Toner, developer, toner storage unit and image forming apparatus

Abstract

To provide a toner that has high low temperature fixability and heat-resistant storage properties and can have excellent cleaning properties.SOLUTION: A toner according to the present invention is a toner containing two or more types of resin and a mold release agent, and includes a toner base particle containing binder resin and the mold release agent and a plurality of organic resin fine particles arranged on the surface of the toner base particle. The ratio of a first adhesive force A1 of the organic resin fine particles to a second adhesive force A2 on the surface of the toner base particle (A1 / A2) measured by a scanning probe microscope is 0.3-0.9.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a toner, a developer, a toner storage unit, and an image forming apparatus. [Background technology]

[0002] Image forming devices using toner, such as multi-function peripherals (MFPs) and printers, are widely used in various places, including offices. Toner is required to have good cleaning properties in order to prevent cleaning failures in developing machines caused by insufficient mechanical durability and to form high-quality images.

[0003] As a toner with improved cleaning properties, for example, a toner for developing electrostatic latent images has been proposed, which contains a binder resin, a wax, a colorant, and organic resin fine particles, and in which particles having a circularity of 0.963 or more and 0.984 or less account for 45.0 to 50.0% of the entire toner in the circularity distribution of the toner (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, the toner for developing electrostatic latent images in Patent Document 1 does not consider improvements in low-temperature fixability and heat-resistant storage stability. When the low-temperature fixability of the toner is reduced, power consumption during fixing increases. Also, when the heat-resistant storage stability of the toner is reduced, resistance to high temperature and high humidity during storage and transportation is reduced.

[0005] An object of one aspect of the present invention is to provide a toner that has high low-temperature fixability and heat-resistant storage stability as well as excellent cleanability. [Means for solving the problem]

[0006] One embodiment of the toner according to the present invention is a toner containing two or more types of resins and a release agent, comprising toner base particles containing a binder resin and the release agent, and a plurality of organic resin microparticles arranged on the surfaces of the toner base particles, wherein the ratio A1 / A2 of a first adhesive force A1 of the organic resin microparticles to a second adhesive force A2 of the surfaces of the toner base particles, as measured by a scanning probe microscope, is 0.3 to 0.9. Effect of the Invention

[0007] One aspect of the present invention provides a toner that has high low-temperature fixability and heat-resistant storage stability, as well as excellent cleanability. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, the embodiments of the present invention will be described in detail. Note that the embodiments are not limited by the following description, and can be modified as appropriate without departing from the gist of the present invention. In addition, in this specification, a tilde "~" indicating a numerical range means that the numerical values ​​before and after it are included as the lower and upper limits, unless otherwise specified.

[0009] <Toner> The toner according to the embodiment is a toner containing two or more kinds of resins and a release agent, and includes toner base particles containing a binder resin and a release agent, and a plurality of organic resin fine particles arranged on the surfaces of the toner base particles. The toner according to the embodiment has a ratio A1 / A2 of a first adhesive force A1 of the organic resin fine particles to a second adhesive force A2 of the surfaces of the toner base particles measured by a scanning probe microscope (SPM) (hereinafter also referred to as "the ratio A1 / A2 of the first adhesive force A1 to the second adhesive force A2") of 0.3 to 0.9.

[0010] As a result of intensive research, the present inventors have focused on the relationship between the first adhesive force A1 of the organic resin fine particles and the second adhesive force A2 of the surface of the toner base particle when measured by SPM in a toner having a plurality of organic resin fine particles on the surface of the toner base particle. Therefore, the ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles to the second adhesive force A2 of the surface of the toner base particle when measured by a scanning probe microscope is set to 0.3 to 0.9. As a result, the toner can ensure the affinity between the toner base particle and the organic resin fine particles, and can exert the protective effect of the organic resin fine particles on the surface of the toner base particle, and therefore it has been found that it can have high low-temperature fixability and heat-resistant storage stability. In addition, the toner can have excellent cleaning properties because the increase in the adhesive force of the toner can be suppressed by covering at least a part of the surface of the toner base particle with the organic resin fine particles.

[0011] [Toner base particles] The toner base particles contain a binder resin and a release agent.

[0012] [Binding resin] The binder resin may be any binder resin for toner. The binder resin preferably contains a polyester resin in order to exhibit superior low-temperature fixing properties. The toner base particles may contain a binder resin other than the polyester resin.

[0013] (polyester resin) The polyester resin preferably contains at least one of a crystalline polyester resin and an amorphous polyester resin.

[0014] (Crystalline polyester resin) The crystalline polyester resin can achieve both low-temperature fixability and heat-resistant storage stability of the toner base particles. The crystalline polyester resin is obtained by using a polyhydric alcohol and a polycarboxylic acid or its derivative, such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic ester. In this embodiment, the crystalline polyester resin refers to a resin obtained by modifying a polyester resin, such as a prepolymer, which will be described later, and a resin obtained by crosslinking and / or elongating the prepolymer.

[0015] -Polyhydric alcohol- The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyhydric alcohol include diols and trihydric or higher alcohols.

[0016] Examples of the diol include saturated aliphatic diols. Examples of the saturated aliphatic diol include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols having 2 to 12 carbon atoms are more preferred. If the saturated aliphatic diol is a branched type, the crystallinity of the crystalline polyester resin may decrease, resulting in a decrease in melting point. In addition, if the carbon number of the saturated aliphatic diol exceeds 12, it becomes difficult to obtain a practical material. It is more preferred that the carbon number is 12 or less.

[0017] Examples of the saturated aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, etc. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred in terms of high crystallinity of the crystalline polyester resin and excellent sharp melt properties.

[0018] Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. These may be used alone or in combination of two or more.

[0019] -Polycarboxylic acids- The polyvalent carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include divalent carboxylic acids and trivalent or higher carboxylic acids.

[0020] Examples of the divalent carboxylic acid include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; and aromatic dicarboxylic acids such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and further, anhydrides of these acids and lower (carbon number: 1 to 3) alkyl esters of these acids.

[0021] Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, as well as anhydrides and lower (carbon number 1 to 3) alkyl esters thereof.

[0022] The polycarboxylic acid may contain a dicarboxylic acid having a sulfonic acid group in addition to the saturated aliphatic dicarboxylic acid or aromatic dicarboxylic acid. The polycarboxylic acid may contain a dicarboxylic acid having a double bond in addition to the saturated aliphatic dicarboxylic acid or aromatic dicarboxylic acid. These may be used alone or in combination of two or more.

[0023] The crystalline polyester resin is preferably composed of a linear saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a linear saturated aliphatic diol having 2 to 12 carbon atoms. That is, the crystalline polyester resin preferably has a constitutional unit derived from a saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a constitutional unit derived from a saturated aliphatic diol having 2 to 12 carbon atoms. This is preferable in that the resin has high crystallinity and excellent sharp melting properties, and can therefore exhibit excellent low-temperature fixability.

[0024] The melting point of the crystalline polyester resin is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 60° C. to 120° C. If the melting point is less than 60° C., the crystalline polyester resin is likely to melt at low temperatures, and the heat-resistant storage stability of the toner may decrease, whereas if the melting point exceeds 120° C., the crystalline polyester resin may not melt sufficiently due to heating during fixing, and the low-temperature fixability may decrease.

[0025] The molecular weight of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint that a low molecular weight resin with a sharp molecular weight distribution has excellent low-temperature fixability and that a large amount of low molecular weight components reduces heat-resistant storage stability, it is preferable that the orthodichlorobenzene-soluble portion of the crystalline polyester resin has a weight average molecular weight (Mw) of 10,000 or more as measured by gel permeation chromatography (GPC). There is no upper limit to the weight average molecular weight, but from the viewpoint of ease of production, it is preferable that it is 35,000 or less.

[0026] The content of the crystalline polyester resin is not particularly limited and can be appropriately selected according to the purpose, but is preferably 3 to 20 parts by mass, more preferably 5 to 15 parts by mass, relative to 100 parts by mass of the toner. If the content is less than 3 parts by mass, the sharp melting by the crystalline polyester resin is insufficient, and the low-temperature fixing property may be poor. If the content exceeds 20 parts by mass, the heat-resistant storage stability may decrease and the image may easily become foggy. If the content is within the above more preferred range, it is advantageous in that both high image quality and low-temperature fixing property are excellent.

[0027] The method of introducing the crystalline polyester resin into the toner base particles is not particularly limited and can be appropriately selected depending on the purpose. In general, the crystalline polyester resin is mechanically crushed and dispersed using a bead mill or the like, and then introduced in the form of a dispersion liquid.

[0028] ((Amorphous polyester resin)) Amorphous polyester resins (also referred to as amorphous polyester resins or amorphous polyesters) can exhibit superior low-temperature fixability.

[0029] The amorphous polyester resin contains, as its constituent components, a diol component and a crosslinking component.

[0030] The diol component contained in the non-crystalline polyester resin contains an aliphatic diol having 3 to 10 carbon atoms in an amount of 50 mol % or more, preferably 80 mol % or more, and more preferably 90 mol % or more. It is more preferable that the content is 100% or more.

[0031] Examples of the aliphatic diol having 3 to 10 carbon atoms include 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol.

[0032] In the non-crystalline polyester resin, it is preferable that the main chain of the diol component has an odd number of carbon atoms, and the diol component has an alkyl group on the side chain.

[0033] The aliphatic diol having 3 to 10 carbon atoms preferably has an odd number of carbon atoms in the main chain and has an alkyl group in the side chain, and is preferably an aliphatic diol represented by the following general formula (1). HO-(CR 1 R 2 ) n -OH...General formula (1) In the general formula (1), R 1 , and R 2 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms; n represents an odd number from 3 to 9. In the n repeating units, R 1 and R 2 may be the same or different.

[0034] The crosslinking component contained in the non-crystalline polyester resin contains a trihydric or higher aliphatic alcohol, and preferably contains a trihydric to tetrahydric aliphatic alcohol from the viewpoint of the gloss and image density of the fixed image. The crosslinking component may be only a trihydric or higher aliphatic alcohol.

[0035] Examples of trihydric or higher aliphatic alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, and dipentaerythritol.

[0036] The proportion of the crosslinking component is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 5% by mass, and more preferably 1% by mass to 3% by mass.

[0037] The proportion of the trivalent or higher aliphatic alcohol in the crosslinking component is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50% by mass to 100% by mass, and more preferably 90% by mass to 100% by mass.

[0038] The crosslinking component preferably contains an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, and more preferably contains 50 mol % or more and less than 60 mol % of an aliphatic dicarboxylic acid having 4 to 12 carbon atoms.

[0039] Examples of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid.

[0040] The amorphous polyester resin is preferably used in combination with another amorphous polyester resin.

[0041] ((Other amorphous polyester resins)) The other non-crystalline polyester resin includes, for example, a diol component and a dicarboxylic acid component as a constituent component. The other non-crystalline polyester resin may further include a crosslinking component as a constituent component. Examples of the crosslinking component include aliphatic alcohols having a valence of 3 or more.

[0042] -Diol component- The diol component is not particularly limited and can be appropriately selected depending on the purpose. For example, aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol; diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and the like. Examples of the diol include diols having an oxyalkylene group such as polypropylene glycol and polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols such as bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. Among these, aliphatic diols having 4 to 12 carbon atoms are preferred. These diols may be used alone or in combination of two or more.

[0043] -Dicarboxylic acid component- The dicarboxylic acid component is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, etc. In addition, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of these may be used.

[0044] The aliphatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid.

[0045] The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Among these, aliphatic dicarboxylic acids having 4 to 12 carbon atoms are preferred.

[0046] These dicarboxylic acids may be used alone or in combination of two or more.

[0047] -Trivalent or higher aliphatic alcohols- The trihydric or higher aliphatic alcohol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, dipentaerythritol, etc. Among these, trihydric to tetrahydric aliphatic alcohols are preferred. These trihydric or higher aliphatic alcohols may be used alone or in combination of two or more.

[0048] The other non-crystalline polyester resin preferably has at least one of a urethane bond and a urea bond in terms of better adhesion to recording media such as paper. By having at least one of a urethane bond and a urea bond in the other non-crystalline polyester resin, the urethane bond or the urea bond behaves like a pseudo-crosslinking point, the rubber-like properties of the other non-crystalline polyester resin are strengthened, and the heat-resistant storage stability and high-temperature offset resistance of the toner are better.

[0049] -Non-crystalline polyester resin having at least one of a urethane bond and a urea bond- The amorphous polyester resin having at least one of a urethane bond and a urea bond is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a reaction product of an amorphous polyester resin having an active hydrogen group and a polyisocyanate. The reaction product is a component insoluble in tetrahydrofuran, and can be used as a reaction precursor (hereinafter, sometimes referred to as a "prepolymer") to be reacted with a curing agent described later.

[0050] --Non-crystalline polyester resin having active hydrogen groups-- Examples of the non-crystalline polyester resin having an active hydrogen group include non-crystalline polyester resin having a hydroxyl group.

[0051] --Polyisocyanate-- The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyisocyanate include diisocyanates and tri- or higher valent isocyanates.

[0052] Examples of diisocyanates include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and those blocked with phenol derivatives, oximes, caprolactams, etc.

[0053] The aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.

[0054] The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the alicyclic diisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate.

[0055] The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3-methyldiphenylmethane, 4,4'-diisocyanato-diphenyl ether, etc. The aromatic aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include α,α,α',α'-tetramethylxylylene diisocyanate, etc.

[0056] The isocyanurates are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include tris(isocyanatoalkyl)isocyanurate, tris(isocyanatocycloalkyl)isocyanurate, and the like.

[0057] These polyisocyanates may be used alone or in combination of two or more kinds.

[0058] --Hardening agent-- The curing agent is not particularly limited as long as it reacts with the prepolymer, and can be appropriately selected depending on the purpose. For example, an active hydrogen group-containing compound can be used.

[0059] ---Compounds containing active hydrogen groups--- The active hydrogen group in the active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, etc. These may be used alone or in combination of two or more.

[0060] The active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, but amines are preferred because they are capable of forming a urea bond.

[0061] The amines are not particularly limited and can be appropriately selected according to the purpose, and examples thereof include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and blocked amino groups thereof. These may be used alone or in combination of two or more. Among these, diamines and mixtures of diamines and small amounts of trivalent or higher amines are preferred.

[0062] The diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophoronediamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0063] The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diethylenetriamine and triethylenetetramine.

[0064] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.

[0065] The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.

[0066] The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino acid include aminopropionic acid and aminocaproic acid.

[0067] The blocked amino group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ketimine compounds and oxazoline compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0068] The molecular structure of the polyester resin can be confirmed by NMR measurement in solution or solid, as well as X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. -1 and 990±10cm -1 One method is to detect polyester resins that do not have absorption due to olefin δCH (out-of-plane bending vibration).

[0069] The content of the polyester resin is not particularly limited and can be appropriately selected according to the purpose, but is preferably 90% by mass or more based on the total binder resin. The upper limit of the content of the polyester resin is preferably 100% by mass. The polyester resin refers to both crystalline polyester and amorphous polyester. Therefore, in a toner containing crystalline polyester and amorphous polyester, the content of the polyester resin refers to the sum of the content of the crystalline polyester and the content of the amorphous polyester. When the content of the polyester resin is 90% by mass or more, low-temperature fixability can be improved.

[0070] (Other binder resins) The toner base particles may contain other binder resin components in addition to the polyester resin described above. Examples of other binder resins include known binder resins such as silicone resins, styrene-acrylic resins, styrene resins, acrylic resins, epoxy resins, diene resins, phenol resins, terpene resins, coumarin resins, amide-imide resins, butyral resins, urethane resins, and ethylene-vinyl acetate resins.

[0071] The content of the binder resin in the toner base particles can be changed as appropriate, but is preferably 10% by mass to 95% by mass in the toner base particles. When the content is within the above range, the toner base particles can have excellent fixing properties, charging properties, etc.

[0072] (Release agent) The release agent is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include carbonyl group-containing wax, polyolefin wax, long chain hydrocarbon, etc. These may be used alone or in combination of two or more. Among these, carbonyl group-containing wax is preferred.

[0073] Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkyl amides, and dialkyl ketones.

[0074] Examples of polyalkanoic acid esters include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecanediol distearate.

[0075] Examples of polyalkanol esters include tristearyl trimellitate and distearyl maleate.

[0076] An example of the polyalkanoic acid amide is dibehenyl amide.

[0077] An example of the polyalkylamide is trimellitic acid tristearylamide.

[0078] An example of the dialkyl ketone is distearyl ketone.

[0079] Among these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.

[0080] Examples of the polyolefin wax include polyethylene wax and polypropylene wax.

[0081] Examples of the long chain hydrocarbon include paraffin wax and sazol wax.

[0082] The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50° C. to 100° C., and more preferably 60° C. to 90° C. If the melting point is 50° C. to 100° C., it is possible to prevent problems that adversely affect the heat-resistant storage stability and problems that cause cold offset during fixing at low temperatures.

[0083] The melting point of the release agent can be measured, for example, by using a differential scanning calorimeter (TA-60WS and DSC-60, manufactured by Shimadzu Corporation).

[0084] First, 5.0 mg of the release agent is placed in an aluminum sample container, the sample container is placed on a holder unit, and set in an electric furnace. Next, in a nitrogen atmosphere, the temperature is increased from 0°C to 150°C at a rate of 10°C / min. After that, the temperature is decreased from 150°C to 0°C at a rate of 10°C / min, and then the temperature is increased again to 150°C at a rate of 10°C / min to measure a DSC curve. From the obtained DSC curve, the maximum peak temperature of the heat of fusion in the 2nd heating can be determined as the melting point using the analysis program in the DSC-60 system.

[0085] The melt viscosity of the release agent is preferably 5 mPa·sec to 100 mPa·sec, more preferably 5 mPa·sec to 50 mPa·sec, and even more preferably 5 mPa·sec to 20 mPa·sec, as measured at 100° C. If the melt viscosity is 5 mPa·sec or more, the release agent may exhibit sufficient releasability, and if the melt viscosity is 100 mPa·sec or less, the release agent may exhibit sufficient hot offset resistance and low-temperature releasability.

[0086] The content of the release agent is preferably 3 parts by mass to 15 parts by mass, and more preferably 3 parts by mass to 13 parts by mass, relative to 100 parts by mass of the toner. When the content is 1 part by mass to 20 parts by mass, it is possible to prevent problems such as a decrease in hot offset resistance, a decrease in heat-resistant storage stability, or the occurrence of toner adhesion (filming) to the carrier, photoconductor, and blade.

[0087] [Other ingredients] The toner base particles may contain other components as necessary. The other components are not particularly limited as long as they are used in normal toners, and can be appropriately selected depending on the purpose. Examples of the other components include colorants, charge control agents, external additives, flowability improvers, cleaning improvers, magnetic materials, etc.

[0088] (Coloring agent) As the colorant, for example, carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, chalco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triarylmethane dyes, and other conventionally known dyes and pigments can be used. These can be used alone or in combination, and can be used as both black toners and full-color toners.

[0089] The content of the colorant is preferably 1% by mass to 30% by mass, and more preferably 3% by mass to 20% by mass, based on the binder resin.

[0090] (Charge control agent) The charge control agent is not particularly limited and can be appropriately selected according to the purpose. Examples of the charge control agent include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdic acid chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, salicylic acid metal salts, and salicylic acid derivative metal salts. Specific examples include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, and the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.).

[0091] The content of the charge control agent can be appropriately selected depending on the purpose, and is preferably 0.01 to 5 parts by mass, and more preferably 0.02 to 2 parts by mass, relative to 100 parts by mass of the toner. When the content is 0.01 to 5 parts by mass, it is possible to prevent problems such as insufficient charge rise property or charge amount affecting the toner image, and problems such as excessive charge property of the toner increasing the electrostatic attraction force with the developing roller, resulting in reduced fluidity of the developer and reduced image density.

[0092] (External additives) The external additive is not particularly limited and can be appropriately selected depending on the purpose. Examples of the external additive include silica, fatty acid metal salts, metal oxides, hydrophobized titanium oxide, and fluoropolymers.

[0093] Examples of fatty acid metal salts include zinc stearate and aluminum stearate.

[0094] Examples of metal oxides include titanium oxide, aluminum oxide, tin oxide, and antimony oxide.

[0095] Commercially available silica products include, for example, R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.).

[0096] Commercially available examples of titanium oxide include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-150W, MT-500B, MT-600B, MT-150A (all manufactured by Teika Co., Ltd.), and the like.

[0097] Commercially available hydrophobically treated titanium oxide products include, for example, T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, TAF-1500T (all manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-100S, MT-100T (all manufactured by Teika Co., Ltd.), and IT-S (manufactured by Ishihara Sangyo Kaisha, Ltd.).

[0098] Examples of the hydrophobic treatment method include a method in which hydrophilic fine particles are treated with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane.

[0099] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass, relative to 100 parts by mass of the toner.

[0100] The average particle size of the primary particles of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 nm or less, more preferably 3 nm to 70 nm. If the average particle size is 3 nm or more, the external additive is not embedded in the toner base particles and can effectively exert its function, and if the average particle size is 100 nm or less, uneven damage to the photoreceptor surface can be suppressed.

[0101] (Flow improver) The flowability improver is not particularly limited as long as it is capable of performing a surface treatment to increase hydrophobicity and prevent deterioration of flowability and charging properties even under high humidity, and can be appropriately selected according to the purpose, and examples thereof include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, etc. It is particularly preferable that the silica and titanium oxide are surface-treated with such a flowability improver and used as hydrophobic silica and hydrophobic titanium oxide.

[0102] (Cleaning improver) The cleaning property improver is not particularly limited as long as it is added to the toner to remove the developer remaining on the photoconductor or primary transfer medium after transfer, and can be appropriately selected depending on the purpose, and examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and are preferably ones having a volume average particle size of 0.01 μm to 1 μm.

[0103] (Magnetic material) The magnetic material is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, a white material is preferable in terms of color tone.

[0104] <Organic resin fine particles> The organic resin fine particles are disposed on the surface of the toner base particle. The organic resin fine particles are attached to the surface of the toner base particle, and are disposed in a scattered state on the surface of the toner base particle, not in a state of being layered covering the surface of the toner base particle. The organic resin fine particles may also be attached to the surface of the toner base particle in a state of being partially embedded therein.

[0105] The organic resin fine particles preferably contain two types of resins (b1) and (b2). The organic resin fine particles more preferably have a core-shell structure consisting of a shell having resin (b1) and a core having resin (b2). The organic resin fine particles do not necessarily have to have a shell, and may be composed of only a core.

[0106] The organic resin fine particles preferably contain one or more types of styrene-acrylic resin having a carboxylic acid.

[0107] When the organic resin particles contain two types of resins (b1) and (b2), the organic resin particles preferably contain a resin (b1) containing a styrene-acrylic resin and a resin (b2) containing a styrene-acrylic resin. The styrene-acrylic resin contained in the resin (b1) and the styrene-acrylic resin contained in the resin (b2) are preferably different types, but may be the same type.

[0108] When the organic resin fine particles are organic resin fine particles containing vinyl units consisting of resin (b1) and resin (b2), the resin (b1) and the resin (b2) can be polymers obtained by homopolymerizing or copolymerizing vinyl monomers. Examples of the vinyl monomer include the following (1) to (12). The resin (b1) and the resin (b2) may be synthesized by using one of the following vinyl monomers (1) to (12) alone or by combining two or more of them.

[0109] (1) Vinyl hydrocarbons Examples of vinyl hydrocarbons include aliphatic vinyl hydrocarbons, alicyclic vinyl hydrocarbons, and aromatic vinyl hydrocarbons.

[0110] (1-1) Aliphatic vinyl hydrocarbons Aliphatic vinyl hydrocarbons include alkenes and alkadienes.

[0111] Alkenes include ethylene, propylene, and α-olefins.

[0112] Examples of alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene.

[0113] (1-2) Alicyclic vinyl hydrocarbons Alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples include (di)cyclopentadiene, terpene, and the like.

[0114] (1-3) Aromatic vinyl hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and / or alkenyl) substituted derivatives, and specific examples thereof include α-methylstyrene, 2,4-dimethylstyrene and vinylnaphthalene.

[0115] (2) Carboxyl-containing vinyl monomers and their salts Examples of the carboxyl group-containing vinyl monomer and its salt include unsaturated monocarboxylic acids (salts) having 3 to 30 carbon atoms, unsaturated dicarboxylic acids (salts), and their anhydrides (salts), and their monoalkyl (carbon number 1 to 24) esters or salts.

[0116] Specific examples thereof include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid, and metal salts thereof.

[0117] In the present embodiment, the term "(salt)" refers to an acid or a salt thereof. For example, an unsaturated monocarboxylic acid (salt) having 3 to 30 carbon atoms refers to an unsaturated monocarboxylic acid or a salt thereof.

[0118] In this embodiment, "(meth)acrylic" means methacrylic acid or acrylic acid. In other words, "(meth)acryloyl" means methacryloyl or acryloyl, and "(meth)acrylate" means methacrylate or acrylate.

[0119] (3) Sulfonic acid-containing vinyl monomers, vinyl sulfate monoesters, and their salts Examples of sulfone group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof include alkene sulfonic acids (salts) having 2 to 14 carbon atoms, alkyl sulfonic acids (salts) having 2 to 24 carbon atoms, sulfo(hydroxy)alkyl-(meth)acrylates (salts) or (meth)acrylamides (salts), and alkylarylsulfosuccinic acids (salts).

[0120] Examples of the alkene sulfonic acid having 2 to 14 carbon atoms include vinyl sulfonic acid (salt), etc. Examples of the alkyl sulfonic acid (salt) having 2 to 24 carbon atoms include α-methylstyrene sulfonic acid (salt), etc. Examples of the sulfo(hydroxy)alkyl-(meth)acrylate (salt) or (meth)acrylamide (salt) include sulfopropyl (meth)acrylate (salt), sulfuric acid ester (salt), and sulfonic acid group-containing vinyl monomer (salt).

[0121] (4) Phosphate-containing vinyl monomers and their salts: Examples of the phosphoric acid group-containing vinyl monomer and its salt include (meth)acryloyloxyalkyl (C1-24) phosphoric acid monoester (salt) and (meth)acryloyloxyalkyl (C1-24) phosphonic acid (salt).

[0122] Specific examples of the (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphate monoester (salt) include 2-hydroxyethyl (meth)acryloyl phosphate (salt) and phenyl-2-acryloyloxyethyl phosphate (salt).

[0123] Specific examples of (meth)acryloyloxyalkyl (carbon number: 1 to 24)phosphonic acids (salts) include 2-acryloyloxyethylphosphonic acid (salts).

[0124] Examples of the salts of (2) to (4) above include alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

[0125] (5) Hydroxyl-containing vinyl monomers Examples of hydroxyl group-containing vinyl monomers include hydroxystyrene, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethyl propenyl ether, and sucrose allyl ether.

[0126] (6) Nitrogen-containing vinyl monomers Examples of the nitrogen-containing vinyl monomer include an amino group-containing vinyl monomer, an amide group-containing vinyl monomer, a nitrile group-containing vinyl monomer, a quaternary ammonium cation group-containing vinyl monomer, and a nitro group-containing vinyl monomer.

[0127] Examples of the amino group-containing vinyl monomer include aminoethyl (meth)acrylate.

[0128] Examples of the amide group-containing vinyl monomer include (meth)acrylamide and N-methyl(meth)acrylamide.

[0129] Examples of the nitrile group-containing vinyl monomer include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate.

[0130] Examples of the vinyl monomer containing a quaternary ammonium cation group include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized using a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate).

[0131] The nitro group-containing vinyl monomer includes nitrostyrene and the like.

[0132] (7) Epoxy group-containing vinyl monomer Examples of the epoxy group-containing vinyl monomer include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenyl phenyl oxide.

[0133] (8) Halogen-containing vinyl monomers Examples of halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0134] (9) Vinyl ester Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl 4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meth)acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl α-ethoxyacrylate, and alkyl (meth)acrylates having an alkyl group having 1 to 50 carbon atoms [methyl (meth)acrylate]. (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, etc.)], dialkyl fumarate (wherein the two alkyl groups are linear, branched, or alicyclic groups having 2 to 8 carbon atoms), dialkyl Examples of the polyalkylene glycol include maleates (wherein the two alkyl groups are straight-chain, branched-chain or alicyclic groups having 2 to 8 carbon atoms), poly(meth)allyloxyalkanes (diallyloxyethane, triallyloxyethane, tetraallyloxyethane, tetraallyloxypropane, tetraallyloxybutane, tetramethallyloxyethane, etc.), vinyl monomers having polyalkylene glycol chains (polyethylene glycol (molecular weight 300) mono(meth)acrylate, polypropylene glycol (molecular weight 500) monoacrylate, methyl alcohol ethylene oxide 10 mol adduct (meth)acrylate, lauryl alcohol ethylene oxide 30 mol adduct (meth)acrylate, etc.), poly(meth)acrylates (poly(meth)acrylates of polyhydric alcohols: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, etc.).

[0135] (10) Vinyl (thio) ether An example of the vinyl (thio)ether is vinyl methyl ether.

[0136] (11) Vinyl ketone An example of the vinyl ketone is vinyl methyl ketone.

[0137] (12) Other vinyl monomers Other vinyl monomers include tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0138] From the viewpoint of low-temperature fixing property of the toner according to one embodiment, the resin (b1) and the resin (b2) preferably contain a styrene-(meth)acrylic acid ester copolymer and a (meth)acrylic acid ester copolymer, and more preferably contain a styrene-(meth)acrylic acid ester copolymer.

[0139] The viscoelastic loss modulus G'' of resin (b1) at 100°C and a frequency of 1 Hz is 1.5 to 100 MPa, preferably 1.7 to 30 MPa, and more preferably 2.0 to 10 MPa. Within this range, a structure is easily formed in which resin fine particles containing resin (b1) as a constituent within the same particle are attached to the surface of the toner.

[0140] The loss modulus G'' of the viscoelastic properties of resin (b2) at a frequency of 1 Hz and at 100°C is 0.01 to 1.0 MPa, preferably 0.02 to 0.5 MPa, and more preferably 0.05 to 0.3 MPa. Within this range, toner particles are easily formed in which organic resin fine particles containing resin (b2) as a constituent within the same particle are attached to the surface of the toner particle.

[0141] The loss modulus G″ of the viscoelastic properties of resin (b1) and resin (b2) at a frequency of 1 Hz and 100° C. can be adjusted by changing the types and composition ratio of the constituent monomers or by adjusting the polymerization conditions (types and amounts of initiator and chain transfer agent, reaction temperature, etc.).

[0142] Specifically, by using the composition as shown below, it is possible to adjust the loss modulus G'' of the viscoelastic properties of resin (b1) and resin (b2) at a frequency of 1 Hz and 100°C to be within the above-mentioned range.

[0143] (1) Regarding the glass transition temperature Tg1 calculated from the constituent monomers of the resin (b1) and the glass transition temperature Tg2 calculated from the constituent monomers of the resin (b2), the glass transition temperature Tg1 is preferably 0° C. to 150° C., more preferably 50 to 100° C. The glass transition temperature Tg2 is preferably −30° C. to 100° C., more preferably 0° C. to 80° C., and even more preferably 30° C. to 60° C.

[0144] The glass transition temperature Tg calculated from the constituent monomers can be calculated by the Fox method.

[0145] Here, the Fox method [TGFox, Phys. Rev., 86, 652 (1952)] is a method for estimating the Tg of a copolymer from the Tg of each homopolymer represented by the following formula. 1 / Tg=W1 / Tg1+W2 / Tg2++Wn / Tgn (In the formula, Tg is the glass transition temperature (expressed in absolute temperature) of the copolymer, Tg1, Tg2...Tgn are the glass transition temperatures (expressed in absolute temperature) of the homopolymers of each monomer component, and W1, W2...Wn are the weight fractions of each monomer component.)

[0146] (2) Regarding the calculated acid value (AV1) of the resin (b1) and the calculated acid value (AV2) of the resin (b2), the calculated acid value (AV1) is preferably 75 mgKOH / g to 400 mgKOH / g, more preferably 150 mgKOH / g to 300 mgKOH / g. The calculated acid value (AV2) is preferably 0 mgKOH / g to 50 mgKOH / g, more preferably 0 mgKOH / g to 20 mgKOH / g, and even more preferably 0 mgKOH / g.

[0147] The calculated acid value is a theoretical acid value calculated from the molar amount of acidic groups contained in the constituent monomers and the total weight of the constituent monomers.

[0148] As for the resin (b1), an example of a constituent monomer that satisfies the conditions (1) and (2) is a resin that contains, as a constituent monomer, preferably 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene, and preferably 10% by mass to 60% by mass, and more preferably 30% by mass to 50% by mass of methacrylic acid and / or acrylic acid in total, based on the total weight of the resin (b1).

[0149] The resin (b2) may, for example, be a resin containing, as a constituent monomer, preferably 10% by mass to 100% by mass, and more preferably 30% by mass to 90% by mass of styrene, and preferably 0% by mass to 7.5% by mass, and more preferably 0% by mass to 2.5% by mass of methacrylic acid and / or acrylic acid, based on the total mass of the resin (b2).

[0150] (3) By adjusting the polymerization conditions (type and amount of initiator and chain transfer agent, reaction temperature, etc.), the number average molecular weights Mn1 and Mn2 of resin (b1) and resin (b2) can be adjusted. The number average molecular weight Mn1 is preferably 2,000 to 2,000,000, more preferably 20,000 to 200,000. The number average molecular weight Mn2 is preferably 1,000 to 1,000,000, more preferably 10,000 to 100,000.

[0151] In the present embodiment, the loss modulus G″ of the viscoelastic properties is measured, for example, using the following viscoelasticity measuring device under the following measurement conditions. Measurement device: ARES-24A (manufactured by Rheometrics) Fixture: 25mm parallel plate Frequency: 1Hz Distortion rate: 10% Heating rate: 5℃ / min

[0152] The acid value AVb1 of the resin (b1) is preferably 75 mgKOH / g to 400 mgKOH / g, more preferably 150 mgKOH / g to 300 mgKOH / g. Within this range, it is easy to form a structure in which organic resin fine particles containing vinyl units containing the resins (b1) and (b2) as constituents in the same particle are attached to the surface of the toner base particle.

[0153] Resin (b1) having an acid value within this range is a resin that contains either or both of methacrylic acid and acrylic acid in a total amount of preferably 10% by mass to 60% by mass, and more preferably 30% by mass to 50% by mass, based on the total mass of resin (b1).

[0154] From the viewpoint of low-temperature fixability, the resin (b2) preferably has an acid value (AVb2) of 0 mgKOH / g to 50 mgKOH / g, more preferably 0 mgKOH / g to 20 mgKOH / g, and even more preferably 0 mgKOH / g.

[0155] Resin (b2) having an acid value within this range is a resin that contains either or both of methacrylic acid and acrylic acid in a total amount of preferably 0% to 7.5% by mass, more preferably 0% to 2.5% by mass, based on the total mass of resin (b2).

[0156] The acid value in this embodiment can be measured by the method of JIS K0070:1992.

[0157] The glass transition temperature Tg of the resin (b1) is preferably higher than the glass transition temperature Tg of the resin (b2). Within this range, the ease of forming a structure in which organic resin particles are attached to the surface of the toner base particle and the low-temperature fixability of the toner according to one embodiment are excellent in balance.

[0158] The glass transition temperature Tg of the resin (b1) is preferably at least 10° C. higher than the glass transition temperature Tg of the resin (b2), and more preferably at least 20° C. higher.

[0159] The glass transition temperature Tg of the resin (b1) is preferably 0° C. to 150° C., and more preferably 50° C. to 100° C. When the glass transition temperature Tg of the resin (b1) is 0° C. or higher, the toner according to the embodiment has excellent storage stability. When the glass transition temperature Tg of the resin (b1) is 150° C. or lower, the toner according to the embodiment has little inhibition of low-temperature fixability.

[0160] The glass transition temperature Tg of the resin (b2) is preferably from -30°C to 100°C, more preferably from 0°C to 80°C, and even more preferably from 30 to 60°C. When the glass transition temperature Tg of the resin (b2) is -30°C or higher, the toner according to the embodiment has excellent storage stability. When the glass transition temperature Tg of the resin (b2) is 100°C or lower, the toner according to the embodiment can be less susceptible to inhibition of low temperature fixability.

[0161] The glass transition temperature Tg can be measured by the method (DSC) specified in ASTM D3418-82 using a DSC20, SSC / 580 (manufactured by Seiko Instruments Inc.).

[0162] The solubility parameter (hereinafter, abbreviated as SP value) of the resin (b1) is set to 9 (cal / cm) from the viewpoint of ease of forming a toner in which organic resin fine particles containing the resin (b1) and the resin (b2) as constituents in the same particle are attached to the surface of the toner base particle. 3 ) 1 / 2 ~13(cal / cm 3 ) 1 / 2 , and preferably 9.5 (cal / cm 3 ) 1 / 2 ~12.5(cal / cm 3 ) 1 / 2 More preferably, it is 10.5 (cal / cm 3 ) 1 / 2 ~11.5(cal / cm 3 ) 1 / 2 It is even more preferable that:

[0163] The SP value of the resin (b1) can be adjusted by changing the types and composition ratio of the constituent monomers.

[0164] The SP value of the resin (b2) is set to 8.5 (cal / cm) from the viewpoint of ease of forming a toner in which organic resin fine particles containing the resins (b1) and (b2) as constituent components in the same particle are attached to the surface of the toner base particle. 3 ) 1 / 2 ~12.5(cal / cm 3 ) 1 / 2 9 (cal / cm 3 ) 1 / 2 ~12(cal / cm 3 ) 1 / 2 More preferably, it is 10 (cal / cm 3 ) 1 / 2 ~11(cal / cm 3 ) 1 / 2 It is even more preferable that:

[0165] The SP value of the resin (b2) can be adjusted by changing the types and composition ratio of the constituent monomers.

[0166] The SP value can be calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

[0167] From the viewpoint of the glass transition temperature Tg of the resin (b1) and copolymerizability with other monomers, the resin (b1) preferably contains 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene as a constituent monomer, based on the total mass of the resin (b1).

[0168] From the viewpoint of the glass transition temperature Tg of the resin (b2) and copolymerizability with other vinyl monomers, the resin (b2) preferably contains 10% by mass to 100% by mass, and more preferably 30% by mass to 90% by mass, of styrene as a constituent monomer based on the total mass of the resin (b2).

[0169] The number average molecular weight Mn of the resin (b1) is preferably 2,000 to 2,000,000, and more preferably 20,000 to 200,000. When the number average molecular weight Mn is 2,000 or more, the toner according to the embodiment has excellent storage stability. When the number average molecular weight Mn is 2,000,000 or less, the toner according to the embodiment has little inhibition of low temperature fixability.

[0170] The weight average molecular weight Mw of the resin (b1) is preferably larger than that of the resin (b2). If the weight average molecular weight Mw of the resin (b1) is larger than that of the resin (b2), a good balance is achieved between the ease of forming a toner in which organic resin particles are attached to the surfaces of the toner base particles and the low-temperature fixability of the glass transition temperature Tg of the resin (b1).

[0171] The weight average molecular weight Mw of the resin (b1) is preferably at least 1.5 times, and more preferably at least 2.0 times, larger than the weight average molecular weight of the resin (b2).

[0172] The weight average molecular weight Mw of the resin (b1) is preferably 20,000 to 20,000,000, and more preferably 200,000 to 2,000,000. If the weight average molecular weight Mw is 20,000 or more, the toner according to the embodiment has excellent storage stability. If the weight average molecular weight Mw is 20,000,000 or less, the toner according to the embodiment has little inhibition of low temperature fixability.

[0173] The number average molecular weight Mn of the resin (b2) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000. When the number average molecular weight Mn is 1,000 or more, the toner according to an embodiment has excellent storage stability, and when the number average molecular weight Mn is 1,000,000 or less, the toner according to an embodiment has little inhibition of low-temperature fixability.

[0174] The weight average molecular weight Mw of the resin (b2) is preferably 10,000 to 10,000,000, and more preferably 100,000 to 1,000,000. When the weight average molecular weight Mw is 10,000 or more, the toner according to the embodiment has excellent storage stability. When the weight average molecular weight Mw is 10,000,000 or less, the toner according to the embodiment has little inhibition of low temperature fixability.

[0175] It is particularly preferred that the weight average molecular weight Mw of resin (b1) is 200,000 to 2,000,000, the weight average molecular weight Mw of resin (b2) is 100,000 to 500,000, and the weight average molecular weight Mw of resin (b1) is larger than the weight average molecular weight Mw of resin (b2).

[0176] The number average molecular weight Mn and the weight average molecular weight Mw can be measured by gel permeation chromatography (GPC) under the following conditions. Measuring device: HLC-8120, manufactured by Tosoh Corporation Column: TSK GEL GMH6, Tosoh Corporation, 2 columns ·Measurement temperature: 40℃ Sample solution: 0.25% by mass tetrahydrofuran solution (undissolved matter was removed by filtration using a glass filter) ·Solution injection volume: 100μl Detector: Refractive index detector Reference material: 12 standard polystyrenes (TSKstandard POLYSTYRENE) (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000), manufactured by Tosoh Corporation

[0177] <Characteristics of toner> As described above, the toner according to one embodiment has the following properties. The methods for measuring each of these properties are described below. (1) A plurality of organic resin particles are present on the surface of a toner base particle. (2) The ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles to the second adhesive force A2 of the surface of the toner base particle, as measured by a scanning probe microscope (SPM), is 0.3 to 0.9.

[0178] (1) Method for observing organic resin particles present on the surface of toner base particles (1-1) The external additives are removed as much as possible by a process of isolating the external additives using ultrasonic waves, and the external additives are brought into a state close to that of the toner base particles.

[0179] [How to separate external additives] [1] Add 50 ml of a 5% aqueous solution containing a surfactant (product name: Noigen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to a 100 ml screw tube, add 3 g of toner to the mixture, and gently move it up and down and left and right. Then, mix it with a ball mill for 30 minutes so that the toner blends into the dispersion solution.

[0180] [2] Then, using an ultrasonic homogenizer (product name homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS LLC), set the output to 40 W and apply ultrasonic energy for 60 minutes. (Ultrasonic conditions) Vibration time: 60 minutes continuous ·Amplitude: 40W ·Vibration start temperature: 23±1.5℃. ·Temperature during vibration: 23±1.5℃

[0181] [3] The dispersion liquid is suction-filtered using filter paper (e.g., qualitative filter paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice again with ion-exchanged water, filtered, and the liberated additives are removed, and the toner is then dried.

[0182] (1-2) The toner obtained in (1-1) above is observed with a scanning electron microscope (SEM). First, a backscattered electron image is observed to detect external additives and fillers containing Si.

[0183] (1-3) The image of (1-1) above is binarized using image processing software (ImageJ) to remove the external additives and fillers.

[0184] (1-4) Observe the secondary electron image at the same position as in (1-1) above. Since organic resin fine particles are not observed in the reflected electron image but only in the secondary electron image, by comparing it with the image obtained in (1-3) above, fine particles present in the parts other than the remaining external additives and filler (parts other than those removed in (1-3) above) can be identified as organic resin fine particles.

[0185] (2) Method for measuring the adhesive force of organic resin particles and the adhesive force of the surface of toner base particles using SPM As a measuring device, an SPM probe station (NanoNaviReal, Hitachi High-Tech Science Corporation) equipped with an SPM (multi-function unit AFM5200S, Hitachi High-Tech Science Corporation) was used. (SPM measurement conditions) Measurement unit movement range (measurable sample size): 100μm (Small Unit) Measurement probe: Cantilever (SI-DF3-R, tip radius: 30 nm, probe coating material: rhodium (Rh), spring constant: 1.6 N / m, resonance frequency: 26 kHz, Hitachi High-Tech Science Corporation) Measurement mode: SIS-DFM (SIS: Sampling Intelligent Scan, DFM: Dynamic Force Mode) Measurement range (one field of view): 1μm×1μm Resolution (X data / Y data): 256 / 256

[0186] In an environment with a temperature of 25°C and a humidity of 50% RH, the measurement range (XY plane: 1 μm × 1 μm) of the toner surface was scanned horizontally with the cantilever using the above measurement mode (SIS-DFM) to measure the AFM force curve and obtain a mapping image of the interfacial adhesion force. The AFM force curve is a curve that shows the relationship between the distance between the probe (tip of the cantilever) and the toner and the force (deflection amount) acting on the cantilever. The interfacial adhesion force of the toner (the force required for the cantilever to separate from the surface of the toner base particle) can be obtained from the AFM force curve. In the above measurement device, the pressing force (deflection signal) of the cantilever is detected by an optical lever method. Specifically, a semiconductor laser device irradiates laser light toward the back of the cantilever, and a position sensor detects the laser light (deflection signal) reflected by the back of the cantilever.

[0187] Based on the mapping image of the interfacial adhesion obtained as described above, the interfacial adhesion of the toner base particles was determined. In the above measurement, a cantilever was applied to the organic resin fine particles present on the surface of the toner base particles and to the exposed surface portion of the toner base particles, respectively, to obtain a mapping image of the interfacial adhesion. For five toner base particles contained in the toner, the interfacial adhesion was measured at 10 points for each particle, and 20 measured values ​​were obtained for each of the surface portions of the organic resin fine particles and the toner base particles for each toner. The arithmetic mean value of the 20 measured values ​​for the organic resin fine particles was designated as A1, and the arithmetic mean value of the 20 measured values ​​for the surfaces of the toner base particles was designated as A2.

[0188] [Glass transition temperature (Tg 1st )] The toner according to one embodiment has a glass transition temperature (Tg 1st ) is preferably from 20°C to 50°C, and more preferably from 25°C to 50°C.

[0189] For conventional toners, when the glass transition temperature Tg is about 50° C. or less, the toner is likely to aggregate due to temperature changes during transportation and storage in summer and tropical regions. As a result, the toner solidifies in the toner bottle and adheres to the developing machine. In addition, toner clogging in the toner bottle can cause poor replenishment, and toner adherence in the developing machine can easily cause image abnormalities.

[0190] The toner according to the embodiment has a lower glass transition temperature Tg than conventional toners. However, since the polyester resin, which is a low Tg component in the toner, is non-linear, the toner according to the embodiment can maintain heat-resistant storage stability. In particular, when the polyester resin has a urethane bond or urea bond with high cohesive force, the effect of maintaining heat-resistant storage stability becomes more pronounced.

[0191] When the toner according to an embodiment contains a crystalline polyester resin and a non-crystalline polyester resin, the crystalline polyester resin and the non-crystalline polyester resin, which exist in an incompatible state before heating (before the first temperature increase), become compatible after heating (after the first temperature increase).

[0192] Glass transition temperature Tg at first heating 1st If the glass transition temperature Tg is less than 20° C., the heat resistance storage stability is deteriorated, blocking in the developing machine, and filming on the photoconductor is likely to occur. 1st If the temperature exceeds 50° C., the low-temperature fixing property of the toner decreases.

[0193] The glass transition temperature Tga of the component insoluble in tetrahydrofuran of the toner according to one embodiment at the first temperature rise in DSC 1st The glass transition temperature Tga is preferably from -40°C to 10°C, and more preferably from -30°C to 0°C. The components of the toner that are insoluble in tetrahydrofuran include the reaction products (prepolymers) used as the non-crystalline polyester resin having at least one of the above-mentioned urethane bond and urea bond. 1st However, if the temperature is within the range of -40°C to 10°C, low-temperature fixability and heat-resistant storage stability can be achieved at the same time.

[0194] [Volume average particle size] The volume average particle diameter of the toner according to one embodiment is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 μm to 7 μm.

[0195] <Calculation method for various characteristics of toner components> The glass transition temperature Tg and the melting point of the binder resin may be measured for each of them. Alternatively, the glass transition temperature Tg, the melting point, and the mass ratio of the components may be calculated by separating the components contained in the toner from an actual toner by GPC or the like and measuring the separated components by the analytical method described below.

[0196] Separation of each component by GPC can be carried out, for example, by the following method.

[0197] First, in a GPC measurement using THF (tetrahydrofuran) as the mobile phase, the eluate is fractionated using a fraction collector or the like, and fractions corresponding to a desired molecular weight portion within the full integral of the elution curve are collected.

[0198] The combined eluate is concentrated and dried using an evaporator or the like, and the solid content is dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, 1 H-NMR measurement is performed, and the ratio of constituent monomers can be calculated from the integral ratio of each element.

[0199] As another method, the eluate is concentrated, then hydrolyzed with sodium hydroxide or the like, and the decomposition products are subjected to qualitative and quantitative analysis by high performance liquid chromatography (HPLC) or the like, whereby the ratio of the constituent monomers can be calculated.

[0200] In addition, when the toner forms toner base particles while generating a non-crystalline polyester resin by an elongation reaction and / or a crosslinking reaction between a non-linear reactive precursor and a curing agent, the non-crystalline polyester resin may be separated from the actual toner by GPC or the like to determine the glass transition temperature Tg, etc. of the non-crystalline polyester resin. Alternatively, the non-crystalline polyester resin may be synthesized by an elongation reaction and / or a crosslinking reaction between a non-linear reactive precursor and a curing agent, and the glass transition temperature Tg, etc. may be measured from the synthesized non-crystalline polyester resin.

[0201] [Means for separating toner components] An example of a method for separating each component when analyzing a toner is described in detail. First, 1 g of toner is put into 100 mL of THF, and the solution is obtained by dissolving the soluble portion while stirring for 30 minutes under the condition of 25°C. The solution is filtered through a membrane filter with an opening of 0.2 μm to obtain the THF-soluble portion in the toner. Next, the THF-soluble portion is dissolved in THF to prepare a sample for GPC measurement, and is injected into the GPC used to measure the molecular weight of each resin described above. Meanwhile, a fraction collector is placed at the eluate outlet of the GPC, and the eluate is fractionated at a predetermined count, and the eluate is obtained at 5% area ratios from the start of elution of the elution curve (the rise of the curve). Next, for each elution portion, 30 mg of a sample is dissolved in 1 mL of deuterated chloroform, and 0.05 vol% of tetramethylsilane (TMS) is added as a reference substance. The solution is filled into a 5 mm diameter glass tube for NMR measurement, and a spectrum is obtained by integrating 128 times at a temperature of 23° C. to 25° C. using a nuclear magnetic resonance apparatus (JNM-AL400 manufactured by JEOL Ltd.). The monomer composition and composition ratio of the crystalline polyester resin and non-crystalline polyester resin contained in the toner can be determined from the peak integral ratio of the obtained spectrum.

[0202] For example, the components originating from the peaks can be identified from the peak positions, and the component ratios of the constituent monomers can be calculated from the respective integral ratios, as described below. Peak at around 8.25 ppm: Benzene ring of trimellitic acid (one hydrogen) Peaks around 8.07 ppm to 8.10 ppm: benzene ring of terephthalic acid (4 hydrogen atoms) Peaks around 7.1 ppm to 7.25 ppm: Benzene ring of bisphenol A (4 hydrogen atoms) Peaks around 6.8 ppm: Benzene ring of bisphenol A (4 hydrogens) and double bond of fumaric acid (2 hydrogens) Peaks around 5.2 ppm to 5.4 ppm: Methine derivatives of bisphenol A propylene oxide adducts (one hydrogen atom) Peaks around 4.0 ppm to 5.0 ppm: derived from methylene of aliphatic alcohol (2 hydrogen atoms) Peaks around 3.7 ppm to 4.7 ppm: methylene-derived compounds of bisphenol A propylene oxide adducts (two hydrogen atoms) and methylene-derived compounds of bisphenol A ethylene oxide adducts (four hydrogen atoms) Peaks around 2.2 ppm to 2.6 ppm: derived from methylene of aliphatic dicarboxylic acid (2 hydrogens) Peaks around 1.6 ppm: Bisphenol A and methyl groups of aliphatic alcohols (6 hydrogen atoms)

[0203] From these results, for example, the extract recovered in the fraction in which the crystalline polyester resin accounts for 90% or more of the binder resin can be treated as a crystalline polyester resin.Similarly, the extract recovered in the fraction in which the amorphous polyester resin accounts for 90% or more of the binder resin can be treated as an amorphous polyester resin.

[0204] [Measuring method of melting point and glass transition temperature Tg] The melting point and glass transition temperature Tg can be measured, for example, using a DSC system (differential scanning calorimeter) ("Q-200", manufactured by TA Instruments). Specifically, the melting point and glass transition temperature of the target sample can be measured by the following procedure.

[0205] First, about 5.0 mg of the target sample is placed in an aluminum sample container, the sample container is placed on a holder unit, and set in an electric furnace. Next, in a nitrogen atmosphere, the sample is heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). After that, the sample is cooled from 150°C to -80°C at a heating rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min (second heating). During each of the first and second heating, a DSC curve is measured using a differential scanning calorimeter ("Q-200", manufactured by TA Instruments).

[0206] From the obtained DSC curves, the analysis program in the Q-200 system can be used to select the DSC curve at the first temperature rise and determine the glass transition temperature of the target sample at the first temperature rise. Similarly, the DSC curve at the second temperature rise can be selected and the glass transition temperature of the target sample at the second temperature rise can be determined.

[0207] Furthermore, from the obtained DSC curves, the analysis program in the Q-200 system can be used to select the DSC curve during the first heating and determine the endothermic peak top temperature during the first heating of the target sample as the melting point. Similarly, the DSC curve during the second heating can be selected and the endothermic peak top temperature during the second heating of the target sample as the melting point.

[0208] When toner was used as the target sample, the glass transition temperature during the first heating was determined as Tg 1st Let us assume that.

[0209] Furthermore, unless otherwise specified, the melting point and glass transition temperature of the toner components such as the binder resin may be the endothermic peak top temperature and glass transition temperature Tg during the second heating process.

[0210] As described above, the toner according to one embodiment includes a toner base particle and a plurality of organic resin fine particles arranged on the surface of the toner base particle, and the ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles and the second adhesive force A2 of the surface of the toner base particle is set to 0.3 to 0.9. The presence of the organic resin fine particles on the surface of the toner base particle allows the organic resin fine particles to function as a protective layer for protecting the toner base particle, thereby improving the heat-resistant storage stability of the toner and improving the mechanical durability of the toner. In addition, even if the organic resin fine particles are present on the surface of the toner base particle, the inhibition of thermal conduction between the toner particles during fixing can be suppressed. If the ratio A1 / A2 is greater than 0.9, the organic resin fine particles cannot fully exert the protective effect on the surface of the toner base particle. In addition, the toner lacks mechanical durability and cannot suppress the occurrence of cleaning failure in the developing machine. On the other hand, if the ratio A1 / A2 is less than 0.3, the affinity between the organic resin fine particles and the toner base particle cannot be sufficiently ensured, and sufficient low-temperature fixability cannot be exhibited.

[0211] In the toner according to the embodiment, the ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles to the second adhesive force A2 of the surface of the toner base particle is set to 0.3 to 0.9, so that the organic resin fine particles can function as a protective layer for protecting the toner base particle, and the mechanical durability of the toner can be improved to suppress the occurrence of cleaning failure. Furthermore, the inhibition of thermal conduction between toner particles during fixing can be suppressed. Therefore, the toner according to the embodiment can have high low-temperature fixing property and heat-resistant storage stability, as well as excellent cleaning property.

[0212] The toner according to an embodiment can have a ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles to the second adhesive force A2 of the surface of the toner base particle, measured by a scanning probe microscope, of 0.4 to 0.6, thereby allowing the toner according to an embodiment to have higher low-temperature fixability and heat-resistant storage stability as well as superior cleanability.

[0213] The toner according to one embodiment has a glass transition temperature Tg 1st The glass transition temperature Tga of the toner insoluble in tetrahydrofuran at the first temperature rise of the DSC was 1st can be set to -40° C. to 10° C. This allows the toner to maintain its low-temperature fixability and heat-resistant storage stability, thereby reducing the occurrence of blocking in a developing machine and filming on a photoconductor.

[0214] The toner according to an embodiment may contain a crystalline polyester as a binder resin, which can further improve the low-temperature fixability of the toner.

[0215] In the toner according to an embodiment, the organic resin fine particles can have a core-shell structure composed of two types of resins (b1) and (b2). The organic resin fine particles can have a core-shell structure composed of a shell having resin (b1) and a core having resin (b2). Therefore, when the toner is washed with an organic solvent during the production of the toner, at least a part of the shell dissolves, and a part of the organic resin fine particles attached to the toner base particles can be detached. In addition, even if the toner is washed with an organic solvent, the core is difficult to dissolve in the organic solvent and can remain on the surface of the toner base particles. Therefore, the organic resin fine particles composed of the core can be present scattered on the surface of the toner base particles, so that the low-temperature fixability of the toner can be suppressed from being hindered, and the heat resistance can be improved.

[0216] In the toner according to an embodiment, the organic resin fine particles may contain a styrene-acrylic resin. As a result, even if the toner is washed with an organic solvent, the organic resin fine particles are difficult to dissolve in the organic solvent and can remain on the surface of the toner base particles. Therefore, the organic resin fine particles are likely to be present in a scattered manner on the surface of the toner base particles. As a result, the low-temperature fixability of the toner can be ensured by suppressing the inhibition of low-temperature fixability, and the heat resistance and cleaning ability can be improved.

[0217] The toner according to the embodiment can have an average particle size of organic resin particles of 10 nm to 100 nm. This allows the coverage rate of the toner base particle surface to be optimized, and prevents the coverage rate of the toner surface from becoming too high, while suppressing the size of the voids on the surface of the toner base particle. Therefore, the toner according to the embodiment can maintain good low-temperature fixing performance and heat-resistant storage performance.

[0218] In the toner according to an embodiment, the glass transition temperature Tg of the organic resin fine particles can be set to 30° C. to 60° C. This allows the toner to maintain low-temperature fixability and heat-resistant storage stability, thereby reducing the occurrence of blocking in a developing machine and filming on a photoconductor.

[0219] <Toner manufacturing method> The method for producing the toner according to the embodiment is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include a wet granulation method, a pulverization method, etc. Examples of the wet granulation method include a dissolution suspension method, an emulsion aggregation method, etc. In view of molecular scission due to kneading and the difficulty of uniformly kneading a high molecular weight resin and a low molecular weight resin, the dissolution suspension method and the emulsion aggregation method, which are production methods that do not involve kneading a binder resin, are preferred, and from the viewpoint of resin uniformity in the toner, the dissolution suspension method is more preferred.

[0220] [Dissolution suspension method] The dissolution suspension method includes, for example, a toner material phase preparation step, an aqueous medium phase preparation step, an emulsification or dispersion preparation step, and an organic solvent removal step, and may further include other steps as necessary.

[0221] (Toner material phase (oil phase) preparation process) In the toner material phase preparation step, a toner material containing at least a binder resin and, if necessary, a colorant, a release agent, etc. is dissolved or dispersed in an organic solvent to prepare a solution or dispersion of the toner material (also referred to as a toner material phase or an oil phase).

[0222] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of ease of removal, it is preferable to use a volatile organic solvent having a boiling point of less than 150°C.

[0223] Examples of organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferred, and ethyl acetate is more preferred. These may be used alone or in combination of two or more.

[0224] The amount of the organic solvent used is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 300 parts by mass or less, more preferably 100 parts by mass or less, and particularly preferably 25 parts by mass to 70 parts by mass, relative to 100 parts by mass of the toner materials.

[0225] (Aqueous medium phase (aqueous phase) preparation process) In the aqueous medium phase preparation step, an aqueous medium phase containing resin fine particles in an aqueous medium is prepared.

[0226] The aqueous medium is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include water, a solvent miscible with water, a mixture thereof, etc. Among these, water is particularly preferred.

[0227] The water-miscible solvent is not particularly limited as long as it is miscible with water and can be appropriately selected depending on the purpose. Examples of the water-miscible solvent include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones.

[0228] Examples of the alcohol include methanol, isopropanol, and ethylene glycol.

[0229] Examples of the lower ketones include acetone and methyl ethyl ketone.

[0230] These may be used alone or in combination of two or more.

[0231] The aqueous medium phase is prepared, for example, by dispersing resin particles in an aqueous medium in the presence of a surfactant. The surfactant, organic resin particles, and the like are appropriately added to the aqueous medium in order to improve the dispersion of the toner materials.

[0232] The amounts of the surfactant and organic resin particles added to the aqueous medium are not particularly limited and can be appropriately selected depending on the purpose, and are preferably 0.5% by mass to 10% by mass, respectively, relative to the aqueous medium.

[0233] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the surfactant include anionic surfactants, cationic surfactants, and amphoteric surfactants.

[0234] Examples of the anionic surfactant include fatty acid salts, alkyl sulfate salts, alkylaryl sulfonates, alkyl diaryl ether disulfonates, dialkyl sulfosuccinates, alkyl phosphates, naphthalenesulfonate-formaldehyde condensates, polyoxyethylene alkyl phosphate salts, and glyceryl borate fatty acid esters.

[0235] The resin microparticles can be any resin that can form an aqueous dispersion, and may be a thermoplastic resin or a thermosetting resin. Examples of the material of the resin microparticles include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, polycarbonate resins, etc. These may be used alone or in combination of two or more. Among these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because they are easy to obtain an aqueous dispersion of fine spherical resin particles.

[0236] Examples of vinyl resins include polymers obtained by homopolymerizing or copolymerizing vinyl monomers, such as styrene-(meth)acrylic acid ester copolymers, styrene-butadiene copolymers, (meth)acrylic acid-acrylic acid ester polymers, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, and styrene-(meth)acrylic acid copolymers.

[0237] The average particle size of the resin fine particles can be appropriately selected depending on the purpose, and is, for example, preferably from 5 nm to 200 nm, and more preferably from 20 nm to 300 nm.

[0238] In preparing the aqueous medium phase, cellulose may be used as a dispersant, such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose, etc.

[0239] (Emulsification or dispersion preparation process) In the emulsion or dispersion preparation step, a solution or dispersion of the toner materials (toner material phase) is mixed with an aqueous medium phase and emulsified or dispersed to prepare an emulsion or dispersion.

[0240] The method of emulsification or dispersion is not particularly limited and can be appropriately selected depending on the purpose, and can be performed using, for example, a known dispersing machine, etc. Examples of the dispersing machine include a low-speed shearing dispersing machine and a high-speed shearing dispersing machine.

[0241] The amount of the aqueous medium phase used relative to 100 parts by mass of the toner material phase can be appropriately selected depending on the purpose, and is preferably 50 parts by mass to 2000 parts by mass, and more preferably 100 parts by mass to 1000 parts by mass. If the amount is 50 parts by mass to 2000 parts by mass, it is possible to prevent the dispersion state of the toner material phase from being poor, and thus to prevent problems such as not being able to obtain toner particles of a predetermined particle size and problems that become uneconomical.

[0242] (Organic solvent removal process) In the organic solvent removal step, the organic solvent is removed from the emulsion or dispersion to obtain a solvent-free slurry.

[0243] The organic solvent can be removed by (1) gradually increasing the temperature of the entire reaction system to completely evaporate and remove the organic solvent in the oil droplets of the emulsion or dispersion, or (2) spraying the emulsion or dispersion in a dry atmosphere to completely remove the organic solvent in the oil droplets of the emulsion or dispersion. By removing the organic solvent, a toner (toner particles) is formed.

[0244] (Other processes) Examples of other steps include a washing step and a drying step.

[0245] ((Cleaning process)) In the washing step, after the organic solvent removal step, the solvent-free slurry is washed with water. Examples of water include ion-exchanged water.

[0246] ((Drying process)) In the drying step, the toner particles obtained in the washing step are dried.

[0247] The water is removed in a drying step to obtain the toner according to one embodiment.

[0248] [Crushing method] The pulverization method is a method in which toner base particles are produced by melting and kneading toner materials containing at least a binder resin, pulverizing the mixture, and classifying the mixture.

[0249] The melt kneading is carried out by feeding the mixture obtained by mixing the toner materials into a melt kneader. Examples of the melt kneader include a single-screw or twin-screw continuous kneader and a batch kneader using a roll mill. Specific examples include a KTK twin-screw extruder manufactured by Kobe Steel, Ltd., a TEM type extruder manufactured by Toshiba Machine Co., Ltd., a twin-screw extruder manufactured by KCK Corporation, a PCM type twin-screw extruder manufactured by Ikegai Iron Works, and a co-kneader manufactured by Buss Co., Ltd. This melt kneading is preferably carried out under appropriate conditions that do not cause scission of the molecular chain of the binder resin. Specifically, the melt kneading temperature is carried out with reference to the softening point of the binder resin. If the temperature is higher than the softening point, scission occurs violently, and if the temperature is lower than the softening point, dispersion may not proceed.

[0250] The pulverization is performed by pulverizing the kneaded product obtained by melt kneading. In this pulverization, it is preferable to first coarsely pulverize the kneaded product and then finely pulverize it. In this case, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing by colliding particles with each other in a jet stream, or pulverizing in a narrow gap between a mechanically rotating rotor and a stator is preferably used.

[0251] Classification is a process for adjusting the pulverized product obtained by the above-mentioned pulverization to particles of a predetermined particle size. Classification can be carried out, for example, by removing fine particles using a cyclone, decanter, centrifugal separator, etc.

[0252] By removing the fine particle portion through classification, the toner according to the embodiment is obtained.

[0253] <Developer> The developer according to an embodiment includes the toner according to an embodiment, and may include other components, such as a carrier, which are appropriately selected as necessary. This allows the developer to have excellent transferability, chargeability, and the like, and to stably form high-quality images.

[0254] The developer may be a one-component developer, or may be a two-component developer mixed with a carrier. In particular, when used in a high-speed printer or the like that corresponds to the recent improvement in information processing speed, a two-component developer is preferable from the viewpoint of improving the lifespan.

[0255] When the toner according to one embodiment is used as a single-component developer, even if the toner is balanced, there is little variation in the particle size of the toner, and there is little filming of the toner on the developing roller or fusion of the toner to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term use (stirring) in the developing device.

[0256] When the toner according to one embodiment is used as a two-component developer, even if the toner is balanced over a long period of time, there is little fluctuation in the particle size of the toner, and good and stable developability and images can be obtained even with long-term stirring in a developing device.

[0257] The content of the carrier in the two-component developer can be appropriately selected depending on the purpose, but is preferably 90 parts by mass to 98 parts by mass, and more preferably 93 parts by mass to 97 parts by mass, relative to 100 parts by mass of the two-component developer.

[0258] The developer according to an embodiment can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

[0259] The developer according to an embodiment can also be used as a refill developer.

[0260] [Career] The carrier is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the carrier has a core material and a resin layer (coating layer) that coats the core material.

[0261] (Core material) The core material is not particularly limited as long as it is a magnetic particle and can be appropriately selected depending on the purpose, but preferred are ferrite, magnetite, iron, nickel, etc. Furthermore, in consideration of the adaptability to environmental aspects that have progressed significantly in recent years, it is preferred that the ferrite is not a conventional copper-zinc ferrite but rather manganese ferrite, manganese-magnesium ferrite, manganese-strontium ferrite, manganese-magnesium-strontium ferrite, or lithium ferrite.

[0262] (Resin layer) The material constituting the resin layer is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include amino resins, polyvinyl resins, polystyrene resins, halogenated olefin resins, polyester resins, polycarbonate resins, polyethylene resins, polyvinyl fluoride resins, polyvinylidene fluoride resins, polytrifluoroethylene resins, polyhexafluoropropylene resins, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, fluoro terpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride and non-fluorinated monomers, silicone resins, etc. These may be used alone or in combination of two or more.

[0263] The silicone resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the silicone resin include straight silicone resins consisting only of organosiloxane bonds; modified silicone resins modified with alkyd resins, polyester resins, epoxy resins, acrylic resins, urethane resins, etc.

[0264] As the silicone resin, commercially available products can be used.

[0265] Examples of straight silicone resins include KR271, KR255, and KR152 manufactured by Shin-Etsu Chemical Co., Ltd.; and SR2400, SR2406, and SR2410 manufactured by Dow Corning Toray Silicones Co., Ltd.

[0266] Examples of modified silicone resins include KR206 (alkyd-modified silicone resin), KR5208 (acrylic-modified silicone resin), ES1001N (epoxy-modified silicone resin), and KR305 (urethane-modified silicone resin), all manufactured by Shin-Etsu Chemical Co., Ltd.; and SR2115 (epoxy-modified silicone resin) and SR2110 (alkyd-modified silicone resin), all manufactured by Dow Corning Toray Silicone Co., Ltd.

[0267] Although the silicone resin can be used alone, it is also possible to use a crosslinking component, a charge amount adjusting component, etc., simultaneously.

[0268] The content of the component forming the resin layer in the carrier is preferably 0.01% by mass to 5.0% by mass. When the content is within the above-mentioned preferred range, it is possible to prevent a problem in which a uniform resin layer cannot be formed on the surface of the core material, and a problem in which the resin layer becomes too thick, causing granulation of the carrier particles and making it impossible to obtain uniform carrier particles.

[0269] When the developer is a two-component developer, the toner content is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2.0 parts by mass to 12.0 parts by mass, and more preferably 2.5 parts by mass to 10.0 parts by mass, relative to 100 parts by mass of carrier.

[0270] <Toner storage unit> The toner storage unit according to the embodiment can store the toner according to the embodiment. The toner storage unit according to the embodiment refers to a unit having a function of storing toner and storing the toner. Here, examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.

[0271] The toner storage container refers to a container that stores toner.

[0272] The developing device has a means for containing toner and developing the toner.

[0273] The process cartridge is a cartridge that integrates at least an electrostatic latent image carrier (also called an image carrier) and a developing means, contains toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, a cleaning means, etc.

[0274] The toner storage unit according to the embodiment stores the toner according to the embodiment. By mounting the toner storage unit according to the embodiment on an image forming apparatus and forming an image, the toner according to the embodiment is used to form an image. Therefore, by taking advantage of the characteristics of the toner having high low-temperature fixing property and heat-resistant storage stability as well as excellent cleaning property, it is possible to form a high-quality, high-definition image with long-term image stability.

[0275] <Image forming device> An image forming apparatus according to one embodiment has an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, and may further have other components as necessary.

[0276] The image forming apparatus according to one embodiment more preferably further includes a transfer unit that transfers the toner image formed on the electrostatic latent image carrier onto a surface of a recording medium, and a fixing unit that fixes the transferred image onto the surface of the recording medium.

[0277] In the developing section, a toner according to an embodiment is used. Preferably, a developer containing the toner according to an embodiment and, if necessary, other components such as a carrier may be used to form a toner image.

[0278] (Electrostatic latent image carrier) The material, shape, structure, size, etc. of the electrostatic latent image carrier (sometimes called "electrophotographic photoreceptor" or "photoreceptor") are not particularly limited and can be appropriately selected from known materials. Examples of materials for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Among these, amorphous silicon is preferred in terms of long life.

[0279] As the amorphous silicon photoreceptor, for example, a photoreceptor having a photoconductive layer made of a-Si formed on the support by heating the support to 50° C. to 400° C. and forming a film on the support by a vacuum deposition method, a sputtering method, an ion plating method, a thermal CVD (chemical vapor deposition) method, a photo CVD method, a plasma CVD method, etc. Among these, the plasma CVD method, that is, a method in which a raw material gas is decomposed by a direct current, a high frequency wave, or a microwave glow discharge to form an a-Si deposition film on the support, is preferable.

[0280] The shape of the electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably cylindrical. The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 mm to 100 mm, more preferably 5 mm to 50 mm, and particularly preferably 10 mm to 30 mm.

[0281] (Electrostatic latent image forming section) The electrostatic latent image forming unit is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image carrier, and can be appropriately selected according to the purpose. The electrostatic latent image forming unit includes, for example, a charging member (charger) for uniformly charging the surface of the electrostatic latent image carrier, and an exposure member (exposure device) for imagewise exposing the surface of the electrostatic latent image carrier.

[0282] The charger is not particularly limited and can be appropriately selected depending on the purpose. Examples of the charger include a contact charger equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., and a non-contact charger that utilizes corona discharge such as a corotron or scorotron.

[0283] The shape of the charger may be any shape, such as a roller, a magnetic brush, a fur brush, etc., and can be selected according to the specifications and shape of the image forming apparatus.

[0284] The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying superimposed DC and AC voltages to the electrostatic latent image carrier. Also, the charger is preferably a charging roller that is arranged in close proximity to the electrostatic latent image carrier in a non-contact manner via a gap tape and charges the surface of the electrostatic latent image carrier by applying superimposed DC and AC voltages to the charging roller.

[0285] The charger is not limited to a contact type charger, but it is preferable to use a contact type charging member since it provides an image forming apparatus in which the amount of ozone generated from the charger is reduced.

[0286] The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger in the shape of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposure device include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

[0287] The light source used in the exposure device is not particularly limited and can be appropriately selected depending on the purpose. Examples of the light source include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence (EL), and other light-emitting materials in general.

[0288] In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used.

[0289] It is also possible to employ a backlight system in which exposure is performed imagewise from the back side of the electrostatic latent image bearing member.

[0290] (Developing section) The developing unit is not particularly limited as long as it can develop the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and can be appropriately selected according to the purpose. For example, the developing unit can be suitably used one that contains toner and has a developing device that can apply the toner to the electrostatic latent image in a contact or non-contact manner, and a developing device equipped with a toner container is preferable.

[0291] The developing device may be a single-color developing device or a multi-color developing device. As the developing device, for example, a developing device having an agitator that frictionally agitates the toner to charge it, a magnetic field generating unit fixed inside, and a rotatable developer carrier that carries a developer containing toner on its surface is preferable.

[0292] (Transfer section) The transfer section preferably has a first transfer section that transfers a visible image onto an intermediate transfer body to form a composite transfer image, and a second transfer section that transfers the composite transfer image onto a recording medium. The intermediate transfer body is not particularly limited and can be appropriately selected from known transfer bodies depending on the purpose, and a transfer belt or the like is preferably used.

[0293] The transfer section (first transfer means and secondary transfer section) preferably has at least a transfer device that peels and charges a visible image formed on an electrostatic latent image carrier (photoconductor) onto a recording medium. The number of transfer sections may be one or more.

[0294] Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

[0295] The recording medium is typically plain paper, but there are no particular limitations as long as it is capable of transferring the unfixed image after development, and it can be selected appropriately according to the purpose. A PET base for overhead projectors can also be used.

[0296] (Fixing part) The fixing unit is not particularly limited and can be appropriately selected depending on the purpose, but a known heating and pressing unit is suitable. Examples of the heating and pressing unit include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller, and an endless belt.

[0297] The fixing section is preferably a heating and pressurizing section having a heating element having a heat generating element, a film in contact with the heating element, and a pressure member in pressure contact with the heating element via the film, and capable of heat-fixing the recording medium on which an unfixed image has been formed by passing the recording medium between the film and the pressure member.

[0298] The heating temperature in the heating and pressurizing section is usually preferably 80°C to 200°C.

[0299] The surface pressure in the heating and pressing section is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 N / cm 2 ~80N / cm 2 It is preferable that:

[0300] In this embodiment, depending on the purpose, for example, a known optical fixing device may be used together with or instead of the fixing unit.

[0301] (others) The image forming apparatus according to the first embodiment may further include, for example, a static eliminator, a recycle unit, a controller, and the like.

[0302] ((Static charge removal section)) The charge removing section is not particularly limited as long as it can apply a charge removing bias to the electrostatic latent image bearing member, and can be appropriately selected from among known charge removers. For example, a charge removing lamp or the like is preferably used.

[0303] (Cleaning Department) The cleaning unit may be any type capable of removing the toner remaining on the electrostatic latent image carrier, and may be appropriately selected from among known cleaners. Examples of the cleaning unit include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0304] The image forming apparatus according to the first embodiment has a cleaning section, which improves the cleaning performance. That is, by controlling the adhesion between toner particles, the fluidity of the toner is controlled, and the cleaning performance can be improved. In addition, by controlling the characteristics of the toner after deterioration, it is possible to maintain excellent cleaning quality even under severe conditions such as a long life or high temperature and humidity. Furthermore, since the external additive can be sufficiently liberated from the toner on the photoreceptor, a deposition layer (dam layer) of the external additive in the cleaning blade nip can be formed, thereby achieving high cleaning performance.

[0305] (Recycling Department) The recycling section is not particularly limited, and examples thereof include known conveying means.

[0306] ((Control Unit)) The control unit can control the movement of each of the above-mentioned parts. The control unit is not particularly limited as long as it can control the movement of each of the above-mentioned parts, and can be appropriately selected depending on the purpose. For example, the control unit can be a control device such as a sequencer or a computer.

[0307] The image forming apparatus according to an embodiment can form images using the toner according to an embodiment, and therefore can reduce power consumption and stably provide high-quality images.

[0308] <Image forming method> An image forming method according to an embodiment includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and a developing step of developing the electrostatic latent image with toner to form a toner image, and may further include other steps as necessary. The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming step can be suitably performed by the electrostatic latent image forming unit, the developing step can be suitably performed by the developing unit, and the other steps can be suitably performed by the other units.

[0309] Furthermore, the image forming method according to one embodiment more preferably includes, in addition to the electrostatic latent image forming process and the developing process described above, a transfer process of transferring the toner image onto a recording medium, and a fixing process of fixing the transferred image onto the surface of the recording medium.

[0310] In the developing step, the toner according to an embodiment is used. Preferably, a developer containing the toner according to an embodiment and, if necessary, other components such as a carrier may be used to form a toner image.

[0311] The electrostatic latent image forming process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging process of charging the surface of the electrostatic latent image carrier and an exposure process of exposing the charged surface of the electrostatic latent image carrier to light to form an electrostatic latent image. Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier to light in an imagewise manner using the exposure device. The electrostatic latent image can be formed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it to light in an imagewise manner, and can be performed by an electrostatic latent image forming unit.

[0312] The developing step is a step of sequentially developing the electrostatic latent image with toners of multiple colors to form a visible image. The visible image can be formed, for example, by developing the electrostatic latent image with the toners, using a developing device.

[0313] In the developing device, for example, toner and carrier are mixed and stirred, and the toner becomes charged by friction during this process and is held in a standing state on the surface of the rotating magnet roller, forming a magnetic brush. Since the magnet roller is disposed near an electrostatic latent image carrier (photoconductor), a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier (photoconductor) by electrical attraction. As a result, the electrostatic latent image is developed by the toner, and a visible image made of the toner is formed on the surface of the electrostatic latent image carrier (photoconductor).

[0314] The transfer step is a step of transferring a visible image to a recording medium. The transfer step is preferably performed using an intermediate transfer body, and after the visible image is primarily transferred onto the intermediate transfer body, the visible image is secondarily transferred onto the recording medium. The transfer step is more preferably performed using toner of two or more colors, preferably full-color toner, and includes a primary transfer step of transferring the visible image onto the intermediate transfer body to form a composite transfer image, and a secondary transfer step of transferring the composite transfer image onto the recording medium. The transfer can be performed, for example, by charging an electrostatic latent image carrier (photoconductor) with a transfer charger, and can be performed by a transfer section.

[0315] The fixing process is a process in which the visible image transferred to the recording medium is fixed using a fixing device, and may be performed for each color developer each time it is transferred to the recording medium, or may be performed simultaneously for each color developer in a stacked state.

[0316] The image forming method according to the first embodiment may further include other steps appropriately selected as necessary, such as a static elimination step, a cleaning step, a recycling step, and the like.

[0317] The charge removing step is a step of removing electricity by applying a charge removing bias to the electrostatic latent image bearing member, and can be suitably performed by the charge removing unit.

[0318] The cleaning step is a step of removing the toner remaining on the electrostatic latent image bearing member, and can be suitably performed by a cleaning unit.

[0319] The recycling step is a step in which the toner removed in the cleaning step is recycled to the developing unit, and can be suitably carried out by the recycling unit.

[0320] The image forming method according to an embodiment can form an image using the toner according to an embodiment, and therefore can reduce power consumption and stably provide high-quality images. EXAMPLES

[0321] The embodiments will be described in more detail below with reference to examples and comparative examples, but the embodiments are not limited to these examples and comparative examples.

[0322] <Manufacturing example A-1> [Synthesis of prepolymer (amorphous polyester resin) A-1] Into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added together with titanium tetraisopropoxide (1000 ppm relative to the resin component) so that the molar ratio of hydroxyl groups to carboxyl groups, OH / COOH, was 1.5, the diol component was 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in all monomers was 1 mol%.

[0323] The mixture in the reaction vessel was then heated to 200°C over about 4 hours, then heated to 230°C over 2 hours, and reacted until no water was discharged. The reaction was then continued for 5 hours under reduced pressure of 10mmHg to 15mmHg to obtain intermediate polyester A-1.

[0324] Next, in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, intermediate polyester A-1 and isophorone diisocyanate (IPDI) were added so that the molar ratio (isocyanate group of IPDI / hydroxyl group of intermediate polyester) was 2.0. After that, the mixture was diluted with ethyl acetate to a 50% ethyl acetate solution, and reacted at 100°C for 5 hours to obtain prepolymer A-1.

[0325] The prepolymer A-1 is a non-crystalline polyester resin having at least one of a urethane bond and a urea bond, and is insoluble in tetrahydrofuran. The prepolymer A-1 produces a polyester resin component A-1 corresponding to the polyester resin component A of the toner according to one embodiment during the process of producing the toner in the examples and comparative examples described below.

[0326] <Manufacturing example B-1> [Production of Resin Particle Dispersion B-1] In a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, 3710 parts by mass of water and 200 parts by mass of polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku) were charged, and the mixture was homogenized by stirring at 200 rpm. After that, the mixture in the reaction vessel was heated to raise the temperature in the system to 75°C, and then 90 parts by mass of a 10% by mass ammonium persulfate aqueous solution was added, and then a mixture consisting of 450 parts by mass of styrene, 250 parts by mass of butyl acrylate, and 300 parts by mass of methacrylic acid was dropped over 4 hours. After dropping, the mixture was aged at 75°C for 4 hours to obtain a resin microparticle dispersion B-1 containing a resin (a1-1) which is a polymer in which a monomer and polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium were copolymerized. The volume average particle size of the microparticles in the resin microparticle dispersion B-1 was 15 nm. A part of the resin particle dispersion B-1 was dried to isolate a resin (a1-1). The resin had a glass transition temperature Tg of 53° C. and an acid value of 195 mg KOH / g.

[0327] <Manufacturing example B-2> In a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, 3710 parts by mass of water and 200 parts by mass of polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku) were charged, and the mixture was homogenized by stirring at 200 rpm. After that, the mixture in the reaction vessel was heated to raise the temperature in the system to 75°C, and then 90 parts by mass of a 10% by mass ammonium persulfate aqueous solution was added, and then a mixture consisting of 350 parts by mass of styrene, 350 parts by mass of butyl acrylate, and 300 parts by mass of methacrylic acid was dropped over 4 hours. After dropping, the mixture was aged at 75°C for 4 hours to obtain a resin microparticle dispersion B-2 containing a resin (a1-2) which is a polymer in which a monomer and polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ammonium were copolymerized. The volume average particle size of the microparticles in the resin microparticle dispersion B-2 was 15 nm. A part of the resin particle dispersion B-2 was dried to isolate a resin (a1-2). The resin had a glass transition temperature Tg of 53° C. and an acid value of 195 mg KOH / g.

[0328] <Manufacturing example B-3> In a reaction vessel equipped with a stirring rod and a thermometer, 683 parts by mass of water, 11 parts by mass of sodium salt of methacrylic acid ethylene oxide adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 138 parts by mass of styrene, 138 parts by mass of methacrylic acid, and 1 part by mass of ammonium persulfate were charged and stirred at 400 rpm for 15 minutes. As a result, a white emulsion was obtained. Thereafter, the mixture in the reaction vessel was heated to raise the temperature in the system to 75°C, and reacted for 5 hours. Furthermore, 30 parts by mass of a 1% aqueous ammonium persulfate solution was added, and the mixture was aged at 75°C for 5 hours to obtain a resin microparticle dispersion B-3, which is an aqueous dispersion of a vinyl resin (a copolymer of styrene-methacrylic acid-sodium salt of methacrylic acid ethylene oxide adduct sulfate).

[0329] <Manufacturing example B-4> 20 parts by mass of polyester resin A, 70 parts by mass of ethyl acetate, and 30 parts by mass of methyl ethyl ketone were placed in a beaker, and the mixture was stirred at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to dissolve uniformly, and a polyester resin solution was prepared. Meanwhile, 0.5% by mass of a dispersant (sodium dodecylbenzenesulfonate) and 0.5% by mass of polyvinyl alcohol were dissolved in 450 parts by mass of ion-exchanged water to prepare an aqueous medium. The polyester resin solution was suspended in the aqueous medium using a TK homomixer to form an O / W type emulsion. At this time, the rotation speed of the TK homomixer was set to 12,000 rpm, and the suspension was stirred for 30 minutes. Thereafter, the suspension was heated while being stirred at a rotation speed of 200 rpm using the TK homomixer to remove the mixed solvent. As a result, an aqueous dispersion B-4 containing resin fine particles having a volume average particle size of 110 nm was obtained.

[0330] <Manufacturing example C-1> [Synthesis of amorphous polyester resin C-1] In a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, bisphenol A ethylene oxide side 2 mole adduct, bisphenol A propylene oxide 3 mole adduct, terephthalic acid, adipic acid and trimethylolpropane were charged so that the molar ratio of bisphenol A ethylene oxide side 2 mole adduct and bisphenol A propylene oxide 3 mole adduct (bisphenol A ethylene oxide side 2 mole adduct / bisphenol A propylene oxide 3 mole adduct) was 85 / 15, the molar ratio of terephthalic acid and adipic acid (terephthalic acid / adipic acid) was 75 / 25, the amount of trimethylolpropane in the total monomers was 1 mol%, and the molar ratio of hydroxyl group to carboxyl group, OH / COOH, was 1.2, and the mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at normal pressure and 230°C for 8 hours. After that, the reaction was continued for another 4 hours under reduced pressure of 10 mmHg to 15 mmHg, and then trimellitic anhydride was added to the reaction vessel so as to be 1 mol % relative to the total resin components, and the reaction was continued for 3 hours at 180° C. and normal pressure to obtain amorphous polyester resin C-1.

[0331] <Manufacturing example D-1> [Synthesis of crystalline polyester resin D-1] Dodecanedioic acid and 1,6-hexanediol were charged into a 5L four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple so that the molar ratio of hydroxyl groups to carboxyl groups, OH / COOH, was 0.9, and reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours. The mixture in the four-neck flask was then heated to 200°C and reacted for 3 hours, and further reacted for 2 hours at a pressure of 8.3 kPa. This produced crystalline polyester resin D-1.

[0332] <Preparation of Crystalline Polyester Resin Dispersion> In a container equipped with a stirring rod and a thermometer, 50 parts by mass of crystalline polyester resin D-1 and 450 parts by mass of ethyl acetate were charged, and the temperature was raised to 80°C under stirring, and the temperature was maintained at 80°C for 5 hours. After that, the mixture was cooled to 30°C in 1 hour, and dispersed using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) under conditions of a liquid delivery rate of 1 kg / hour, a disk peripheral speed of 6 m / second, and 80% by volume of zirconia beads with a diameter of 0.5 mm, and 3 passes. Thus, a crystalline polyester resin dispersion 1 was obtained.

[0333] <Example 1> [Preparation of Masterbatch MB] 1200 parts by mass of water, 500 parts by mass of carbon black (Printex35, manufactured by Dexa, DBP oil absorption=42mL / 100mg, pH=9.5) and 500 parts by mass of amorphous polyester resin C-1 were added and mixed in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and the mixture was kneaded using two rolls at 150°C for 30 minutes. Thereafter, the mixture was rolled and cooled, and pulverized with a pulverizer. As a result, master batch 1 was obtained.

[0334] [Preparation of wax dispersion] In a container equipped with a stirring rod and a thermometer, 50 parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiro Co., Ltd., melting point 75°C, SP value 8.8) which is a hydrocarbon wax as a mold release agent 1 and 450 parts by mass of ethyl acetate were charged, and the temperature was raised to 80°C under stirring, and the mixture was kept at 80°C for 5 hours. After that, the mixture was cooled to 30°C in 1 hour, and dispersion was performed using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) under the conditions of a liquid delivery speed of 1 kg / hour, a disk peripheral speed of 6 m / second, 80% by volume of zirconia beads with a diameter of 0.5 mm, and 3 passes. As a result, a wax dispersion liquid 1 was obtained.

[0335] [Synthesis of ketimine compounds] A reaction vessel equipped with a stirring bar and a thermometer was charged with 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone, and the mixture was reacted at 50° C. for 5 hours to obtain ketimine compound 1. The amine value of ketimine compound 1 was 418.

[0336] [Preparation of oil phase] Wax dispersion 1, crystalline polyester dispersion 1, prepolymer A-1, amorphous polyester resin C-1, master batch 1, and ketimine compound 1 as a curing agent were placed in a container in the amounts shown below, and mixed with a TK homomixer (manufactured by Tokushu Kika Co., Ltd.) at 5,000 rpm for 60 minutes to obtain oil phase 1. Wax dispersion 1:600 ​​parts by weight Crystalline polyester dispersion 1:1050 parts by weight Prepolymer A-1: ​​152 parts Amorphous polyester resin C-1: 1000 parts [Masterbatch 1: 100 parts by mass Hardener (ketimine compound 1): 2 parts by weight

[0337] [Preparation of aqueous phase] 990 parts by mass of water, microparticle dispersion B-1, 48.5% aqueous solution of sodium dodecyldiphenyletherdisulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.) and ethyl acetate were mixed and stirred in the amounts shown below to obtain a milky white liquid. This was designated as aqueous phase 1. ·Water: 990 parts by mass ·Fine particle dispersion B-1: 83 parts by mass 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries, Ltd.): 37 parts by weight Ethyl acetate: 90 parts by weight

[0338] [Emulsification / solvent removal] To the container containing the oil phase 1, 1200 parts by mass of the water phase 1 was added, and mixed for 20 minutes at 13,000 rpm with a TK homomixer to obtain emulsified slurry 1. Next, the emulsified slurry 1 was placed in a container equipped with a stirrer and a thermometer, and the solvent was removed at 30°C for 8 hours, and then aged at 45°C for 4 hours to obtain dispersed slurry 1.

[0339] [Washing and drying] 100 parts by mass of the dispersion slurry 1 was filtered under reduced pressure, and the following operations (1) to (4) were carried out twice to obtain a filter cake. (1): 100 parts by mass of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (rotation speed: 12,000 rpm, 10 minutes), and then filtered. (2): 100 parts by mass of a 10% aqueous sodium hydroxide solution was added to the filter cake obtained in (1), and the mixture was mixed with a TK homomixer (rotation speed: 12,000 rpm, 30 minutes), and then filtered under reduced pressure. (3): 100 parts by mass of 10% hydrochloric acid was added to the filter cake obtained in (2), and the mixture was mixed with a TK homomixer (rotation speed: 12,000 rpm, 10 minutes), and then filtered. (4) 300 parts by mass of ion-exchanged water is added to the filter cake obtained in (3), mixed with a TK homomixer (rotation speed: 12,000 rpm, 10 minutes), and then filtered.

[0340] The obtained filter cake was dried in a circulating air dryer at 45° C. for 48 hours and sieved through a mesh having an opening of 75 μm to obtain toner base particles 1.

[0341] [External Addition Treatment] Toner 1 was obtained by mixing 100 parts by weight of toner base particles 1 with 2.2 parts by weight of hydrophobic silica A having an average particle size of 160 nm, 1.0 part by weight of titanium oxide having an average particle size of 20 nm, and 0.8 parts by weight of hydrophobic silica fine powder having an average particle size of 15 nm in a Henschel mixer.

[0342] [Measurement of adhesion force of organic resin particles and the surface of toner base particles using SPM] The adhesive force of the organic resin fine particles contained in the toner 1 and the adhesive force of the surface of the toner base particle 1 were measured as follows.

[0343] The measurement device used was an SPM probe station (NanoNaviReal, Hitachi High-Tech Science Corporation) equipped with an SPM (multi-function unit AFM5200S, Hitachi High-Tech Science Corporation), and the measurement conditions were as follows: (SPM measurement conditions) Measurement unit movement range (measurable sample size): 100μm (Small Unit) Measurement probe: Cantilever (SI-DF3-R, tip radius: 30 nm, probe coating material: rhodium (Rh), spring constant: 1.6 N / m, resonance frequency: 26 kHz, Hitachi High-Tech Science Corporation) Measurement mode: SIS-DFM (SIS: Sampling Intelligent Scan, DFM: Dynamic Force Mode) Measurement range (one field of view): 1μm×1μm Resolution (X data / Y data): 256 / 256

[0344] In an environment with a temperature of 25°C and a humidity of 50% RH, the measurement range (XY plane: 1 μm × 1 μm) of the toner surface was scanned horizontally with the cantilever using the above measurement mode (SIS-DFM) to measure the AFM force curve and obtain a mapping image of the interfacial adhesion force. The AFM force curve is a curve that shows the relationship between the distance between the probe (tip of the cantilever) and the toner and the force (deflection amount) acting on the cantilever. The interfacial adhesion force of the toner (the force required for the cantilever to separate from the surface of the toner base particle) can be obtained from the AFM force curve. In the above measurement device, the pressing force (deflection signal) of the cantilever is detected by an optical lever method. Specifically, a semiconductor laser device irradiates laser light toward the back of the cantilever, and a position sensor detects the laser light (deflection signal) reflected by the back of the cantilever.

[0345] Based on the mapping image of the interfacial adhesion obtained as described above, the interfacial adhesion of the toner base particles was determined. In the above measurement, a cantilever was applied to the organic resin fine particles present on the surface of the toner base particles and to the exposed surface portion of the toner base particles, respectively, to obtain a mapping image of the interfacial adhesion. For five toner base particles contained in the toner, the interfacial adhesion was measured at 10 points for each particle, and 20 measured values ​​were obtained for each of the surface portions of the organic resin fine particles and the toner base particles for each toner. The arithmetic mean value of the 20 measured values ​​for the organic resin fine particles was designated as A1, and the arithmetic mean value of the 20 measured values ​​for the surfaces of the toner base particles was designated as A2.

[0346] The ratio A1 / A2 of the first adhesive force A1 of the organic resin fine particles to the second adhesive force A2 of the surface of the toner base particle measured by SPM was calculated. The calculation results are shown in Table 1.

[0347] [Creating the carrier] 100 parts by mass of silicone resin (organo straight silicone), 5 parts by mass of γ-(2-aminoethyl)aminopropyltrimethoxysilane, and 10 parts by mass of carbon black were added to 100 parts by mass of toluene, and dispersed for 20 minutes with a homomixer to prepare a resin layer coating liquid. Using a fluidized bed type coating device, the resin layer coating liquid was applied to the surface of 1000 parts by mass of spherical magnetite with an average particle size of 50 μm to prepare a carrier.

[0348] [Preparation of developer] A developer was prepared by mixing 5 parts by mass of toner 1 and 95 parts by mass of carrier using a ball mill.

[0349] <Example 2> Toner base particles 2 were obtained in the same manner as in Example 1, except that the content of prepolymer A-1 used in [Preparation of oil phase] was changed to 0 parts by mass and the content of amorphous polyester resin C-1 was changed to 1126 parts by mass. Toner base particles 2 were used to prepare toner 2.

[0350] <Example 3> The procedure of Example 1 was repeated except that the content of the crystalline polyester dispersion 1 used in [Preparation of oil phase] in Example 1 was changed to 0 parts by mass, to obtain toner base particles 3. Toner 3 was produced using these toner base particles 3.

[0351] <Example 4> The procedure of Example 1 was repeated except that the resin particles B-1 used in [Preparation of the aqueous phase] in Example 1 were changed to resin particles B-2, thereby obtaining toner base particles 4. Toner 4 was produced using these toner base particles 4.

[0352] <Example 5> Toner base particles 5 were obtained in the same manner as in Example 1, except that the aqueous sodium hydroxide solution was not used in [washing and drying] in Example 1. Toner base particles 5 were used to prepare toner 5.

[0353] <Example 6> The procedure of Example 1 was repeated to obtain toner base particles 6, except that the resin fine particles B-1 used in [Preparation of aqueous phase] in Example 1 were changed to resin fine particles B-3, and no aqueous sodium hydroxide solution was used in [Washing and drying]. Toner 6 was produced using these toner base particles 6.

[0354] <Comparative Example 1> Toner base particles 7 were obtained in the same manner as in Example 1, except that the resin fine particles B-1 used in [Preparation of aqueous phase] in Example 1 were changed to resin fine particles B-3. Toner 7 was produced using these toner base particles 7. In Toner 7, no organic resin fine particles were observed to adhere to the surfaces of the toner base particles.

[0355] <Comparative Example 2> The procedure of Example 1 was repeated except that the resin fine particles B-1 used in [Preparation of the aqueous phase] in Example 1 were changed to the resin fine particles B-4, thereby obtaining toner base particles 8. Toner 8 was produced using the toner base particles 8.

[0356] <Comparative Example 3> Toner base particles 9 were obtained in the same manner as in Example 1, except that the content of crystalline polyester dispersion 1 used in [Preparation of oil phase] in Example 1 was changed to 1650 parts by mass. Toner base particles 9 were used to prepare toner 9.

[0357] <Evaluation> For each of the toners 1 to 9 prepared in the examples and comparative examples, the low-temperature fixability, heat-resistant storage stability, and cleaning property were evaluated by the following methods. The evaluation results are shown in Table 1.

[0358] [Low temperature fixability] Composite resin particles are applied to the paper surface at 0.8 mg / cm 2 The powder was applied evenly to the paper surface using a printer with the heat fixing unit removed. The paper was then placed on the pressure roller at a fixing speed (heat roller peripheral speed) of 213 mm / sec and a fixing pressure (pressure roller pressure) of 10 kg / cm. 2The temperature at which cold offset occurs (MFT) was measured when the sheet was passed through the above conditions. The lower the temperature at which cold offset occurs, the better the low-temperature fixing ability. (Cold offset evaluation criteria) ◎: Minimum fixing temperature is 130℃ or less ○: The minimum fixing temperature is greater than 130°C and less than or equal to 135°C. △: The minimum fixing temperature is greater than 135°C and less than 140°C ×: The minimum fixing temperature is higher than 140° C.

[0359] [Heat-resistant storage stability] After storing the toner at 50°C for 8 hours, it was sieved through a 42 mesh sieve for 2 minutes and the residual ratio on the wire mesh was measured. At this time, the better the heat resistance storage stability of the toner, the smaller the residual ratio. The evaluation criteria for heat resistance storage stability were as follows. [Evaluation Criteria] ◎: Residual rate is less than 5% ○: Residual rate is 5% or more and less than 15% △: Residual rate is between 15% and 30% ×: Residual rate is 30% or more

[0360] [Cleaning ability] Using an image forming apparatus (imageo MP C5002, manufactured by Ricoh Co., Ltd.), 50,000 sheets (A4 size landscape) of a chart with an image area ratio of 5% were outputted at 3 prints / job in a laboratory environment of 21°C and 65% RH, and 50,000 sheets were passed through. After that, in a laboratory environment of 32°C and 54% RH, 100 sheets of a vertical band pattern (relative to the paper running direction) with 43 mm width and 3 charts were outputted as evaluation images in A4 size landscape, and the obtained images were visually observed, and the cleaning performance was evaluated based on the presence or absence of image abnormalities due to poor cleaning. (Evaluation Criteria) ⊚: Toner that has slipped through due to poor cleaning cannot be visually confirmed on the printed paper or on the photoconductor, and no streaks of toner can be confirmed even when observing the photoconductor in the longitudinal direction with a microscope. ◯: The toner that has slipped through due to poor cleaning cannot be visually confirmed on the printed paper or on the photoconductor. ×: Toner that has slipped through due to poor cleaning can be visually confirmed on the printed paper and on the photoconductor.

[0361] [Table 1]

[0362] From Table 1, it was confirmed that the toners of Examples 1 to 6 all satisfied the conditions for use in terms of low-temperature fixability, heat-resistant storage stability, and cleanability. In contrast, it was confirmed that the toners obtained in Comparative Examples 1 to 3 did not satisfy the conditions for use in terms of at least one of low-temperature fixability, heat-resistant storage stability, and cleanability, or that the organic resin particles did not adhere to the surfaces of the toner base particles, and thus had practical problems.

[0363] Therefore, unlike the toners of Comparative Examples 1 to 3, the toners of Examples 1 to 6 have multiple organic resin microparticles on the surface of the toner, and the ratio A1 / A2 of the first adhesive force A1 of the organic resin microparticles measured by SPM to the second adhesive force A2 on the surface of the toner base particle is set to 0.3 to 0.9, so that the toners of Examples 1 to 6 can be said to be high-quality toners with excellent low fixing properties, heat-resistant storage properties and cleanability.

[0364] Although the embodiment has been described above, the above embodiment is presented as an example, and the present invention is not limited to the above embodiment. The above embodiment can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0365] 1. Image forming device 10 Electrostatic latent image carrier (photoconductor drum) 20 Charging roller (charging part) 30 Exposure device (exposure section) 40 Developing device (developing section) 50 Intermediate transfer body (intermediate transfer belt) 60 Cleaning device (cleaning section) 70 Transfer roller (transfer section) 80 Static electricity removal lamp (static electricity removal part) [Prior art documents] [Patent documents]

[0366] [Patent Document 1] JP 2019-159253 A

Claims

1. A toner comprising two or more types of resin and a release agent, toner base particles containing a binder resin and the release agent; a plurality of organic resin fine particles arranged on the surface of the toner base particle; Including, a ratio A1 / A2 of a first adhesive force A1 of the organic resin fine particles to a second adhesive force A2 of the surface of the toner base particle, which is measured by a scanning probe microscope, is 0.3 to 0.9; The binder resin contains a crystalline polyester, The toner contains an organic resin fine particle having a core-shell structure composed of two kinds of resins, and the organic resin fine particle has a styrene-acrylic resin.

2. a ratio A1 / A2 of a first adhesive force A1 of the organic resin fine particles to a second adhesive force A2 of the surface of the toner base particle measured by a scanning probe microscope is 0.4 to 0.6; The toner according to claim 1 .

3. Glass transition temperature Tg at the first temperature rise in differential scanning calorimetry １ｓｔ is between 20°C and 50°C, The glass transition temperature Tga of the component of the toner that is insoluble in tetrahydrofuran during the first temperature rise in differential scanning calorimetry １ｓｔ 3. The toner according to claim 1, wherein the temperature is from -40°C to 10°C.

4. 4. The toner according to claim 1, wherein the organic resin fine particles have a glass transition temperature Tg of 30° C. to 60° C.

5. A developer comprising the toner according to any one of claims 1 to 4 and a carrier.

6. A toner storage unit containing the toner according to any one of claims 1 to 4.

7. An electrostatic latent image carrier; an electrostatic latent image forming unit for forming an electrostatic latent image on the electrostatic latent image carrier; a developing section for developing the electrostatic latent image with toner to form a visible image; a transfer section for transferring the visible image onto a recording medium; a fixing unit that fixes the transferred image on the recording medium, 5. An image forming apparatus, wherein the toner is the toner according to claim 1.

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