), and an electrostatic latent image is formed. Then, development is performed using the toner of the embodiment supplied from the developer 4a, and a first toner image is obtained.

[0153] The second toner image and the first toner image are sequentially transferred to the intermediate transfer belt 7 using the primary transfer rollers 8a, 8b.

[0154] The image on which the second toner image and the first toner image are sequentially layered on the intermediate transfer belt 7 is secondary transferred to a recording medium not shown in the drawing by the secondary transfer roller 9 and the support roller 10. Thereby, an image on which the first toner image and the second toner image are sequentially layered on the recording medium is formed.

[0155] The developer containing the toner of the embodiment can be applied to Figure 1 the image forming device shown. Figure 1 The image forming device shown is a manner in which a toner image is fixed, but is not limited to this form, and can also be a manner of an inkjet type.

[0156] The toner of at least one embodiment described above has excellent heating roller service life, low-temperature offset resistance, and high-temperature offset resistance.

[0157] Example

[0158] An example is shown below, and the embodiment is more specifically described.

[0159] The non-crystalline polyester resin A used in the example is shown below. By polycondensing an acid component and an alcohol component, and adjusting the weight average molecular weight, the number average molecular weight, and the molecular weight distribution, the following non-crystalline polyester resin A is obtained.

[0160] The non-crystalline polyester resin A1 (weight average molecular weight (Mw A ): 1.2 x 10 4 , number average molecular weight (MnA ) : 3.5 x 10 3 , Mw A / Mn A : 3.43)

[0161] Amorphous polyester resin A2 (mass average molecular weight (Mw A ) : 0.9 x 10 4 , number average molecular weight (Mn A ) : 3.0 x 10 3 , Mw A / Mn A : 3.0)

[0162] Amorphous polyester resin A3 (mass average molecular weight (Mw A ) : 1.5 x 10 4 , number average molecular weight (Mn A ) : 3.9 x 10 3 , Mw A / Mn A : 3.85)

[0163] Amorphous polyester resin A4 (mass average molecular weight (Mw A ) : 0.8 x 10 4 , number average molecular weight (Mn A ) : 2.8 x 10 3 , Mw A / Mn A : 2.86)

[0164] Amorphous polyester resin A5 (mass average molecular weight (Mw A ) : 1.6 x 10 4 , number average molecular weight (Mn A ) : 4.1 x 10 3 , Mw A / Mn A : 3.90)

[0165] The amorphous polyester resin B used in the examples is shown below. By condensing an acid component and an alcohol component, and adjusting the mass average molecular weight, the number average molecular weight, the molecular weight distribution, the following amorphous polyester resin B is obtained.

[0166] Amorphous polyester resin B1 (mass average molecular weight (Mw B ) : 7.1 x 10 4 , number average molecular weight (Mn B ) : 2.8 x 10 3 , Mw B / Mn B : 25.4)

[0167] Amorphous polyester resin B2 (mass average molecular weight (Mw B ): 4.0 x 10 4 , number average molecular weight (Mn B ): 2.2 x 10 3 , Mw B / Mn B : 18.2)

[0168] Amorphous polyester resin B3 (mass average molecular weight (Mw B ): 11.0 x 10 4 , number average molecular weight (Mn B ): 3.5 x 10 3 , Mw B / Mn B : 31.4)

[0169] Amorphous polyester resin B4 (mass average molecular weight (Mw B ): 13.0 x 10 4 , number average molecular weight (Mn B ): 4.0 x 10 3 , Mw B / Mn B : 32.5)

[0170] Amorphous polyester resin B5 (mass average molecular weight (Mw B ): 3.1 x 10 4 , number average molecular weight (Mn B ): 2.0 x 10 3 , Mw B / Mn B : 15.5)

[0171] The crystalline polyester resin C used in the examples is shown below. By condensing an acid component and an alcohol component, and adjusting the mass average molecular weight, the number average molecular weight, and the molecular weight distribution, the following crystalline polyester resin C is obtained.

[0172] Crystalline polyester resin C1 (mass average molecular weight (Mw C ): 9.5 x 10 3 , number average molecular weight (Mn C ): 2.2 x 10 3 , Mw C / Mn C : 4.32)

[0173] The additives used in the examples are shown below.

[0174] Ester wax: NISSAN ELECTOL WEP-3, NISSAN CORPORATION

[0175] Carbon black: Mitsubishi Chemical Corporation #44)

[0176] The method for evaluating viscosity is described.

[0177] For each example of toner, the viscosity was measured using a flow tester CFT500D manufactured by Shimadzu Corporation under the following conditions.

[0178] Ramp rate: 2.5°C / min; test load: 10 Kg; preheating time: 300 sec; die diameter: 1.0 mm; die length: 1.0 mm.

[0179] Based on the results of the measurement of viscosity, the viscosity was evaluated according to the following criteria.

[0180] O: The viscosity was 1.0 x 104Pa-s or less.

[0181] X: The viscosity exceeded 1.0 x 104Pa-s.

[0182] The method for evaluating the service life of a heating roller is described.

[0183] Using a Toshiba-made MFP e-STUDIO 5008A in which each example of toner was accommodated, paper was passed at a print rate of 8%. The temperature at the time of printing was 160°C. The material of the heating roller of the MFP e-STUDIO 5008A was PTFE.

[0184] While confirming the damage to the heating roller, paper was passed, and based on the number of sheets of paper passed when the heating roller was damaged, the service life of the heating roller was evaluated according to the following criteria.

[0185] ◎: The number of sheets of paper passed when the heating roller was damaged was 450 x 10 3 sheets or more.

[0186] O: The number of sheets of paper passed when the heating roller was damaged was 330 x 10 3 sheets to less than 450 x 10 3 sheets.

[0187] X: The number of sheets of paper passed when the heating roller was damaged was less than 330 x 10 3 sheets.

[0188] The method for evaluating low-temperature offset resistance is described.

[0189] Using a Toshiba-made MFP e-STUDIO 5008A, the temperature at the time of printing was gradually lowered. The temperature at which offset occurred was recorded, and the low-temperature offset resistance was evaluated according to the following criteria.

[0190] ◎: The temperature at which offset occurred was 120°C or less.

[0191] O: The temperature at which offset occurred was 130°C or less.

[0192] X: The temperature at which offset occurred was more than 130°C.

[0193] The evaluation method for high-temperature offset resistance is described.

[0194] Using MFP e-STUDIO 5008A manufactured by Toshiba, the temperature at the time of printing was gradually increased. The temperature at which offset occurred was recorded, and the high-temperature offset resistance was evaluated according to the following criteria.

[0195] X: The temperature at which offset occurred was more than 200°C.

[0196] O: The temperature at which offset occurred was 190°C or more.

[0197] X: The temperature at which offset occurred was less than 190°C.

[0198] (Example 1)

[0199] A colorant raw material was added to a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) and mixed.

[0200] The composition of the colorant raw material is shown below.

[0201]

[0202] The mixture of the colorant raw material was melt-kneaded using a twin-screw extruder. The melt-kneaded product was cooled, and then coarsely pulverized using a hammer mill. The coarsely pulverized product was finely pulverized using a jet mill. The finely pulverized product was classified to obtain a colorant base. The mass average particle diameter of the colorant base was 8.5 μm. Hydrophobic silica 1.5 mass% and titanium oxide 0.4 mass% were added to the colorant base, as the colorant of Example 1.

[0203] The temperature at which low-temperature offset occurred was 125°C. The temperature at which high-temperature offset occurred was 195°C. The viscosity of the colorant after being left in an environment of 160°C for 24 hours was 0.8 x 104Pa s. The number of sheets passed until the heating roller was damaged was 390 x 104sheets. 3

[0204] (Example 2)

[0205] Example 2 colorant was manufactured in the same manner as Example 1, except that the composition of the colorant raw material was changed as follows.

[0206]

[0207] ​The temperature at which low temperature offset occurred was 118°C. The temperature at which high temperature offset occurred was 195°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.7 x 104Pa-s. The number of sheets passed when damage occurred to the heating roller was 460 x 103sheets. 3 Zhang.

[0208] (Example 3)

[0209] Example 3 toner was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0210]

[0211] The temperature at which low temperature offset occurred was 127°C. The temperature at which high temperature offset occurred was 205°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.8 x 104Pa-s. The number of sheets passed when damage occurred to the heating roller was 360 x 103sheets. 4 3 Zhang.

[0212] (Example 4)

[0213] Example 4 toner was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0214]

[0215] The temperature at which low temperature offset occurred was 116°C. The temperature at which high temperature offset occurred was 193°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.7 x 104Pa-s. The number of sheets passed when damage occurred to the heating roller was 340 x 103sheets. 4 3 Zhang.

[0216] (Example 5)

[0217] Example 5 toner was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0218]

[0219] The temperature at which low temperature offset occurred was 128°C. The temperature at which high temperature offset occurred was 210°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 1.0 x 104Pa-s. The number of sheets passed when damage occurred to the heating roller was 390 x 103sheets. 4 3 Zhang.

[0220] (Example 6)

[0221] ​​​The toner of Example 6 was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0222]

[0223] The temperature at which low temperature offset occurred was 123°C. The temperature at which high temperature offset occurred was 197°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.7 x 10 4 Pa-s. The number of paper sheets passed when damage occurred to the heating roller was 460 x 10 3 sheets.

[0224] (Example 7)

[0225] The toner of Example 7 was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0226]

[0227] The temperature at which low temperature offset occurred was 124°C. The temperature at which high temperature offset occurred was 196°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 1.0 x 10 4 Pa-s. The number of paper sheets passed when damage occurred to the heating roller was 460 x 10 3 sheets.

[0228] (Comparative Example 1)

[0229] The toner of Comparative Example 1 was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0230]

[0231] The temperature at which low temperature offset occurred was 113°C. The temperature at which high temperature offset occurred was 185°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.7 x 10 4 Pa-s. The number of paper sheets passed when damage occurred to the heating roller was 410 x 10 3 sheets.

[0232] (Comparative Example 2)

[0233] The toner of Comparative Example 2 was produced in the same manner as Example 1 except that the composition of the toner raw material was changed as follows.

[0234]

[0235] The temperature at which low temperature offset occurred was 140°C. The temperature at which high temperature offset occurred was 195°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 1.5 x 104 Pa-s. The number of paper sheets passed when the heating roller was damaged was 260 x 10 3 sheets.

[0236] (Comparative Example 3)

[0237] The toner of Comparative Example 3 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0238]

[0239]

[0240] The temperature at which low temperature offset occurred was 135°C. The temperature at which high temperature offset occurred was 205°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 2.0 x 10 4 Pa-s. The number of paper sheets passed when the heating roller was damaged was 180 x 10 3 sheets.

[0241] (Comparative Example 4)

[0242] The toner of Comparative Example 4 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0243]

[0244] The temperature at which low temperature offset occurred was 128°C. The temperature at which high temperature offset occurred was 175°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.6 x 10 4 Pa-s. The number of paper sheets passed when the heating roller was damaged was 460 x 10 3 sheets.

[0245] (Comparative Example 5)

[0246] The toner of Comparative Example 5 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0247]

[0248] The temperature at which low temperature offset occurred was 140°C. The temperature at which high temperature offset occurred was 210°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 9.0 x 10 4 Pa-s. The number of paper sheets passed when the heating roller was damaged was 120 x 10 3 sheets.

[0249] (Comparative Example 6)

[0250] The toner of Comparative Example 6 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0251]

[0252] The temperature at which low temperature offset occurred was 123°C. The temperature at which high temperature offset occurred was 165°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.5 x 10 4 Pa-s. The number of paper sheets passed when damage occurred in the heating roller was 500 x 10 3 sheets.

[0253] (Comparative Example 7)

[0254] The toner of Comparative Example 7 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0255]

[0256] The temperature at which low temperature offset occurred was 121°C. The temperature at which high temperature offset occurred was 185°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 0.7 x 10 4 Pa-s. The number of paper sheets passed when damage occurred in the heating roller was 470 x 10 3 sheets.

[0257] (Comparative Example 8)

[0258] The toner of Comparative Example 8 was produced in the same manner as in Example 1, except that the composition of the toner raw material was changed as follows.

[0259]

[0260] The temperature at which low temperature offset occurred was 142°C. The temperature at which high temperature offset occurred was 213°C. The viscosity of the toner after being left in an environment of 160°C for 24 hours was 2.5 x 10 4 Pa-s. The number of paper sheets passed when damage occurred in the heating roller was 80 x 10 3 sheets.

[0261] The evaluation results of Examples 1 to 7 and Comparative Examples 1 to 8 are shown in Table 1.

[0262] [Table 1]

[0263]

[0264] As for the determination column in Table 1, in the evaluation of the low-temperature offset resistance, the high-temperature offset resistance, the viscosity, and the heating roller life, a case where there is no x evaluation is determined as O. In addition, in the evaluation of the low-temperature offset resistance, the high-temperature offset resistance, the viscosity, and the heating roller life, a case where there is at least one x evaluation is determined as X.

[0265] As shown in Table 1, the toners of Examples 1 to 7 had excellent heating roller life, low-temperature offset resistance, and high-temperature offset resistance.

[0266] In Comparative Example 1, the Mw A , Mn A , Mw A / Mn A was larger than that of Examples 1 to 7. The high-temperature offset resistance was insufficient in Comparative Example 1.

[0267] In Comparative Example 2, the Mw A , Mn A was larger than that of Examples 1 to 7. The low-temperature offset resistance and the heating roller life were insufficient in Comparative Example 2.

[0268] In Comparative Example 3, the Mw B , Mn B was larger than that of Examples 1 to 7. The low-temperature offset resistance and the heating roller life were insufficient in Comparative Example 3.

[0269] In Comparative Example 4, the Mw B , Mn B was smaller than that of Examples 1 to 7. The high-temperature offset resistance was insufficient in Comparative Example 4.

[0270] In Comparative Example 5, the content of the non-crystalline polyester resin A was smaller than that of Examples 1 to 7. In addition, the content of the non-crystalline polyester resin B was larger than that of Examples 1 to 7. The low-temperature offset resistance and the heating roller life were insufficient in Comparative Example 5.

[0271] In Comparative Example 6, the content of the non-crystalline polyester resin A was larger than that of Examples 1 to 7. In addition, the content of the non-crystalline polyester resin B was smaller than that of Examples 1 to 7. The high-temperature offset resistance was insufficient in Comparative Example 6.

[0272] In Comparative Example 7, the content of the non-crystalline polyester resin A was larger than that of Examples 1 to 7. In addition, the content of the non-crystalline polyester resin B was smaller than that of Examples 1 to 7. The high-temperature offset resistance was insufficient in Comparative Example 7.

[0273] In Comparative Example 8, the content of the non-crystalline polyester resin A was smaller than that of Examples 1 to 7. In addition, the content of the non-crystalline polyester resin B was larger than that of Examples 1 to 7. The low-temperature offset resistance and the heating roller life were insufficient in Comparative Example 8.

[0274] The present application has been described with reference to several embodiments thereof. However, these embodiments are presented by way of example only, and are not intended to limit the scope of the present application. These embodiments can be carried out in various other forms, and various omissions, substitutions and changes can be made without departing from the scope and spirit of the present application. These embodiments or their modifications are included within the scope and spirit of the present application, and are also included within the scope of the application as recited in the claims and equivalents thereof.

Claims

1. A toner, characterized in that, contain: Colorant; Mass-average molecular weight: Mw A 0.9×10 4 ~1.5×10 4 Amorphous polyester resin A; and Mass-average molecular weight: Mw B 4.0×10 4 ~11.0×10 4 Non-crystalline polyester resin B, Number average molecular weight of amorphous polyester resin A: Mn A 3.0×10 3 ~4.0×10 3 , Molecular weight distribution of non-crystalline polyester resin A: Mw A / Mn A The value is 3.1 to 4.

0. Number average molecular weight of amorphous polyester resin B: Mn B 2.2×10 3 ~3.5×10 3 , Molecular weight distribution of non-crystalline polyester resin B: Mw B / Mn B The range is 18.2 to 50. The content of non-crystalline polyester resin A is 50-60% by mass relative to 100% of the total toner. The content of non-crystalline polyester resin B is 20-30% by mass relative to 100% of the total amount of toner.

2. The toner according to claim 1, wherein, It also contains crystalline polyester resin C.

3. The toner according to claim 2, wherein, The content of crystalline polyester resin C is 3 to 20% by mass relative to 100% of the total amount of colorant.

4. A toner box, characterized in that, It contains the toner as described in any one of claims 1 to 3.

5. An image forming apparatus, characterized in that, It contains the toner as described in any one of claims 1 to 3.

Images