JP7375399B2 - Toner, toner storage unit, and image forming device - Google Patents

Description

The present invention relates to a toner, a toner storage unit, and an image forming apparatus.

In recent years, there has been a demand in the market for improved low-temperature fixability of toners in order to save energy. In order to achieve low-temperature fixability of toner, many toners have been proposed that use both a crystalline resin and an amorphous resin as a binder resin (for example, Patent Document 1). Furthermore, in order to provide toner with good fixability not only at low temperatures but also at high temperatures, a method of adding, for example, wax as a release agent is generally used. By adding wax, it is possible to suppress the problem of toner melting excessively in a high temperature region and fusing to the fixing member (hot offset).

However, when the crystalline resin is exposed on the toner surface, aggregates of toner particles are generated due to stirring stress in the developing device, etc., which causes problems related to the reliability of the toner. On the other hand, if a certain amount or more of wax is not placed near the toner particles, the release effect will not be sufficient and the hot offset described above may occur.
In this way, in order to exhibit excellent fixing properties over a wide range and to have excellent stress resistance, it is important to arrange the crystalline resin and wax mentioned above at appropriate positions in the toner particles. There is active development of such related technologies.

For example, Patent Document 2 uses an infrared analysis method to define a preferable range for the relative amount of the release agent present near the toner surface, and Patent Document 3 specifies the relative amount of the release agent present in the vicinity of the toner surface. A method is described that can provide a toner that can be fixed at a low temperature without deteriorating image quality by sufficiently encapsulating the toner inside the toner particles.

An object of the present invention is to solve the problems in the conventional art and to achieve the following objects. That is, an object of the present invention is to provide a toner that exhibits excellent low-temperature fixing properties and hot offset resistance, as well as excellent heat-resistant storage stability and low filming properties.

Means for solving the above problem are as follows.
That is, the toner includes toner particles containing an amorphous polyester resin, a crystalline polyester resin, and a release agent, and the toner particles satisfy the following (1) and (2). .
(1) The "crystalline polyester resin coverage on the toner particle surface" calculated from a transmission electron microscope (TEM) image of the cross section of the toner particle is less than 10%.
(2) The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by the DSC (differential scanning calorimetry) method into mass, and is 3% by mass or more and 15% by mass of the total toner mass. % or less and is determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method as a value that defines the amount of the release agent present in a depth region of up to 0.3 μm from the surface of the toner particles. , the intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is 0. It is in the range of 10 or more and 0.25 or less.

According to the present invention, it is possible to provide a toner that exhibits excellent low-temperature fixing properties and hot offset resistance, as well as excellent heat-resistant storage stability and low filming properties.

FIG. 1 is a schematic configuration diagram showing an example of an image forming apparatus according to the present invention.

The present invention will be explained in detail below. Note that the present invention is not limited to the embodiments shown below, and may be modified within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. These are also included within the scope of the present invention as long as they exhibit the functions and effects of the present invention.

(toner)
The toner of the present invention includes toner particles containing an amorphous polyester resin, a crystalline polyester resin, and a release agent, and the toner particles satisfy the following (1) and (2). do.
(1) The "crystalline polyester resin coverage on the toner particle surface" calculated from a transmission electron microscope (TEM) image of the cross section of the toner particle is less than 10%.
(2) The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by the DSC (differential scanning calorimetry) method into mass, and is 3% by mass or more and 15% by mass of the total toner mass. % or less and is determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method as a value that defines the amount of the release agent present in a depth region of up to 0.3 μm from the surface of the toner particles. , the intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is 0. It is in the range of 10 or more and 0.25 or less.

In order to prevent the exposure of the crystalline resin to the toner surface and place a certain amount of the release agent near the toner surface, the affinity of the crystalline resin and release agent for the amorphous resin must be appropriately designed. It is important to. In the present invention, it is preferable that the crystalline resin is encapsulated and the release agent is placed in a certain amount near the surface of the toner particles, so that the affinity of the crystalline resin for the amorphous resin is improved. However, it is desirable that the affinity of the mold release agent for the amorphous resin be relatively higher than that of the mold release agent. To this end, it is desirable not only to appropriately combine the configurations of each material, but also to add, if necessary, a material that can control the affinity of the crystalline resin and mold release agent for the amorphous resin.

The inventors of the present invention have found that by appropriately designing the constituent materials of the toner based on the above idea, a toner having the following characteristics can be obtained.
-Excellent low-temperature fixing properties and hot offset resistance.
・Excellent heat-resistant storage stability and low filming properties.

<Binder resin>
The binder resin preferably contains a crystalline polyester resin, and further contains other components as necessary.

<<Crystalline polyester resin>>
The crystalline polyester resin (hereinafter also referred to as "crystalline polyester") is contained in order to achieve both low-temperature fixability and heat-resistant storage stability.

The monomer used for producing the crystalline polyester is not particularly limited and can be appropriately selected depending on the purpose, and examples include the diol component and dicarboxylic acid component described below.

The melting point of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of low-temperature fixability, it is preferably 60° C. to 120° C.
In this specification, a numerical range indicated using "-" indicates a range that includes the numerical values written before and after "-" as the lower limit and upper limit, respectively. That is, 60°C to 120°C means 60°C or more and 120°C or less.

Further, it is preferable that the crystalline polyester has a small amount of residual monomer oligomer.

The weight average molecular weight of the crystalline polyester is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10,000 or more. There is no upper limit to the weight average molecular weight, but from the viewpoint of ease of production, etc., it is preferably 35,000 or less.

There is no particular restriction on the method of introducing the crystalline polyester resin into the toner, and it can be appropriately selected depending on the purpose. In general, the crystalline polyester resin is mechanically crushed and dispersed using a bead mill, etc., and introduced in the form of a dispersion, or it is introduced in the form of a masterbatch, which is kneaded with other binder resins. be.

<<Other ingredients>>
As other components contained in the binder resin, any known resin for toners other than crystalline polyester can be used. Among these, in order to exhibit better low-temperature fixability, it is preferable to use an amorphous polyester resin (hereinafter also referred to as "amorphous polyester resin" or "amorphous polyester"). The amorphous polyester resin has, for example, a benzene ring. The composition of the polyester resin can be changed as appropriate, and it may be one that takes into account affinity with a mold release agent such as a pigment or wax, which will be described later, or it may be a monomer such as a diol component or dicarboxylic acid component. .

Examples of the diol component and dicarboxylic acid component used in the crystalline polyester resin or the amorphous polyester resin are described below. When synthesizing a crystalline polyester resin or an amorphous polyester resin, a diol component and a dicarboxylic acid component appropriately selected from these diol components and dicarboxylic acid components may be used.

-Diol component-
The diol component is not particularly limited and can be appropriately selected depending on the purpose, for example, 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, 1, Aliphatic diols such as 12-dodecane diol; diols having oxyalkylene groups such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; 1,4-cyclohexanedimethanol, hydrogenated bisphenol Alicyclic diols such as A; alicyclic diols with alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; bisphenols with ethylene oxide, propylene Examples include alkylene oxide adducts of bisphenols, such as those to which alkylene oxides such as oxide and butylene oxide are 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.

-Dicarboxylic acid component-
The dicarboxylic acid component is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, aliphatic dicarboxylic acids, aromatic dicarboxylic acids, and the like. Further, anhydrides of these may be used, lower alkyl esters (having 1 to 3 carbon atoms), or halides may be used.

The aliphatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid.
The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferred.
The aromatic dicarboxylic acid having 8 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phthalic acid, isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, and the like.
Among these, aliphatic dicarboxylic acids having 4 to 12 carbon atoms are preferred.
These dicarboxylic acids may be used alone or in combination of two or more.
A branching component and a crosslinking component may be included for the purpose of controlling melting properties.
Examples of the branching component and crosslinking component include monomer components such as polyfunctional aliphatic alcohols such as trimethylolpropane and pentaerythritol, polyfunctional carboxylic acids such as trimellitic acid, and isocyanurate consisting of a trimer of hexamethylene diisocyanate. .

Moreover, it is preferable to use an amorphous polyester (polyester prepolymer) having a functional group containing a nitrogen atom in combination with an unmodified amorphous polyester resin.

-Polyester prepolymer-
The polyester prepolymer is not particularly limited as long as it is a polyester resin having a group capable of reacting with a curing agent, and can be appropriately selected depending on the purpose.
Examples of the group capable of reacting with the curing agent in the polyester prepolymer include a group capable of reacting with an active hydrogen group. Examples of the group capable of reacting with the active hydrogen group include an isocyanate group. Isocyanate groups are preferable because they can introduce urethane bonds or urea bonds into the amorphous polyester resin. When the amorphous polyester resin has either a urethane bond or a urea bond, the urethane bond or urea bond behaves like a pseudo-crosslinking point, and the rubbery properties of the amorphous polyester resin become stronger. , the heat resistant storage stability and hot offset resistance of the toner are better.

--Polyester resin containing isocyanate groups--
The polyester resin containing an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include reaction products of polyester resins having active hydrogen groups and polyisocyanate. The polyester resin having active hydrogen groups can be obtained, for example, by polycondensing a diol component, a dicarboxylic acid component, and at least one of a trihydric or higher alcohol and a trivalent or higher carboxylic acid. The trivalent or higher alcohol and the trivalent or higher carboxylic acid impart a branched structure to the isocyanate group-containing polyester resin.

--Polyisocyanate--
The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, diisocyanate, trivalent or higher valent isocyanate, and the like.

Examples of the diisocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, isocyanurates, and those blocked with phenol derivatives, oximes, caprolactam, and the like.

The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose, and examples include isophorone diisocyanate and cyclohexylmethane diisocyanate.

-Hardening agent-
The curing agent is not particularly limited as long as it reacts with the polyester prepolymer, and can be appropriately selected depending on the purpose. Examples thereof include active hydrogen group-containing compounds.

--Compound containing active hydrogen group--
The active hydrogen group in the active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, such as hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), amino group, carboxyl group, mercapto group. Examples include. These may be used alone or in combination of two or more. As the active hydrogen group-containing compound, amines are preferable since they can form a urea bond.

The amines are not particularly limited and can be selected as appropriate depending on the purpose, such as diamines, trivalent or higher amines, amino alcohols, aminomercaptans, amino acids, and those with blocked amino groups of these. Can be mentioned. These may be used alone or in combination of two or more.
Among these, diamines and mixtures of diamines and a small amount of trivalent or higher amines are preferred.

The diamine is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, aromatic diamine, alicyclic diamine, aliphatic diamine, and the like. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phenylene diamine, 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 isophorone diamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose, such as ethylene diamine, tetramethylene diamine, hexamethylene diamine, and the like.

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

The content of the polyester resin is preferably 90% by mass or more based on the entire binder resin. Note that the upper limit of the content of the polyester resin is preferably 100% by mass. The polyester resin refers to both crystalline polyester resin and amorphous polyester resin. Therefore, in a toner containing a crystalline polyester resin and an amorphous polyester resin, the polyester resin content refers to the sum of the crystalline polyester resin content and the amorphous polyester resin content.
When the content of the polyester resin is 90% by mass or more, low-temperature fixability can be improved.

The content of the binder resin is not particularly limited and can be appropriately selected depending on the purpose. % to 95% by mass is preferred. Within the above range, low-temperature fixing properties, charging properties, etc. are excellent.

<Colorant>
Examples of the colorant used in the toner of the present invention include carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, calco oil blue, chrome yellow, quinacridone, benzidine yellow, Conventionally known dyes and pigments such as rose bengal and triallylmethane dyes can be used. These can be used alone or in combination, and can be used as a black toner or a full color toner.

The content of these colorants is preferably 1% by mass to 30% by mass, more preferably 3% by mass to 20% by mass, based on the binder resin component of the toner.

<Release agent>
The mold release agent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include carbonyl group-containing waxes, polyolefin waxes, long-chain hydrocarbons, and the like. These may be used alone or in combination of two or more. Among these, carbonyl group-containing waxes are preferred.

Examples of the carbonyl group-containing wax include polyalkanoic acid esters, polyalkanol esters, polyalkanoic acid amides, polyalkylamides, dialkyl ketones, and the like.

Examples of the polyalkanoic acid ester include carnauba wax, montan wax, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, and 1,18-octadecane. Examples include diol distearate.
Examples of the polyalkanol ester include tristearyl trimellitate and distearyl maleate.
Examples of the polyalkanoic acid amide include dibehenylamide.
Examples of the polyalkylamides include trimellitic acid tristearylamide.
Examples of the dialkyl ketone include distearyl ketone.
Among these carbonyl group-containing waxes, polyalkanoic acid esters are particularly preferred.
Examples of the polyolefin wax include polyethylene wax and polypropylene wax.
Examples of the long-chain hydrocarbon include paraffin wax and Sasol wax.

The melting point of the mold release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50°C to 100°C, more preferably 60°C to 90°C. When the melting point is 50° C. to 100° C., heat-resistant storage stability is better, and cold offset during fixing at low temperatures can be further prevented.

The melting point of the mold release agent can be measured using, for example, a differential scanning calorimeter (TA-60WS and DSC-60, manufactured by Shimadzu Corporation).
First, 5.0 mg of a mold release agent is placed in an aluminum sample container, and the sample container is placed on a holder unit and set in an electric furnace. Next, in a nitrogen atmosphere, the temperature was raised from 0 °C to 150 °C at a temperature increase rate of 10 °C/min, and then the temperature was lowered from 150 °C to 0 °C at a temperature decrease rate of 10 °C/min, and then further heated at a temperature increase rate of 10 °C/min. The temperature is raised to 150° C. at min and the DSC curve is measured. From the obtained DSC curve, 2nd. The maximum peak temperature of heat of fusion during heating can be determined as the melting point.

The melt viscosity of the mold release agent is preferably 5 mPa·sec to 100 mPa·sec, more preferably 5 mPa·sec to 50 mPa·sec, particularly preferably 5 mPa·sec to 20 mPa·sec, as measured at 100°C. When the melt viscosity is from 5 mPa·sec to 100 mPa·sec, the mold releasability is excellent and the hot offset resistance is even more excellent.

<Other ingredients>
The other components are not particularly limited as long as they are used in ordinary toners, and can be appropriately selected depending on the purpose. Examples thereof include charge control agents, external additives, and the like.

<<Charge control agent>>
The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Examples include a simple substance or a compound of tungsten, a simple substance or a compound of tungsten, a fluorine-based activator, a metal salt of salicylic acid, a metal salt of a salicylic acid derivative, and the like. Specifically, Bontron 03 is a nigrosine dye, Bontron P-51 is a quaternary ammonium salt, Bontron S-34 is a metal-containing azo dye, E-82 is an oxynaphthoic acid metal complex, and E is a salicylic acid metal complex. -84, phenolic condensate E-89 (manufactured by Orient Chemical Industry Co., Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (all manufactured by Hodogaya Chemical Industry Co., Ltd.), LRA-901 , LR-147 (manufactured by Nippon Carlit Co., Ltd.), which is a boron complex, and the like.

The content of the charge control agent is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 0.01 parts by mass to 5 parts by mass, and 0.01 parts by mass to 5 parts by mass, based on 100 parts by mass of the toner. 02 parts by mass to 2 parts by mass is more preferable. When the content is from 0.01 parts by mass to 5 parts by mass, the charge rise property and charge amount will be sufficient, the toner image will be excellent, the fluidity of the developer will be good, and the image density will be excellent.

<<External additives>>
The external additive is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include silica, fatty acid metal salts, metal oxides, hydrophobized titanium oxide, and fluoropolymers.

Examples of the fatty acid metal salt include zinc stearate and aluminum stearate.
Examples of the metal oxide include titanium oxide, aluminum oxide, tin oxide, and antimony oxide.

Examples of commercially available silica include R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.).
Commercially available titanium oxide products include, for example, P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), and TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.). , MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika).
Examples of commercially available hydrophobized titanium oxides include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, and TAF. -1500T (all manufactured by Fuji Titanium Industries), MT-100S, MT-100T (all manufactured by Teika), and IT-S (manufactured by Ishihara Sangyo).
Examples of the hydrophobic treatment include a method of treating hydrophilic fine particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane.

The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.1 parts by mass to 5 parts by mass, and 0.1 parts by mass to 5 parts by mass, based on 100 parts by mass of the toner. More preferably 3 parts by mass to 3 parts by mass.

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 less than 3 nm, the external additive may be buried in the toner, making it difficult to effectively exert its function, and if it exceeds 100 nm, the surface of the photoreceptor may be unevenly damaged. .

<Characteristics of toner>
The toner of the present invention has the following characteristics.
(1) The "crystalline polyester resin coverage on the toner particle surface" calculated from a transmission electron microscope (TEM) image of the cross section of the toner particle is less than 10%.
(2) The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by the DSC (differential scanning calorimetry) method into mass, and is 3% by mass or more and 15% by mass of the total toner mass. % or less and is determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method as a value that defines the amount of the release agent present in a depth region of up to 0.3 μm from the surface of the toner particles. , the intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is 0. It is in the range of 10 or more and 0.25 or less.

<<Crystalline polyester resin coverage on toner particle surface>>
The coverage of the crystalline polyester resin on the surface of the toner particles calculated from a TEM image of the cross section of the toner particles is preferably less than 10%, more preferably less than 5%. When the crystalline polyester resin coverage is 10% or more, a large amount of the crystalline polyester resin is exposed on the surface of the toner, and the toner does not have sufficient low-temperature fixing properties, heat-resistant storage stability, and low filming properties. Further, the coverage rate of the crystalline polyester resin on the surface of the toner particles is preferably as low as possible, and is preferably 0%.

The crystalline polyester resin coverage on the surface of the toner particle calculated from a TEM image of the cross section of the toner particle can be measured by observing the cross section of the toner particle using a transmission electron microscope. As a measurement method, for example, the measurement can be performed by the following procedure.
[Sample preparation]
(1) After the toner is sufficiently dispersed in a room temperature curable epoxy resin, it is left to stand for one day or more to allow the epoxy resin to undergo a curing reaction to obtain a cured product in which the toner is embedded.
(2) A thin film section is cut out from the cured product in which the toner is embedded under the following cutting conditions, and the obtained thin film section is stained with ruthenium tetroxide.
-Cutting conditions-
・Cutting thickness: 75nm
・Cutting speed: 0.05-0.2 mm/sec
- Using a diamond knife (Ultra Sonic 35°) Using a transmission electron microscope (TEM), take a cross-sectional image of a toner particle so that one toner particle fits within the entire field of view. By staining with ruthenium tetroxide, components with different degrees of crystallinity contained in the toner particles are dyed with contrast, so that the domains of the crystalline resin contained in the toner particles can be identified. Note that, in the observed cross section of the toner particles, those that are dyed in a rod-like or linear shape and have a lamellar structure derived from crystallinity can be considered to be crystalline polyester resin.
From the observed cross-sectional image, the circumferential length of the toner particle cross-section is measured and designated as A. Next, the length of each crystalline polyester resin localized on the toner particle contour is measured from the observed cross-sectional image, and the total value is defined as B. The B/A calculated above is treated as the "crystalline polyester resin coverage on the toner particle surface" in the present invention.

Furthermore, if it is difficult to distinguish between the crystalline polyester resin and the mold release agent, the treatment shown in (3) below may be added between (1) and (2) above. By performing observation after extracting only the release agent from the toner, the crystalline polyester resin can be observed more clearly.
(3) Using a microtome equipped with a diamond blade, expose the cross section of the cured product, and immerse the cured product with the exposed cross section in an organic solvent (hexane) that dissolves only the mold release agent for 3 hours. , dissolves only the domains of the mold release agent.

The observation conditions of the transmission electron microscope can be carried out, for example, according to the conditions shown below.
[Observation conditions]
・Equipment used: JEOL transmission electron microscope JEM-2100F
・Acceleration voltage: 200kV
・Morphological observation: Bright field method ・Setting conditions: spot size: 3, CLAP: 1, OLAP: 3, Alpha: 3

Based on the above TEM image, the coverage of the crystalline polyester resin is measured. Specifically, the cross sections of 50 toner particles are observed. The cross section of the toner particle to be observed is one in which the major axis of the cross section is within a range of ±20% of the number average particle diameter of the toner particle. The number average particle diameter of the toner particles is measured using a particle size distribution measuring device (Multisizer III, manufactured by Coulter Inc.).

<<Content of mold release agent and relative quantification of mold release agent present near the surface>>
In the toner of the present invention, the dispersion state of the release agent can be defined by the total amount of the release agent in the toner particles and the amount of the release agent near the surface of the toner particles by the measurement shown below.

<<<Content of mold release agent>>>
The total amount of release agent in the toner particles is obtained by DSC (differential scanning calorimetry) method. A toner sample and a sample of a release agent alone are measured using the following measuring device and conditions, and the amount of heat absorbed by each release agent is determined from the ratio of the endothermic amounts of the release agents obtained.
・Measuring device: DSC device (DSC60; manufactured by Shimadzu Corporation)
・Sample amount: Approximately 5mg
・Heating temperature: 10℃/min
・Measurement range: Room temperature to 150℃
- Measurement environment: In a nitrogen gas atmosphere The total amount of mold release agent was calculated using the following formula 1.
Total amount of release agent (mass%) = (endothermic amount of release agent of toner sample (J/g)) x 100)/(endothermic amount of release agent alone (J/g))...Formula 1
In this way, the above analysis shows that even if the release agent flows out during the toner manufacturing process and all of the released agent is not contained in the toner, the total amount of the release agent in the toner particles can be effectively determined. be able to.

<<<Relative quantification of mold release agent present near the surface>>>
The amount of the release agent near the surface of the toner particles can be obtained by FTIR-ATR (total internal reflection absorption infrared spectroscopy) method. Based on the measurement principle, the analysis depth is approximately 0.3 μm, and this analysis allows determining the relative amount of release agent in a 0.3 μm depth region from the surface of the toner particles. The measurement method is as follows.

First, as a sample, 3 g of toner was pressed with an automatic pellet molding machine (Type M No. 50 BRP-E; manufactured by MAEKAWA TESTING MACHINE CO.) under a load of 6 tons for 1 minute to produce a 40 mmφ (approximately 2 mm thick) pellet. . The surface of the toner pellet was measured by FTIR-ATR method. The micro FTIR device used was Spectrum One manufactured by PERKIN ELMER, which was equipped with a MultiScope FTIR unit, and the measurement was performed using a germanium (Ge) crystal micro ATR with a diameter of 100 μm. Measurements were taken at an infrared incident angle of 41.5°, a resolution of 4 cm ⁻¹ , and a cumulative total of 20 times.
The intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is calculated as the toner particle. This was taken as the relative amount of release agent near the surface. The average value after measuring four times at different measurement locations was used as the value.
Note that the peak derived from the mold release agent (2850 cm ^-1 ) is absorption based on the C--H symmetric stretching vibration of the methylene group, and the peak derived from the amorphous polyester resin (828 cm ^-1 ) is due to the benzene structure. This absorption is based on C-H out-of-plane bending vibration.
From the analysis results of various toners, the value of the total amount of release agent determined by the above DSC method and the value of the intensity ratio (P2850/P828) determined by the FTIR-ATR method are due to differences in the toner manufacturing process, etc. Different correlations were observed depending on the dispersion state.

In a preferred embodiment of the present invention, at least a crystalline polyester resin, an amorphous polyester resin, a polyester prepolymer having a nitrogen atom-containing functional group, a curing agent, a coloring agent, and a mold release agent are dispersed in an organic solvent. Toner produced by dispersing a toner material liquid in an aqueous medium in the presence of fine resin particles and subjecting it to crosslinking and/or elongation reactions does not have a release agent on the outermost surface of the toner particles and is uniformly dispersed in the particles. The above correlation was investigated by varying the total amount of release agent in this toner, and the results were as follows.

In a region where the total amount of release agent is small, the amount of release agent near the surface of the toner particles, indicated by the value of the intensity ratio (P2850/P828), is constant at 0, and after the total amount of release agent exceeds a certain value, , an increase in the value of the intensity ratio (P2850/P828) is observed.
This confirms that the release agent in the toner particles is not selectively dispersed near the surface, but is uniformly dispersed in the region inside the outermost surface of the toner particle.
In addition, the release agent present at a depth of 0.3 μm from the toner particle surface, which is analyzed by the FTIR-ATR method, is located in a position where it is easy to seep out onto the toner surface, so it effectively exhibits toner release properties. It is something to do.
The total amount of the mold release agent determined by the DSC method is 3% by mass or more and 15% by mass or less, preferably 3% by mass or more and 13% by mass or less. If the total amount of the release agent is less than 3% by mass, the amount of the release agent contained in the toner particles is too small, making it impossible to obtain sufficient release properties during fixing, resulting in a decrease in hot offset resistance. Furthermore, if the total amount of the mold release agent exceeds 15% by mass, although a mold release effect is obtained, problems such as a decrease in heat-resistant storage stability and toner adhesion (filming) to the carrier, photoreceptor, and blade may occur. .
Furthermore, the relative amount of release agent near the surface of the toner particles determined by the FTIR-ATR method is in the range of 0.10 or more and 0.25 or less in terms of intensity ratio (P2850/P828), and is 0.15 or more. It is preferably 0.22 or less.
When the intensity ratio is less than 0.10, the amount of release agent near the surface of the toner particles is small, resulting in a decrease in hot offset resistance.
Moreover, if the intensity ratio exceeds 0.25, the amount of release agent on the outermost surface of the toner particles increases, which is not preferable because heat-resistant storage stability and filming properties are reduced.
In order to achieve good compatibility between low-temperature fixing properties and hot offset resistance, heat-resistant storage stability, low filming properties, etc., the above-mentioned intensity ratio is more preferably in the range of 0.15 or more and 0.22 or less. Good.

As mentioned above, in order to prevent the exposure of the crystalline polyester resin to the toner surface and to arrange a certain amount or more of the release agent near the toner surface, the crystalline polyester resin and the crystalline polyester resin of the release agent must be It is important to appropriately design the affinity for other binder resins. In the present invention, a material that has a high affinity with the crystalline polyester resin and a relatively low affinity with the mold release agent compared to the crystalline polyester resin is added to the toner. Specifically, for example, a mixture of melt-kneaded crystalline polyester resin and amorphous polyester resin (hybrid resin) is introduced into the toner.
As a result, although the principle is not clear, the transesterified product produced by melt-kneading crystalline polyester resin and amorphous polyester resin has an affinity for crystalline polyester resin and amorphous polyester resin. It exhibits a enhancing effect and encapsulates crystalline polyester resin. On the other hand, since the release agent has a lower affinity than the crystalline polyester resin, it is thought that the effect of being relatively pushed out to the surface of the toner particles appears.
In the present invention, by adding the hybrid resin to the toner and optimizing its amount, it is possible to reduce the coverage of the crystalline polyester resin on the surface of the toner particles to less than 10%, and to reduce the amount of the hybrid resin in the toner. The content of the molding agent is 3% by mass or more and 15% by mass or less of the total toner mass, as calculated by mass conversion of the endothermic amount of the mold release agent determined by DSC (differential scanning calorimetry) method, and A peak derived from the mold release agent determined by FTIR-ATR (total internal reflection absorption infrared spectroscopy) as a value that defines the amount of the mold release agent present in a depth region of up to 0.3 μm from the surface of the particle. The intensity ratio (P2850/P828) between the intensity (P2850) at (2850 cm ^-1 ) and the intensity (P828) at the peak (828 cm ^-1 ) derived from the amorphous polyester resin is in the range of 0.10 or more and 0.25 or less. It can be done.

<<Toner particle size>>
The volume average particle diameter (Dv) of the toner of the present invention is preferably 3 μm to 8 μm, for example.

The ratio (Dv/Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) in the toner is preferably 1.00 to 1.25.

The above (Dv) and (Dn) can be measured by Coulter counter method. Examples of the measuring device include Coulter Counter TA-II, Coulter Multisizer II, and Coulter Multisizer III (all manufactured by Coulter Inc.).
The measurement method will be described below.
First, 0.1 mL to 5 mL of a surfactant (preferably an alkylbenzene sulfonate) as a dispersant is added to 100 mL to 150 mL of an electrolytic aqueous solution. Here, the electrolyte is an approximately 1% by mass NaCl aqueous solution prepared using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 mg to 20 mg of the measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of toner particles or toner were measured using the above measuring device using a 100 μm aperture as an aperture. , calculate the volume distribution and number distribution. From the obtained distribution, the volume average particle diameter (Dv) and number average particle diameter (Dn) of the toner can be determined.

As a channel, 2.00 μm or more and less than 2.52 μm; 2.52 μm or more and less than 3.17 μm; 3.17 μm or more and less than 4.00 μm; 4.00 μm or more and less than 5.04 μm; 5.04 μm or more and less than 6.35 μm; 6 .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; 20.20 μm or more and less than 25. Thirteen channels of less than 40 μm; 25.40 μm or more and less than 32.00 μm; 32.00 μm or more and less than 40.30 μm are used, and particles with a particle size of 2.00 μm or more and less than 40.30 μm are targeted.

<Toner manufacturing method>
The method for producing the toner is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include wet granulation, pulverization, and the like. Examples of the wet granulation method include a dissolution suspension method and an emulsion aggregation method. Due to the difficulty of molecular cutting during kneading and uniform kneading of high molecular weight resin and low molecular weight resin, the dissolution suspension method and emulsion aggregation method, which are manufacturing methods that do not involve kneading of the binder resin, are preferred. The dissolution suspension method is more preferred from the viewpoint of resin uniformity.

-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 further includes other steps as necessary. Examples include methods of including.

--Toner material phase (oil phase) preparation process--
The toner material phase preparation step includes, for example, the crystalline polyester resin, the amorphous polyester resin, the polyester prepolymer, the hybrid resin, the curing agent, the release agent, and the colorant. There is no particular restriction as long as the process involves dissolving or dispersing a toner material containing the above in an organic solvent to prepare a solution or dispersion of the toner material (sometimes referred to as a toner material phase or oil phase). It can be selected as appropriate depending on the purpose.

The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but a volatile one with a boiling point of less than 150° C. is preferred from the viewpoint of ease of removal.
Examples of the organic solvent include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, and ethyl acetate. , methyl ethyl ketone, methyl isobutyl ketone, and the like. 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.
The amount of the organic solvent to be 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, based on 100 parts by mass of the toner material. Particularly preferred is 25 parts by weight to 70 parts by weight.

--Aqueous medium phase (aqueous phase) preparation process--
The aqueous medium phase preparation step is not particularly limited as long as it is a step of preparing an aqueous medium phase, and can be appropriately selected depending on the purpose. In this step, it is preferable to prepare an aqueous medium phase containing fine resin particles in an aqueous medium.
The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, water, water-miscible solvents, and mixtures thereof. Among these, water is particularly preferred.
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, such as alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, etc. can be mentioned.
Examples of the alcohol include methanol, isopropanol, and ethylene glycol.
Examples of the lower ketones include acetone and methyl ethyl ketone.
These may be used alone or in combination of two or more.

The aqueous medium phase is prepared, for example, by dispersing the resin fine particles in the aqueous medium in the presence of a surfactant. The purpose of appropriately adding the surfactant, the resin fine particles, etc. to the aqueous medium is to improve the dispersion of the toner material.
The amounts of the surfactant and the resin fine particles to be added to the aqueous medium are not particularly limited and can be appropriately selected depending on the purpose, but each is 0.5% by mass relative to the aqueous medium. ~10% by mass is preferred.
The surfactant is not particularly limited and can be appropriately selected depending on the purpose, and includes, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like.
Examples of the anionic surfactant include fatty acid salts, alkyl sulfate ester salts, alkylaryl sulfonates, alkyl diaryl ether disulfonates, dialkyl sulfosuccinates, alkyl phosphates, naphthalene sulfonic acid formalin condensates, and polyesters. Examples include oxyethylene alkyl phosphate ester salts and glyceryl borate fatty acid esters.

The resin fine particles may 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 fine particles include vinyl resin, polyurethane resin, epoxy resin, polyester resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin. Examples include. 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 from the standpoint of easily obtaining an aqueous dispersion of fine spherical resin particles.
Examples of the vinyl resin include polymers obtained by homopolymerizing or copolymerizing vinyl monomers, such as styrene-(meth)acrylic acid ester copolymer, styrene-butadiene copolymer, and (meth)acrylic acid-acrylic acid. Examples include acid ester polymers, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, and styrene-(meth)acrylic acid copolymers.

The average particle size of the resin fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 nm to 200 nm, more preferably 20 nm to 300 nm.
In preparing the aqueous medium phase, cellulose may be used as a dispersant. Examples of the cellulose include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, sodium carboxymethylcellulose, and the like.

--Emulsification or dispersion preparation process--
The emulsification or dispersion preparation step is a step of mixing and emulsifying or dispersing the toner material solution or dispersion (toner material phase) and the aqueous medium phase to prepare an emulsion or dispersion; There is no particular restriction, and it can be selected as appropriate depending on the purpose.

The method of emulsification or dispersion is not particularly limited and can be appropriately selected depending on the purpose, and can be carried out using, for example, a known dispersing machine. Examples of the disperser include a low-speed shear type disperser, a high-speed shear type disperser, and the like.

The amount of the aqueous medium phase to be used with respect to 100 parts by mass of the toner material phase is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 parts by mass to 2,000 parts by mass, and 100 parts by mass. ˜1,000 parts by mass is more preferable.

--Organic solvent removal process--
The organic solvent removal step is not particularly limited as long as it is a step of removing the organic solvent from the emulsification or dispersion to obtain a solvent-free slurry, and can be appropriately selected depending on the purpose.
The organic solvent can be removed by (1) gradually raising the temperature of the entire reaction system to completely evaporate and remove the organic solvent in the oil droplets of the emulsification or dispersion, or (2) removing the organic solvent from the oil droplets of the emulsion or dispersion. Examples include a method of completely removing the organic solvent in the oil droplets of the emulsion or dispersion by spraying into a dry atmosphere. Upon removal of the organic solvent, toner particles are formed.

--Other processes--
Examples of the other steps include a washing step and a drying step.

---Washing process---
The washing step is not particularly limited as long as it is a step of washing the desolventized slurry with water after the organic solvent removal step, and can be appropriately selected depending on the purpose. Examples of the water include ion exchange water.

---Drying process---
The drying step is not particularly limited as long as it dries the toner particles obtained in the washing step, and can be appropriately selected depending on the purpose.

-Crushing method-
The pulverization method is a method of producing base particles of the toner by, for example, pulverizing and classifying a melt-kneaded toner material containing at least a binder resin.

The melt-kneading is performed by charging the mixture obtained by mixing the toner materials into a melt-kneader. Examples of the melt-kneading machine include a single-screw or twin-screw continuous kneading machine, a batch-type kneading machine using a roll mill, and the like. Specifically, for example, a KTK type twin screw extruder manufactured by Kobe Steel, a TEM type extruder manufactured by Toshiba Machinery Co., Ltd., a twin screw extruder manufactured by KC Corporation, a PCM type twin screw extruder manufactured by Ikegai Iron Works, a type manufactured by Busu Co., Ltd. Examples include Koneydar. This melt-kneading is preferably carried out under appropriate conditions that do not cause molecular chain scission of the binder resin. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin; if it is higher than the softening point, severe cutting may occur, and if it is too low, dispersion may not proceed.

The pulverization is a step of pulverizing the kneaded material obtained by the melt-kneading. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, it is preferable to use a method of pulverizing the particles by colliding with a collision plate in a jet stream, pulverizing the particles by colliding with each other in a jet stream, or pulverizing the particles in a narrow gap between a mechanically rotating rotor and a stator.

The classification is a process of adjusting the pulverized material obtained by the pulverization into particles having a predetermined particle size. The classification can be performed by removing fine particles using, for example, a cyclone, a decanter, a centrifuge, or the like.

(Developer)
The developer of the present invention contains the toner of the present invention. The developer may be used as a one-component developer, or may be mixed with a carrier and used as a two-component developer. Among these, the two-component developer is preferable in terms of improved lifespan, etc. when used in high-speed printers that are compatible with recent improvements in information processing speed.

In the case of the one-component developer using the toner, there is little variation in the particle size of the toner even when the toner is accounted for, and filming of the toner on the developing roller is less likely to occur.
In addition, in the case of the two-component developer using the toner, even if toner balance is maintained over a long period of time, there is little variation in the toner particle diameter in the developer, and toner filming on the developing roller is less likely to occur. .
Further, the developer of the present invention can also be used as a replenishment developer.

<Career>
The carrier is not particularly limited and can be appropriately selected depending on the purpose, but preferably has a core material and a resin layer covering the core material.

＜＜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 ferrite, magnetite, iron, and nickel are preferable. In addition, in consideration of adaptability to the environment, which has progressed significantly in recent years, the ferrite is not the conventional copper-zinc ferrite, but manganese ferrite, manganese-magnesium ferrite, manganese-strontium ferrite, manganese-magnesium-strontium ferrite. , lithium-based ferrite is preferred.

<<Resin layer>>
The material of the resin layer is not particularly limited and can be appropriately selected depending on the purpose, for example, amino resin, polyvinyl resin, polystyrene resin, halogenated olefin resin, polyester resin, polycarbonate resin. , polyethylene resin, polyvinyl fluoride resin, polyvinylidene fluoride resin, polytrifluoroethylene resin, polyhexafluoropropylene resin, copolymer of vinylidene fluoride and acrylic monomer, vinylidene fluoride and vinyl fluoride copolymers, fluoroterpolymers such as terpolymers of tetrafluoroethylene, vinylidene fluoride, and non-fluorinated monomers, and silicone resins. These may be used alone or in combination of two or more.

The silicone resin is not particularly limited and can be selected as appropriate depending on the purpose, such as straight silicone resins consisting only of organosilosane bonds; alkyd resins, polyester resins, epoxy resins, acrylic resins, urethane resins, etc. Examples include modified silicone resins modified with.

As the silicone resin, commercially available products can be used.
Examples of the straight silicone resin include KR271, KR255, and KR152 manufactured by Shin-Etsu Chemical Co., Ltd.; SR2400, SR2406, and SR2410 manufactured by Dow Corning Toray Silicone Co., Ltd., and the like.
Examples of the modified silicone resin include KR206 (alkyd-modified silicone resin), KR5208 (acrylic-modified silicone resin), ES1001N (epoxy-modified silicone resin), and KR305 (urethane-modified silicone resin) manufactured by Shin-Etsu Chemical Co., Ltd.; Examples include SR2115 (epoxy-modified silicone resin) and SR2110 (alkyd-modified silicone resin) manufactured by Dow Corning Silicone Co., Ltd.
Although it is possible to use the silicone resin alone, it is also possible to use a component that undergoes a crosslinking reaction, a charge amount adjusting component, etc. at the same time.
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 developer is a two-component developer, the content of the toner is not particularly limited and can be appropriately selected depending on the purpose, but 2.0 parts by mass per 100 parts by mass of the carrier. The amount is preferably from 12.0 parts by weight to 12.0 parts by weight, and more preferably from 2.5 parts to 10.0 parts by weight.

(toner storage unit)
The toner storage unit in the present invention refers to a unit that has the function of storing toner and stores toner therein. Here, examples of the toner storage unit include a toner storage container, a developing device, and a process cartridge.
The toner storage container refers to a container that stores toner.
A developing device has means for storing and developing toner.
A process cartridge is a cartridge that integrates at least an electrostatic latent image carrier (also referred to as an image carrier) and a developing means, stores toner, and is removably attached to an image forming apparatus. The process cartridge may further include at least one selected from charging means, exposure means, and cleaning means.
By attaching the toner storage unit of the present invention to an image forming apparatus and forming an image, an image using a toner that can achieve both low-temperature fixing properties, hot offset resistance, heat-resistant storage stability, and low filming properties can be obtained. can be formed.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and further includes other means as necessary.
The image forming method according to the present invention includes at least an electrostatic latent image forming step and a developing step, and further includes other steps as necessary.
The image forming method can be preferably performed by the image forming apparatus, the electrostatic latent image forming step can be suitably performed by the electrostatic latent image forming means, and the developing step can be suitably performed by the developing means. The above-mentioned other steps can be suitably carried out by the above-mentioned other means.

The image forming apparatus of the present invention more preferably includes an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, and an electrostatic latent image carrier. and a developing means provided with toner, which develops the electrostatic latent image formed on the body using toner to form a toner image. More preferably, the image forming apparatus further includes a transfer means for transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium. .
Further, the image forming method of the present invention more preferably 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 using toner to form a toner image. More preferably, the method further includes a transfer step of transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium. .
The toner is used in the developing means and the developing step. Preferably, the toner image is formed by using a developer containing the toner and, if necessary, other components such as a carrier.

<Electrostatic latent image carrier>
The material, structure, and size of the electrostatic latent image carrier (also referred to as "photoreceptor") are not particularly limited and may be appropriately selected from known materials. Examples of the material include amorphous Examples include inorganic photoreceptors such as silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine.

<Electrostatic latent image forming means>
The electrostatic latent image forming means is not particularly limited as long as it forms an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected depending on the purpose. Examples include means having at least a charging member that charges the surface of the electrostatic latent image carrier and an exposure member that imagewise exposes the surface of the electrostatic latent image carrier.

<Developing means>
The developing means is not particularly limited as long as it is a developing means equipped with toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and may be used depending on the purpose. can be selected as appropriate.

<Other means>
Examples of the other means include a transfer means, a fixing means, a cleaning means, a static elimination means, a recycling means, a control means, and the like.

The image forming apparatus of the present invention preferably does not include a lubricant application means. The lubricant application means is a means for applying a lubricant to the photoreceptor.
The lubricant refers to a lubricant applied to the surface of a photoreceptor or the like. Examples of the lubricant include zinc stearate.
Examples of the purpose of applying the lubricant include the following.
- Lowering the coefficient of friction μ stabilizes the behavior of the cleaning blade edge and assists the cleaning means.
-Protects the surface of the photoreceptor from charging current when AC voltage is applied to the charging roller.
- By using a cleaning blade to scrape off the lubricant applied to the surface of the image carrier, etc., it is possible to suppress the adhesion of toner components to the image carrier, etc., and the contamination by external additives, paper maze, etc.
As a method of applying the lubricant, for example, there is a method of applying the lubricant to the surface of the image carrier using a brush roller, and the lubricant is obtained by scratching the solid lubricant, which is a lump of the lubricant, with a coating brush, and is applied to the surface of the image carrier. be able to.
In general, in image forming apparatuses that do not include a lubricant application means, the behavior of the cleaning blade edge is unstable, which causes cleaning failures, and the cleaning blade comes into direct contact with the image carrier, etc., resulting in increased surface abrasion. .

Next, one embodiment of the method for forming an image using the image forming apparatus of the present invention will be described with reference to FIG.
FIG. 1 is a schematic configuration diagram of an example of the image forming apparatus. A charging roller 120 as a charging device, an exposure device 130, a cleaning device 160 having a cleaning blade, a static elimination lamp 170 as a static elimination device, and a developing device are arranged around the photoconductor drum (hereinafter referred to as photoconductor) 110 as an image carrier. A device 140 and an intermediate transfer body 150 as an intermediate transfer body are provided. The intermediate transfer body 150 is suspended by a plurality of suspension rollers 151 and is configured to run endlessly in the direction of the arrow by a driving means such as a motor (not shown). A portion of this suspension roller 151 also serves as a transfer bias roller that supplies a transfer bias to the intermediate transfer body, and a predetermined transfer bias voltage is applied from a power source (not shown). A cleaning device 190 having a cleaning blade for the intermediate transfer body 150 is also provided. Further, a transfer roller 180 is provided as a transfer means to face the intermediate transfer body 150 and transfer the developed image to a transfer paper 1100 as a final transfer material, and the transfer roller 180 is supplied with a transfer bias by a power supply device (not shown). Supplied. A corona charger 152 is provided around the intermediate transfer body 150 as a charge applying means.
The developing device 140 includes a developing belt 141 as a developer carrier, a black (hereinafter referred to as Bk) developing unit 145K, a yellow (hereinafter referred to as Y) developing unit 145Y, and a magenta (hereinafter referred to as Y) developing unit 145K, which are provided around the developing belt 141. A developing unit 145M (hereinafter referred to as magenta) and a developing unit 145C (hereinafter referred to as C) developing unit cyan (hereinafter referred to as C). Further, the developing belt 141 is stretched over a plurality of belt rollers, and is configured to run endlessly in the direction of the arrow by a driving means such as a motor (not shown). move at approximately the same speed.
Since the configuration of each developing unit is common, the following explanation will be made only for the Bk developing unit 145K, and for the other developing units 145Y, 145M, and 145C, the parts corresponding to those in the Bk developing unit 145K in the figure are Y, M, and C are added after the numbers assigned to the units, and explanation thereof will be omitted. The Bk developing unit 145K includes a developing tank 142K containing a high-viscosity, high-concentration liquid developer containing toner particles and carrier liquid components, and is arranged so that its lower part is immersed in the liquid developer in the developing tank 142K. The developer belt 141 is composed of a pumping roller 143K that has been pumped up by the pumping roller 143K, and a coating roller 144K that thins the developer pumped up from the pumping roller 143K and applies the thin layer to the developing belt 141. The application roller 144K is electrically conductive, and a predetermined bias is applied from a power source (not shown).
Next, the operation of the image forming apparatus according to this embodiment will be explained. In FIG. 1, a photoreceptor 110 is uniformly charged by a charging roller 120 while being rotationally driven in the direction of the arrow, and then an exposure device 130 uses an optical system (not shown) to form an image and project the reflected light from the document onto the photoreceptor 110. Forms an electrostatic latent image. This electrostatic latent image is developed by the developing device 140 to form a toner image as a developed image. The developer layer on the developing belt 141 is peeled off from the developing belt 141 in a thin layer due to contact with the photoreceptor in the developing area, and transferred to a portion of the photoreceptor 110 where the latent image is formed. The toner image developed by this developing device 140 is transferred onto the surface of the intermediate transfer body 150 (primary transfer area) at the contact portion (primary transfer area) between the photoreceptor 110 and the intermediate transfer body 150 that is moving at a constant speed. transcription). When performing transfer in which three or four colors are superimposed, this process is repeated for each color to form a color image on the intermediate transfer body 150.
A corona charger 152 for applying an electric charge to the superimposed toner image on the intermediate transfer body is installed downstream of the contact facing portion of the photoreceptor 110 and the intermediate transfer body 150 in the rotating direction of the intermediate transfer body 150, and The intermediate transfer member 150 and the transfer paper 1100 are installed at a position upstream of the contact facing portion. Then, the corona charger 152 applies a true charge to the toner image with the same polarity as the charging polarity of the toner particles forming the toner image, and the charge is sufficient for good transfer to the transfer paper 1100. is given to the toner image. After the toner image is charged by the corona charger 152, it is transferred all at once onto a transfer paper 1100 conveyed in the direction of the arrow from a paper feed section (not shown) by a transfer bias from the transfer roller 180 (secondary transfer). . Thereafter, the transfer paper 1100 on which the toner image has been transferred is separated from the photoreceptor 110 by a separating device (not shown), and is subjected to a fixing process by a fixing device (not shown), and then discharged from the device. On the other hand, untransferred toner is collected and removed from the photoreceptor 110 after the transfer by a cleaning device 160, and residual charges are removed by a charge removal lamp 170 in preparation for the next charging. Color images are usually formed using four colored toners. One color image includes one to four toner layers. The toner layer passes through primary transfer (transfer from the photoreceptor to the intermediate transfer belt) and secondary transfer (transfer from the intermediate transfer belt to the sheet).

Examples of the present invention will be described below, but the present invention is not limited to the following examples. In addition, "part" and "%" in the following description represent "mass part" and "mass %", respectively.

(Synthesis of amorphous polyester resin 1)
In a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, add 2 moles of bisphenol A ethylene oxide adduct, 3 moles adduct of bisphenol A propylene oxide, terephthalic acid, adipic acid, and trimethylolpropane. The molar ratio of bisphenol A ethylene oxide 2 mole adduct and bisphenol A propylene oxide 3 mole adduct (bisphenol A ethylene oxide 2 mole adduct/bisphenol A propylene oxide 3 mole adduct) is 85/15, and terephthal The molar ratio of acid and adipic acid (terephthalic acid/adipic acid) is 75/25, the amount of trimethylolpropane in all monomers is 1 mol%, and the molar ratio of hydroxyl group to carboxyl group is OH/COOH. 1.2, and reacted with titanium tetraisopropoxide (500 ppm based on the resin component) at normal pressure at 230°C for 8 hours, and after further reaction for 4 hours under reduced pressure of 10 mmHg to 15 mmHg, Trimellitic anhydride was added in an amount of 1 mol % based on the total resin components, and the mixture was reacted at 180° C. and normal pressure for 3 hours to obtain [Amorphous Polyester Resin 1].

(Synthesis of amorphous polyester resin 2)
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen cable introduction tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added in a molar ratio of hydroxyl groups to carboxyl groups. A certain OH/COOH is 1.5, the composition of the diol component is 100 mol% of 3-methyl-1,5-pentanediol, the composition of the dicarboxylic acid component is 40 mol% of isophthalic acid and 60 mol% of adipic acid, and the total Trimellitic anhydride was added together with titanium tetraisopropoxide (1,000 ppm based on the resin component) so that the amount of trimellitic anhydride in the monomer was 1 mol %.
Thereafter, the temperature was raised to 200°C over about 4 hours, and then to 230°C over 2 hours, and the reaction was carried out until there was no more water flowing out.
Thereafter, the mixture was further reacted for 5 hours under reduced pressure of 10 mmHg to 15 mmHg to obtain [Intermediate Polyester 1].
Next, in a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen introduction tube, [Intermediate polyester 1] and isophorone diisocyanate (IPDI) were mixed in a molar ratio (isocyanate group of IPDI/hydroxyl group of intermediate polyester) of 2. After diluting with ethyl acetate to make a 50% ethyl acetate solution, the mixture was reacted at 100° C. for 5 hours to obtain [Amorphous Polyester Resin 2].

(Synthesis of crystalline polyester resin)
Dodecanedioic acid and 1,6-hexanediol were added to a 5L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple at a concentration of OH/COOH, which is the molar ratio of hydroxyl groups to carboxyl groups. was 0.9, and reacted with titanium tetraisopropoxide (500 ppm based on the resin component) at 180°C for 10 hours, then heated to 200°C and reacted for 3 hours, and further 8. [Crystalline polyester resin 1] was obtained by reacting for 2 hours at a pressure of 3 kPa.

(Preparation of crystalline polyester resin dispersion)
50 parts of [crystalline polyester resin 1] and 450 parts of ethyl acetate were placed in a container equipped with a stirring rod and a thermometer, and the temperature was raised to 80°C while stirring, kept at 80°C for 5 hours, and then heated for 1 hour. The mixture was cooled to 30°C and heated using a bead mill (Ultra Visco Mill, manufactured by Imex) at a liquid feeding rate of 1 kg/hr, a disk circumferential speed of 6 m/sec, and filling with 80% by volume of zirconia beads with a diameter of 0.5 mm in 3 passes. Dispersion was carried out under the following conditions to obtain [Crystalline Polyester Resin Dispersion 1].

(Synthesis of hybrid resin 1 for crystalline polyester)
500 parts of [amorphous polyester resin 1] and 500 parts of [crystalline polyester resin 1] were mixed using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), and then mixed at 100°C using two rolls. Kneaded for hours.
Next, after rolling and cooling, it was pulverized using a pulperizer to obtain [Hybrid Resin 1 for Crystalline Polyester].

(Synthesis of hybrid resin 2 for crystalline polyester)
In a 5L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple, 7.2 g of 2,3-butanediol, 6.08 g of 1,2-propanediol, 18.59 g of terephthalic acid, and Add 0.18 g of tin (II) 2-ethylhexanoate, introduce nitrogen gas into the container to maintain an inert atmosphere, raise the temperature, keep the temperature at 180°C for 1 hour, and then increase the temperature from 180°C to 230°C by 10°C. /hr, and then a condensation polymerization reaction was carried out at 230°C for 10 hours, and a further reaction was carried out at 230°C and 8.0 kPa for 1 hour.
After cooling to 160° C., 0.6 g of acrylic acid, 7.79 g of styrene, 1.48 g of 2-ethylhexyl acrylate, and dibutyl peroxide were added dropwise through a dropping funnel over 1 hour.
After dropping, the addition polymerization reaction was allowed to mature for 1 hour while being maintained at 160°C, and then the temperature was raised to 210°C. 4.61 g of trimellitic anhydride was added and the reaction was carried out at 210°C for 2 hours. The reaction was carried out at 210° C. and 10 kPa until a desired softening point was reached to obtain [Hybrid Resin 2 for Crystalline Polyester].

(Synthesis of hybrid resin 3 for crystalline polyester)
6.0 parts of sebacic acid, 5.4 parts of ethylene glycol, 3.4 parts of fumaric acid, and 9.9 parts of xylene were placed in a 5 L four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple. After the reaction was carried out at 180°C for 10 hours, the temperature was raised to 200°C and the reaction was carried out for 3 hours, and the reaction was further carried out at a pressure of 8.3 kPa for 2 hours. Next, a solution of 38.3 parts of styrene, 0.3 parts of methacrylic acid, and 1.2 parts of di-t-butyl peroxide dissolved in 3.9 parts of xylene was added dropwise over 3 hours, and the solution was heated to 170°C for 30 minutes. After holding for a minute, the solvent was removed to obtain a hybrid resin 3 for crystalline polyester.

(Preparation of release agent dispersion)
In a container equipped with a stirring rod and a thermometer, 50 parts of paraffin wax (manufactured by Nippon Seirin Co., Ltd., HNP-9, hydrocarbon wax, melting point 75°C, SP value 8.8) and ethyl acetate were added as mold release agent 1. After charging 283 parts, the temperature was raised to 80°C with stirring, maintained at 80°C for 5 hours, cooled to 30°C in 1 hour, and the liquid feeding rate was adjusted using a bead mill (Ultra Viscomil, manufactured by Imex). Dispersion was carried out under the conditions of 1 kg/hr, disk peripheral speed of 6 m/sec, zirconia beads with a diameter of 0.5 mm at 80% by volume, and 3 passes to obtain [Release Agent Dispersion 1].

(Example 1)
<Preparation of masterbatch (MB)>
Add 1,200 parts of water, 500 parts of carbon black (Printex 35 manufactured by Dexa) [DBP oil absorption = 42 mL/100 mg, pH = 9.5], and 500 parts of [amorphous polyester resin 1], and add Henschel mixer (Mitsui Mining Co., Ltd.). After kneading the mixture using two rolls at 150° C. for 30 minutes, the mixture was rolled, cooled, and pulverized using a pulperizer to obtain [Masterbatch 1].

<Synthesis of ketimine compound>
170 parts of isophorone diamine and 75 parts of methyl ethyl ketone were charged into a reaction vessel equipped with a stirring rod and a thermometer, and the reaction was carried out at 50° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [Ketimine Compound 1] was 418.

<Preparation of oil phase>
[Amorphous polyester resin 1] 680 parts, [Crystalline polyester resin dispersion 1] 800 parts, [Release agent dispersion 1] 900 parts, [Hybrid resin for crystalline polyester 1] 320 parts, [Amorphous 10 parts of polyester resin 2], 100 parts of masterbatch 1, and 2 parts of ketimine compound 1 as a hardening agent were placed in a container, and mixed for 60 minutes at 7,000 rpm with a TK homomixer (manufactured by Tokushu Kika), [Oil phase 1] was obtained.

<Synthesis of organic fine particle emulsion (fine particle dispersion)>
In a reaction vessel equipped with a stirring rod and a thermometer, 683 parts of water, 11 parts of sodium salt of methacrylic acid ethylene oxide adduct sulfate ester (Eleminol RS-30: manufactured by Sanyo Chemical Industries, Ltd.), 138 parts of styrene, and 138 parts of methacrylic acid. 1 part of ammonium persulfate were added, and the mixture was stirred at 400 rpm for 15 minutes to obtain a white emulsion.
The system was heated to an internal temperature of 75° C., and reacted for 5 hours.
Furthermore, 30 parts of a 1% ammonium persulfate aqueous solution was added and aged at 75°C for 5 hours to form an aqueous dispersion of vinyl resin (copolymer of styrene-methacrylic acid-sodium salt of methacrylic acid ethylene oxide adduct sulfate ester) [fine particles]. Dispersion 1] was obtained.
The volume average particle diameter of [Fine Particle Dispersion 1] measured with LA-920 (manufactured by HORIBA) was 0.14 μm.
A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component.

<Preparation of aqueous phase>
990 parts of water, 83 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts of ethyl acetate were mixed and stirred, and a milky white color was obtained. of liquid was obtained.
This was designated as [aqueous phase 1].

<Emulsification/Desolvent>
1,200 parts of [Aqueous phase 1] was added to a container containing [Oil phase 1], and mixed for 20 minutes at a rotation speed of 13,000 rpm using a TK homo mixer to obtain [Emulsified slurry 1]. Next, [Emulsified Slurry 1] was put into 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]. .

<Washing/drying>
After filtering 100 parts of [Dispersion Slurry 1] under reduced pressure, the following operations were performed.
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(4): The operation of (1) to (4) above, in which 300 parts of ion-exchanged water is added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered. was carried out twice to obtain a [filter cake].
The [filter cake] was dried at 45° C. for 48 hours in a circulating air dryer and sieved through a mesh having an opening of 75 μm to obtain [toner base particles 1].

<External addition treatment>
[Toner base particles 1] 0.6 parts by mass of hydrophobic silica with an average particle diameter of 100 nm, 1.0 parts by mass of titanium oxide with an average particle diameter of 20 nm, and hydrophobic silica with an average particle diameter of 15 nm per 100 parts by mass of [toner base particles 1] 0.8 parts of fine powder was mixed with a Henschel mixer to obtain [Toner 1].

<Preparation of carrier>
To 100 parts by mass of toluene, 100 parts by mass of silicone resin (organostraight silicone), 5 parts by mass of γ-(2-aminoethyl)aminopropyltrimethoxysilane, and 10 parts by mass of carbon black were added, and dispersed for 20 minutes with a homomixer. In this way, a resin layer coating solution was prepared.
[Carrier] was prepared by applying the resin layer coating liquid onto the surface of 1,000 parts by mass of spherical magnetite having an average particle size of 50 μm using a fluidized bed coating device.

<Preparation of developer>
Using a ball mill, 5 parts by mass of [Toner 1] and 95 parts by mass of [Carrier] were mixed to prepare a developer.
(Example 2)
Example 1 except that in <Preparation of oil phase> of Example 1, 680 parts of [amorphous polyester resin 1] was changed to 840 parts, and 320 parts of [hybrid resin 1 for crystalline polyester] were changed to 160 parts. [Toner base particles 2] were obtained in the same manner as above. "Toner 2" was produced using this [toner base particle 2].

(Example 3)
Example 1 except that in <Preparation of oil phase> of Example 1, 680 parts of [amorphous polyester resin 1] was changed to 520 parts, and 320 parts of [hybrid resin 1 for crystalline polyester] were changed to 480 parts. [Toner base particles 3] were obtained in the same manner as above. "Toner 3" was produced using this [toner base particle 3].

(Example 4)
[Toner base particles 4] were obtained in the same manner as in Example 1, except that in <Preparation of oil phase> of Example 1, 900 parts of [Release agent dispersion 1] was changed to 400 parts. "Toner 4" was produced using this [toner base particle 4].

(Example 5)
[Toner base particles 5] were obtained in the same manner as in Example 1, except that in <Preparation of oil phase> of Example 1, 900 parts of [Release agent dispersion 1] was changed to 1300 parts. "Toner 5" was produced using this [toner base particle 5].

(Comparative example 1)
Example 1 except that in <Preparation of oil phase> of Example 1, 680 parts of [amorphous polyester resin 1] was changed to 360 parts, and 320 parts of [hybrid resin 1 for crystalline polyester] were changed to 640 parts. [Toner base particles 6] were obtained in the same manner as above. "Toner 6" was produced using this [toner base particle 6].

(Comparative example 2)
In the <Preparation of oil phase> of Example 1, [Toner base particles 7 ] was obtained. "Toner 7" was produced using this [toner base particle 7].

(Comparative example 3)
In the <Preparation of oil phase> of Example 1, [Toner base particles 8 ] was obtained. "Toner 8" was produced using this [toner base particle 8].

(Comparative example 4)
[Toner base particles 9] were obtained in the same manner as in Example 1, except that in <Preparation of oil phase> of Example 1, 900 parts of [Release agent dispersion 1] was changed to 200 parts. "Toner 9" was produced using this [toner base particle 9].

(Comparative example 5)
[Toner base particles 10] were obtained in the same manner as in Example 1, except that in <Preparation of oil phase> of Example 1, 900 parts of [Release agent dispersion 1] was changed to 1500 parts. "Toner 10" was produced using this [toner base particle 10].

(Comparative example 6)
In <Preparation of oil phase> of Example 1, except that [Hybrid resin 1 for crystalline polyester] was changed to [Hybrid resin 2 for crystalline polyester], and [Release agent dispersion liquid 1] 900 parts was changed to 1500 parts. [Toner base particles 11] were obtained in the same manner as in Example 1. "Toner 11" was produced using this [toner base particle 11].

(measurement)
For each toner obtained above, the crystalline polyester resin coverage [crystalline polyester coverage] on the toner particle surface was determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method using the method described in this specification. The intensity ratio (P2850/P828) of the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin [Surface relative separation The mold release agent amount] and the mass-converted value of the endothermic amount of the mold release agent determined by DSC (differential scanning calorimetry) method [mold release agent content] were measured.
The results are shown in Table 1.

(evaluation)
The toner and developer obtained above were evaluated as follows.
Note that the developer was prepared in the same manner as in Example 1.
The results are shown in Table 2.

<<Low temperature fixing properties and hot offset resistance>>
A copying test was conducted on Type 6200 paper (manufactured by Ricoh Co., Ltd.) using a modified fixing section of a copying machine MF2200 (manufactured by Ricoh Co., Ltd.) using a Teflon (registered trademark) roller as a fixing roller.
Specifically, the fixing temperature was changed to determine a cold offset temperature (lower limit fixing temperature) and a high temperature offset temperature (upper limit fixing temperature).
The evaluation conditions for the lower limit fixing temperature were as follows: paper feeding linear speed of 120 mm/sec to 150 mm/sec, surface pressure of 1.2 kgf/cm ² , and nip width of 3 mm.
Further, the evaluation conditions for the upper limit temperature of fixing were as follows: linear speed of paper feeding was 50 mm/sec, surface pressure was 2.0 kgf/cm ² , and nip width was 4.5 mm.
Evaluation was made using the following evaluation criteria.
[Low temperature fixability evaluation criteria]
◎: Lower limit fixing temperature is 115°C or less ○: Lower limit fixing temperature is greater than 115°C and below 120°C △: Lower limit fixing temperature is greater than 120°C and below 125°C ×: Lower limit fixing temperature is greater than 125°C [Hot offset resistance evaluation standard〕
◎: The upper limit fixing temperature is 170°C or more. ○: The upper limit fixing temperature is 165 or more and less than 170°C. △: The upper limit fixing temperature is 160 or more and less than 165°C. ×: The upper limit fixing temperature is less than 160°C.

<Heat-resistant storage stability>
After the toner was stored at 50° C. for 8 hours, it was sieved for 2 minutes using a 42-mesh sieve, and the residual rate on the wire mesh was measured. At this time, the better the heat-resistant storage stability of the toner, the lower the residual rate.
The evaluation criteria for heat-resistant 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 15% or more and less than 30% ×: Residual rate is 30% or more

＜＜Filming＞＞
After forming 10,000 images using an image forming device MF2800 (manufactured by Ricoh Co., Ltd.), the photoconductor was visually inspected to determine whether toner components, mainly release agents, had stuck to the photoconductor. It was evaluated based on the following evaluation criteria.
〔Evaluation criteria〕
◎: Adhesion of toner components to the photoconductor is not confirmed. ○: Adhesion of toner components to the photoconductor is confirmed, but it is not at a level that poses a practical problem. △: Adhesion of toner components to the photoconductor is not confirmed. , is at a level that causes a practical problem. ×: Adhesion of toner components to the photoreceptor can be confirmed, and is at a level that is a serious problem for practical use.

Aspects of the present invention are, for example, as follows.
<1> A toner comprising toner particles containing an amorphous polyester resin, a crystalline polyester resin, and a release agent, the toner particles satisfying the following (1) and (2). This is a toner with special features.
(1) The "crystalline polyester resin coverage on the toner particle surface" calculated from a transmission electron microscope (TEM) image of the cross section of the toner particle is less than 10%.
(2) The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by the DSC (differential scanning calorimetry) method into mass, and is 3% by mass or more and 15% by mass of the total toner mass. % or less and is determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method as a value that defines the amount of the release agent present in a depth region of up to 0.3 μm from the surface of the toner particles. , the intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is 0. It is in the range of 10 or more and 0.25 or less.
<2> The toner according to <1>, wherein the "crystalline polyester resin coverage on the toner particle surface" is less than 5%.
<3> The toner according to any one of <1> to <2>, wherein the intensity ratio (P2850/P828) is in a range of 0.15 or more and 0.22 or less.
<4> The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by DSC (differential scanning calorimetry) method into mass, and is 3% or more by mass of the total toner mass or more than 13% by mass. % or less, the toner according to any one of <1> to <3> above.
<5> A toner storage unit containing the toner according to any one of <1> to <4>.
<6> Electrostatic latent image carrier;
an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
a developing means equipped with the toner, which develops the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a visible image;
The image forming apparatus is characterized in that the toner is the toner according to any one of <1> to <4>.

110 Photosensitive drum 120 Charging roller 130 Exposure device 140 Developing device 141 Developing belt 145K Black (Bk) developing unit 145Y Yellow (Y) developing unit 145M Magenta (M) developing unit 145C Cyan (C) developing unit 150 Intermediate transfer body 152 Corona Charger 160, 190 Cleaning device 170 Static elimination lamp 180 Transfer roller 1100 Transfer paper

Japanese Patent Application Publication No. 2005-015589 Japanese Patent Application Publication No. 2008-276269 Japanese Patent Application Publication No. 2017-003779

Claims (6)

Toner particles containing an amorphous polyester resin, a crystalline polyester resin, a hybrid resin which is a melt-kneaded product of the crystalline polyester resin and the amorphous polyester resin, and which is a transesterified product, and a release agent. 1. A toner comprising: the toner particles satisfying the following (1) and (2).
(1) The "crystalline polyester resin coverage on the toner particle surface" calculated from a transmission electron microscope (TEM) image of the cross section of the toner particle is less than 10%.
(2) The content of the release agent in the toner is a value obtained by converting the amount of heat absorption of the release agent determined by the DSC (differential scanning calorimetry) method into mass, and is 3% by mass or more and 15% by mass of the total toner mass. % or less and is determined by the FTIR-ATR (total internal reflection absorption infrared spectroscopy) method as a value that defines the amount of the release agent present in a depth region of up to 0.3 μm from the surface of the toner particles. , the intensity ratio (P2850/P828) between the intensity (P2850) of the peak (2850 cm ^-1 ) derived from the mold release agent and the intensity (P828) of the peak (828 cm ^-1 ) derived from the amorphous polyester resin is 0. It is in the range of 10 or more and 0.25 or less. The toner according to claim 1, wherein the "crystalline polyester resin coverage on the toner particle surface" is less than 5%. 3. The toner according to claim 1, wherein the intensity ratio (P2850/P828) is in a range of 0.15 or more and 0.22 or less. The content of the release agent in the toner is 3% by mass or more and 13% by mass or less of the total toner mass, based on the mass conversion of the endothermic amount of the release agent determined by DSC (differential scanning calorimetry) method. The toner according to any one of claims 1 to 3. A toner storage unit containing the toner according to any one of claims 1 to 4. an electrostatic latent image carrier;
an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
a developing means equipped with the toner, which develops the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a visible image;
An image forming apparatus characterized in that the toner is the toner according to any one of claims 1 to 4.