JP7501014B2 - Toner, two-component developer using the same, and image forming apparatus - Google Patents

Description

The present invention relates to a toner, a two-component developer using the toner, and an image forming apparatus.

Conventionally, in electrophotographic devices, electrostatic recording devices, etc., electric latent images or magnetic latent images are visualized by electrostatic latent image developing toner (also referred to as "toner" in the present invention). For example, in electrophotography, an electrostatic latent image is formed on a photoreceptor, and then the electrostatic latent image is developed with toner to form a toner image. The toner image is usually transferred onto a recording medium such as paper, and then fixed by a method such as heating.

In recent years, numerous toners have been proposed in the industry to improve image quality. For example, Patent Document 1 discloses a toner that has toner particles containing a binder resin and a colorant, and organic/inorganic composite fine particles, and that specifies the degree of aggregation and angle of repose of the organic/inorganic composite fine particles, and that specifies a specific range for the total energy measured by a powder flowability measuring device, with the aim of improving image quality and uniformity of image density.

However, there are still issues with cleaning and toner transportability with conventional toners.

Therefore, the object of the present invention is to provide a toner that has excellent cleaning properties and toner transport properties.

The above problem is solved by the following configuration 1).
1) A toner comprising a toner base material containing at least a binder resin and a colorant, and inorganic fine particles as an external additive,
The accelerated aggregation degree of the inorganic fine particles, which is determined by the following measurement, is 20% or more and 80% or less,
The toner is characterized in that the binder resin contains a crystalline polyester resin and an amorphous polyester resin having a glass transition temperature of -60°C or higher and 0°C or lower .
<<Measurement of Accelerated Coagulation Degree>>
The accelerated cohesion degree is measured by the following method: A powder tester is used as the measuring device, and the accessories are set on a vibration table in the following order.
(a) Vibro chute (b) Packing (c) Space ring (d) Sieve (3 types) Top>Middle>Bottom (e) Osaever Next, fix with a knob nut and operate the vibration table. The measurement conditions are as follows.
Sieve opening (upper row) 75 μm
Sieve opening (middle) 45μm
Sieve opening (lower row) 20 μm
Amplitude scale 2mm
Sample (inorganic fine particles) amount: 2 g
Vibration time: 160 seconds Vibration acceleration: 100 m/ ^s2
After the measurement, the accelerated coagulation degree is calculated using the following formula.
Weight percent of powder remaining on the upper sieve × 1 (a)
Weight percent of powder remaining on the middle sieve × 0.6 (b)
Weight percent of powder remaining in the lower sieve × 0.2 (c)
The sum of the above three calculated values is the accelerated cohesion degree (%).
That is, the accelerated degree of cohesion (%)=(a)+(b)+(c).

The present invention provides a toner with excellent cleaning properties and toner transport properties.

1 is a schematic diagram illustrating an example of an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram illustrating another example of an image forming apparatus according to the present invention. FIG. 2 is a schematic diagram illustrating another example of an image forming apparatus according to the present invention. FIG. 4 is a partially enlarged view of FIG. 3 . FIG. 2 is a schematic diagram illustrating an example of a process cartridge.

Hereinafter, the embodiments of the present invention will be described in further detail.
The toner of the present invention is characterized in that it contains a toner base material containing at least a binder resin and a colorant, and inorganic fine particles, and the accelerated cohesion degree of the inorganic fine particles is 20% or more and 80% or less.

Conventional toners have an issue with slipping through the cleaning blade at the nip on the photoreceptor surface, causing cleaning failures. There are concerns that the risk of cleaning failures will increase further due to the tendency for the toner to slip through the cleaning blade as the particle size becomes smaller, and the increase in non-electrostatic adhesion as the fixing temperature becomes lower.

The inventors therefore conducted extensive research into the issue of poor cleaning caused by toner slipping through the cleaning blade, and discovered that this issue could be resolved by using a toner to which highly cohesive inorganic fine particles have been added.

In the toner of the present invention, inorganic fine particles detached from the toner accumulate in the nip to form a dam-like structure, which blocks the toner and prevents the toner from slipping through the cleaning blade, improving cleaning performance. By using inorganic fine particles with high cohesive properties, the inorganic fine particles tend to accumulate in the nip, which is advantageous for cleaning performance.

According to the present invention, in order to fully improve the cleaning performance, the accelerated cohesion degree of the inorganic fine particles must be 20% or more, and is preferably 30% or more. In order to further improve the cleaning performance, it is particularly preferable that the accelerated cohesion degree of the inorganic fine particles is 40% or more. If the accelerated cohesion degree of the inorganic fine particles is less than 20%, the inorganic fine particles are unlikely to accumulate in the nip and it is difficult to form a dam-like structure, so that the toner slips through the cleaning blade, and the cleaning performance is deteriorated. If the accelerated cohesion degree of the inorganic fine particles is high, the toner will become more cohesive, and there is a concern that the transportability will deteriorate. In order to ensure sufficient transportability, the accelerated cohesion degree of the inorganic fine particles must be 80% or less.

The method for producing the toner of the present invention will now be described in detail.
It should be noted that the present invention is not limited to the toner production method exemplified here.
In the emulsification or dispersion, it is preferable to use a dispersant, if necessary, from the viewpoint of stabilizing the oil droplets and sharpening the particle size distribution while obtaining a desired shape. The dispersant is not particularly limited and can be appropriately selected according to the purpose, and for example, a surfactant, a poorly water-soluble inorganic compound dispersant, a polymer-based protective colloid, etc. can be used. These may be used alone or in combination of two or more. Among these, a surfactant is preferable. Furthermore, after removing the organic solvent, inorganic fine particles are externally added in the process of externally adding and mixing additives.

[Raw materials used in the production of the toner of the present invention]
The binder resin used in the toner manufacturing method of the present invention is not particularly limited, and preferably contains at least two or more types of resins. Known binder resins such as polyester resins, silicone resins, styrene-acrylic resins, styrene resins, acrylic resins, epoxy resins, diene resins, phenol resins, terpene resins, coumarin resins, amide-imide resins, butyral resins, urethane resins, and ethylene-vinyl acetate resins can be used.
Among these, the resin used in the production of the toner of the present invention is preferably a polyester resin, which has sufficient flexibility even when its molecular weight is reduced, in that it can be sharply melted during fixing and can smooth the image surface, and the polyester resin may be used in combination with other resins.

<Polyester Resin>
(Amorphous polyester resin A)
The amorphous polyester resin A preferably has a structure represented by any one of the following structural formulas 1) to 3), and has a structure in which R2, which is a polyester or modified polyester portion, and R1, which corresponds to a branched structure, are bonded via a urethane or urea group.
Structural formula 1) R1-(NHCONH-R2)n-
Structural formula 2) R1-(NHCOO-R2)n-
Structural formula 3) R1-(OCONH-R2)n-
(In the above formula, n=3, R1 represents an isocyanurate skeleton, and R2 represents a group derived from any one of a polyester resin containing a polycarboxylic acid and a polyol, and a modified polyester resin obtained by modifying a polyester with an isocyanate.)

Since the amorphous polyester resin A has at least one of a urethane bond and a urea bond in the branched structure portion, the urethane bond or the urea bond behaves like a pseudo-crosslinking point, and the rubber-like properties of the amorphous polyester resin A are strengthened, making it possible to produce a toner having excellent heat-resistant storage stability and high-temperature offset resistance.
The amorphous polyester resin A contains, as a constituent component, a diol component, and more preferably contains, as a constituent component, a dicarboxylic acid component.

The amorphous polyester resin A is not particularly limited as long as it is a resin in which R2 corresponding to a polyester or modified polyester portion and R1 corresponding to a branched structure portion are bonded via a urethane or urea group, and may be appropriately selected depending on the purpose.
The method for bonding R1 and R2 is not limited to the following, but examples thereof include the following methods.

a) A method in which a diol component and a dicarboxylic acid component are subjected to an ester reaction to prepare a polyester polyol (R2) having a hydroxyl group at the end, and the obtained polyester polyol is reacted with an isocyanurate (R1).
b) A method in which a diol component and a dicarboxylic acid component are subjected to an ester reaction to produce a polyester polyol (R2) having a hydroxyl group at the end, the obtained polyester polyol is reacted with a divalent polyisocyanate to produce an isocyanate-modified polyester (R2), and the obtained isocyanate-modified polyester is reacted with an isocyanurate (R1) in the presence of pure water.
It is also possible to further react the hydroxyl groups remaining in the polyol obtained by any one of the above a) to b) with a divalent or higher polyisocyanate to form a polyester prepolymer, which can then be reacted with a curing agent in the toner production process.
During the toner production process, a urethane or urea bond is generated by reaction with a curing agent, and the resin behaves like a strong crosslinking point, thereby enhancing the rubber-like properties of the amorphous polyester resin A and further improving the heat resistance storage stability and high-temperature offset resistance. Therefore, it is more preferable that the R2 portion is a modified polyester resin modified with isocyanate.

In order to lower the Tg of the amorphous polyester resin A and to easily impart the property of deformation at low temperatures, the amorphous polyester resin A contains a diol component as a constituent component, and the diol component preferably contains an aliphatic diol having 3 to 12 carbon atoms, and more preferably contains an aliphatic diol having 4 to 12 carbon atoms.

In the amorphous polyester resin A, it is preferable that the aliphatic diol having 3 to 12 carbon atoms is contained in an amount of 50 mol% or more, more preferably 80 mol% or more, and even more preferably 90 mol% or more.

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

In particular, in the amorphous polyester resin A, it is more preferable that the diol component is an aliphatic diol having 4 to 12 carbon atoms, the number of carbon atoms in the main chain of the diol component is an odd number, and the diol component has an alkyl group in the side chain.
Examples of the aliphatic diol having 4 to 12 carbon atoms and an odd-numbered main chain and an alkyl group on the side chain include aliphatic diols represented by the following general formula (1).
HO-(CR1R2)n-OH ... general formula (1)
In the general formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. n represents an odd number from 3 to 9. In the n repeating units, R1 may be the same or different. In the n repeating units, R2 may be the same or different.

In addition, in order to lower the Tg of the amorphous polyester resin A and to easily impart the property of deformation at low temperatures, it is preferable that the amorphous polyester resin A contains 50 mol % or more of an aliphatic diol having 3 to 12 carbon atoms in the total alcohol component.

In order to lower the Tg of the amorphous polyester resin A and to easily impart the property of deformation at low temperatures, the amorphous polyester resin A preferably contains a dicarboxylic acid component as a constituent, and the dicarboxylic acid component preferably contains an aliphatic dicarboxylic acid having 4 to 12 carbon atoms.

The polyester resin preferably contains 30 mol % or more of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms.
Examples of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid.

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

-Dicarboxylic acid component-
The dicarboxylic acid component is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, etc. Furthermore, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of these may be used.
The aliphatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid.
The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably an aromatic dicarboxylic acid having 8 to 20 carbon atoms.
The aromatic dicarboxylic acid having 8 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.
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.

-Trivalent or higher alcohol-
The trihydric or higher alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the trihydric or higher alcohol include aliphatic alcohols of trihydric or higher hydricity, polyphenols of trihydric or higher hydricity, and alkylene oxide adducts of polyphenols of trihydric or higher hydricity.
Examples of the trivalent or higher aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol.
Examples of the trivalent or higher polyphenols include trisphenol PA, phenol novolac, and cresol novolac.
Examples of the alkylene oxide adducts of trivalent or higher polyphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to trivalent or higher polyphenols.

-Polyisocyanate-
The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyisocyanate include diisocyanates and tri- or higher valent isocyanates.
Examples of the diisocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and those blocked with phenol derivatives, oximes, caprolactams, and the like.
Examples of the tri- or higher hydric isocyanate include lysine triisocyanate, or a compound obtained by reacting a tri- or higher hydric alcohol with a diisocyanate, or a compound obtained by reacting a polyisocyanate to form an isocyanurate.
Among these, it is more preferable to use a polyisocyanate having an isocyanurate skeleton, since it acts as a stronger crosslinking point and provides better heat resistance storage stability and high-temperature offset resistance.

The trivalent isocyanate component is preferably 0.2 mol% or more and 1.0 mol% or less of the resin components in the THF-insoluble matter of the toner. When a crosslinked structure is formed by a trivalent isocyanate component, the molecular chain has a high cohesive force due to pseudo-crosslinking by urethane or urea bonds at the crosslinking points, so that the heat-resistant storage stability can be improved even with a low crosslinking density, and a high level of low-temperature fixability can be achieved. When the trivalent isocyanate component is less than 0.2 mol%, the formation of a branched structure becomes insufficient, and the mesh structure becomes non-uniform at the starting point, which may deteriorate the heat-resistant storage stability and filming resistance. When the trivalent isocyanate component is more than 1.0 mol%, the low-temperature fixability may be deteriorated due to the formation of a dense crosslinked structure.

The aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.
The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the alicyclic diisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate.
The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aromatic diisocyanate include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3-methyldiphenylmethane, and 4,4'-diisocyanato-diphenyl ether.
The aromatic aliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the purpose. For example, α,α,α',α'-tetramethylxylylene diisocyanate is exemplified.
The isocyanurates are not particularly limited and can be appropriately selected depending on the purpose. Examples of the isocyanurates include tris(isocyanatoalkyl)isocyanurate and tris(isocyanatocycloalkyl)isocyanurate.
These polyisocyanates may be used alone or in combination of two or more.

- Hardener -
The curing agent is not particularly limited as long as it is a curing agent that can react with a polyester prepolymer (a reaction product of the polyester portion of R2 and the polyisocyanate, i.e., a reaction precursor to be reacted with a curing agent) to produce the polyester resin, and can be appropriately selected depending on the purpose. For example, an active hydrogen group-containing compound can be used.

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

The active hydrogen group-containing compound is not particularly limited and can be selected appropriately depending on the purpose, but amines are preferred because they can form urea bonds.

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

The diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples of the diamine include aromatic diamines, alicyclic diamines, and aliphatic diamines.
The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, etc. 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, isophoronediamine, etc.
The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic diamine include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diethylenetriamine and triethylenetetramine.
The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino alcohol include ethanolamine and hydroxyethylaniline.
The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.
The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino acid include aminopropionic acid and aminocaproic acid.
The compound in which the amino group is blocked is not particularly limited and can be appropriately selected depending on the purpose. Examples of the compound include ketimine compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and oxazoline compounds.

The glass transition temperature of the amorphous polyester resin A is preferably from -60°C to 0°C, and more preferably from -40°C to -20°C.
If the glass transition temperature is lower than −60° C., the flow of the toner at low temperatures cannot be suppressed, and the heat-resistant storage stability and filming resistance may deteriorate.
If the glass transition temperature exceeds 0° C., the toner cannot be sufficiently deformed by the application of heat and pressure during fixing, and low-temperature fixing properties may be insufficient.

In the amorphous polyester resin A, in the structural formulas 1) to 3), R1 preferably has an isocyanurate skeleton represented by the following structural formula (I), from the viewpoints of heat-resistant storage stability and high-temperature offset resistance.

In addition, in the amorphous polyester resin A, although the detailed reasons are not clear, the three-dimensional molecular network structure is suitable for achieving both low-temperature fixability, image gloss, heat-resistant storage stability, and offset resistance, so it is more preferable that n is 3 in the above structural formulas 1) to 3).

The weight average molecular weight of the amorphous polyester resin A is not particularly limited and may be appropriately selected depending on the purpose, but is preferably from 20,000 to 1,000,000 as measured by GPC (gel permeation chromatography).
The weight average molecular weight of the amorphous polyester resin A refers to the molecular weight of the reaction product obtained by reacting the reactive precursor with the curing agent.
If the weight average molecular weight is less than 20,000, the toner tends to flow at low temperatures, and the heat-resistant storage stability may be poor.
Furthermore, the viscosity at the time of melting is decreased, and the high-temperature offset resistance may be deteriorated.

The content of the amorphous polyester resin A is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 part by mass to 10 parts by mass, and more preferably 1 part by mass to 5 parts by mass, per 100 parts by mass of the toner.

<Other polyester resins>
The toner of the present invention may contain, as necessary, a polyester resin other than the above-mentioned as a binder resin.
Other polyester resins have a backbone derived from an alcohol component and a backbone derived from a carboxylic acid component.
The alcohol component contains a trihydric or higher aliphatic alcohol.
The other polyester resin satisfies the following formulas (1) to (3).

4,000≦weight average molecular weight (Mw)≦25,000...Formula (2)
0.5≦(amount of trihydric or higher aliphatic alcohol)≦6.5...Equation (3)

However, the amount of the trivalent or higher aliphatic alcohol in the formulas (1) and (3) (hereinafter sometimes referred to as the "branched component amount") is the mole percentage of the trivalent or higher aliphatic alcohol relative to the alcohol component.

Here, when the alcohol component contains two or more types of the trihydric or higher aliphatic alcohol, the "valence of the trihydric or higher aliphatic alcohol" is the average valence calculated from the molar fraction of the trihydric or higher aliphatic alcohol. For example, when the trihydric or higher aliphatic alcohol contains 50 mol% each of a trihydric aliphatic alcohol and a tetrahydric aliphatic alcohol, the "valence of the trihydric or higher aliphatic alcohol" is 3 x 0.5 + 4 x 0.5 = 3.5. Also, when the trihydric or higher aliphatic alcohol contains 60 mol% of a trihydric aliphatic alcohol and 40 mol% of a hexahydric aliphatic alcohol, the "valence of the trihydric or higher aliphatic alcohol" is 3 x 0.6 + 6 x 0.4 = 4.2.

When the other polyester resin satisfies the formulas (1) to (3), the toner can improve low-temperature fixability, stress resistance, and blocking resistance of the toner image.

The following part of formula (1) represents the average distance between branches of the polyester resin (hereinafter sometimes referred to as "branch distance").

The other polyester resin satisfies the above formula (1) and preferably satisfies the following formula (1-1).

However, the amount of the trihydric or higher aliphatic alcohol in the formula (1-1) is the mole percentage of the trihydric or higher aliphatic alcohol relative to the alcohol component.

If the branch distance exceeds 4,000, the melt viscosity hardly decreases, which is disadvantageous for low-temperature fixability. If the branch distance is less than 500, the molecular size becomes small due to the shorter branch distance, and the stress resistance of the toner decreases. In addition, when cooled from a high-temperature state, the start of molecular entanglement is delayed, which reduces the blocking resistance of the output toner image.

Polyester resins with a branched structure can reduce the melt viscosity at high temperatures while maintaining the glass transition temperature, which makes it possible to improve low-temperature fixability and heat-resistant storage stability. On the other hand, by increasing the amount of branched components inside, it has a dense three-dimensional structure, which suppresses deformation even when a large stress is applied, and is therefore thought to provide a toner with excellent stress resistance.

The weight average molecular weight of the other polyester resin satisfies the above formula (2) and preferably satisfies the following (2-1).
8,000≦weight average molecular weight (Mw)≦20,000...Formula (2-1)
If the weight average molecular weight of the other polyester resin is less than 4,000, the high temperature and high humidity resistant storage stability and stress resistance of the toner deteriorate. If the weight average molecular weight exceeds 30,000, the melt viscosity becomes too high, and the low temperature fixability of the toner cannot be expressed.

The other polyester resin satisfies the above formula (3) and preferably satisfies the following formula (3-1).
2.0≦(amount of trihydric or higher aliphatic alcohol)≦4.0...Equation (3-1)
However, the amount of the tri- or higher hydric aliphatic alcohol in the formula (3-1) is the mole percentage of the tri- or higher hydric aliphatic alcohol relative to the alcohol component.
When the "amount of trihydric or higher aliphatic alcohol" (amount of branched components) is less than 0.5 mol %, high temperature and humidity resistance storage stability and filming resistance are deteriorated, whereas when it exceeds 6.5 mol %, image gloss and low temperature fixability are deteriorated.

As a method for producing the other polyester resin, a method of reacting an alcohol component containing a trihydric or higher aliphatic alcohol with a carboxylic acid component is preferable. In this way, a polyester resin having a branched structure can be formed.

The glass transition temperature (Tg) of the other polyester resin is preferably 40° C. or higher and 70° C. or lower, and more preferably 50° C. or higher and 60° C. or lower.
If the glass transition temperature is lower than 40° C., the toner may have poor heat-resistant storage stability and poor durability against stress such as stirring in a developing machine, and may also have poor filming resistance.
If the glass transition temperature exceeds 70° C., the deformation caused by heating and pressure during fixing of the toner may be insufficient, resulting in insufficient low-temperature fixing property.

It is preferable that the other polyester resin is soluble in tetrahydrofuran (THF) in terms of low-temperature fixability and high image gloss.

<Alcohol content>
Examples of the alcohol component include dihydric alcohols and trihydric or higher alcohols.
The alcohol component contains a trihydric or higher aliphatic alcohol.

Examples of the dihydric alcohol include aliphatic diols, diols having an oxyalkylene group, alicyclic diols, alicyclic diols to which alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) have been added, bisphenols, and alkylene oxide adducts of bisphenols.

Examples of the aliphatic diol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol.
Examples of the diol having an oxyalkylene group include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.
Examples of the alicyclic diol include 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, and the like.
Examples of the bisphenols include bisphenol A, bisphenol F, and bisphenol S.
Examples of the alkylene oxide adducts of bisphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to bisphenols.

Examples of the trihydric or higher alcohol include the trihydric or higher aliphatic alcohols.
Examples of the trivalent or higher aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, and dipentaerythritol.

As the trihydric or higher aliphatic alcohol, trihydric to tetrahydric aliphatic alcohols are preferred.

<Carboxylic Acid Component>
Examples of the carboxylic acid component include divalent carboxylic acids, trivalent or higher carboxylic acids, etc. Furthermore, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of these may be used.

Examples of the dicarboxylic acid include aliphatic dicarboxylic acids and aromatic dicarboxylic acids.

The aliphatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid.
The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

Examples of the trivalent or higher carboxylic acid include trimellitic acid and pyromellitic acid.

These carboxylic acid components may be used alone or in combination of two or more.

<Crystalline Polyester Resin>
The crystalline polyester resin has high crystallinity and exhibits a thermal melting property that shows a rapid viscosity drop near the fixing start temperature. By using the crystalline polyester resin having such a property together with the amorphous polyester resin, the heat-resistant storage stability is good due to the crystallinity until just before the melting start temperature, and at the melting start temperature, the crystalline polyester resin melts and causes a rapid viscosity drop (sharp melt), which causes compatibility with the amorphous polyester resin, and both are fixed by a rapid viscosity drop, so that a toner having both good heat-resistant storage stability and low-temperature fixing property can be obtained. In addition, the release width (the difference between the minimum fixing temperature and the high-temperature offset occurrence temperature) also shows good results.

The crystalline polyester resin can be obtained by using a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic ester.
In the present invention, the crystalline polyester resin refers to a resin obtained by using a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic ester, as described above. Modified polyester resins, for example, the prepolymers and resins obtained by subjecting the prepolymers to a crosslinking and/or elongation reaction, do not belong to the crystalline polyester resins.

The presence or absence of crystallinity of the crystalline polyester resin in the present invention can be confirmed by a crystal analysis X-ray diffraction device (for example, X'Pert Pro MRD, Philips). The measurement method is described below.
First, the target sample is ground in a mortar to prepare a powdered sample, and the powdered sample is evenly applied to a sample holder.Then, the sample holder is set in the diffraction device, and measurements are performed to obtain a diffraction spectrum.
When the half-width of the peak with the greatest intensity among the diffraction peaks obtained in the range of 20°<2θ<25° is 2.0 or less, it is determined that the sample has crystallinity.
In contrast to crystalline polyester resins, polyester resins that do not exhibit the above-mentioned state are referred to as amorphous polyester resins in the present invention.

The conditions for the X-ray diffraction measurement are as follows.
〔Measurement condition〕
Tension kV: 45 kV
Current: 40mA
MPSS
Upper
Gonio
Scanmode: continues
Start angle: 3°
End angle: 35°
Angle Step: 0.02°
Lucid beam optics
Divergence slit: Div slit 1/2
Diffraction beam optics
Anti scatter slit: As Fixed 1/2
Receiving slit ： Prog rec slit

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

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

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

Examples of the trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

-Polycarboxylic acid-
The polyvalent carboxylic acid is not particularly limited and may be appropriately selected depending on the purpose. Examples of the polyvalent carboxylic acid include divalent carboxylic acids and trivalent or higher carboxylic acids.

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

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

The polyvalent carboxylic acid may contain a dicarboxylic acid having a sulfonic acid group in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid. Furthermore, the polyvalent carboxylic acid may contain a dicarboxylic acid having a double bond in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid. These may be used alone or in combination of two or more.

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

The melting point of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C or higher and 80°C or lower. If the melting point is lower than 60°C, the crystalline polyester resin is likely to melt at low temperatures, and the heat-resistant storage stability of the toner may decrease. If the melting point is higher than 80°C, the crystalline polyester resin may not melt sufficiently due to heating during fixing, and low-temperature fixability may decrease.

The molecular weight of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint that a resin with a sharp molecular weight distribution and a low molecular weight has excellent low-temperature fixability, and that a large amount of low-molecular weight components reduces heat-resistant storage stability, it is preferable that the orthodichlorobenzene-soluble portion of the crystalline polyester resin has a weight average molecular weight (Mw) of 3,000 to 30,000, a number average molecular weight (Mn) of 1,000 to 10,000, and Mw/Mn of 1.0 to 10, as measured by GPC. It is further preferable that the weight average molecular weight (Mw) is 5,000 to 15,000, the number average molecular weight (Mn) is 2,000 to 10,000, and Mw/Mn is 1.0 to 5.0.

The acid value of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of affinity between paper and resin, in order to achieve the desired low-temperature fixability, it is preferably 5 mgKOH/g or more, and more preferably 10 mgKOH/g or more. On the other hand, in order to improve high-temperature offset resistance, it is preferably 45 mgKOH/g or less.

The hydroxyl value of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but in order to achieve the desired low-temperature fixability and good charging characteristics, it is preferably 0 mgKOH/g to 50 mgKOH/g, and more preferably 5 mgKOH/g to 50 mgKOH/g.

The molecular structure of the crystalline polyester resin can be confirmed by NMR measurement of a solution or solid, as well as X-ray diffraction, GC/MS, LC/MS, IR measurement, etc. A simple method includes a method of detecting a crystalline polyester resin as a crystalline polyester resin by detecting an absorption due to olefin δCH (out-of-plane bending vibration) at 965±10 cm ⁻¹ or 990±10 cm ⁻¹ in an infrared absorption spectrum.

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

<Other ingredients>
The toner of the present invention contains a release agent, an external additive, and a colorant as essential components, and may contain other components such as a charge control agent, a flowability improver, a cleaning property improver, and a magnetic material.

-Release agent-
The release agent is not particularly limited and can be appropriately selected from known agents.
Examples of waxes and wax release agents include natural waxes such as vegetable waxes such as carnauba wax, cotton wax, and wood wax rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerusin; and petroleum waxes such as paraffin, microcrystalline, and petrolatum.

In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene, and polypropylene; synthetic waxes such as esters, ketones, and ethers; etc. may also be used.

Furthermore, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons; homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate, which are low molecular weight crystalline polymer resins (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); crystalline polymers with long alkyl groups on the side chains, etc. may also be used.

Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60°C or higher and 80°C or lower. If the melting point is lower than 60°C, the release agent may melt easily at low temperatures and may have poor heat resistance storage stability. If the melting point is higher than 80°C, even if the resin melts and is in the fixing temperature range, the release agent may not melt sufficiently, causing fixing offset and image defects.

The content of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, relative to 100 parts by mass of the toner. If the content is less than 2 parts by mass, the high-temperature offset resistance and low-temperature fixability during fixing may be poor, and if it exceeds 10 parts by mass, the heat-resistant storage stability may decrease and image fogging may easily occur. If the content is within the more preferred range, it is advantageous in terms of improving image quality and fixing stability.

-External additives-
The external additives include inorganic fine particles, hydrophobized inorganic fine particles, fatty acid metal salts, oxide particles, and mixtures thereof. The average particle size of the primary particles of the inorganic fine particles is preferably 1 nm to 300 nm, and more preferably 5 nm to 200 nm.

It is also preferred that the inorganic fine particles contain at least one type of inorganic fine particles having an average primary particle size of 30 nm or less and at least one type of inorganic fine particles having an average primary particle size of 30 nm or more, and that the specific surface area measured by the BET method is 20 m ² /g to 500 m ² /g.

The external additive is not particularly limited and can be appropriately selected depending on the purpose. Examples include silica fine particles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titania, alumina, tin oxide, antimony oxide, etc.), fluoropolymers, etc.

Suitable external additives include hydrophobized silica, titania, titanium oxide, and alumina fine particles. Examples of silica fine particles include R972, R974, ∨P RX40S, ∨P RY40S, RX200S, RY200S, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.). Examples of titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, and STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika Co., Ltd.).

Examples of hydrophobically treated titanium oxide particles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, TAF-1500T (all manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-100S, MT-100T (all manufactured by Teika Corporation), and IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

Hydrophobized oxide particles, hydrophobized silica particles, hydrophobized titania particles, and hydrophobized alumina particles can be obtained, for example, by treating hydrophilic particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Silicone oil-treated oxide particles and inorganic particles, which are treated with silicone oil by heating if necessary, are also suitable.

Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, methacryl-modified silicone oil, and α-methylstyrene-modified silicone oil.

Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferred.

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 weight to 5 parts by weight, and more preferably 0.3 parts by weight to 3 parts by weight, per 100 parts by weight of the toner.

The average particle size of the primary particles of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but as described above, it is preferably 1 nm or more and 300 nm or less, and more preferably 5 nm or more and 200 nm or less. When the average particle size is 1 nm or more, the inorganic fine particles are prevented from being embedded in the toner, and their function is effectively exerted. Furthermore, when the average particle size is 300 nm or less, the photoconductor surface is not unevenly damaged.

The inorganic fine particles may be subjected to a crushing treatment as necessary. In this case, it is possible to control the accelerated aggregation degree of the inorganic fine particles by adjusting the crushing strength. Examples of inorganic fine particles to which the crushing treatment is applied include R972, R974, RX40, RY40, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.).

The crushing intensity can be adjusted, for example, by adjusting the mixer's rotation speed and rotation time.

- Coloring agent -
The colorant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow, Red iron oxide, red lead, vermilion, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, physey red, parachlor orthonitroaniline red, lithol fast scarlet G, brilliant fast scarlet, brilliant carmine BS, permanent red (F2R, F4R, FRL, FRLL, F4RH), fast scarlet VD, Belkan fast rubin B, brilliant scarlet G, lithol rubin GX, permanent red F5R, brilliant carmine 6B, pigment scarlet 3B, bordeaux 5B , Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Lithium Blue, Examples of the pigments include Cyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, Prussian blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraquinone Green, Titanium Oxide, Zinc Oxide, and Lithobone.

The content of the colorant is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 part by mass to 15 parts by mass, and more preferably 3 parts by mass to 10 parts by mass, per 100 parts by mass of the toner.

The colorant can also be used as a masterbatch composited with a resin. Examples of resins to be used in the manufacture of the masterbatch or to be kneaded with the masterbatch include, in addition to the other polyester resins mentioned above, polymers of styrene or its substitutes such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene-α-chloromethyl methacrylate copolymer. Examples of such styrene copolymers include styrene-acrylonitrile copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resins, epoxy polyol resins, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resins, rosin, modified rosin, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, and paraffin wax. These may be used alone or in combination of two or more.

The master batch can be obtained by mixing and kneading the resin and colorant for the master batch under high shear force. In this case, an organic solvent can be used to enhance the interaction between the colorant and the resin. In addition, a method called the flushing method, in which an aqueous paste containing water for the colorant is mixed and kneaded with the resin and organic solvent, the colorant is transferred to the resin side, and the water and organic solvent components are removed, is also preferably used because it does not require drying since the wet cake of the colorant can be used as is. A high shear dispersion device such as a three-roll mill is preferably used for mixing and kneading.

-Charge control agent-
The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the charge control agent include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdic acid chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylic acid salts, and metal salts of salicylic acid derivatives.

Specific examples include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

The content of the charge control agent is not particularly limited and can be appropriately selected according to the purpose, but is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the toner. If the content exceeds 10 parts by mass, the chargeability of the toner becomes too high, which reduces the effect of the main charge control agent and increases the electrostatic attraction force with the developing roller, which may lead to a decrease in the fluidity of the developer and a decrease in image density. These charge control agents can be melt-kneaded with the master batch and resin and then dissolved and dispersed, or they can be added when directly dissolved and dispersed in an organic solvent, or they can be fixed on the toner surface after the toner particles are produced.

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

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

- Magnetic materials -
The magnetic material is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, those that are white in color are preferred.

<Amount of Released External Additive>
The amount of external additive released from the toner is measured as follows.
(1) 3.75 g of a toner sample is dispersed in 50 mL of a 0.5% by weight polyoxyalkylene alkyl ether (Noigen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) dispersion liquid contained in a 110 mL vial.
(2) Using an ultrasonic homogenizer (product name: homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS), ultrasonic waves are irradiated for 100 seconds at a frequency of 20 kHz and an output of 40 W. The amount of irradiation energy applied at this time is calculated from the product of the output and the irradiation time (40 W x 100 seconds = 4 kJ). At this time, the toner dispersion is cooled as needed so that the liquid temperature does not exceed 40°C.
(3) The obtained dispersion liquid is suction filtered using filter paper (product name: Qualitative Filter Paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice again with ion-exchanged water, filtered, and the liberated external additives are removed, and the toner is then dried.
(4) The amount of external additive in the toner before and after the removal of the external additive is quantified by calculating the mass % from the intensity according to a calibration curve (or the difference in intensity before and after the removal of the external additive) using a fluorescent X-ray analyzer (ZSX-100e, manufactured by Rigaku Corporation), and the amount of liberated external additive can be obtained.
Release amount=(mass of external additive before dispersion)−(mass of external additive remaining after dispersion) Equation (4)

The liberation rate (mass %) of the external additive can be calculated by the following formula 5.
Freedom ratio=[free amount/total amount of external additives added]×100 (5)

In this case, the total amount of external additives added is defined as follows.
Using an ultrasonic homogenizer, the amount of external additives in the toner irradiated with ultrasonic waves at irradiation energy amounts of 1000 kJ and 1500 kJ in the same manner as above is quantified with a fluorescent X-ray analyzer, and it is confirmed that there is no decrease in the amount of additives at 1000 kJ and 1500 kJ. If there is no decrease, it can be determined that all of the external additives have been removed.
In addition, the toner surface after the treatment may be observed with a field emission scanning electron microscope (FE-SEM) to confirm that all of the external additives have been removed. If any change is observed, the irradiation energy amount is increased by 500 kJ and the same treatment is repeated.
The total amount of added external additives is calculated from the difference between the amount of external additives in the toner from which all the external additives have been removed as described above and that in the untreated toner.

When the "amount of external additives in the toner from which all external additives have been removed" is measured with fluorescent X-rays after all the external additives have been removed as described above, the amount of external additives is either zero, or if the base material contains the same substance as the external additive, it is affected and becomes a certain value. On the other hand, when the amount of external additives in the untreated toner is measured with fluorescent X-rays, if the toner base material contains the same substance as the external additive as described above, the amount of external additives is added by that amount. Therefore, in order to calculate the "total amount of external additives added," the method of calculating the total amount of external additives is used, as described above, from the difference between the amount of external additives in the toner from which all external additives have been removed and the amount of external additives in the untreated toner.

The amount of external additive released from the toner is preferably 20% to 50% by weight when the irradiation energy amount is 4 kJ. A release amount of 20% by weight or more further improves cleaning properties, while a release amount of 50% by weight or less can suppress filming and other problems that occur when released external additive adheres to the transfer body. By setting the irradiation energy to 4 kJ, it is possible to measure the amount of external additive with weak adhesion that is easily released from the toner in the image forming device.

Specific examples of the external additives are as described above.

<Volume average particle size>
The volume average particle diameter of the toner is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 3 μm to 7 μm. The ratio of the volume average particle diameter to the number average particle diameter is preferably 1.2 or less. The toner preferably contains 1% to 10% by number of components having a volume-based particle diameter of 2 μm or less.

<<Methods of calculating and analyzing various properties of toner and toner components>>
The SP value, Tg, acid value, hydroxyl value, molecular weight, and melting point of the amorphous polyester resin, the crystalline polyester resin, and the release agent may be measured for each of them. Alternatively, the SP value, Tg, molecular weight, melting point, and mass ratio of the constituent components may be calculated by separating the components from an actual toner by gel permeation chromatography (GPC) or the like and subjecting each separated component to an analytical method described later.

Separation of each component by GPC can be carried out, for example, by the following method.
In the GPC measurement using THF (tetrahydrofuran) as the mobile phase, the eluate is fractionated using a fraction collector or the like, and fractions corresponding to the desired molecular weight portion are collected from the full integral of the elution curve.

The combined eluate is concentrated and dried using an evaporator or the like, and the solid content is then dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, and ¹ H-NMR measurement is performed. The constituent monomer ratio of the resin in the eluted components is calculated from the integrated ratio of each element.

Another method involves concentrating the eluate, hydrolyzing it with sodium hydroxide or the like, and then qualitatively and quantitatively analyzing the decomposition products using high performance liquid chromatography (HPLC) or the like to calculate the constituent monomer ratios.

In the case where the toner manufacturing method forms toner base particles while generating a polyester resin by an elongation reaction and/or a crosslinking reaction between the non-linear reactive precursor and the curing agent, the polyester resin may be separated from the actual toner by GPC or the like to determine the Tg, etc. of the polyester resin, or a polyester resin may be synthesized separately by an elongation reaction and/or a crosslinking reaction between the non-linear reactive precursor and the curing agent, and the Tg, etc. of the synthesized polyester resin may be measured.

<<Means for separating toner components>>
An example of a means for separating each component when analyzing the toner will be described in detail below.
First, 1 g of the toner is put into 100 mL of THF, and the mixture is stirred for 30 minutes at 25° C. to obtain a solution in which the soluble matter is dissolved.
This is filtered through a membrane filter having an opening of 0.2 μm to obtain the THF-soluble portion of the toner.
Next, this is dissolved in THF to prepare a sample for GPC measurement, and the sample is injected into the GPC used for measuring the molecular weight of each of the above-mentioned resins.
Meanwhile, a fraction collector is placed at the eluate outlet of the GPC to collect the eluate at predetermined counts, and the eluate is obtained at 5% area ratios from the start of elution (the rise of the curve) of the elution curve.
Next, for each elution, 30 mg of a sample is dissolved in 1 mL of deuterated chloroform, and 0.05% by volume of tetramethylsilane (TMS) is added as a standard substance.
The solution is filled into a 5 mm diameter glass tube for NMR measurement, and a spectrum is obtained by 128 accumulations at 23° C. to 25° C. using a nuclear magnetic resonance apparatus (JNM-AL400 manufactured by JEOL Ltd.).
The monomer composition and the constituent ratio of the polyester resin and the crystalline polyester resin contained in the toner can be determined from the peak integral ratio of the obtained spectrum.

For example, the peaks are assigned as follows, and the component ratio of the constituent monomers is determined from the integral ratio of each peak.
Peak assignments can be done, for example,
Around 8.25 ppm: From the benzene ring of trimellitic acid (one hydrogen)
Around 8.07 ppm to 8.10 ppm: From the benzene ring of terephthalic acid (4 hydrogen atoms)
Around 7.1 ppm to 7.25 ppm: From the benzene ring of bisphenol A (4 hydrogen atoms)
Around 6.8 ppm: From the benzene ring of bisphenol A (4 hydrogens) and from the double bond of fumaric acid (2 hydrogens)
Around 5.2 ppm to 5.4 ppm: derived from methine of bisphenol A propylene oxide adduct (one hydrogen)
Around 3.7 ppm to 4.7 ppm: derived from methylene of bisphenol A propylene oxide adduct (2 hydrogens) and derived from methylene of bisphenol A ethylene oxide adduct (4 hydrogens)
Around 1.6 ppm: From the methyl group of bisphenol A (6 hydrogen atoms)
It can be said that:

From these results, for example, an extract recovered in a fraction in which the amorphous polyester resin having a structure represented by any one of the above structural formulas 1) to 3) accounts for 90% or more can be treated as a polyester resin having a structure represented by any one of the above structural formulas 1) to 3).
Similarly, the extract recovered in the fraction in which the other polyester resin accounts for 90% or more can be treated as the other polyester resin.
In addition, the extract recovered in the fraction in which the crystalline polyester resin accounts for 90% or more can be treated as the crystalline polyester resin.

<<Analysis of THF insoluble matter in toner>>
The THF-insoluble matter of the toner can be extracted, for example, as follows.
One part of toner is added to 40 parts of THF, and the mixture is refluxed for 6 hours, after which the insoluble components are precipitated using a centrifuge to separate the insoluble components from the supernatant. The insoluble components are dried at 40° C. for 20 hours to obtain a THF-insoluble fraction. The THF-insoluble fraction corresponds to a nonlinear polyester resin. Therefore, the THF-insoluble fraction contains a plurality of structural parts derived from trivalent isocyanates.
The composition of the THF-insoluble matter can be analyzed by NMR measurement of a solution or solid, as well as by X-ray diffraction, GC/MS, LC/MS, IR measurement, and the like.
Conveniently, the analysis can be performed by a pyrolysis simultaneous methylation GC-MS method using a methylation reagent, for example, by the following method.
Device name: Shimadzu QP2010 Frontier Lab Py2020D
Data analysis software: Shimadzu GCMSsolution
Heating temperature: 280°C
Reaction pyrolysis temperature: 300°C
Column name: Ultra ALLOY-5 L = 30 m ID = 0.25 mm Film = 0.25 μm
Thermostatic chamber temperature: 50°C (hold for 1 minute) - 10°C/min - 330°C (hold for 11 minutes)
Carrier gas: 53.6 kPa constant, He 1.0 mL/min
Injection mode: Split (1:100)
Ionization method: EI method (70 eV)
Measurement mode: Scan mode Library: NIST 20 MASS SPECTRAL

<<Method of measuring hydroxyl value and acid value>>
The hydroxyl value can be measured using a method in accordance with JIS K0070-1966.
Specifically, 0.5 g of sample is weighed out into a 100 mL measuring flask, and 5 mL of acetylation reagent is added to it. Next, the flask is heated in a hot bath at 100±5°C for 1 to 2 hours, and then removed from the bath and allowed to cool. Water is then added and the flask is shaken to decompose the acetic anhydride.
Next, in order to completely decompose acetic anhydride, the flask is again heated in a warm bath for 10 minutes or more, allowed to cool, and then the walls of the flask are thoroughly washed with an organic solvent. Furthermore, the hydroxyl value is measured at 23°C using a potentiometric automatic titrator DL-53 Titrator (manufactured by Mettler Toledo) and an electrode DG113-SC (manufactured by Mettler Toledo), and analyzed using analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL toluene and 30 mL ethanol is used to calibrate the apparatus. At this time, the measurement conditions are as follows.

〔Measurement condition〕
Stir
Speed [%] 25
Time [s] 15
EQP titration
Titrant/Sensor
Titrant CH3ONa
Concentration [mol/L] 0.1
Sensor DG115
Unit of measurement mV
Predispensing to volume
Volume [mL] 1.0
Wait time [s] 0
Titrant Addition Dynamic
dE (set) [mV] 8.0
dV (min) [mL] 0.03
dV(max) [mL] 0.5
Measure mode Equilibrium controlled
dE [mV] 0.5
dt [s] 1.0
t (min) [s] 2.0
t(max) [s] 20.0
Recognition
Threshold 100.0
Steepest jump only No
Range No.
Tendency None
Termination
at maximum volume [mL] 10.0
at potential No
At slope No
after number EQPs Yes
n=1
comb. Termination conditions No.
Evaluation
Procedure Standard
Potential 1 No
Potential 2 No
Stop for revaluation No.

The acid value can be measured using a method in accordance with JIS K0070-1992.
Specifically, 0.5 g of a sample (0.3 g of ethyl acetate soluble matter) is added to 120 mL of toluene and dissolved by stirring at 23° C. for about 10 hours. Next, 30 mL of ethanol is added to obtain a sample solution. If the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used.
Furthermore, the acid value is measured at 23°C using a potentiometric automatic titrator DL-53 Titrator (manufactured by Mettler Toledo) and an electrode DG113-SC (manufactured by Mettler Toledo), and the result is analyzed using analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol is used to calibrate the apparatus.
In this case, the measurement conditions are the same as those for the hydroxyl value described above.

The acid value can be measured as described above, but specifically, it is titrated with a pre-standardized 0.1N potassium hydroxide/alcohol solution, and the acid value is calculated from the titration amount using the formula: acid value [mg KOH/g] = titration amount [mL] x N x 56.1 [mg/mL]/sample [g] (where N is the factor of the 0.1N potassium hydroxide/alcohol solution).

<<Method of measuring particle size distribution>>
The volume average particle diameter (D4) and number average particle diameter (Dn) of the toner, and the ratio thereof (D4/Dn) can be measured using, for example, a Coulter Counter TA-II or a Coulter Multisizer II (both manufactured by Coulter Corporation).
In the present invention, a Coulter Multisizer II was used.
The measurement method is described below.
First, 0.1 mL to 5 mL of a surfactant (preferably polyoxyethylene alkyl ether (nonionic surfactant)) is added as a dispersant to 100 mL to 150 mL of the electrolytic solution. Here, the electrolytic solution is a 1 mass % NaCl aqueous solution prepared using first-class sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Then, 2 mg to 20 mg of a measurement sample is further added.
The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of the toner particles or toner are measured using the measuring device with a 100 μm aperture as an aperture, and the volume distribution and number distribution are calculated.
From the distribution thus obtained, the volume average particle diameter (D4) and number average particle diameter (Dn) of the toner can be obtained.
Thirteen channels are used, the following sizes being used: 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 25.40 μm; 25.40 μm or more and less than 32.00 μm; and 32.00 μm or more and less than 40.30 μm, and the target particles are particles with a particle size of 2.00 μm or more and less than 40.30 μm.

<<Measurement of molecular weight>>
The molecular weight of each of the components of the toner can be measured, for example, by the following method.
Gel permeation chromatography (GPC) measuring device: GPC-8220GPC (manufactured by Tosoh Corporation)
Column: TSKgel Super HZM-H 15 cm triple column (Tosoh Corporation)
Temperature: 40°C
Solvent: Tetrahydrofuran (THF)
Flow rate: 0.35 mL / min
Sample: 0.4 mL of a 0.15% by mass sample is injected. Sample pretreatment: Toner is dissolved in tetrahydrofuran (THF) (containing a stabilizer, manufactured by Wako Pure Chemical Industries, Ltd.) at 0.15% by mass, and then filtered through a 0.2 μm filter, and the filtrate is used as the sample.
100 μL of the THF sample solution is injected and measured.
In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithm of a calibration curve prepared using several types of monodisperse polystyrene standard samples and the count number.
As standard polystyrene samples for preparing a calibration curve, Showdex STANDARD Std. Nos. S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, and S-0.580 manufactured by Showa Denko KK are used.
The detector used is a refractive index (RI) detector.

<<Measurement of Accelerated Coagulation Degree>>
The accelerated cohesion degree was measured by the following method: For example, a powder tester manufactured by Hosokawa Micron Corporation was used as a measuring device, and the accessories were set on a vibration table in the following manner.

(A) Vibro chute (B) Packing (C) Space ring (D) Sieve (3 types) Top > Middle > Bottom (E) Osaever

Next, secure it with a knob nut and start the vibration table. The measurement conditions are as follows:

Sieve opening (upper row) 75 μm
Sieve opening (middle) 45μm
Sieve opening (lower row) 20 μm
Amplitude scale 2mm
Sample (inorganic fine particles) amount: 2 g
Vibration time: 160 seconds Vibration acceleration: 100 m/ ^s2

After the measurement, the accelerated coagulation rate is calculated using the following formula:

Weight percent of powder remaining on the upper sieve × 1 (a)
Weight percent of powder remaining on the middle sieve × 0.6 (b)
Weight percent of powder remaining in the lower sieve × 0.2 (c)
The sum of the above three calculated values is the accelerated cohesion degree (%).
That is, the accelerated degree of cohesion (%)=(a)+(b)+(c).

The toner of the present invention also contains inorganic fine particles as an external additive, and the total content of inorganic fine particles in the toner of the present invention is, for example, preferably 0.5 to 20.0 parts by mass, and more preferably 0.5 to 10.0 parts by mass, per 100 parts by mass of the toner of the present invention.

<Toner Manufacturing Method>
The method for producing the toner is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferable that the toner contains the amorphous polyester resin and, if necessary, the other polyester resin, and further contains the crystalline polyester resin, and is granulated by dispersing an oil phase containing the release agent, the colorant, and the like in an aqueous medium.

One example of the method for producing such a toner is a known solution suspension method. As an example of the method for producing the toner, a method for forming toner base particles while producing a polyester resin having a structure represented by any one of the above structural formulas 1) to 3) by an elongation reaction and/or crosslinking reaction between the polyester prepolymer and the curing agent is shown below. In such a method, an aqueous medium is prepared, an oil phase containing the toner materials is prepared, the toner materials are emulsified or dispersed, and the organic solvent is removed.

- Preparation of aqueous medium (aqueous phase) -
The aqueous medium can be prepared, for example, by dispersing resin particles in the aqueous medium. The amount of the resin particles added to the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of the aqueous medium.

The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aqueous medium include water, a solvent miscible with water, and a mixture of these. These may be used alone or in combination of two or more. Of these, water is preferred.

The water-miscible solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, etc. The alcohol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methanol, isopropanol, ethylene glycol, etc. The lower ketones are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include acetone, methyl ethyl ketone, etc.

- Preparation of oil phase -
The oil phase containing the toner materials can be prepared by dissolving or dispersing the toner materials, which include at least the amorphous polyester precursor and the crystalline polyester resin, and further include the curing agent, the releasing agent, the colorant, etc., as necessary, in an organic solvent.

The organic solvent is not particularly limited and can be selected appropriately depending on the purpose, but an organic solvent with a boiling point of less than 150°C is preferred because it is easy to remove.

The organic solvent having a boiling point of less than 150°C is not particularly limited and can be appropriately selected depending on the purpose. Examples include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. These may be used alone or in combination of two or more.

Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, etc. are preferred, and ethyl acetate is more preferred.

- Emulsion or dispersion -
The toner materials can be emulsified or dispersed by dispersing an oil phase containing the toner materials in the aqueous medium. When the toner materials are emulsified or dispersed, the curing agent and the polyester prepolymer undergo an elongation reaction and/or a crosslinking reaction to generate the amorphous polyester resin.

The amorphous polyester resin can be produced, for example, by the following methods (1) to (3).
(1) A method in which an oil phase containing the polyester prepolymer and the curing agent is emulsified or dispersed in an aqueous medium, and the curing agent and the polyester prepolymer are subjected to an elongation reaction and/or a crosslinking reaction in the aqueous medium.
(2) A method in which an oil phase containing the polyester prepolymer is emulsified or dispersed in an aqueous medium to which the curing agent has been added in advance, and the curing agent and the polyester prepolymer are subjected to an elongation reaction and/or a crosslinking reaction in the aqueous medium.
(3) A method in which an oil phase containing the polyester prepolymer is emulsified or dispersed in an aqueous medium, and then the curing agent is added to the aqueous medium, and an elongation reaction and/or crosslinking reaction is caused between the curing agent and the polyester prepolymer at the particle interface in the aqueous medium.

The reaction conditions (reaction time, reaction temperature) for producing the amorphous polyester resin are not particularly limited and can be appropriately selected depending on the combination of the curing agent and the polyester prepolymer.

The reaction time is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 10 minutes to 40 hours, and more preferably 2 hours to 24 hours.

The reaction temperature is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0°C to 150°C, and more preferably 40°C to 98°C.

The method for stably forming a dispersion containing the polyester prepolymer in the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. For example, an oil phase prepared by dissolving or dispersing toner materials in a solvent is added to the aqueous medium phase, and the toner materials are dispersed by shear force.

The dispersing machine used for the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples include low-speed shear dispersing machines, high-speed shear dispersing machines, friction dispersing machines, high-pressure jet dispersing machines, and ultrasonic dispersing machines.

Among these, high-speed shear dispersers are preferred because they can control the particle size of the dispersion (oil droplets) to 2 μm to 20 μm.

When using the high-speed shear disperser, the conditions such as the rotation speed, dispersion time, and dispersion temperature can be appropriately selected according to the purpose.

The rotation speed is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 1,000 rpm to 30,000 rpm, and more preferably 5,000 rpm to 20,000 rpm.

There are no particular limitations on the dispersion time and it can be selected appropriately depending on the purpose, but in the case of a batch method, it is preferably 0.1 to 5 minutes.

The amount of the aqueous medium used when emulsifying or dispersing the toner materials is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 parts by weight to 2,000 parts by weight, and more preferably 100 parts by weight to 1,000 parts by weight, per 100 parts by weight of the toner materials.

If the amount of the aqueous medium used is less than 50 parts by mass, the dispersion state of the toner materials may become poor, and toner base particles of the specified particle size may not be obtained. If the amount of the aqueous medium used is more than 2,000 parts by mass, production costs may become high.

When emulsifying or dispersing the oil phase containing the toner materials, it is preferable to use a dispersant in order to stabilize the dispersion of oil droplets, etc., to give them a desired shape, and to sharpen the particle size distribution.

The dispersant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the dispersant include surfactants, poorly water-soluble inorganic compound dispersants, and polymer-based protective colloids.
These may be used alone or in combination of two or more. Among these, surfactants are preferred.

The surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used.

The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples include alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters. Among these, those having a fluoroalkyl group are preferred.

- Removal of organic solvents -
The method for removing the organic solvent from the dispersion liquid such as the emulsified slurry is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of gradually increasing the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, a method of spraying the dispersion liquid in a dry atmosphere to remove the organic solvent in the oil droplets, and the like can be mentioned.

When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, and further classified. The classification can be performed by removing fine particles in a liquid using a cyclone, decanter, or centrifugation, or the classification can be performed after drying.

The obtained toner base particles may be mixed with particles of the external additive, the charge control agent, etc. In this case, by applying a mechanical impact force, it is possible to prevent the particles of the external additive, etc. from being detached from the surface of the toner base particles.

The method of applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method of applying an impact force to the mixture using blades rotating at high speed, and a method of introducing the mixture into a high-speed air stream and accelerating it to cause the particles to collide with each other or with an appropriate collision plate.

The equipment used in the above method is not particularly limited and can be appropriately selected depending on the purpose. Examples include an Ang Mill (manufactured by Hosokawa Micron Corporation), an equipment modified from an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) to reduce the grinding air pressure, a Hybridization System (manufactured by Nara Machinery Works), a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), an automatic mortar, etc.

(Developer)
The developer of the present invention contains at least the toner, and optionally contains other components such as a carrier that are appropriately selected.
For this reason, it is possible to stably form high-quality images with excellent transferability, charging property, etc. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer corresponding to the recent improvement in information processing speed, a two-component developer is preferable because of its improved life.

When the developer is used as a one-component developer, there is little variation in the particle size of the toner even when the toner is balanced, there is little filming of the toner on the developing roller, and there is little melting of the toner on components such as blades that thin the toner layer, and good, stable developability and images can be obtained even with long-term stirring in the developing device.

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

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

-Core material-
The material for the core material is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include manganese-strontium-based materials of 50 emu/g to 90 emu/g and manganese-magnesium-based materials of 50 emu/g to 90 emu/g. In order to ensure image density, it is preferable to use high magnetization materials such as iron powder of 100 emu/g or more and magnetite of 75 emu/g to 120 emu/g. In addition, it is preferable to use low magnetization materials such as copper-zinc-based materials of 30 emu/g to 80 emu/g, because this can reduce the impact of the developer in a standing state on the photoconductor and is advantageous for improving image quality.

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

The volume average particle diameter of the core material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm to 150 μm, and more preferably 40 μm to 100 μm. If the volume average particle diameter is less than 10 μm, the amount of fine powder in the carrier increases, the magnetization per particle decreases, and the carrier may scatter, while if it exceeds 150 μm, the specific surface area decreases, the toner may scatter, and the reproduction of the solid areas may be particularly poor in full color with many solid areas.

When the toner is used in a two-component developer, it may be mixed with the carrier. The content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 90 parts by mass to 98 parts by mass, more preferably 93 parts by mass to 97 parts by mass, based on 100 parts by mass of the two-component developer.
The developer of the present invention can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

The toner storage unit in the present invention refers to a unit having a function of storing toner and storing the toner. Examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.
The toner storage container refers to a container that stores toner.
The developing device has a means for containing toner and developing the toner.
The process cartridge is a cartridge which integrates at least an image carrier and a developing means, contains toner, and is detachably mountable to an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, and a cleaning means.
By mounting the toner storage unit of the present invention in an image forming apparatus and forming an image, it is possible to form an image taking advantage of the characteristics of the toner, such as no filming, excellent low-temperature fixing property, high-temperature offset resistance, high gloss, high color reproducibility, and heat-resistant storage stability.
In the following, a developer container that contains a developer including a toner will be described in particular.

(Developer Storage Container)
The developer storage container according to the present invention contains the developer of the present invention. The container is not particularly limited and can be appropriately selected from among known containers, and examples of the container include those having a container body and a cap.

The size, shape, structure, material, etc. of the container body are not particularly limited, but the shape is preferably cylindrical, etc., and the inner surface is formed with spiral irregularities, which allows the developer contents to move to the outlet side by rotating, and it is particularly preferable that some or all of the spiral irregularities have a bellows function. Furthermore, the material is not particularly limited, but it is preferable that it is one with good dimensional accuracy, and examples of such materials include resin materials such as polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, and polyacetal resin.

The developer storage container is easy to store, transport, and handle, and can be detachably attached to a process cartridge, image forming device, etc., described below, and used to replenish developer.

(Image forming apparatus and image forming method)
The image forming apparatus of the present invention is characterized by using the toner of the present invention, and has, for example, at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and further has other means as necessary.
The image forming method according to the present invention includes a charging step, an exposure step, a development step, a primary transfer step, a secondary transfer step, a fixing step, and a cleaning step, and further includes other steps as necessary.
The image forming method can be suitably performed by the image forming apparatus, the charging step and the exposure step can be suitably performed by the electrostatic latent image forming means, the developing step can be suitably performed by the developing means, and the other steps can be suitably performed by the other means.

<Electrostatic Latent Image Bearing Member>
The material, structure, and size of the electrostatic latent image bearing member are not particularly limited and may be appropriately selected from known materials, and examples of the material include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors such as polysilane and phthalopolymethine, etc. Among these, amorphous silicon is preferred in terms of long life.

The amorphous silicon photoreceptor may be, for example, a photoreceptor having a photoconductive layer made of a-Si formed on the support by heating the support to 50°C to 400°C and forming a film on the support by a deposition method such as vacuum deposition, sputtering, ion plating, thermal CVD (Chemical Vapor Deposition), photo-CVD, or plasma CVD. Among these, the plasma CVD method, that is, the method of decomposing a raw material gas by direct current, high frequency, or microwave glow discharge to form an a-Si deposition film on the support, is preferred.

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

<Electrostatic latent image forming unit and electrostatic latent image forming process>
The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and may be appropriately selected depending on the purpose. For example, there may be mentioned a means having at least a charging member that charges the surface of the electrostatic latent image carrier, and an exposure member that exposes the surface of the electrostatic latent image carrier to light in an imagewise manner.
The electrostatic latent image forming step is not particularly limited as long as it is a step of forming an electrostatic latent image on the electrostatic latent image bearing member, and can be appropriately selected depending on the purpose. For example, the electrostatic latent image forming step can be performed by charging the surface of the electrostatic latent image bearing member and then exposing it to light in an imagewise manner, using the electrostatic latent image forming means.

--Charging member and charging--
The charging member is not particularly limited and can be appropriately selected depending on the purpose. Examples of the charging member include a contact charger known per se having a conductive or semiconductive roller, brush, film, rubber blade, etc., and a non-contact charger utilizing corona discharge such as a corotron or scorotron.
The charging can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image bearing member using the charging member.

The shape of the charging member may be any shape, such as a roller, a magnetic brush, a fur brush, etc., and can be selected according to the specifications and shape of the image forming apparatus.
The charging member is not limited to the contact-type charging member, but it is preferable to use a contact-type charging member because it allows an image forming apparatus in which the amount of ozone generated from the charging member is reduced.

--Exposure member and exposure--
The exposure member is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charging member in the shape of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposure member include various exposure members such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
The light source used in the exposure member is not particularly limited and can be appropriately selected depending on the purpose. Examples of the light source include general light-emitting materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (EL).
In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used.
The exposure can be carried out, for example, by imagewise exposing the surface of the electrostatic latent image bearing member using the exposure member.
In the present invention, a backlight system may be adopted in which exposure is performed imagewise from the back side of the electrostatic latent image bearing member.

<Developing means and developing process>
The developing unit is not particularly limited as long as it is a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image and has a toner, and can be appropriately selected depending on the purpose.
The developing step is not particularly limited as long as it is a step of developing the electrostatic latent image formed on the electrostatic latent image carrier with a toner to form a visible image, and can be appropriately selected depending on the purpose. For example, the developing step can be performed by the developing unit.

The developing means may be of a dry developing type or a wet developing type, and may be a single-color developing means or a multi-color developing means.
The developing means is preferably a developing device having an agitator that frictionally agitates the toner to charge it, a magnetic field generating means fixed inside, and a developer carrier that can rotate and carries a developer containing the toner on its surface.
In the developing means, for example, the toner and the carrier are mixed and stirred, and the toner is charged by friction during this process and held in a standing state on the surface of a rotating magnet roller to form a magnetic brush. The magnet roller is disposed in the vicinity of the electrostatic latent image carrier. Therefore, a part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier by electrical attraction. As a result, the electrostatic latent image is developed by the toner, and a visible image by the toner is formed on the surface of the electrostatic latent image carrier.

<Other Means and Other Steps>
Examples of the other means include a transfer means, a fixing means, a cleaning means, a discharging means, a recycling means, and a control means.
Examples of the other steps include a transfer step, a fixing step, a cleaning step, a discharging step, a recycling step, and a control step.

-Transfer means and transfer process-
The transfer means is not particularly limited as long as it is a means for transferring a visible image onto a recording medium, and can be appropriately selected depending on the purpose. However, a preferred embodiment has a primary transfer means for transferring the visible image onto an intermediate transfer body to form a composite transfer image, and a secondary transfer means for transferring the composite transfer image onto a recording medium.
The transfer step is not particularly limited as long as it is a step of transferring a visible image onto a recording medium, and may be appropriately selected depending on the purpose. However, a preferred embodiment is one in which an intermediate transfer body is used, a visible image is primarily transferred onto the intermediate transfer body, and then the visible image is secondarily transferred onto the recording medium.
The transfer step can be carried out, for example, by charging the visible image on the photoconductor using a transfer charger, and can be carried out by the transfer unit.
Here, when the image to be secondarily transferred onto the recording medium is a color image made up of toners of multiple colors, the transfer means can be configured to sequentially overlay toners of each color on the intermediate transfer body to form an image on the intermediate transfer body, and the intermediate transfer means can be configured to secondarily transfer the image on the intermediate transfer body onto the recording medium all at once.
The intermediate transfer body is not particularly limited and can be appropriately selected from known transfer bodies depending on the purpose. For example, a transfer belt is preferably used.

The transfer means (the primary transfer means and the secondary transfer means) preferably includes at least a transfer device that peels and charges the visible image formed on the photoreceptor onto the recording medium. Examples of the transfer device include a corona transfer device that uses corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.
The recording medium is typically plain paper, but is not particularly limited as long as it is capable of transferring an unfixed image after development, and can be appropriately selected depending on the purpose. A PET base for overhead projectors can also be used.

-Fixing means and fixing process-
The fixing means is not particularly limited as long as it is a means for fixing the transferred image transferred to the recording medium, and can be appropriately selected depending on the purpose, but is preferably a known heating and pressing member. Examples of the heating and pressing member include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller, and an endless belt.
The fixing step is not particularly limited as long as it is a step of fixing the visible image transferred to the recording medium, and can be appropriately selected depending on the purpose. For example, the fixing step may be performed for each color toner each time it is transferred to the recording medium, or may be performed simultaneously for each color toner in a stacked state.
The fixing step can be carried out by the fixing means.
The heating temperature in the heating and pressing member is preferably from 80°C to 200°C.
In the present invention, depending on the purpose, for example, a known optical fixing device may be used together with or instead of the fixing means.

The surface pressure in the fixing step is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 N/cm ² to 80 N/cm ² .

--Cleaning means and cleaning process--
The cleaning means is not particularly limited as long as it is capable of removing the toner remaining on the photoreceptor, and can be appropriately selected depending on the purpose. Examples of the cleaning means include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.
The cleaning step is not particularly limited as long as it is a step that can remove the toner remaining on the photoreceptor, and can be appropriately selected depending on the purpose. For example, the cleaning step can be performed by the cleaning unit.

--Static charge removal means and static charge removal process--
The charge removing means is not particularly limited as long as it is a means for removing electricity by applying a charge removing bias to the photoconductor, and may be appropriately selected depending on the purpose. For example, a charge removing lamp may be used.
The charge removal step is not particularly limited as long as it is a step of removing electricity by applying a charge removal bias to the photoconductor, and may be appropriately selected depending on the purpose. For example, the charge removal step may be performed by the charge removal unit.

- Recycling methods and processes -
The recycling means is not particularly limited as long as it is a means for recycling the toner removed in the cleaning step to the developing device, and can be appropriately selected depending on the purpose. For example, a known transport means can be used.
The recycling process is not particularly limited as long as it is a process for recycling the toner removed by the cleaning process back into the developing device, and can be appropriately selected depending on the purpose. For example, the recycling process can be performed by the recycling means.

-Control means and control process-
The control means is not particularly limited as long as it is a means capable of controlling the movement of each of the means, and can be appropriately selected depending on the purpose. For example, devices such as a sequencer and a computer can be mentioned.
The control step is not particularly limited as long as it is a step that can control the movement of each step, and can be appropriately selected depending on the purpose. For example, it can be performed by the control means.

Next, one embodiment of a method for forming an image using the image forming apparatus of the present invention will be described with reference to FIG. 1. The color image forming apparatus 100A shown in FIG. 1 includes a photoconductor drum 10 (hereinafter sometimes referred to as "photoconductor 10") as the electrostatic latent image carrier, a charging roller 20 as the charging means, an exposure device 30 as the exposure means, a developing device 40 as the developing means, an intermediate transfer body 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a discharging lamp 70 as the discharging means.

The intermediate transfer body 50 is an endless belt, and is designed to be movable in the direction of the arrow by three rollers 51 arranged inside and stretching it. Some of the three rollers 51 also function as transfer bias rollers that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer body 50. In addition, a transfer roller 80 as the transfer means that can apply a transfer bias for transferring (secondary transfer) the developed image (toner image) to a transfer paper 95 as a recording medium is arranged near the intermediate transfer body 50, facing the intermediate transfer body 50. Around the intermediate transfer body 50, a corona charger 58 for applying a charge to the toner image on the intermediate transfer body 50 is arranged between the contact portion between the photoconductor 10 and the intermediate transfer body 50 and the contact portion between the intermediate transfer body 50 and the transfer paper 95 in the rotation direction of the intermediate transfer body 50.

The developing device 40 is composed of a developing belt 41 as the developer carrier, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C arranged around the developing belt 41. The black developing unit 45K includes a developer container 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. The developing belt 41 is an endless belt that is rotatably stretched around multiple belt rollers, and a portion of it is in contact with the electrostatic latent image carrier 10.

In the color image forming apparatus 100A shown in FIG. 1, for example, the charging roller 20 uniformly charges the photoconductor drum 10. The exposure device 30 exposes the photoconductor drum 10 to light in an image-wise manner to form an electrostatic latent image. The electrostatic latent image formed on the photoconductor drum 10 is developed by supplying toner from the developing device 40 to form a toner image. The toner image is transferred (primary transfer) onto the intermediate transfer body 50 by the voltage applied from the roller 51, and is further transferred (secondary transfer) onto the transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. The remaining toner on the photoconductor 10 is removed by the cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by the discharge lamp 70.

Figure 2 shows another example of the image forming apparatus of the present invention. Image forming apparatus 100B has the same configuration as image forming apparatus 100A shown in Figure 1, except that it does not have a developing belt 41 and has a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C arranged directly opposite each other around the photoconductor drum 10.

Another example of the image forming apparatus of the present invention is shown in Fig. 3. The image forming apparatus shown in Fig. 3 comprises a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.
An endless belt-like intermediate transfer member 50 is provided in the center of the copying machine main body 150 .
The intermediate transfer body 50 is stretched around support rollers 14, 15, and 16, and can rotate clockwise in FIG. 3. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is disposed near the support roller 15. A tandem developing device 120 is disposed on the intermediate transfer body 50 stretched around the support rollers 14 and 15 along the conveying direction of the intermediate transfer body 50, in which four image forming means 18 for yellow, cyan, magenta, and black are arranged in a row facing each other. An exposure device 21, which is the exposure member, is disposed near the tandem developing device 120. A secondary transfer device 22 is disposed on the side of the intermediate transfer body 50 opposite to the side where the tandem developing device 120 is disposed. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper conveyed on the secondary transfer belt 24 and the intermediate transfer body 50 can come into contact with each other. A fixing device 25, which is the fixing means, is disposed near the secondary transfer device 22. The fixing device 25 includes a fixing belt 26, which is an endless belt, and a pressure roller 27 disposed so as to be pressed against the fixing belt 26.
In the tandem image forming apparatus, a sheet reversing device 28 is disposed near the secondary transfer device 22 and the fixing device 25 for reversing the transfer paper in order to form images on both sides of the transfer paper.

Next, we will explain how to form a full-color image (color copy) using the tandem developing device 120. That is, first, set the document on the document table 130 of the automatic document feeder (ADF) 400, or open the automatic document feeder 400 and set the document on the contact glass 40 of the scanner 300, and then close the automatic document feeder 400.

When a start switch (not shown) is pressed, the scanner 300 starts after the document is transported and moved onto the contact glass 32 when the document is set on the automatic document feeder 400, or immediately when the document is set on the contact glass 32. Then, the first travelling body 33 and the second travelling body 34 start to travel. At this time, light from a light source is irradiated by the first travelling body 33, and the reflected light from the document surface is reflected by a mirror in the second travelling body 34, and is received by the reading sensor 36 through the imaging lens 35 to read the color document (color image), which is converted into image information of black, yellow, magenta and cyan.

Then, the image information for black, yellow, magenta, and cyan is transmitted to each image forming means 18 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120. Then, in each image forming means, a toner image for black, yellow, magenta, and cyan is formed. That is, as shown in FIG. 4, each image forming means 18 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120 is composed of an electrostatic latent image carrier 10 (electrostatic latent image carrier for black 10K, electrostatic latent image carrier for yellow 10Y, electrostatic latent image carrier for magenta 10M, and electrostatic latent image carrier for cyan 10C), a charging device 160 which is the charging means for uniformly charging the electrostatic latent image carrier 10, and a charging device 160 which is a charging device for charging the electrostatic latent image carrier 10 based on each color image information. The image forming apparatus 18 includes an exposure device that exposes the electrostatic latent image carrier to light (L in FIG. 4) in the form of an image corresponding to each color image to form an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, a developing device 61 that is the developing means that develops the electrostatic latent image with each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner, a transfer charger 62 that transfers the toner image onto the intermediate transfer body 50, a cleaning device 63, and a charge remover 64. Each image forming means 18 is capable of forming a single color image (black image, yellow image, magenta image, and cyan image) based on image information of the respective color. The black image, yellow image, magenta image, and cyan image thus formed are sequentially transferred (primary transfer) onto the intermediate transfer body 50 which is rotated by the support rollers 14, 15, and 16: the black image formed on the black electrostatic latent image carrier 10K, the yellow image formed on the yellow electrostatic latent image carrier 10Y, the magenta image formed on the magenta electrostatic latent image carrier 10M, and the cyan image formed on the cyan electrostatic latent image carrier 10C. Then, the black image, the yellow image, the magenta image, and the cyan image are superimposed on the intermediate transfer body 50 to form a composite color image (color transfer image).

On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. The sheets are separated one by one by the separation roller 145 and sent to the paper feed path 146, transported by the transport roller 147 and guided to the paper feed path 148 in the copier body 150, where they are stopped by hitting the registration roller 49. Alternatively, the paper feed roller 142 is rotated to feed a sheet (recording paper) on the manual feed tray 54, separated one by one by the separation roller 52, and placed in the manual feed path 53, where they are also stopped by hitting the registration roller 49. The registration roller 49 is generally used while being grounded, but may be used with a bias applied to remove paper dust from the sheets. Then, the registration roller 49 rotates in time with the composite color image (color transfer image) composited on the intermediate transfer body 50, and a sheet (recording paper) is sent between the intermediate transfer body 50 and the secondary transfer device 22, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device 22. In this way, a color image is transferred and formed on the sheet (recording paper). Note that any residual toner on the intermediate transfer body 50 after the image transfer is cleaned by the intermediate transfer body cleaning device 17.

The sheet (recording paper) on which the color image has been transferred and formed is transported by the secondary transfer device 22 and sent to the fixing device 25, where the composite color image (color transfer image) is fixed onto the sheet (recording paper) by heat and pressure. The sheet (recording paper) is then switched by the switching claw 55 and discharged by the discharge rollers 56, and stacked on the paper output tray 57. Alternatively, the sheet is switched by the switching claw 55 and inverted by the sheet inverting device 28, and led back to the transfer position, an image is also recorded on the back side, and then discharged by the discharge rollers 56 and stacked on the paper output tray 57.

(Process cartridge)
The process cartridge according to the present invention is molded so as to be detachably mountable to various image forming apparatuses, and has at least an electrostatic latent image carrier for carrying an electrostatic latent image, and a developing means for developing the electrostatic latent image carried on the electrostatic latent image carrier with the toner of the present invention to form a toner image. The process cartridge of the present invention may further have other means as necessary.

The developing means includes at least a developer container that contains the developer of the present invention, and a developer carrier that carries and transports the developer contained in the developer container. The developing means may further include a regulating member or the like for regulating the thickness of the developer carried.

Figure 5 shows an example of a process cartridge according to the present invention. The process cartridge 110 has a photosensitive drum 10, a corona charger 58, a developing device 40, a transfer roller 80, and a cleaning device 90. The reference numeral 95 denotes transfer paper, and L denotes exposure light.

The following describes examples of the present invention, but the present invention is not limited to the following examples. "Parts" refers to "parts by mass" unless otherwise specified. "%" refers to "% by mass" unless otherwise specified.

[Toner manufacturing]
Specific examples of the toner used in the evaluation will be described below, but the toner used in the present invention is not limited to these examples.

Example 1
<Synthesis of ketimines>
In a reaction vessel equipped with a stirring bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50° C. for 5 hours to obtain [Ketimine Compound 1]. [Ketimine Compound 1] had an amine value of 418.

<Synthesis of amorphous polyester resin A>
-Synthesis of prepolymer A-
Into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 3-methyl-1,5-pentanediol, terephthalic acid, adipic acid, and titanium tetraisopropoxide (1,000 ppm with respect to the resin component) were added so that the molar ratio of hydroxyl groups to carboxyl groups, OH/COOH, was 1.2, the diol component was 100 mol% 3-methyl-1,5-pentanediol, and the dicarboxylic acid component was 50 mol% terephthalic acid and 50 mol% adipic acid.
Thereafter, the temperature was raised to 200° C. over about 4 hours, and then raised to 230° C. over 2 hours, and the reaction was continued until no water was discharged.
Thereafter, the mixture was further reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg to obtain an intermediate polyester A'.
The resulting intermediate polyester A' had a Tg of -40°C, an Mw of 15,000 and an Mw/Mn of 2.0.
Next, intermediate polyester A' and hexamethylene diisocyanate (HDI) trimer were charged into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate groups of HDI/hydroxyl groups of intermediate polyester) of 0.2, diluted with ethyl acetate to give a 50% ethyl acetate solution, and reacted at 100°C for 5 hours to obtain an intermediate polyester A solution.
The resulting intermediate polyester A had a Tg of -35°C, an Mw of 20,000 and an Mw/Mn of 2.2.
Next, the intermediate polyester A solution and isophorone diisocyanate (IPDI) were charged into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate groups of IPDI/hydroxyl groups of intermediate polyester) of 1.5, and the mixture was diluted with ethyl acetate to give a 50% ethyl acetate solution, followed by reaction at 100° C. for 5 hours to obtain a prepolymer A solution.

-Synthesis of amorphous polyester resin A-
The obtained prepolymer A was stirred in a reaction vessel equipped with a heater, a stirrer, and a nitrogen inlet tube, and further, [ketimine compound 1] was added dropwise to the reaction vessel in an amount such that the amine amount of [ketimine compound 1] was equimolar to the amount of isocyanate in prepolymer A. After stirring at 45°C for 10 hours, the prepolymer elongation product was taken out.
The obtained prepolymer elongated product was dried under reduced pressure at 50° C. until the amount of residual ethyl acetate was 100 ppm or less, to obtain an amorphous polyester resin A.
The Tg of the amorphous polyester resin A was -25°C.

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

<Synthesis of Other Polyester Resin B>
In a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A ethylene oxide 2 mole adduct (BisA-EO), bisphenol A propylene oxide 3 mole adduct (BisA-PO), trimethylolpropane (TMP), terephthalic acid, and adipic acid were added to the flask in a molar ratio of bisphenol A ethylene oxide 2 mole adduct, bisphenol A propylene oxide 3 mole adduct, and trimethylolpropane (bisphenol A ethylene oxide 2 mole adduct/bisphenol A propylene oxide 3 mole adduct/trimethylolpropane). The mixture was charged with a molar ratio of 38.6/57.9/3.5 (terephthalic acid/adipic acid), a molar ratio of 85/15 (terephthalic acid/adipic acid), and a molar ratio of 1.12 (OH/COOH) between hydroxyl groups and carboxyl groups, and reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at 230°C under normal pressure for 8 hours, and then reacted for 4 hours at a reduced pressure of 10 mmHg to 15 mmHg. After that, trimellitic anhydride was added to the reaction vessel in an amount of 1 mol% relative to the total resin components, and the reaction was continued for 3 hours at 180°C and normal pressure to obtain polyester resin B.

<Preparation of Masterbatch (MB)>
1,200 parts of water and 500 parts of carbon black (Printex 35 manufactured by Dexa) [DBP oil absorption = 42 mL/100 mg, pH = 9.5] were added and mixed in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). The mixture was kneaded using two rolls at 150°C for 30 minutes, then cooled by rolling and pulverized with a pulverizer to obtain [Masterbatch 1].

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

<Preparation of Crystalline Polyester Resin Dispersion>
A vessel equipped with a stirring rod and a thermometer was charged with 50 parts of crystalline polyester resin and 450 parts of ethyl acetate, and the temperature was raised to 80°C with stirring. The temperature was maintained at 80°C for 5 hours, and then the mixture was cooled to 30°C over 1 hour. Dispersion was then carried out using a bead mill (Ultra Visco Mill, manufactured by Imex) at a liquid feed rate of 1 kg/hr, a disk peripheral speed of 6 m/sec, a filling rate of 80% by volume of zirconia beads with a diameter of 0.5 mm, and 3 passes to obtain [Crystalline Polyester Resin Dispersion 1].

<Preparation of Oil Phase>
500 parts of [WAX dispersion 1], 820 parts of [Amorphous polyester resin A], 750 parts of [Crystalline polyester resin dispersion 1], 7,500 parts of [Polyester resin B], 100 parts of [Master batch 1], and 2 parts of [Ketimine compound 1] as a curing agent were placed in a container and mixed with a TK Homomixer (manufactured by Tokushu Kika Co., Ltd.) at 5,000 rpm for 60 minutes to obtain [Oil phase 1].

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

<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 dodecyldiphenyletherdisulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts of ethyl acetate were mixed and stirred to obtain a milky white liquid. This was designated as [aqueous phase 1].

<Emulsification and desolvation>
To the vessel containing the [oil phase 1], 1,200 parts of [water phase 1] was added and mixed for 20 minutes at 13,000 rpm using a TK homomixer to obtain [emulsified slurry 1].
[Emulsified slurry 1] was placed in a container equipped with a stirrer and a thermometer, and the solvent was removed at 30° C. for 8 hours, and then aged at 45° C. for 4 hours to obtain [Dispersed slurry 1].

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

<External Addition Treatment>
Toner 1 was obtained by mixing 100 parts by mass of toner base particles 1 with 2.5 parts by mass of hydrophobic silica having an average particle size of 80 nm, 0.3 parts by mass of titanium oxide having an average particle size of 20 nm, and 1.2 parts by mass of hydrophobic silica fine powder having an average particle size of 15 nm in a Henschel mixer.

As the hydrophobic silica, VP RX40S (manufactured by Nippon Aerosil Co., Ltd.) with its crushing strength weakened was used. Table 1 shows the crushing strength of the hydrophobic silica used in Example 1, when the crushing strength of VP RX40S before its crushing strength was weakened is taken as 100%. The mixing energy of the Henschel mixer is also shown in Table 1.

The crushing strength is measured as follows:

<Preparation of carrier>
A resin layer coating liquid was prepared by adding 100 parts by mass of silicone resin (organo straight silicone), 5 parts by mass of γ-(2-aminoethyl)aminopropyltrimethoxysilane, and 10 parts by mass of carbon black to 100 parts by mass of toluene and dispersing them with a homomixer for 20 minutes. The resin layer coating liquid was applied to the surface of 1,000 parts by mass of spherical magnetite having an average particle size of 50 μm using a fluidized bed type coating device to prepare a carrier.

<Preparation of Developer>
Using a ball mill, 5 parts by weight of the toner 1 and 95 parts by weight of the carrier were mixed to prepare a developer. Next, the prepared developers were used to evaluate various properties as follows. The evaluation results are shown in Table 1.

(Examples 2 to 24 and Comparative Examples 1 to 12)
A toner was prepared in the same manner as in Example 1, except that hydrophobic silica that had been subjected to a crushing treatment at the crushing intensity shown in Table 1 was used and the mixing intensity of the Henschel mixer was adjusted under the conditions shown in Table 1.

The degree of accelerated aggregation of inorganic fine particles and the amount of external additive (in the examples and comparative examples, this refers to inorganic fine particles) released were measured as described above, and are shown in Table 1 or Table 2. The evaluation results are also shown in Table 2. In addition, the overall judgment in Table 2 is recorded as an × rating if there is even one × rating in the evaluation of cleaning ability and transportability.

[Evaluation item]
(Method for evaluating cleaning performance)
An image forming apparatus, Image MP C5002 (manufactured by Ricoh Co., Ltd.), was used to output a monochrome black halftone image in full color mode (high transfer current), and the cleaning ability of the intermediate transfer belt was evaluated. After the test was completed, a fibrous tape was attached to the belt surface to collect the toner remaining on the belt. The amount of the collected toner was measured and evaluated according to the following evaluation criteria. ◎, ◯, and △ are pass, and × is fail.
(Criteria for evaluating cleaning performance)
The evaluation was based on the following criteria.
◎: Less than 0.05g ○: 0.05g or more and less than 0.1g △: 0.1g or more and less than 0.5g ×: 0.5g or more

(Transportability Evaluation Method)
After the cleaning performance evaluation, clogging of the toner at the supply port of the developing unit was confirmed and evaluated according to the following evaluation criteria: ◯ and Δ are acceptable, and × is unacceptable.
◯: No toner clogging at the supply port.
Δ: Toner clogging was observed in some areas, but toner could be transported to the developing unit through the supply port.
x: The supply port is completely clogged with toner, making it impossible to transport toner to the developing unit.

(Filming Evaluation Method)
Using an image forming apparatus Imageo MP C5002 (manufactured by Ricoh Co., Ltd.), a chart with a 20% image area was printed under the condition of an image density of 1.4±0.2, and evaluated according to the following evaluation criteria: ⊚, ◯, △ are acceptable, and × is unacceptable.
(Evaluation Criteria for Filming)
◎: Very few blank areas in the image, and quite excellent. ○: Blank areas are rarely observed. △: Blank areas are noticeable. ×: Blank areas are very numerous.

From the results in Table 2, it was confirmed that a toner containing a toner base containing a binder resin and a colorant, and inorganic fine particles as an external additive, in which the accelerated aggregation degree of the inorganic fine particles is 20% or more and 80% or less, has excellent cleaning properties, transport properties, and filming properties.
In contrast, in Comparative Examples 1 to 3 and 7 to 9, the toners contained inorganic fine particles with an accelerated cohesion degree of less than 20%, and therefore the cleaning performance was deteriorated.
In Comparative Examples 4 to 6 and 10 to 12, the toner contained inorganic fine particles with an accelerated cohesion degree exceeding 80%, and therefore the transportability was deteriorated.

10: electrostatic latent image carrier (photosensitive drum)
10K Black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Cleaning device 18 Image forming means 20 Charging roller 21 Exposure device 22 Secondary transfer device 23 Roller 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Developing device 41 Developing belt 42K Developer container 42Y Developer container 42M Developer container 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K Developing roller 44Y Developing roller 44M Developing roller 44C Developing roller 45K, black developing unit 45Y, yellow developing unit 45M, magenta developing unit 45C, cyan developing unit 49, registration roller 50, intermediate transfer body 51, roller 52, separation roller 53, manual paper feed path 54, manual feed tray 55, switching claw 56, discharge roller 57, discharge tray 58, corona charging device 60, cleaning device 61, developing device 62, transfer charger 63, cleaning device 64, charge removal lamp 70, charge removal lamp 80, transfer roller 90, cleaning device 95, transfer paper 100A, 100B, 100C, image forming apparatus 110, process cartridge 120, tandem type developing device 130, document table 142, paper feed roller 143, paper bank 144, paper feed cassette 145, separation roller 146, paper feed path 147, transport roller 148, paper feed path 150, copying apparatus main body 160, charging device 200, paper feed table 300, scanner 400 Automatic document feeder (ADF)

JP 2018-36596 A

Claims (7)

A toner comprising a toner base material containing at least a binder resin and a colorant, and inorganic fine particles as an external additive,
The accelerated aggregation degree of the inorganic fine particles, which is determined by the following measurement, is 20% or more and 80% or less,
The toner is characterized in that the binder resin contains a crystalline polyester resin and an amorphous polyester resin having a glass transition temperature of -60°C or higher and 0°C or lower .
<<Measurement of Accelerated Coagulation Degree>>
The accelerated cohesion degree is measured by the following method: A powder tester is used as the measuring device, and the accessories are set on a vibration table in the following order.
(a) Vibro chute (b) Packing (c) Space ring (d) Sieve (3 types) Top>Middle>Bottom (e) Osaever Next, fix with a knob nut and operate the vibration table. The measurement conditions are as follows.
Sieve opening (upper row) 75 μm
Sieve opening (middle) 45μm
Sieve opening (lower row) 20 μm
Amplitude scale 2mm
Sample (inorganic fine particles) amount: 2 g
Vibration time: 160 seconds Vibration acceleration: 100 m/ ^s2
After the measurement, the accelerated coagulation degree is calculated using the following formula.
Weight percent of powder remaining on the upper sieve × 1 (a)
Weight percent of powder remaining on the middle sieve × 0.6 (b)
Weight percent of powder remaining in the lower sieve × 0.2 (c)
The sum of the above three calculated values is the accelerated cohesion degree (%).
That is, the accelerated degree of cohesion (%)=(a)+(b)+(c). The toner according to claim 1, characterized in that the accelerated cohesion degree of the inorganic fine particles is 30% or more and 80% or less. The toner according to claim 2, characterized in that the accelerated cohesion degree of the inorganic fine particles is 40% or more and 80% or less. The toner according to any one of claims 1 to 3, characterized in that when ultrasonic vibrations are applied with an irradiation energy amount of 4 kJ to a toner dispersion liquid obtained by dispersing the toner in a dispersant, the amount of the external additive released from the toner is 20% by mass or more and 50% by mass or less with respect to the total amount of the external additive in the toner. The toner according to any one of claims 1 to 4, characterized in that the inorganic fine particles having an accelerated coagulation degree of 20% or more and 80% or less are hydrophobic silica and/or titanium oxide. A two-component developer containing the toner according to any one of claims 1 to 5. An image forming device using the toner according to any one of claims 1 to 5.

Images