JP5953668B2 - Toner, toner manufacturing method, full-color image forming method, and process cartridge - Google Patents

Description

  The present invention relates to a toner, a toner manufacturing method, a full-color image forming method, and a process cartridge.

  In recent years, in the field of electrophotographic image forming technology, development competition of color image forming apparatuses capable of high-speed image formation and high image quality has intensified. For this reason, in order to obtain a full-color image at a high speed, a plurality of electrophotographic photosensitive members are arranged in series in the image forming method, and an image for each color component is formed on each electrophotographic photosensitive member, and is superimposed on the intermediate transfer member. Many so-called tandem systems that batch transfer onto a recording medium have been employed (see, for example, Patent Document 1 and Patent Document 2). When an intermediate transfer member is used, if background stains occur on the electrophotographic photosensitive member during development, there is an effect of preventing the background stains from being transferred directly to a recording medium such as paper. The method used is a transfer process (secondary transfer) from an electrophotographic photosensitive member to an intermediate transfer member and a transfer step (secondary transfer) onto a recording medium for obtaining a final image from the intermediate transfer member (secondary transfer). Therefore, there is a problem that transfer efficiency is lowered.

  On the other hand, in addition to the above problems, there is a demand for higher-quality full-color image formation, and developers have been designed for higher image quality. In order to meet the demand for higher image quality, particularly full-color image quality, toners are increasingly becoming smaller in particle size and are being studied to faithfully reproduce latent images. In order to reduce the particle size, a toner manufacturing method using a polymerization method has been proposed as a means for controlling the toner to a desired toner shape and surface structure (for example, Patent Document 3 and Patent Document 3). 4). In the case of the polymerization toner, in addition to controlling the particle size of the toner particles, shape control is possible. In addition, by reducing the particle size together with this, the reproducibility of dots and fine lines can be improved, the pile height (image layer thickness) can be lowered, and higher image quality can be expected.

  However, when a small-diameter toner is used, the non-electrostatic adhesion force between the toner particles and the electrophotographic photosensitive member or between the toner particles and the intermediate transfer member is increased, so that the transfer efficiency is likely to further decrease. There is. For this reason, when a small-diameter toner is used in a high-speed full-color image forming apparatus, the transfer efficiency is particularly lowered in the secondary transfer. The reason for this is that non-electrostatic adhesion to the intermediate transfer member per toner particle is increasing due to the reduction in the toner particle size, and in the secondary transfer, it exists in a state where a plurality of color toners are superimposed. This is because the time during which the toner particles are subjected to the transfer electric field at the nip portion of the secondary transfer is shortened as the speed is increased, and the transfer is more difficult.

  In order to cope with the above problems, it is conceivable to further increase the transfer electric field of the secondary transfer. However, if the transfer electric field is excessively increased, the transfer efficiency is lowered. is there. In addition, it is conceivable to increase the time during which the toner particles are subjected to the transfer electric field by increasing the width of the nip portion of the secondary transfer. However, in the case of a contact-type voltage application method such as a bias roller, the nip width is increased. There is only one method of increasing the contact pressure of the bias roller or increasing the roller diameter of the bias roller. Increasing the contact pressure has a limit due to the relationship with the image quality, and increasing the roller diameter has a limit due to the relationship with the downsizing of the apparatus. Further, in the case of a non-contact voltage application method using a charger or the like, there is a limit because the nip width of secondary transfer must be increased by increasing the number of chargers. Therefore, it can be said that it is practically impossible to widen the nip width until a transfer efficiency higher than this is obtained, particularly in a high-speed machine.

In contrast, as a means for reducing the non-electrostatic adhesion between the toner particles and the electrophotographic photosensitive member, or between the toner particles and the intermediate transfer member, the type and amount of the toner additive are adjusted (particularly the particle size of the toner). A method of adding a large additive to the toner has been proposed (see, for example, Patent Document 5 and Patent Document 6).
However, with this proposed technique, if the toner has been subjected to mechanical stress such as agitation for a long time in the developing device of the image forming apparatus, the additive is buried in the toner base, and the adhesive force is reduced by the additive. There is a problem that the effect is not exhibited and the transfer efficiency of the image forming apparatus is lowered. Particularly in the case of a high-speed machine, since the stirring in the developing device is intense, this mechanical stress is large, and the embedding of the additive in the toner base is easily accelerated. Therefore, transfer efficiency is lowered at a relatively early stage.

On the other hand, a method for reducing the non-electrostatic adhesion between the toner particles and the intermediate transfer member by arranging organic fine particles on the toner surface and forming a shell layer has also been proposed (see, for example, Patent Document 7). .
However, in the proposed technique, when forming the shell layer, it is necessary to control the aggregation of the organic fine particles and to arrange them uniformly on the surface. When the organic fine particles form an aggregate, a desired shell layer is not formed, and the effect of reducing the non-electrostatic adhesion force of the toner particles is diminished, resulting in a decrease in transfer efficiency. Further, when the coating amount of the shell layer is increased, there is a problem that the low-temperature fixability is lowered.

  Therefore, in high-speed full-color image formation, there is a need to provide a toner having excellent transfer efficiency and low-temperature fixability, a method for producing the toner, a full-color image forming method using the toner, and a process cartridge. is the current situation.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention provides a toner having excellent transfer efficiency and excellent low-temperature fixability in high-speed full-color image formation, a method for producing the toner, a full-color image forming method using the toner, and a process cartridge. For the purpose.

Means for solving the problems are as follows. That is,
<1> core particles containing a binder resin;
A shell layer formed of acrylic resin fine particles on the surface of the core particles;
Styrene-acrylic resin fine particles are present outside the shell layer,
The ζ potential (X) of the 10% by mass aqueous dispersion of the acrylic resin fine particles satisfies the following formula (1):
The toner is characterized in that the ζ potential (Y) of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles satisfies the following formula (2).
−90 mV ≦ ζ potential (X) ≦ −60 mV (1)
−60 mV ≦ ζ potential (Y) ≦ −30 mV (2)
<2> A step of preparing an oil phase in which at least a binder resin is dissolved or dispersed in an organic solvent, a step of preparing an aqueous phase containing styrene-acrylic resin fine particles, and the oil phase in the aqueous phase. A method for producing a toner, comprising: a step of preparing an emulsified or dispersed liquid by dispersion; and a step of removing an organic solvent contained in the emulsified or dispersed liquid.
In the step of preparing the emulsification or dispersion, when the oil phase is dispersed in the water phase, at least one of the water phase and the oil phase contains acrylic resin fine particles,
The formed toner has core particles containing the binder resin, a shell layer formed of the acrylic resin fine particles on the surface of the core particles, and the styrene-acrylic resin fine particles outside the shell layer. ,
The binder resin contains an unmodified polyester resin having an acid value of 10 mgKOH / g to 30 mgKOH / g,
The volume average particle size of the styrene-acrylic resin fine particles is 10 nm to 50 nm, the acid value is 150 mgKOH / g to 250 mgKOH / g,
The pH of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles is 2.0 to 4.5, and the electric conductivity is 0.5 mS / cm to 1.5 mS / cm,
The volume average particle diameter of the acrylic resin fine particles is 30 nm to 200 nm, the acid value is 0 mgKOH / g to 20 mgKOH / g,
The pH of a 10% by mass aqueous dispersion of the acrylic resin fine particles is 1.5 to 4.0, and the electrical conductivity is 1.0 mS / cm to 2.5 mS / cm. It is a manufacturing method.
<3> A charging step for charging the surface of the electrophotographic photosensitive member, an exposure step for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the electrophotographic photosensitive member, and the electrophotographic photosensitive member The electrostatic latent image formed on the toner is developed with toner to form a toner image, a primary transfer step for transferring the toner image onto the intermediate transfer member, and the toner image transferred to the intermediate transfer member. A secondary transfer step of transferring to a recording medium, and a cleaning step of removing toner remaining on the surface of the electrophotographic photosensitive member,
The full-color image forming method, wherein the toner is the toner according to <1>.
<4> A process cartridge that has at least an electrophotographic photosensitive member and a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and is detachable from the image forming apparatus Because
The toner is the toner according to <1>, wherein the toner is a process cartridge.

  According to the present invention, the conventional problems can be solved, and in high-speed full-color image formation, a toner excellent in transfer efficiency and excellent in low-temperature fixability, a method for producing the toner, and the toner are used. A full-color image forming method and a process cartridge can be provided.

FIG. 1 is a schematic diagram of the toner of the present invention. FIG. 2 is a schematic configuration diagram of an example of a contact-type roller charging device. FIG. 3 is a schematic configuration diagram of an example of a contact-type brush charging device. FIG. 4 is a schematic configuration diagram of an example of a developing device. FIG. 5 is a schematic configuration diagram of an example of the fixing device. FIG. 6 is a diagram illustrating a layer configuration of the fixing belt. FIG. 7 is a schematic configuration diagram of an example of the image forming apparatus. FIG. 8 is a schematic configuration diagram of another example of the image forming apparatus. FIG. 9 is a schematic configuration diagram of an example of the process cartridge of the present invention. 10A is a scanning electron micrograph of the toner base particles of Example 1. FIG. FIG. 10B is an enlarged photograph of FIG. 10A. FIG. 11A is a scanning electron micrograph of the toner base particles of Comparative Example 7. FIG. 11B is an enlarged photograph of FIG. 11A.

(toner)
The toner of the present invention has core particles containing a binder resin, a shell layer formed of acrylic resin fine particles on the surface of the core particles, and at least styrene-acrylic resin fine particles outside the shell layer, If necessary, it has other components.

<Core particles>
The core particle contains at least a binder resin, and further contains other components as necessary.

-Binder resin-
The binder resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyester resin, silicone resin, styrene-acrylic resin, styrene resin, acrylic resin, epoxy resin, diene resin, phenol Resins, terpene resins, coumarin resins, amideimide resins, butyral resins, urethane resins, ethylene-vinyl acetate resins and the like can be mentioned.

Among these, a polyester resin having sufficient flexibility even when the molecular weight is reduced is preferable, and an unmodified polyester resin is more preferable in that it can sharply melt at the time of fixing and smooth the image surface.
There is no restriction | limiting in particular as an acid value of the said non-modified polyester resin, Although it can select suitably according to the objective, 10 mgKOH / g-30 mgKOH / g are preferable.

It is preferable that the binder resin is incompatible with the acrylic resin fine particles. For example, when the binder resin is a polyester resin and the acrylic resin fine particles are fine particles of a crosslinked resin containing an acrylate polymer or a methacrylic ester polymer, the binder resin and the acrylic resin fine particles are non-phased. It is preferable to be dissolved.
Here, whether compatible or incompatible is determined by the following method.
A binder resin and acrylic resin fine particles are blended at a predetermined ratio, and then melted and uniformed to prepare a sample. This sample and the glass transition temperature (Tg) of each resin are analyzed by DSC (differential scanning calorimetry). Then, in the graph in which the blend ratio is on the horizontal axis and Tg is on the vertical axis, if there is Tg of the measured sample on the straight line connecting Tg of each resin alone, it is determined that they are compatible. If there is no Tg of the sample measured above, it is judged as incompatible. For example, when the binder resin and the acrylic resin fine particles are blended at 50:50 (mass ratio), when the Tg of the blended sample is a value obtained by adding the Tg of each resin alone and dividing by 2, It is judged that the binder resin and the acrylic resin fine particles are compatible. In the case of incompatibility, two Tg are often measured.

--- Polyester resin--
The polyester resin is obtained by polyesterifying a polyol and a polycarboxylic acid or a derivative thereof.

  Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1, 5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanetetrol, 1 , 4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, Examples thereof include hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, and hydrogenated bisphenol A propylene oxide adduct.

  Examples of the polycarboxylic acid include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n- Dodecenyl succinic acid, isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1, 2, 4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3- Dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-si Rhohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, emporic trimer acid, cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenyl Examples include sulfonetetracarboxylic acid and ethylene glycol bis (trimellitic acid).

  Examples of the polycarboxylic acid derivatives include polycarboxylic acid esters and polycarboxylic acid anhydrides.

--Modified polyester resin--
The toner preferably contains a modified polyester resin in the core particles. When the toner contains the modified polyester resin in the core particles, the mechanical strength of the toner is increased, and the acrylic resin fine particles and the external additive can be suppressed from being embedded in the core particles.
The modified polyester resin is obtained by crosslinking and / or extending a polyester resin having a site capable of reacting with an active hydrogen group-containing compound and the active hydrogen group-containing compound.

--- Active hydrogen group-containing compound ---
The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent or the like when a polyester resin having a site capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like.

  There is no restriction | limiting in particular as said active hydrogen group, According to the objective, it can select suitably, For example, a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

The active hydrogen group-containing compound is not particularly limited and may be appropriately selected depending on the purpose. The polyester resin having a site capable of reacting with the active hydrogen group-containing compound is a polyester resin containing an isocyanate group. In some cases, amines are preferred because they can be polymerized with the polyester resin by elongation reaction, crosslinking reaction, or the like.
The amines are not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and those amino groups blocked. Can be mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, diamine and a mixture of a diamine and a small amount of trivalent or higher amine are preferable.

  There is no restriction | limiting in particular as said diamine, According to the objective, it can select suitably, For example, aromatic diamine, alicyclic diamine, aliphatic diamine etc. are mentioned. There is no restriction | limiting in particular as said aromatic diamine, According to the objective, it can select suitably, For example, phenylenediamine, diethyltoluenediamine, 4,4'- diaminodiphenylmethane etc. are mentioned. The alicyclic diamine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diaminocyclohexane and isophorone diamine. It is done. There is no restriction | limiting in particular as said aliphatic diamine, According to the objective, it can select suitably, For example, ethylenediamine, tetramethylenediamine, hexamethylenediamine etc. are mentioned.

  The trivalent or higher amine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include diethylenetriamine and triethylenetetramine.

  The amino alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethanolamine and hydroxyethylaniline.

  The amino mercaptan is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan.

  The amino acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aminopropionic acid and aminocaproic acid.

  There is no restriction | limiting in particular as what blocked the said amino group, According to the objective, it can select suitably, For example, it is obtained by blocking an amino group with ketones, such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples include ketimine compounds and oxazolidone compounds.

  When the active hydrogen group-containing compound has a cationic polarity, the acrylic resin fine particles can be electrostatically attracted. Further, the fluidity of the toner during heat fixing can be adjusted, and the fixing temperature range can be widened.

--- Polyester resin having a site capable of reacting with active hydrogen group-containing compound ---
There is no restriction | limiting in particular as a polyester resin which has a site | part which can react with the said active hydrogen group containing compound, According to the objective, it can select suitably, For example, polyester resin containing an isocyanate group (henceforth "isocyanate group. And may be referred to as “polyester prepolymer having”). There is no restriction | limiting in particular as the polyester resin containing the said isocyanate group, According to the objective, it can select suitably, For example, the polyester resin which has an active hydrogen group obtained by polycondensing a polyol and polycarboxylic acid, Reaction products with polyisocyanate and the like can be mentioned.

There is no restriction | limiting in particular as said polyol, According to the objective, it can select suitably, For example, diol, trihydric or more alcohol, the mixture of diol and trihydric or more alcohol, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.
Among these, diol, and a mixture of diol and a small amount of trihydric or higher alcohol are preferable.

The diol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6 -Alkylene glycol such as hexanediol; diol having an oxyalkylene group such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol; 1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc. Alicyclic diols; those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to alicyclic diols; bisphenol A, bisphenol F, bisphenol S Bisphenols; the bisphenols include ethylene oxide, propylene oxide, alkylene oxide adducts of bisphenols such as those obtained by adding alkylene oxides such as butylene oxide; and the like. In addition, there is no restriction | limiting in particular as carbon number of the said alkylene glycol, Although it can select suitably according to the objective, 2-12 are preferable.
Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferable, alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. And a mixture thereof is more preferable.

The trihydric or higher alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. For example, trihydric or higher aliphatic alcohol, trihydric or higher polyphenol, alkylene of trihydric or higher polyphenols. Examples include oxide adducts.
The trihydric or higher aliphatic alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol.
The trihydric or higher polyphenols are not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trisphenol PA, phenol novolac, and cresol novolak.
Examples of the alkylene oxide adducts of trihydric or higher polyphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide to trihydric or higher polyphenols.
When the diol and the trihydric or higher alcohol are mixed and used, the mass ratio of the trihydric or higher alcohol to the diol is not particularly limited and may be appropriately selected depending on the intended purpose. % To 10% by mass is preferable, and 0.01% to 1% by mass is more preferable.

The polycarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dicarboxylic acids, trivalent or higher carboxylic acids, and mixtures of dicarboxylic acids and trivalent or higher carboxylic acids. . These may be used individually by 1 type and may use 2 or more types together.
Among these, a dicarboxylic acid, a mixture of a dicarboxylic acid and a small amount of a tricarboxylic or higher polycarboxylic acid is preferable.

There is no restriction | limiting in particular as said dicarboxylic acid, According to the objective, it can select suitably, For example, a bivalent alkanoic acid, a bivalent alkenoic acid, aromatic dicarboxylic acid etc. are mentioned.
The divalent alkanoic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include succinic acid, adipic acid and sebacic acid.
There is no restriction | limiting in particular as said bivalent alkenoic acid, Although it can select suitably according to the objective, C4-C20 bivalent alkenoic acid is preferable. The divalent alkenoic acid having 4 to 20 carbon atoms is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include maleic acid and fumaric acid.
There is no restriction | limiting in particular as said aromatic dicarboxylic acid, Although it can select suitably according to the objective, C8-C20 aromatic dicarboxylic acid is preferable. There is no restriction | limiting in particular as said C8-C20 aromatic dicarboxylic acid, According to the objective, it can select suitably, For example, a phthalic acid, isophthalic acid, a terephthalic acid, naphthalene dicarboxylic acid etc. are mentioned.

The trivalent or higher carboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trivalent or higher aromatic carboxylic acids.
There is no restriction | limiting in particular as said trivalent or more aromatic carboxylic acid, Although it can select suitably according to the objective, C9-C20 trivalent or more aromatic carboxylic acid is preferable. The trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trimellitic acid and pyromellitic acid.

As the polycarboxylic acid, an acid anhydride or a lower alkyl ester of any of dicarboxylic acid, trivalent or higher carboxylic acid, and a mixture of dicarboxylic acid and trivalent or higher carboxylic acid may be used.
There is no restriction | limiting in particular as said lower alkyl ester, According to the objective, it can select suitably, For example, methyl ester, ethyl ester, isopropyl ester etc. are mentioned.
When the dicarboxylic acid and the trivalent or higher carboxylic acid are used in combination, the mass ratio of the trivalent or higher carboxylic acid to the dicarboxylic acid is not particularly limited and can be appropriately selected according to the purpose. 0.01 mass% to 10 mass% is preferable, and 0.01 mass% to 1 mass% is more preferable.

  The equivalent ratio of the hydroxyl group of the polyol to the carboxyl group of the polycarboxylic acid in the polycondensation of the polyol and the polycarboxylic acid is not particularly limited and may be appropriately selected depending on the intended purpose. ˜2 is preferable, 1 to 1.5 is more preferable, and 1.02 to 1.3 is particularly preferable.

There is no restriction | limiting in particular as content of the structural unit derived from the polyol in the polyester prepolymer which has the said isocyanate group, Although it can select suitably according to the objective, 0.5 mass%-40 mass% are preferable, 1 mass%-30 mass% are more preferable, and 2 mass%-20 mass% are especially preferable.
When the content is less than 0.5% by mass, the high temperature offset resistance is lowered, and it may be difficult to achieve both the heat resistant storage stability and the low temperature fixability of the toner. When the content exceeds 40% by mass, Low temperature fixability may be reduced.

The polyisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and phenol derivatives thereof. , Oxime, caprolactam and the like blocked.
The aliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene Examples thereof include diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.
The alicyclic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include isophorone diisocyanate and cyclohexylmethane diisocyanate.
The aromatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. For example, tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4′-diisocyanato Examples include diphenyl, 4,4′-diisocyanato-3,3′-dimethyldiphenyl, 4,4′-diisocyanato-3-methyldiphenylmethane, 4,4′-diisocyanato-diphenyl ether, and the like.
The araliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include α, α, α ′, α′-tetramethylxylylene diisocyanate.
There is no restriction | limiting in particular as said isocyanurates, According to the objective, it can select suitably, For example, a tris (isocyanatoalkyl) isocyanurate, a tris (isocyanatocycloalkyl) isocyanurate, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  When the polyisocyanate and the polyester resin having a hydroxyl group are reacted, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester resin is not particularly limited and may be appropriately selected depending on the purpose. 1-5 are preferable, 1.2-4 are more preferable, and 1.5-3 are especially preferable. When the equivalent ratio is less than 1, offset resistance may be lowered. When the equivalent ratio is more than 5, low-temperature fixability may be lowered.

  There is no restriction | limiting in particular as content of the structural unit derived from polyisocyanate in the polyester prepolymer which has the said isocyanate group, Although it can select suitably according to the objective, 0.5 mass%-40 mass% are preferable. 1 mass%-30 mass% are more preferable, and 2 mass%-20 mass% are especially preferable. When the content is less than 0.5% by mass, the high temperature offset resistance may be deteriorated, and when it exceeds 40% by mass, the low temperature fixability may be deteriorated.

  There is no restriction | limiting in particular as an average number of the isocyanate groups which the polyester prepolymer which has the said isocyanate group has per molecule, Although it can select suitably according to the objective, 1 or more are preferable and 1.2-5 are More preferably, 1.5-4 is especially preferable. When the average number is less than 1, the molecular weight of the urea-modified polyester resin is lowered, and the high temperature offset resistance may be lowered.

-Other ingredients-
As said other component which the said core particle contains, a coloring agent etc. are mentioned, for example.

--Colorant--
There is no restriction | limiting in particular as said coloring agent, According to the objective, it can select suitably, For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow Iron oxide, 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), Vulcan fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sared, parac Luort Nitroaniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carnmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Tolujing 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, pi Zoron Red, Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indance Ren Blue (RS, BC), Indigo, Ultramarine Blue, Bitumen, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green , Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Gree Rake, phthalocyanine green, anthraquinone green, titanium oxide, zinc white, litbon and the like.
There is no restriction | limiting in particular as content of the said coloring agent, Although it can select suitably according to the objective, 1 mass part-15 mass parts are preferable with respect to 100 mass parts of said toners, and 3 mass parts-10 parts. Part by mass is more preferable.

The colorant can also be used as a master batch combined with a resin. Examples of the resin to be kneaded together with the production of the master batch or the master batch include, in addition to the amorphous polyester resin, a polymer of styrene such as polystyrene, poly p-chlorostyrene, polyvinyl toluene, or a substituted product thereof; 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, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylo Tolyl copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene copolymers such as copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid Examples thereof include resins, rosins, modified rosins, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, and paraffin waxes. These may be used individually by 1 type and may use 2 or more types together.
The masterbatch can be obtained by mixing a masterbatch resin and a colorant under high shear force and kneading to obtain a masterbatch. In this case, an organic solvent can be used in order to enhance the interaction between the colorant and the resin. In addition, a so-called flushing method, which is a wet method of colorant, is a method of mixing and kneading an aqueous paste containing water of a colorant together with a resin and an organic solvent, transferring the colorant to the resin side, and removing moisture and organic solvent components. Since the cake can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

<Shell layer>
The shell layer is a shell layer formed on the surface of the core particle and is not particularly limited as long as it is a shell layer formed of acrylic resin fine particles, and can be appropriately selected according to the purpose.

-Acrylic resin fine particles-
The acrylic resin fine particle is not particularly limited as long as it is a resin fine particle that contains at least one of acrylic acid ester and methacrylic acid ester as a constituent component and does not contain styrene as a constituent component, and is appropriately selected according to the purpose. Can do.
Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate.
Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and n-butyl methacrylate.

  The acrylic resin fine particles may be a crosslinked resin or an uncrosslinked resin, but a crosslinked resin is preferable from the viewpoint of transfer efficiency.

  The acrylic resin fine particles preferably have a cationic group such as an amino group or an ammonium group.

  The acrylic resin fine particles are preferably incompatible with the unmodified polyester resin.

  The acrylic resin fine particles are incompatible with the binder resin, and the aqueous dispersion is preferably a white emulsion, and the degree of swelling with respect to the organic solvent is preferably different depending on the difference in crosslinking density. As a method for controlling the swellability, there is a method of appropriately selecting the crosslinking density and the constituent monomer, but the constituent monomer may be changed to control physical properties other than the swellability of the acrylic resin fine particles. It is preferable to control.

  In producing the toner, the acrylic resin fine particles are preferably a cross-linked resin in order to be dissolved on the emulsified liquid droplets (oil droplets) and not to be dissolved on the surface of the core particles. Those copolymerized with a monomer having at least two unsaturated groups are preferred. The monomer having at least two unsaturated groups is not particularly limited and may be appropriately selected depending on the intended purpose. For example, divinyl compounds such as divinylbenzene; ethylene glycol dimethacrylate, 1,6-hexanediol Examples include diacrylate compounds such as acrylate and dimethacrylate compounds.

  The method for synthesizing the acrylic resin fine particles is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably obtained as an aqueous dispersion. Examples thereof include a method of directly producing an aqueous dispersion of acrylic resin fine particles by any polymerization reaction selected from suspension polymerization, emulsion polymerization, seed polymerization, and dispersion polymerization.

There is no restriction | limiting in particular as a volume average particle diameter of the said acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 30 nm-200 nm are preferable and 50 nm-100 nm are more preferable. When the volume average particle size is less than 30 nm, the granulation property of the toner is lowered, the toner of the present invention is hardly obtained, and the low-temperature fixability of the obtained toner may be lowered. Also, since the spacer effect cannot be obtained sufficiently, the non-electrostatic adhesion force of the toner particles cannot be reduced, and the toner is manufactured using a device with a large mechanical stress over time such as a high-speed machine. In this case, the acrylic resin fine particles and the external additive are easily buried in the surface of the toner, and there is a possibility that sufficient transfer efficiency cannot be maintained for a long time. When the volume average particle size exceeds 200 nm, the granulation property of the toner is lowered, it becomes difficult to obtain the toner of the present invention, and the fluidity of the obtained toner is deteriorated, and the uniform transfer property is hindered. There is a case.
In this specification, the volume average particle diameter can be measured by a scanning electron microscope (SEM), a transmission electron microscope (TEM), a light scattering method, a laser scattering measurement method, or the like. In the laser scattering measurement method, LA-920 manufactured by HORIBA, Ltd., Microtrac UPA-150 manufactured by Nikkiso Co., Ltd. is used, and a measurement sample (acrylic resin fine particles, styrene-acrylic resin) is adjusted to an appropriate concentration so as to enter the measurement range. (Resin fine particles) can be diluted and measured.

  There is no restriction | limiting in particular as an acid value of the said acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 0 mgKOH / g-20 mgKOH / g are preferable, and 5 mgKOH / g-15 mgKOH / g are more preferable. When the acid value exceeds 20 mgKOH / g, the granulation property of the toner is lowered, the toner of the present invention is hardly obtained, and the transfer efficiency of the obtained toner may be lowered. When the acid value is in the more preferable range, it is advantageous in that a toner having excellent transfer efficiency and minimum fixing temperature can be obtained.

The ζ potential (X) of the 10% by mass aqueous dispersion of the acrylic resin fine particles satisfies the following formula (1).
−90 mV ≦ ζ potential (X) ≦ −60 mV (1)
When the ζ potential (X) is less than −90 mV, the acrylic resin fine particles may enter the core particles and the shell layer may not be formed. When the ζ potential (X) exceeds −60 mV, the acrylic resin fine particles are more than the styrene-acrylic fine particles. May not enter the inner side (core particle side) and may not be granulated. When the ζ potential (X) satisfies the formula (1), a toner having excellent transfer efficiency and a minimum fixing temperature can be obtained.
In addition, producing a 10% by mass aqueous dispersion of acrylic resin fine particles having a ζ potential (X) of less than −90 mV in the formula (1) means that the stern potential of the acrylic resin fine particles itself is specified by the monomer species. However, it is difficult in terms of the molecular skeleton of the surfactant to be used and the addition amount.
The 10 mass% aqueous dispersion of the acrylic resin fine particles can be prepared by, for example, diluting or concentrating the obtained aqueous dispersion after producing the acrylic resin fine particles as an aqueous dispersion.
Note that the concentration of the aqueous dispersion when measuring the ζ potential is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, the measurement accuracy deteriorates, and 10% by mass. This is because the detection sensitivity is weakened at a lower concentration.

There is no restriction | limiting in particular as pH of the 10 mass% aqueous dispersion of the said acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 1.5-4.0 are preferable and 2.0-3.5 Is more preferable. When the pH is less than 1.5, it is difficult to obtain the toner of the present invention, and the transfer efficiency of the obtained toner may be reduced. When the pH exceeds 4.0, the toner of the present invention is difficult to obtain. As a result, the transfer efficiency of the obtained toner may be reduced. When the pH is within the more preferable range, it is advantageous in that the toner of the present invention is easily obtained.
In addition, the concentration of the aqueous dispersion when measuring pH is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because if the concentration is too low, the detection sensitivity is weakened.

There is no restriction | limiting in particular as electrical conductivity of the 10 mass% aqueous dispersion of the said acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 1.0mS / cm-2.5mS / cm are preferable, and 1 .2 mS / cm to 2.0 mS / cm is more preferable. When the electrical conductivity is less than 1.0 mS / cm, it is difficult to obtain the toner of the present invention, and the transfer efficiency of the obtained toner may be reduced. Toner may be difficult to obtain, and the transfer efficiency of the resulting toner may be reduced. It is advantageous in that the toner of the present invention is easily obtained when the electric conductivity is in the more preferable range.
The concentration of the aqueous dispersion when measuring the electrical conductivity is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because the detection sensitivity is weakened when the concentration is lower than%.
In the present specification, the electrical conductivity can be measured by, for example, an electrical conductivity meter.

  There is no restriction | limiting in particular as content of the said acrylic resin microparticles | fine-particles in the said toner, Although it can select suitably according to the objective, 0.5 mass%-5 mass% are preferable, and 1 mass%-4 mass% are preferable. More preferred. When the content is less than 0.5% by mass, the spacer effect cannot be sufficiently obtained, so that it may be difficult to reduce the non-electrostatic adhesion force of the toner. The toner fluidity is deteriorated, the uniform transferability is hindered, or the acrylic resin fine particles cannot be sufficiently fixed to the toner and are easily detached, and adhere to the carrier and the electrophotographic photosensitive member. There is a risk of contaminating. The content of the acrylic resin fine particles in the toner can also be referred to as the content of the shell layer.

There is no restriction | limiting in particular as average thickness of the said shell layer, Although it can select suitably according to the objective, 10 nm-200 nm are preferable, and 30 micrometers-100 micrometers are more preferable. If the average thickness is less than 10 nm, the heat resistance and mechanical strength may be weakened, whereby transfer efficiency may be deteriorated. When the average thickness is within the more preferable range, it is advantageous in that both low-temperature fixability and storage stability can be achieved.
The average thickness can be confirmed by observing the cross section of the toner.

<Styrene-acrylic resin fine particles>
The styrene-acrylic resin fine particles are not particularly limited as long as they are resin fine particles containing styrene and at least one of acrylic acid ester and methacrylic acid ester as constituent components, and can be appropriately selected according to the purpose.
Examples of the acrylate ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-butyl acrylate.
Examples of the methacrylic acid ester include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, and n-butyl methacrylate.

  The styrene-acrylic resin fine particles may be a crosslinked resin or an uncrosslinked resin.

  The styrene-acrylic resin fine particles preferably have an anionic group such as a carboxylic acid group or a sulfonic acid group.

  There is no restriction | limiting in particular as a synthesis | combining method of the said styrene-acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, It is preferable to obtain as an aqueous dispersion. Examples thereof include a method of directly producing an aqueous dispersion of styrene-acrylic resin fine particles by any polymerization reaction selected from suspension polymerization, emulsion polymerization, seed polymerization, and dispersion polymerization.

  There is no restriction | limiting in particular as a volume average particle diameter of the said styrene-acrylic resin fine particle, Although it can select suitably according to the objective, 10 nm-50 nm are preferable and 20 nm-40 nm are more preferable. When the volume average particle size is less than 10 nm, the granulation property of the toner is lowered, the toner of the present invention is hardly obtained, and the low-temperature fixability of the obtained toner may be lowered. When the volume average particle diameter exceeds 50 nm, the granulation property of the toner is lowered, and the toner of the present invention may be difficult to obtain.

There is no restriction | limiting in particular as an acid value of the said styrene-acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 150 mgKOH / g-250 mgKOH / g are preferable, and 180 mgKOH / g-220 mgKOH / g are more preferable. When the acid value is less than 150 mgKOH / g, the granulation property of the toner is lowered and the toner of the present invention may be difficult to obtain. When the acid value exceeds 250 mgKOH / g, the granulation property of the toner is lowered. The toner of the present invention may be difficult to obtain. When the acid value is within a more preferable range, it is advantageous in that a toner having excellent transfer efficiency and minimum fixing temperature can be obtained.
The acid value (A) of the unmodified polyester resin, the acid value (B) of the acrylic resin fine particles, and the acid value (C) of the styrene-acrylic resin fine particles in the binder resin are C>A> B It is preferable to satisfy.

The ζ potential (Y) of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles satisfies the following formula (2).
−60 mV ≦ ζ potential (Y) ≦ −30 mV (2)
When the ζ potential is less than −60 mV, the shell layer may not be formed, and when it exceeds −30 mV, the toner may not be granulated. When the ζ potential satisfies the formula (2), a toner having excellent transfer efficiency and a minimum fixing temperature can be obtained.
The preparation of a 10% by mass aqueous dispersion of styrene-acrylic resin fine particles having a ζ potential (Y) of less than −60 mV in the above formula (2) means that the stern potential of the styrene-acrylic resin fine particles itself is determined by the monomer type. This is difficult in view of the molecular skeleton of the surfactant used and the amount added. Further, even when a 10% by mass aqueous dispersion of styrene-acrylic resin fine particles having a ζ potential (Y) of less than −60 mV in the formula (2) can be produced, when the toner is produced, styrene-acrylic is used. Since there is a large difference between the electrical conductivity and pH of the aqueous phase before the addition of the resin fine particles and the electrical conductivity and pH of the styrene-acrylic resin fine particle aqueous dispersion, the styrene-acrylic resin fine particles are changed to the aqueous phase. When added, a dilution shock occurs, and aggregation of styrene-acrylic resin fine particles becomes remarkable. Then, since the styrene-acrylic resin fine particles are aggregated in the aqueous phase preparation step described later, even if the oil phase and the aqueous phase are mixed and emulsified, the styrene-acrylic resin fine particles may remain as aggregates. As a result, good toner cannot be produced, and transfer efficiency is lowered.
The 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles can be prepared, for example, by diluting or concentrating the obtained aqueous dispersion after producing the styrene-acrylic resin fine particles as an aqueous dispersion.
Note that the concentration of the aqueous dispersion when measuring the ζ potential is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, the measurement accuracy deteriorates, and 10% by mass. This is because the detection sensitivity is weakened at a lower concentration.

There is no restriction | limiting in particular as pH of the 10 mass% aqueous dispersion of the said styrene-acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 2.0-4.5 are preferable, 2.5- 4.0 is more preferable. When the pH is less than 2.0, the granulation property of the toner is lowered, and the toner of the present invention may be difficult to obtain. When the pH exceeds 4.5, the granulation property of the toner is lowered, The toner of the present invention may be difficult to obtain. When the pH is within the more preferable range, it is advantageous in that the toner of the present invention is easily obtained.
In addition, the concentration of the aqueous dispersion when measuring pH is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because if the concentration is too low, the detection sensitivity is weakened.

There is no restriction | limiting in particular as an electrical conductivity of the 10 mass% water dispersion of the said styrene-acrylic resin microparticles | fine-particles, Although it can select suitably according to the objective, 0.5 mS / cm-1.5 mS / cm are preferable. 0.8 mS / cm to 1.2 mS / cm is more preferable. When the electric conductivity is less than 0.5 mS / cm, the granulation property of the toner is lowered, and the toner of the present invention may be difficult to obtain. Graininess may deteriorate and it may be difficult to obtain the toner of the present invention. It is advantageous in that the toner of the present invention is easily obtained when the electric conductivity is in the more preferable range.
The concentration of the aqueous dispersion when measuring the electrical conductivity is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because the detection sensitivity is weakened when the concentration is lower than%.

  There is no restriction | limiting in particular as content of the said styrene-acrylic resin microparticles | fine-particles in the said toner, Although it can select suitably according to the objective, 1.0 mass%-4.0 mass% are preferable, 1.5 mass is preferable. % To 3.0% by mass is more preferable. If the content is less than 1.0% by mass, the toner may not be granulated, and if it exceeds 4.0% by mass, the toner may not be granulated.

<Other ingredients>
Examples of the other components include a release agent, a charge control agent, inorganic fine particles, a fluidity improver, a cleaning property improver, and a magnetic material.

-Release agent-
There is no restriction | limiting in particular as said mold release agent, Although it can select suitably according to the objective, Melting | fusing point has a low melting point mold release agent of 50 to 120 degreeC. The low melting point release agent is effectively dispersed between the fixing roller and the toner interface as a release agent by being dispersed together with the binder resin. Even if no agent is applied), the hot offset property is good.

Examples of the release agent include waxes and waxes.
Examples of the waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax and rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cercin; paraffin and micro wax And natural waxes such as petroleum waxes such as crystallin and petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax; synthetic waxes such as esters, ketones and ethers; Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbons; poly-n-stearyl methacrylate and poly-n-lauryl which are low molecular weight crystalline polymer resins A homopolymer or copolymer of a polyacrylate such as methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.); a crystalline polymer having a long alkyl group in the side chain may be used. These may be used individually by 1 type and may use 2 or more types together.

There is no restriction | limiting in particular as melting | fusing point of the said mold release agent, Although it can select suitably according to the objective, 50 to 120 degreeC is preferable and 60 to 90 degreeC is more preferable. When the melting point is less than 50 ° C., the wax may adversely affect the heat resistant storage stability, and when it exceeds 120 ° C., a cold offset may easily occur during fixing at a low temperature.
The melt viscosity of the release agent is preferably 5 cps to 1,000 cps, more preferably 10 cps to 100 cps, as measured at a temperature 20 ° C. higher than the melting point of the wax. If the melt viscosity is less than 5 cps, the releasability may be lowered, and if it exceeds 1,000 cps, the effect of improving hot offset resistance and low-temperature fixability may not be obtained.
There is no restriction | limiting in particular as content in the said toner of the said mold release agent, Although it can select suitably according to the objective, 0 mass%-40 mass% are preferable, and 3 mass%-30 mass% are more preferable. . When the content exceeds 40% by mass, the fluidity of the toner may be deteriorated.

  The release agent can be used for any of the resin in the core particles, the resin in the shell layer (resin in the acrylic resin fine particles), and the styrene-acrylic resin fine particles by utilizing the difference in affinity for the resin. Can be contained. By selectively containing the release agent in the shell layer and styrene-acrylic resin fine particles present in the toner outer layer, the release of the release agent occurs sufficiently even in a short heating time at the time of fixing. Can be obtained. Further, by selectively containing the release agent in the core particles existing in the toner inner layer, it is possible to suppress the spent of the release agent to other members such as an electrophotographic photosensitive member and a carrier. In the present invention, the arrangement of the release agent may be designed relatively freely, and any arrangement can be taken according to each image forming process.

-Charge control agent-
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose.For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, Alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus alone or compounds thereof, tungsten alone or compounds thereof, fluorine activators, metal salts of salicylic acid, metals of salicylic acid derivatives Examples include salt.
These may be used individually by 1 type and may use 2 or more types together.

  Commercially available products may be used as the charge control agent. Examples of the commercially available products include bontron 03 of a nigrosine dye, bontron P-51 of a quaternary ammonium salt, and bontron S-34 of a metal-containing azo dye. , Oxynaphthoic acid metal complex E-82, salicylic acid metal complex E-84, phenolic condensate E-89 (above, manufactured by Orient Chemical Industries), quaternary ammonium salt molybdenum complex TP-302 TP-415 (above, manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, boron complex LR-147 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, azo pigment, other sulfonic acid groups, carboxyl And a polymer compound having a functional group such as a quaternary ammonium salt.

  The charge control agent utilizes the difference in affinity for the binder resin in the toner particles, the resin of the acrylic resin fine particles, and the resin of the styrene-acrylic resin fine particles, so that the resin in the core particles, the shell Any of the resin in the layer (resin in the acrylic resin fine particles) and the styrene-acrylic resin fine particles can be arbitrarily contained. By selectively containing the charge control agent in the shell layer and the styrene-acrylic resin fine particles existing in the outer layer of the toner, it becomes easy to obtain an effect on charging with a smaller amount of the charge control agent. Further, by selectively containing the charge control agent in the core particles existing in the toner inner layer, it is possible to suppress the spent of the charge control agent to other members such as an electrophotographic photosensitive member and a carrier. In the toner of the present invention, the arrangement of the charge control agent may be designed relatively freely, and an arbitrary arrangement can be taken according to each image forming process.

  The content of the charge control agent with respect to the toner varies depending on the type of resin, the presence or absence of an additive, a dispersion method, and the like, and cannot be generally defined. For example, with respect to 100 parts by mass of the binder resin, 0.1 mass part-10 mass parts are preferable, and 0.2 mass part-5 mass parts are more preferable. When the content of the charge control agent is less than 0.1 parts by mass, the charge controllability may not be obtained. When the content exceeds 10 parts by mass, the chargeability of the toner becomes too high. By reducing the effect, the electrostatic attraction force with the developing roller may increase, leading to a decrease in developer fluidity and a decrease in image density.

-Inorganic fine particles-
The inorganic fine particles are used as an external additive for imparting fluidity, developability, chargeability and the like to the toner.
The inorganic fine particles are not particularly limited and can be appropriately selected depending on the purpose. For example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, Tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Is mentioned.
These may be used individually by 1 type and may use 2 or more types together.

As the inorganic fine particles for assisting the fluidity, developability and chargeability of the toner, in addition to the large inorganic particles having a primary average particle size of 80 nm to 500 nm, small inorganic particles are preferable. Can be used. In particular, hydrophobic silica and hydrophobic titanium oxide are preferable.
The primary average particle diameter of the inorganic fine particles having a small particle diameter is preferably 5 nm to 50 nm, and more preferably 10 nm to 30 nm.
Further, BET specific surface area of the inorganic fine ^particles, 20m ² / ^g~500m 2 / g are preferred.
The use ratio of the inorganic fine particles is preferably 0.01% by mass to 5% by mass, and particularly 0.01% by mass to 2.0% by mass with respect to the toner, each having a large particle size and a small particle size. % Is preferred.

-Fluidity improver-
The fluidity improver is an agent that performs surface treatment to increase hydrophobicity and prevents deterioration of flow characteristics and charging characteristics even under high humidity. For example, a silane coupling agent, a silylating agent, Examples thereof include a silane coupling agent having a fluoroalkyl group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, and modified silicone oil. Silica and titanium oxide are particularly preferably subjected to surface treatment with such a fluidity improver and used as hydrophobic silica and hydrophobic titanium oxide.

-Cleaning improver-
The cleaning property improving agent is an agent added to the toner to remove the developer after transfer remaining on the electrophotographic photosensitive member and the primary transfer medium. For example, zinc stearate, calcium stearate, stearic acid And 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 preferably have a volume average particle size of 0.01 μm to 1 μm.

-Magnetic material-
There is no restriction | limiting in particular as said magnetic material, According to the objective, it can select suitably, For example, iron powder, magnetite, a ferrite, etc. are mentioned. Among these, white is preferable in terms of color tone.

  There is no restriction | limiting in particular as a volume average particle diameter of the said toner, Although it can select suitably according to the objective, 1 micrometer-6 micrometers are preferable, and 2 micrometers-5 micrometers are more preferable. When the volume average particle size is less than 1 μm, toner dust may easily occur in primary transfer and secondary transfer. When the volume average particle size exceeds 6 μm, dot reproducibility becomes insufficient, and the graininess of the halftone portion is insufficient. It may worsen and a high-definition image may not be obtained.

  The toner includes a step of preparing an oil phase in which at least a binder resin is dissolved or dispersed in an organic solvent, a step of preparing an aqueous phase containing styrene-acrylic resin fine particles, and the oil phase in the aqueous phase. In the step of preparing the emulsification or dispersion, the step of preparing the emulsification or dispersion includes the step of preparing an emulsification or dispersion, and the step of removing the solvent contained in the emulsification or dispersion. When dispersing the toner, it is preferable that at least one of the water phase and the oil phase is a toner obtained by a method for producing a toner containing acrylic resin fine particles.

  The method for producing the toner is not particularly limited and may be appropriately selected depending on the intended purpose. However, the method for producing the toner of the present invention described later is preferable.

A schematic diagram of the toner of the present invention is shown in FIG. As shown in FIG. 1, the toner 1 of the present invention has a shell layer 2 formed of fine acrylic resin particles on the surface of core particles containing a binder resin, and a styrene-acrylic resin outside the shell layer. Fine particles 3 are attached.
The styrene-acrylic resin fine particles need not be present only on the outer side of the shell layer, and may be present in the core particle, or may be present between the core particle and the shell layer. Also good.

(Toner production method)
The method for producing a toner of the present invention prepares an oil phase in which at least a binder resin is dissolved or dispersed in an organic solvent (oil phase preparation step), and an aqueous phase containing styrene-acrylic resin fine particles. A step (aqueous phase preparation step), a step of dispersing the oil phase in the aqueous phase to prepare an emulsification or dispersion (emulsion or dispersion preparation step), and an organic solvent contained in the emulsification or dispersion. At least a removal step (solvent removal step), preferably a heating step, and further include other steps as necessary.

  In the toner production method, when the oil phase is dispersed in the water phase in the emulsification or dispersion preparation step, at least one of the water phase and the oil phase contains acrylic resin fine particles.

  The toner formed by the toner manufacturing method includes core particles containing the binder resin, a shell layer formed of the acrylic resin fine particles on the surface of the core particles, and the styrene-containing resin on the outside of the shell layer. Has acrylic resin fine particles.

  In the toner production method, the acrylic resin fine particles are added before or after emulsification or dispersion. At this timing, since the organic solvent is present in the droplets made of the oil phase, the acrylic resin microparticles adhere to the surface of the droplet after adhering to the droplet surface to some extent, and the organic solvent is removed and fixed on the toner surface. It is possible to realize a desirable form such as. In that case, the ζ potential difference between the acrylic resin fine particles and the core particles is preferably larger than the ζ potential difference between the styrene-acrylic resin fine particles and the core particles.

<Oil phase preparation process>
The oil phase preparation step is not particularly limited as long as it is a step of preparing an oil phase in which at least a binder resin is dissolved or dispersed in an organic solvent, and can be appropriately selected according to the purpose.
The binder resin contains an unmodified polyester resin having an acid value of 10 mgKOH / g to 30 mgKOH / g. When the acid value is less than 10 mgKOH / g, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the acid value exceeds 30 mgKOH / g, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.

As the method for preparing the oil phase, for example, while stirring the organic solvent, at least a binder resin, if necessary, an active hydrogen group-containing compound, a site capable of reacting with the active hydrogen group-containing compound in the organic solvent A polyester resin having colorant, a colorant, a release agent, a charge control agent and the like are gradually added to dissolve or disperse the resin.
When using a pigment as the colorant, or when adding a material that is difficult to dissolve in an organic solvent such as the charge control agent to the organic solvent, the particles are made smaller prior to addition to the organic solvent. It is preferable to keep.
Making the colorant into a masterbatch is also one suitable means, and the same method can be applied to the mold release agent and the charge control agent.

As another method, it is also possible to add a dispersion aid as necessary in the organic solvent and disperse the colorant, the release agent, the charge control agent, etc. in a wet manner to obtain a wet master. is there.
Further, as another method, if a material that melts below the boiling point of the organic solvent is dispersed, a dispersion aid is added in the organic solvent as necessary, and the mixture is heated while stirring with the dispersoid. It is possible to perform a method in which, after once dissolved, crystallization is performed by cooling while applying stirring or shearing to produce fine crystals of dispersoids.

  The colorant dispersed using the above method, the release agent, and if necessary, the charge control agent may be further dispersed after being dissolved or dispersed together with the binder resin in the organic solvent. . For the dispersion, a known disperser such as a bead mill or a disk mill can be used.

  In addition, a polyester resin having a site capable of reacting with the active hydrogen group of the active hydrogen group-containing compound in the oil phase for the purpose of increasing the mechanical strength of the obtained toner or preventing high temperature offset during fixing. It is preferable that the toner is produced in a state in which a polyester resin having a site where the oil phase can react with the active hydrogen group of the active hydrogen group-containing compound is contained.

There is no restriction | limiting in particular as an organic solvent used in the said oil phase preparation process, Although it can select suitably according to the objective, The point which a subsequent organic solvent removal becomes easy that a boiling point is less than 100 degreeC. To preferred. Examples of such organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, Examples include ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. These may be used individually by 1 type and may use 2 or more types together.
When the binder resin to be dissolved or dispersed in the organic solvent is a resin having a polyester skeleton, an ester solvent such as methyl acetate, ethyl acetate, or butyl acetate, or a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone is used. Is preferable from the viewpoint of excellent solubility. Of these, methyl acetate, ethyl acetate, and methyl ethyl ketone, which have high solvent removability, are particularly preferable.

<Aqueous phase preparation process>
The aqueous phase preparation step is not particularly limited as long as it is a step of preparing an aqueous phase containing styrene-acrylic resin fine particles, and can be appropriately selected according to the purpose. For example, the presence of an anionic surfactant The process etc. which disperse | distribute a styrene-acrylic resin microparticles | fine-particles to an aqueous medium below are mentioned.

  The volume average particle size of the styrene-acrylic resin fine particles is 10 nm to 50 nm, preferably 20 nm to 40 nm. When the volume average particle size is less than 10 nm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. In addition, the low-temperature fixability of the obtained toner is reduced. When the volume average particle size exceeds 50 nm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.

  The acid value of the styrene-acrylic resin fine particles is 150 mgKOH / g to 250 mgKOH / g, preferably 180 mgKOH / g to 220 mgKOH / g. When the acid value is less than 150 mgKOH / g, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the acid value exceeds 250 mgKOH / g, the granulation property of the toner is lowered, and it may be difficult to obtain the toner of the present invention.

The pH of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles is 2.0 to 4.5, preferably 2.5 to 4.0. When the pH is less than 2.0, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the pH exceeds 4.5, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.
In addition, the concentration of the aqueous dispersion when measuring pH is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because if the concentration is too low, the detection sensitivity is weakened.

The electric conductivity of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles is 0.5 mS / cm to 1.5 mS / cm, preferably 0.8 mS / cm to 1.2 mS / cm. When the electrical conductivity is less than 0.5 mS / cm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the electric conductivity exceeds 1.5 mS / cm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.
The concentration of the aqueous dispersion when measuring the electrical conductivity is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because the detection sensitivity is weakened when the concentration is lower than%.

  The styrene-acrylic resin fine particles adhere to the toner surface, and are fused and fused to form a relatively hard surface. Therefore, there is an effect of preventing the shell layer formed of the adhered and fixed acrylic resin fine particles from being buried or moved due to mechanical stress. In addition, when anionic styrene-acrylic resin fine particles are used as the styrene-acrylic resin fine particles, they have the effect of adsorbing to the droplets (oil droplets) containing the toner material and suppressing the coalescence of the droplets. It is suitable for controlling the distribution. Furthermore, negative chargeability can be imparted to the toner. And in order to exhibit these effects, it is preferable that the volume average particle diameter of the anionic styrene-acrylic resin fine particles is smaller than that of the acrylic resin fine particles, and the volume average particle diameter is 10 nm to 50 nm.

  The content of the styrene-acrylic resin fine particles contained in the aqueous medium is not particularly limited and may be appropriately selected depending on the intended purpose, but the concentration in the aqueous medium is 0.5% by mass to 10 mass% is preferable.

  In the aqueous phase preparation step, acrylic resin fine particles may be dispersed in an aqueous medium. When the acrylic resin fine particles are cohesive with a surfactant (for example, an anionic surfactant), the aqueous medium is preferably dispersed with a high-speed shearing disperser before emulsification.

  The volume average particle diameter of the acrylic resin fine particles is 30 nm to 200 nm, and preferably 50 nm to 100 nm. When the volume average particle size is less than 30 nm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the volume average particle diameter exceeds 200 nm, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.

  The acid value of the acrylic resin fine particles is 0 mgKOH / g to 20 mgKOH / g, preferably 5 mgKOH / g to 15 mgKOH / g. When the acid value exceeds 20 mgKOH / g, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.

The pH of the 10% by mass aqueous dispersion of the acrylic resin fine particles is 1.5 to 4.0, preferably 2.0 to 3.5. When the pH is less than 1.5, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained. When the pH exceeds 4.0, the granulation property of the toner is lowered and the toner of the present invention cannot be obtained.
In addition, the concentration of the aqueous dispersion when measuring pH is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because if the concentration is too low, the detection sensitivity is weakened.

The electric conductivity of the 10% by mass aqueous dispersion of the acrylic resin fine particles is 1.0 mS / cm to 2.5 mS / cm, preferably 1.2 mS / cm to 2.0 mS / cm. When the electrical conductivity is less than 1.0 mS / cm, the toner of the present invention cannot be obtained. When the electric conductivity exceeds 2.5 mS / cm, the toner of the present invention cannot be obtained.
The concentration of the aqueous dispersion when measuring the electrical conductivity is 10% by mass. If the concentration is higher than 10% by mass, an interparticle interaction occurs, and the measurement accuracy deteriorates. This is because the detection sensitivity is weakened when the concentration is lower than%.

  The acrylic resin fine particles are preferably incompatible with the binder resin. In the emulsification or dispersion preparation process, after the acrylic resin fine particles are attached to the surface of the droplets because the organic solvent is present in the droplets of the toner material when the acrylic resin fine particles are added before or after the emulsification or dispersion. It may dissolve. When the resin component constituting the toner is a polyester resin, and the acrylic resin fine particles are fine particles of a crosslinked resin containing an acrylate polymer or a methacrylic ester polymer, the acrylic resin fine particles are It can exist in a state of adhering without being incompatible with the droplet formed of the oil phase. Accordingly, it is possible to achieve a desirable form in which the ink enters to some extent from the surface of the droplet and is adhered and fixed to the toner surface after the organic solvent is removed.

  It is preferable that the acrylic resin fine particles have a property of forming an aggregate in an aqueous medium containing an anionic surfactant. In the toner manufacturing method of the present invention, when the acrylic resin fine particles are added before or after emulsification or dispersion in the emulsification or dispersion preparation step, the acrylic resin fine particles are not attached to the droplets made of the oil phase. Therefore, it is not preferable to exist stably. Since the acrylic resin fine particles have the property of forming an aggregate in an aqueous medium containing an anionic surfactant, the acrylic resin fine particles present on the aqueous phase side during or after emulsification or dispersion are converted into the oil phase. It can move to the surface of the liquid droplet and can easily adhere to the surface of the liquid droplet. That is, in an aqueous medium containing an anionic surfactant, the acrylic resin fine particles are unstable and usually aggregate, and if there are droplets made of an oil phase, the attractive force with the droplets of the toner material is reduced. When strong, a complex of different particles is formed.

There is no restriction | limiting in particular as an aqueous medium used in the said aqueous phase preparation process, According to the objective, it can select suitably, For example, water is mentioned. The aqueous medium may be water alone or an organic solvent miscible with water. Examples of water-miscible organic solvents include alcohol (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like. .
These may be used individually by 1 type and may use 2 or more types together.

The aqueous medium preferably further contains a surfactant.
The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, and disulfonates. Agent (anionic surfactant); alkylamine salt, amino alcohol fatty acid derivative, polyamine fatty acid derivative, amine salt type such as imidazoline, alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkyl Cationic surfactants such as quaternary ammonium salts such as isoquinolinium salts and benzethonium chloride (cationic surfactants); nonionic surfactants such as fatty acid amide derivatives and polyhydric alcohol derivatives; alanine and dodecyl di ( Aminoethyl) Lysine, di (octyl aminoethyl) glycine, N- alkyl -N, such amphoteric surfactants such as N- dimethyl ammonium betaine and the like. Among these, in order to efficiently disperse oil droplets containing a solvent, a disulfonate having a high HLB is preferable.

  There is no restriction | limiting in particular as content of surfactant contained in the said aqueous medium, Although it can select suitably according to the objective, The density | concentration in the said aqueous medium is 0.5 mass%-10 mass. % Is preferred.

  It is preferable that the styrene-acrylic resin fine particles used in the aqueous phase preparation step be anionic in terms of preventing aggregation when an anionic surfactant is used.

<Emulsification or dispersion preparation process>
The emulsification or dispersion preparation step is not particularly limited as long as it is a step of preparing an emulsification or dispersion by dispersing the oil phase in the aqueous phase, and can be appropriately selected according to the purpose.
There is no restriction | limiting in particular as a dispersion method, According to the objective, it can select suitably, For example, it can carry out using a well-known disperser etc. Examples of the disperser include a low speed shear disperser and a high speed shear disperser.

  At the time of emulsification or dispersion, a modified polyester resin is produced by subjecting an active hydrogen group-containing compound and a polyester resin having a site capable of reacting with the active hydrogen group-containing compound to an extension reaction or a crosslinking reaction. The reaction conditions for producing the modified polyester resin by emulsification or dispersion are not particularly limited, and are appropriately determined depending on the combination of the polyester resin having a site capable of reacting with the active hydrogen group-containing compound and the active hydrogen group-containing compound. You can choose. The reaction time is preferably 10 minutes to 40 hours, more preferably 2 hours to 24 hours.

The acrylic resin fine particles may be added to the aqueous medium during or after emulsification, or may be previously contained in the aqueous phase.
It is preferable to carry out while dispersing with a high-speed shearing disperser, or by switching to low-speed agitation after emulsification and adding the acrylic resin fine particles to the toner appropriately and checking the immobilization state.

In the emulsification or dispersion, the amount of the aqueous medium used is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 50 parts by mass to 2,000 parts by mass with respect to 100 parts by mass of the toner material. 100 mass parts-1,000 mass parts are more preferable. If the amount used is less than 50 parts by mass, the toner material may be poorly dispersed, and toner particles having a predetermined particle size may not be obtained. If the amount exceeds 2,000 parts by mass, the production cost increases. Sometimes.
In addition to the surfactant and styrene-acrylic resin fine particles described above, an inorganic compound dispersant and a polymeric protective colloid can be used in combination with the aqueous medium.

<Solvent removal step>
The solvent removal step is not particularly limited as long as it is a step for removing the organic solvent contained in the emulsification or dispersion, and can be appropriately selected according to the purpose. A step of completely removing the solvent is preferable, for example, a method of evaporating and removing the organic solvent in the droplets by gradually raising the temperature while stirring the emulsified or dispersed liquid, while stirring the emulsified or dispersed liquid. Examples thereof include a method of completely removing the organic solvent in the droplets by spraying in a dry atmosphere, and a method of evaporating and removing the organic solvent by reducing the pressure while stirring the emulsified or dispersed liquid. The latter two means can be used in combination with the first means.
There is no restriction | limiting in particular as dry atmosphere in which the said emulsification thru | or dispersion liquid is sprayed, According to the objective, it can select suitably, For example, the gas which heated air, nitrogen, a carbon dioxide gas, combustion gas etc. is mentioned.
There is no restriction | limiting in particular as temperature of the said dry atmosphere, Although it can select suitably according to the objective, Temperature more than the boiling point of the highest boiling point solvent is preferable.
The spraying is performed using, for example, a spray dryer, a belt dryer, a rotary kiln, or the like. When these are used, the target quality can be sufficiently obtained in a short time.

<Heating process>
The heating step is not particularly limited as long as it is a step of heating the emulsification or dispersion, and can be appropriately selected according to the purpose. ) A method of heat-treating with stirring.
There is no restriction | limiting in particular as heating temperature in the said heating process, Although it can select suitably according to the objective, 40 to 60 degreeC is preferable from the point which adheres and fixes acrylic resin microparticles | fine-particles.
When the heating step is performed, toner particles having a smooth surface are formed. Further, when the toner particles are dispersed with ion-exchanged water, the heating step may be performed before washing or after washing.

<Other processes>
As said other process, a washing | cleaning process, a drying process, etc. are mentioned, for example.

-Washing process-
The washing step is not particularly limited as long as it is a step for washing the toner (toner base particles) contained in the emulsified or dispersed liquid following the solvent removing step, and is appropriately selected depending on the purpose. Can do.
Since the emulsified or dispersed liquid contains auxiliary materials such as a surfactant, in addition to the toner base particles, washing is performed to take out only the toner base particles from the emulsified or dispersed liquid.
The cleaning method for the toner base particles is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a centrifugal separation method, a vacuum filtration method, and a filter press method. Either method can provide a cake of toner base particles. If the cake cannot be sufficiently washed by a single operation, the obtained cake is dispersed again in an aqueous medium to form a slurry, and the toner can be obtained by any of the above methods. The step of taking out the base particles may be repeated, and if cleaning is performed by a vacuum filtration method or a filter press method, an aqueous medium is passed through the cake to wash away the secondary material that the toner base particles have embraced. Also good. As the aqueous medium used for the washing, water or a mixed solvent obtained by mixing water and alcohol such as methanol or ethanol is used. However, in view of cost and environmental load due to wastewater treatment, it is preferable to use water.

-Drying process-
The drying step is not particularly limited as long as it is a step of drying the toner base particles after the washing step, and can be appropriately selected according to the purpose.
Since the toner base particles cleaned by the cleaning step contain a large amount of water, only toner base particles can be obtained by drying and removing the water from the particles.
The method for removing moisture from the toner base particles is not particularly limited and may be appropriately selected depending on the intended purpose. For example, spray dryer, vacuum freeze dryer, vacuum dryer, stationary shelf dryer, transfer Examples include a method using a dryer such as a type shelf dryer, a fluidized tank dryer, a rotary dryer, and a stirring dryer.
It is preferable to remove the water until the water content of the toner base particles is less than 1% by mass. In addition, if the toner base particles after moisture removal are softly agglomerated and inconvenience occurs, use a device such as a jet mill, Henschel mixer, super mixer, coffee mill, auster blender, or food processor. Crushing may be performed to loosen the soft agglomeration.

(Full-color image forming method and full-color image forming apparatus)
The full-color image forming method of the present invention includes at least a charging step, an exposure step, a development step, a primary transfer step, a secondary transfer step, and a cleaning step, and further includes other steps as necessary. .
A full-color image forming apparatus according to the present invention includes an electrophotographic photoreceptor (hereinafter sometimes referred to as “photoreceptor”), a charging unit, an exposure unit, a developing unit, a primary transfer unit, and a secondary transfer unit. And at least a cleaning unit, and further includes other units as necessary.

  The full-color image forming method of the present invention can be preferably carried out by the full-color image forming apparatus according to the present invention, the charging step can be performed by the charging unit, and the exposure step can be performed by the exposing unit. The developing step can be performed by the developing unit, the primary transfer step can be performed by the primary copying unit, the secondary transfer step can be performed by the secondary transfer unit, and the cleaning step can be performed. It can be performed by the cleaning means, and the other steps can be performed by the other means.

  In the full-color image forming method, in the secondary transfer step, the linear velocity of transfer of the toner image to the recording medium is 100 mm / sec to 1,000 mm / sec, and the transfer time at the nip portion of the secondary transfer means is It is preferably 0.5 msec to 60 msec.

  The full color image forming method preferably employs a tandem electrophotographic image forming process.

<Charging step and charging means>
The charging step is not particularly limited as long as it is a step for charging the surface of the electrophotographic photosensitive member, and can be appropriately selected according to the purpose. For example, it can be performed by the charging unit.
The charging means is not particularly limited as long as it is a means for charging the surface of the electrophotographic photosensitive member, and can be appropriately selected according to the purpose. For example, a conductive or semiconductive roll, brush, film In addition, a known contact charging device provided with a rubber blade or the like can be used.
The charging method of the electrophotographic photosensitive member may be a contact charging method or a proximity charging method.

  FIG. 2 shows a schematic configuration of an example of a roller charging device 500 which is a kind of contact charging device. An electrophotographic photosensitive member 505 as an image bearing member to be charged is rotated at a predetermined speed (process speed) in the direction of the arrow. A charging roller 501 which is a charging member brought into contact with the electrophotographic photosensitive member 505 is basically composed of a cored bar 502 and a conductive rubber layer 503 formed on the roller concentrically and integrally with the outer periphery of the cored bar 502, and has both ends of the cored bar. Is rotatably held by a bearing member (not shown) and the like and is pressed against the photosensitive drum by a pressing means (not shown) with a predetermined pressing force. In this case, the charging roller 501 is an electrophotographic photosensitive member 505. Rotates following the rotational drive. The charging roller 501 is formed to have a diameter of 16 mm by coating a medium resistance conductive rubber layer 503 of about 100,000 Ω · cm on a core metal having a diameter of 9 mm. The cored bar 502 of the charging roller 501 and the illustrated power source 504 are electrically connected, and a predetermined bias is applied to the charging roller 501 by the power source 504. As a result, the peripheral surface of the electrophotographic photosensitive member 505 is uniformly charged to a predetermined polarity and potential.

  FIG. 3 shows a schematic configuration of an example of a brush-type charging device 510 which is a kind of contact-type charging device. An electrophotographic photosensitive member 515 as an image carrier as a member to be charged is rotationally driven at a predetermined speed (process speed) in the direction of the arrow. A fur brush roller 511 constituted by a fur brush is brought into contact with the electrophotographic photosensitive member 515 with a predetermined nip width with a predetermined pressing force against the elasticity of the brush portion 513.

  The fur brush roller 511 as a contact charging device in this example is a metal cored bar 512 having a diameter of 6 mm which also serves as an electrode, and conductive rayon fiber REC-B manufactured by Unitika Ltd. as a brush part 513 on a pile ground. The tape is wound in a spiral shape to form a roll brush having an outer diameter of 14 mm and a longitudinal length of 250 mm. The brush of the brush part 513 has a density of 300 denier / 50 filaments and 155 brushes per square millimeter. This roll brush was inserted into a pipe having an inner diameter of 12 mm while rotating in one direction, and the brush and the pipe were set to be concentric, and left in a high-temperature and high-humidity atmosphere to bend and bevel.

  The fur brush roller 511 is rotationally driven at a predetermined peripheral speed (surface speed) in a direction opposite to the rotation direction (counter) of the electrophotographic photosensitive member 515, and contacts the electrophotographic photosensitive member surface with a speed difference. By applying a predetermined charging voltage from the power source 514 to the brush roller 511, the surface of the rotating photosensitive member is uniformly contact-charged to a predetermined polarity and potential.

<Exposure process and exposure means>
The exposure step is not particularly limited as long as it is a step of exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the electrophotographic photosensitive member, and is appropriately selected according to the purpose. For example, it can be performed by the exposure means.
The exposure means is not particularly limited as long as it is a means for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the electrophotographic photosensitive member, and is appropriately selected according to the purpose. Examples thereof include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.
In addition, you may employ | adopt the back light system which exposes imagewise from the back surface side of the said electrophotographic photoreceptor.

<Development process and development means>
The developing step is not particularly limited as long as it is a step of developing a toner image by developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and can be appropriately selected according to the purpose. .
The developing unit is not particularly limited as long as it is a unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and can be appropriately selected according to the purpose. For example, the toner or developer may be stored, and at least a developing device capable of bringing the toner or developer into contact or non-contact with the electrostatic latent image may be used.
The toner is the toner of the present invention.

  In the developing device 600 shown in FIG. 4, during development, a vibration bias voltage obtained by superimposing an AC voltage on a DC voltage is applied to the developing sleeve 601 as a developing bias by the power source 602. The background portion potential and the image portion potential are located between the maximum value and the minimum value of the vibration bias potential. As a result, an alternating electric field whose direction changes alternately is formed in the developing unit 603. In this alternating electric field, the developer toner and the carrier vibrate vigorously, and the toner 605 shakes off the electrostatic binding force to the developing sleeve 601 and the carrier and flies to the electrophotographic photosensitive member 604, and the latent image of the electrophotographic photosensitive member. It adheres corresponding to. The toner 605 is the toner of the present invention.

<Primary transfer step and secondary transfer step, and primary transfer unit and secondary transfer unit>
The primary transfer step is not particularly limited as long as it is a step of transferring the toner image onto an intermediate transfer member, and can be appropriately selected according to the purpose. For example, the primary transfer step can be performed by the primary transfer unit. .
The secondary transfer step is not particularly limited as long as the toner image transferred to the intermediate transfer member is transferred to a recording medium, and can be appropriately selected according to the purpose. For example, the secondary transfer step It can be performed by a transfer means.
The primary transfer means is not particularly limited as long as it is a means for transferring the toner image onto the intermediate transfer member, and can be appropriately selected according to the purpose.
The secondary transfer unit is not particularly limited as long as it is a unit that transfers the toner image transferred to the intermediate transfer member to a recording medium, and can be appropriately selected according to the purpose.

  The intermediate transfer member is not particularly limited and can be appropriately selected from known transfer members according to the purpose. Examples thereof include a transfer belt.

  The transfer unit (the primary transfer unit and the secondary transfer unit) preferably includes at least a transfer unit that peels and charges the toner image formed on the electrophotographic photosensitive member toward the recording medium. There may be one transfer means or two or more transfer means. Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

  The recording medium is not particularly limited and can be appropriately selected from known recording media (recording paper).

<Cleaning process and cleaning means>
The cleaning step is not particularly limited as long as it is a step for removing the toner remaining on the electrophotographic photosensitive member, and can be appropriately selected according to the purpose. For example, the cleaning step is performed. be able to.
The cleaning unit is not particularly limited as long as it is a unit that removes the toner remaining on the electrophotographic photosensitive member, and can be appropriately selected according to the purpose. For example, a magnetic brush cleaner or an electrostatic brush Examples include cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, web cleaners, and the like.

<Other processes and other means>
Examples of the other steps include a fixing step.
Examples of the other means include a fixing means.

-Fixing process and fixing means-
The fixing step is a step of fixing the transferred image transferred to the recording medium. The fixing step can be performed by the fixing unit.
The transferred transfer image is fixed by fixing the transferred image transferred to the recording medium onto the recording medium by fixing means including a heating and pressing member, and transferring the toner of each color to the recording medium. It may be performed every time, or may be performed simultaneously at the same time in a state where the toner of each color is laminated.
There is no restriction | limiting in particular as said fixing means, Although it can select suitably according to the objective, A well-known heating-pressing member is suitable.

  An example of a fixing device which is a fixing unit is shown in FIG. A fixing device 700 shown in FIG. 5 includes a heating roller 710 that is heated by electromagnetic induction of an induction heating unit 760, a fixing roller 720 (opposite rotating body) arranged in parallel with the heating roller 710, a heating roller 710, and a fixing roller. An endless belt-like fixing belt (heat-resistant belt, toner heating medium) 730 that is stretched between the belt 720 and heated by the heating roller 710 and rotated in the direction of arrow A by at least one of these rollers rotating; A pressure roller 740 (pressure rotator) that is pressed against the fixing roller 720 via the 730 and rotates in the forward direction with respect to the fixing belt 730 is configured.

The heating roller 710 is made of, for example, a hollow cylindrical magnetic metal member such as iron, cobalt, nickel, or an alloy of these metals, and has an outer diameter of, for example, 20 mm to 40 mm, and a thickness of, for example, 0.3 mm to 1.0 mm. As a result, the temperature rises quickly with a low heat capacity.
The fixing roller 720 (opposing rotating body) includes, for example, a metal cored bar 721 such as stainless steel, and an elastic member 722 covered with a cored bar 721 in a solid or foamed heat-resistant silicone rubber. . In order to form a contact portion having a predetermined width between the pressure roller 740 and the fixing roller 720 by the pressing force from the pressure roller 740, the outer shape is set to about 20 mm to 40 mm, which is larger than the heating roller 710. The elastic member 722 has a thickness of about 4 mm to 6 mm. With this configuration, the heat capacity of the heating roller 710 is smaller than the heat capacity of the fixing roller 720, so that the heating roller 710 is rapidly heated and the warm-up time is shortened.

  The fixing belt 730 stretched between the heating roller 710 and the fixing roller 720 is heated at a contact portion W1 with the heating roller 710 heated by the induction heating unit 760. The inner surface of the fixing belt 730 is continuously heated by the rotation of the heating roller 710 and the fixing roller 720, and as a result, the entire belt is heated.

FIG. 6 shows a layer structure of the fixing belt 730. The belt 730 has the following four layers from the inner layer to the surface layer, and can be configured as follows.
Base 731: Resin layer such as polyimide resin Heat generation layer 732: Conductive material layer such as Ni, Ag, SUS Intermediate layer 733: Elastic layer for uniform fixing Release layer 734: Release effect and oilless Resin layer such as fluororesin material for

  The thickness of the release layer 734 is preferably about 10 μm to 300 μm, and particularly preferably about 200 μm. In this manner, in the fixing device 700 as shown in FIG. 5, the surface layer of the fixing belt 730 sufficiently wraps the toner image T formed on the recording medium 770, so that the toner image T is uniformly heated and melted. It becomes possible. The thickness of the release layer 734, that is, the surface release layer, is required to be at least 10 μm in order to ensure the wear resistance over time. Further, when the thickness of the release layer 734 is larger than 300 μm, the heat capacity of the fixing belt 730 increases and the time required for warm-up becomes longer. Further, the surface temperature of the fixing belt 730 is hardly lowered in the toner image fixing step, and the effect of agglomeration of the melted toner at the fixing portion outlet is not obtained, so that the releasability of the fixing belt 730 is lowered and the toner image T The toner adheres to the fixing belt 730 and so-called hot offset occurs. The heat generating layer 732 made of the above metal may be used as the base of the fixing belt 730, but a heat-resistant resin such as a fluorine resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin, or a PPS resin. Layers may be used.

  The pressure roller 740 includes, for example, a metal core 741 made of a metal cylindrical member having high thermal conductivity such as copper or aluminum, and an elastic material having high heat resistance and toner releasability provided on the surface of the metal core 741. And a member 742. In addition to the above metal, SUS may be used for the core metal 741. The pressure roller 740 presses the fixing roller 720 via the fixing belt 730 to form the fixing nip portion N, but in this embodiment, the pressure roller 740 has a hardness higher than that of the fixing roller 720. As a result, the pressure roller 740 bites into the fixing roller 720 (and the fixing belt 730), and the recording medium 770 follows the circumferential shape of the surface of the pressure roller 740 by this biting. 730 has an effect of being easily separated from the surface. The outer diameter of the pressure roller 740 is about 20 mm to 40 mm, which is the same as that of the fixing roller 720, but the wall pressure is about 0.5 mm to 2.0 mm, which is thinner than the fixing roller 720.

  As shown in FIG. 5, the induction heating means 760 that heats the heating roller 710 by electromagnetic induction has an excitation coil 761 that is a magnetic field generation means and a coil guide plate 762 around which the excitation coil 761 is wound. Yes. The coil guide plate 762 has a semi-cylindrical shape that is disposed close to the outer peripheral surface of the heating roller 710, and the excitation coil 761 is formed by passing a single long excitation coil wire along the coil guide plate 762 of the heating roller 710. These are wound alternately in the axial direction. The exciting coil 761 has an oscillation circuit connected to a drive power source (not shown) whose frequency is variable. Outside the excitation coil 761, a semi-cylindrical excitation coil core 763 made of a ferromagnetic material such as ferrite is fixed to the excitation coil core support member 764 and is disposed close to the excitation coil 761.

  As the full-color image forming apparatus used in the full-color image forming method of the present invention, for example, the tandem image forming apparatus 100 shown in FIGS. 7 and 8 can be used. In FIG. 7, an image forming apparatus 100 mainly includes image writing units 120Bk, 120C, 120M, and 120Y, image forming units 130Bk, 130C, 130M, and 130Y, and a paper feeding unit 140 for performing color image formation by electrophotography. It is configured. Based on the image signal, image processing is performed by an image processing unit (not shown), and converted into black (Bk), cyan (C), magenta (M), and yellow (Y) color signals for image formation, It transmits to the image writing unit 120Bk, 120C, 120M, 120Y. The image writing units 120Bk, 120C, 120M, and 120Y are laser scanning optical systems that include, for example, a laser light source, a deflector such as a rotary polygon mirror, a scanning imaging optical system, and a mirror group (all not shown). The image forming unit 130Bk, 130C, 130M, and 130Y has four writing optical paths corresponding to the color signals and performs image writing corresponding to the color signals.

  The image forming units 130Bk, 130C, 130M, and 130Y include photoconductors 210Bk, 210C, 210M, and 210Y for black, cyan, magenta, and yellow, and the photoconductors 210Bk, 210C, 210M, and 210Y for these colors are included. Usually, an OPC photoreceptor is used. Around each of the photoreceptors 210Bk, 210C, 210M, and 210Y, there are charging devices 215Bk, 215C, 215M, and 215Y, laser light exposure units from the image writing units 120Bk, 120C, 120M, and 120Y, and developing devices for the respective colors. 200Bk, 200C, 200M, 200Y, primary transfer devices 230Bk, 230C, 230M, 230Y, cleaning devices 300Bk, 300C, 300M, 300Y, a static eliminator (not shown), and the like are arranged. The developing devices 200Bk, 200C, 200M, and 200Y use a two-component magnetic brush developing system. Further, an intermediate transfer belt 220 is interposed between the respective photosensitive members 210Bk, 210C, 210M, and 210Y and the primary transfer devices 230Bk, 230C, 230M, and 230Y, and toner images of respective colors are transferred from the photosensitive members to the intermediate transfer belt 220. Are sequentially superimposed and transferred to carry a toner image on each photoconductor.

  In some cases, it is preferable that a pre-transfer charger as a pre-transfer charging unit is disposed outside the intermediate transfer belt 220 at a position after passing through the primary transfer position of the final color and before passing through the secondary transfer position. This pre-transfer charger uniformly transfers the toner image to the same polarity as the toner image before transferring the toner image on the intermediate transfer belt 220 transferred to the photosensitive member 210 in the primary transfer portion to a transfer paper as a recording medium. Is charged.

  The toner image on the intermediate transfer belt 220 transferred from each of the photoconductors 210Bk, 210C, 210M, and 210Y includes a halftone portion and a solid portion, or includes portions having different toner overlapping amounts. The amount may vary. Further, there may be a case where a variation in the charge amount occurs in the toner image on the intermediate transfer belt 220 after the primary transfer due to the peeling discharge generated in the gap adjacent to the downstream side of the primary transfer portion in the intermediate transfer belt moving direction. . Such variation in the charge amount in the same toner image lowers the transfer margin in the secondary transfer portion that transfers the toner image on the intermediate transfer belt 220 onto the transfer paper. Therefore, the toner image before being transferred to the transfer paper by the pre-transfer charger is uniformly charged to the same polarity as the toner image, thereby eliminating the variation in the charge amount in the same toner image and the transfer margin in the secondary transfer portion. Has improved.

  As described above, according to this image forming method, the toner image on the intermediate transfer belt 220 transferred from each of the photoconductors 210Bk, 210C, 210M, and 210Y is uniformly charged by the pre-transfer charger, thereby the toner on the intermediate transfer belt 220. Even if there is a variation in the charge amount in the image, the transfer characteristics in the secondary transfer portion can be made almost constant over the respective portions of the toner image on the intermediate transfer belt 220. Therefore, it is possible to suppress a decrease in transfer margin when transferring to transfer paper and to stably transfer a toner image.

  In this image forming method, the amount of charge charged by the pre-transfer charger varies depending on the moving speed of the intermediate transfer belt 220 that is the object to be charged. For example, if the moving speed of the intermediate transfer belt 220 is slow, the time for the same portion of the toner image on the intermediate transfer belt 220 to pass through the charging region by the pre-transfer charger becomes long, and the charge amount increases. Conversely, when the moving speed of the intermediate transfer belt 220 is fast, the charge amount of the toner image on the intermediate transfer belt 220 becomes small. Therefore, when the moving speed of the intermediate transfer belt 220 changes while the toner image on the intermediate transfer belt 220 passes through the charging position by the pre-transfer charger, the transfer speed depends on the moving speed of the intermediate transfer belt 220. Therefore, it is desirable to control the pre-transfer charger so that the charge amount for the toner image does not change during the process.

  Conductive rollers 241, 242, and 243 are provided between the primary transfer devices 230Bk, 230C, 230M, and 230Y. The transfer sheet is fed from the sheet feeding unit 140 and is then carried on the transfer belt 180 via the registration roller pair 160. When the intermediate transfer belt 220 and the transfer belt 180 come into contact with each other, the secondary transfer roller 170 performs the intermediate transfer. The toner image on the belt 220 is transferred to transfer paper, and a color image is formed.

  Then, the transfer paper after the image formation is conveyed to the fixing device 150 by the transfer belt 180, and the image is fixed to obtain a color image.

  Since the toner polarity on the intermediate transfer belt 220 before transfer onto the transfer paper is the same negative polarity as that during development, a positive transfer bias voltage is applied to the secondary transfer roller 170, and the toner is transferred onto the transfer paper. The The nip pressure at this portion affects the transfer property and greatly affects the fixability. Further, the toner on the intermediate transfer belt 220 remaining without being transferred is discharged and charged to the positive polarity side and charged to 0 to the positive side at the moment when the transfer paper and the intermediate transfer belt 220 are separated. Note that the toner image formed when the transfer paper is jammed or in the non-image area is not affected by the secondary transfer, and of course remains in the negative polarity.

  The thickness of the photosensitive layer is 30 μm, the beam spot diameter of the optical system is 50 μm × 60 μm, and the light quantity is 0.47 mW. The developing process is performed with the charging (exposure side) potential V0 of the photoreceptor (black) 210Bk being −700V, the post-exposure potential VL being −120V, the developing bias voltage being −470V, that is, the developing potential 350V. The visible image of the toner (black) formed on the photoconductor (black) 210Bk is then transferred (intermediate transfer belt and transfer paper) and completed as an image through a fixing process. First, all colors are transferred from the primary transfer devices 230Bk, 230C, 230M, and 230Y to the intermediate transfer belt 220, and then transferred onto a transfer sheet by applying a bias to another secondary transfer roller 170.

  Next, the photoconductor cleaning device will be described in detail. In FIG. 7, the developing devices 200Bk, 200C, 200M, and 200Y and the cleaning devices 300Bk, 300C, 300M, and 300Y are connected by toner transfer tubes 250Bk, 250C, 250M, and 250Y, respectively (broken lines in FIG. 7). ). Each toner transfer pipe 250Bk, 250C, 250M, 250Y contains a screw (not shown), and the toner collected by each cleaning device 300Bk, 300C, 300M, 300Y is transferred to each developing device 200Bk. , 200C, 200M, 200Y.

  In the conventional direct transfer method using a combination of the four electrophotographic photosensitive members and the belt conveyance, paper dust adheres when the photosensitive member and the transfer paper come into contact with each other, and paper dust is contained when the toner is collected. Occasionally, the image was deteriorated such as toner missing and could not be used. In addition, in a conventional system combining an electrophotographic photosensitive member and an intermediate transfer, the use of the intermediate transfer member eliminates the adhesion of paper dust to the photosensitive member during transfer paper transfer. When recycling is performed, it is practically impossible to separate the mixed color toner. There is also a proposal to use a mixed color toner as a black toner, but even if all the colors are mixed, it does not become black, and the color changes depending on the print mode. Therefore, it is impossible to recycle the toner with one photoconductor configuration.

  On the other hand, in this full-color image forming apparatus, since the intermediate transfer belt 220 is used, paper dust is less mixed and paper dust is prevented from adhering to the intermediate transfer belt 220 during paper transfer. Since the photosensitive members 210Bk, 210C, 210M, and 210Y use independent color toners, it is not necessary to contact and separate the photosensitive member cleaning devices 300Bk, 300C, 300M, and 300Y, and only the toner can be reliably collected. .

  The positively charged toner remaining on the intermediate transfer belt 220 is cleaned by a conductive fur brush 262 to which a negative voltage is applied. The method of applying a voltage to the conductive fur brush 262 is exactly the same as the conductive fur brush 261 except that the polarity is different. The toner remaining without being transferred is also almost cleaned by the two conductive fur brushes 261 and 262. Here, toner, paper powder, talc, and the like remaining without being cleaned by the conductive fur brush 262 are negatively charged by the negative voltage of the conductive fur brush 262. The next black primary transfer is a transfer with a positive voltage, and negatively charged toner or the like is attracted to the intermediate transfer belt 220 side, so that the transfer to the photoreceptor (black) 210Bk side can be prevented.

(Process cartridge)
The process cartridge of the present invention has at least an electrophotographic photosensitive member and at least developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and further if necessary. , Have other means.
The process cartridge is detachable from the main body of the image forming apparatus.
The developing means includes the above-described toner of the present invention.
The process cartridge of the present invention preferably further includes at least one means selected from the charging means, the transfer means, and the cleaning means.
As the developing unit and the charging unit, the above-described developing device and charging device can be preferably used.

  An example of the process cartridge of the present invention is shown in FIG. A process cartridge 800 shown in FIG. 9 includes a photoreceptor 801, a charging unit 802, a developing unit 803, and a cleaning unit 806. The operation of the process cartridge 800 will be described. The photosensitive member 801 is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member 801 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the charging unit 802, and then image exposure from an image exposure unit (not shown) such as slit exposure or laser beam scanning exposure. The electrostatic latent image is sequentially formed on the peripheral surface of the photoreceptor 801 in this way, and the formed electrostatic latent image is then converted into a toner image by the developing means 803, and the developed toner image is supplied to the paper feeding unit. From the photoconductor 801 and a transfer unit (not shown), the transfer unit sequentially transfers the recording material fed in synchronization with the rotation of the photoconductor 801. The recording material that has undergone image transfer is separated from the surface of the photosensitive member, introduced into an image fixing means (not shown), and fixed on the image, and printed out as a copy (copy). The surface of the photoconductor 801 after the image transfer is cleaned by removing the transfer residual toner by the cleaning unit 806, and after being further neutralized, it is repeatedly used for image formation. Reference numeral 804 denotes a developer, and reference numeral 805 denotes a developing roller.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. In addition, the part in an Example represents a mass part unless there is particular description.

First, the measurement method will be described.
(PH)
The pH was measured using a pH measuring device GST-5721C (manufactured by Toa DKK Corporation) after diluting the aqueous dispersion concentration to 10% by mass. By inserting a dedicated cell into a 10% by mass aqueous dispersion under a room temperature atmosphere, the pH of the aqueous dispersion can be automatically measured.

(Volume average particle diameter of styrene-acrylic resin fine particles and acrylic resin fine particles)
The volume average particle diameters of the styrene-acrylic resin fine particles and the acrylic resin fine particles were measured with Microtrack UPA-150 manufactured by Nikkiso Co., Ltd.

(Electrical conductivity)
The electric conductivity was measured using an electric conductivity measuring device CT-57101B (manufactured by Toa DKK Corporation) after diluting the aqueous dispersion concentration to 10% by mass. By inserting a dedicated cell into a 10% by mass aqueous dispersion under a room temperature atmosphere, the electrical conductivity of the aqueous dispersion can be automatically measured.

(Ζ potential)
The ζ potential was measured using a ζ potential measuring device DT1200 (manufactured by Dispersion Technology) after diluting the aqueous dispersion concentration to 10% by mass. By inserting a dedicated cell into a 10% by mass aqueous dispersion under a room temperature atmosphere, the ζ potential of the aqueous dispersion can be automatically measured.

(Production Example 1)
<Preparation of solution or dispersion of toner material>
-Synthesis of unmodified polyester resin 1 (low molecular weight polyester)-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of bisphenol A ethylene oxide 2-mole adduct, 84 parts of bisphenol A propion oxide 3-mole adduct, 274 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 ° C. for 8 hours under normal pressure. Next, the reaction solution was reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg, and then 15 parts of trimellitic anhydride was added and reacted for 1 hour at 220 ° C. under normal pressure to synthesize unmodified polyester resin 1. An aqueous dispersion was obtained by phase inversion emulsification.
The obtained unmodified polyester resin 1 has an acid value of 17 mgKOH / g, a volume average particle size of 100 nm, a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 5,600, a glass transition temperature ( Tg) was 50 ° C.

-Preparation of masterbatch (MB)-
1,000 parts of water, 540 parts of carbon black (“Printtex35”; manufactured by Degussa, DBP oil absorption = 42 mL / 100 g, pH = 9.5), and 1,200 parts of the unmodified polyester resin 1 were added to a Henschel mixer. (Mitsui Mining Co., Ltd.) was used for mixing. The mixture was kneaded with a two-roller at 150 ° C. for 30 minutes, rolled and cooled, and pulverized with a pulverizer (manufactured by Hosokawa Micron Corporation) to prepare a master batch.

-Synthesis of prepolymer-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, 22 parts of trimellitic anhydride And 2 parts of dibutyltin oxide were allowed to react at 230 ° C. for 8 hours under normal pressure. Subsequently, it was made to react under reduced pressure of 10 mmHg-15 mmHg for 5 hours, and the intermediate polyester was synthesize | combined.
The obtained intermediate polyester has a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 9,600, a glass transition temperature (Tg) of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl group. The value was 49 mgKOH / g.
Next, 411 parts of the intermediate polyester, 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are charged in a reaction vessel equipped with a cooling pipe, a stirrer, and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. A prepolymer (a polyester resin having a site capable of reacting with an active hydrogen group-containing compound) was synthesized.
The free isocyanate content of the obtained prepolymer was 1.60% by mass, and the solid content concentration of the prepolymer (after standing at 150 ° C. for 45 minutes) was 50% by mass.

-Preparation of toner material phase-
In a beaker, 100 parts of the unmodified polyester resin 1 and 130 parts of ethyl acetate were added and stirred to dissolve. Subsequently, 10 parts of carnauba wax (molecular weight = 1,800, acid value = 2.5, penetration = 1.5 mm (40 ° C.)) and 10 parts of the master batch were charged, and a bead mill (“Ultra Visco Mill”) was prepared. Using Imex Co., Ltd.), a raw material solution was prepared by three passes under conditions of a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / s, and 80% by volume of 0.5 mm zirconia beads. 40 parts of the prepolymer (solid content concentration 50% by mass) was added and stirred to prepare [dissolution or dispersion of toner material] (oil phase).

(Production Example 2)
<Synthesis of Unmodified Polyester Resin 2 (Low Molecular Weight Polyester)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of bisphenol A ethylene oxide 2-mole adduct, 84 parts of bisphenol A propion oxide 3-mole adduct, 274 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 ° C. for 8 hours under normal pressure. Next, the reaction solution was reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg, and then 10 parts of trimellitic anhydride was added and reacted for 1 hour at 220 ° C. under normal pressure to synthesize unmodified polyester resin 2. An aqueous dispersion was obtained by phase inversion emulsification.
The obtained unmodified polyester resin 2 has an acid value of 10 mgKOH / g, a volume average particle size of 100 nm, a number average molecular weight (Mn) of 2,100, a weight average molecular weight (Mw) of 5,300, a glass transition temperature ( Tg) was 49 ° C.

(Production Example 3)
<Synthesis of Unmodified Polyester Resin 3 (Low Molecular Weight Polyester)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of bisphenol A ethylene oxide 2-mole adduct, 84 parts of bisphenol A propion oxide 3-mole adduct, 274 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 ° C. for 8 hours under normal pressure. Next, the reaction solution was reacted for 3 hours under a reduced pressure of 10 mmHg to 15 mmHg, then 20 parts of trimellitic anhydride was added and reacted for 1 hour at 220 ° C. under normal pressure to synthesize an unmodified polyester resin 3. An aqueous dispersion was obtained by phase inversion emulsification.
The obtained unmodified polyester resin 3 has an acid value of 30 mgKOH / g, a volume average particle size of 100 nm, a number average molecular weight (Mn) of 2,000, a weight average molecular weight (Mw) of 5,600, a glass transition temperature ( Tg) was 51 ° C.

(Production Example 4)
<Synthesis of Unmodified Polyester Resin 4 (Low Molecular Weight Polyester)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of bisphenol A ethylene oxide 2-mole adduct, 84 parts of bisphenol A propion oxide 3-mole adduct, 274 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 ° C. for 8 hours under normal pressure. Next, the reaction solution was reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg, then 7 parts of trimellitic anhydride was added and reacted for 1 hour at 220 ° C. under normal pressure to synthesize unmodified polyester resin 4. An aqueous dispersion was obtained by phase inversion emulsification.
The obtained unmodified polyester resin 4 has an acid value of 5 mgKOH / g, a volume average particle size of 100 nm, a number average molecular weight (Mn) of 2,000, a weight average molecular weight (Mw) of 5,300, a glass transition temperature ( Tg) was 48 ° C.

(Production Example 5)
<Synthesis of Unmodified Polyester Resin 5 (Low Molecular Weight Polyester)>
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of bisphenol A ethylene oxide 2-mole adduct, 84 parts of bisphenol A propion oxide 3-mole adduct, 274 parts of terephthalic acid, and 2 parts of dibutyltin oxide were added. The reaction was carried out at 230 ° C. for 8 hours under normal pressure. Next, the reaction solution is reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg, and then 25 parts of trimellitic anhydride is added and reacted for 1 hour at 220 ° C. under normal pressure to synthesize unmodified polyester resin 5. An aqueous dispersion was obtained by phase inversion emulsification.
The obtained unmodified polyester resin 5 has an acid value of 50 mgKOH / g, a volume average particle size of 100 nm, a number average molecular weight (Mn) of 2,200, a weight average molecular weight (Mw) of 5,800, a glass transition temperature ( Tg) was 52 ° C.

(Production Example 6)
<Preparation of aqueous dispersion of styrene-acrylic resin fine particles>
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 16 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 83 parts of styrene, 83 parts of methacrylic acid Parts, 110 parts of n-butyl acrylate, and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes to obtain a white emulsion. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% by weight ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours to be a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). An aqueous dispersion [styrene-acrylic resin fine particle aqueous dispersion A1] (solid content: 20% by mass) was obtained. [Styrene-acrylic resin fine particles A1] had a volume average particle diameter of 14 nm, a pH of 3.3, an electric conductivity of 0.9 mS / cm, and an acid value of 180 mgKOH / g.

(Production Examples 7 to 20)
<Preparation of aqueous dispersion of styrene-acrylic resin fine particles>
Styrene-acrylic resin fine particle aqueous dispersions A2 to A15 were produced in the same manner as in Production Example 6 except that the formulation was changed to the formulation shown in Table 1 in Production Example 6.
Table 1 shows the characteristics of the obtained styrene-acrylic resin fine particle aqueous dispersions A2 to A15.

The compounding quantity in Table 1 is a mass part. "RS-30" is a sodium salt of methacrylic acid ethylene oxide adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries).

(Production Example 21)
<Preparation of aqueous dispersion of acrylic resin fine particles>
In a reaction vessel equipped with a stirring bar and a thermometer, 683 parts of water, 10 parts of distearyldimethylammonium chloride (cation DS, manufactured by Kao Corporation), 144 parts of methyl methacrylate, 50 parts of n-butyl acrylate, acrylic acid 2 Parts, 1 part of ammonium persulfate, and 2 parts of ethylene glycol dimethacrylate (EGDMA) were stirred for 15 minutes at 400 rpm, and a white emulsion was obtained. The mixture was heated to raise the temperature in the system to 65 ° C. and reacted for 10 hours. Further, 30 parts of a 1% by mass aqueous ammonium persulfate solution was added and aged at 75 ° C. for 5 hours to obtain an aqueous vinyl resin dispersion [acrylic resin fine particle aqueous dispersion B1] (solid content 20% by mass). [Acrylic resin fine particles B1] had a volume average particle size of 35 nm, a pH of 2.8, an electric conductivity of 1.3 mS / cm, and an acid value of 10 mgKOH / g.

(Production Examples 22 to 39)
<Preparation of aqueous dispersion of acrylic resin fine particles>
Acrylic resin fine particle water dispersions B2 to B19 were produced in the same manner as in Production Example 21, except that the composition in Production Example 21 was changed to the composition shown in Table 2.
Table 2 shows the characteristics of the obtained acrylic resin fine particle aqueous dispersions B2 to B19.

The compounding quantity in Table 2 is a mass part. “Cation DS” is distearyldimethylammonium chloride (cation DS, manufactured by Kao Corporation). “EGDMA” is ethylene glycol dimethacrylate.

(Evaluation of swelling of resin fine particles)
Various resin fine particles having a difference in swellability were added to 30 mL of ASONE screw vials so that each of them would be 20 mm from the bottom with a measuring pipette, and 10 mL of ethyl acetate was added with a measuring pipette, and then allowed to stand for 24 hours. As a result, the emulsion of white resin fine particles phase-separated on the lower side and ethyl acetate on the upper side. And the difference in swelling property was evaluated by observing the height of the resin fine particle emulsion which has white from the bottom of a screw vial. Those having a high swelling property have a high height. The degree of swelling was judged as follows.
In the present invention, “swell” refers to those evaluated as ◎, ○, Δ.
◎ ・ ・ ・ 25mm or more Swells well ○ ・ ・ ・ 21mm or more, less than 25mm Swells △ ・ ・ ・ 20mm or more, less than 21mm Insufficient swelling × ・ ・ ・ less than 20mm Does not swell

(Compatibility)
The compatibility between the resin fine particles and the binder resin (unmodified polyester resin) was determined by the following method.
A binder resin and resin fine particles were blended at a predetermined ratio (mass ratio 50:50), and then melted and made uniform to prepare a sample. This sample and the glass transition temperature (Tg) of each resin were analyzed by DSC (differential scanning calorimetry). Then, in the graph in which the blend ratio is on the horizontal axis and Tg is on the vertical axis, if the Tg of the measured sample is on the straight line connecting the Tg of each resin alone, it is determined that they are compatible. If there was no Tg of the sample measured above, it was judged as incompatible.

  Tables 3-1 and 3-2 show the evaluation results of the swelling properties of the resin fine particles and the compatibility evaluation results with the binder resin (unmodified polyester resin).

Example 1
<Manufacture of toner a>
-Preparation of aqueous medium phase (aqueous phase)-
660 parts of water, 25 parts of styrene-acrylic resin fine particle aqueous dispersion A1, 25 parts of an aqueous solution of 48.5% by mass of sodium dodecyl diphenyl ether disulfonate (“Eleminol MON-7”; manufactured by Sanyo Chemical Industries), and ethyl acetate 60 The parts were mixed and stirred to obtain a milky white liquid (aqueous phase). Furthermore, 50 parts of acrylic resin fine particle dispersion B1 was added to obtain an aqueous medium phase (aqueous phase). When observed with an optical microscope, several hundred μm aggregates were observed. When the aqueous medium phase was stirred at 8,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), it was confirmed by an optical microscope that the aggregates were loosened and could be dispersed into small aggregates of several μm.
Therefore, in the subsequent emulsification step of the toner material, it was expected that the acrylic resin fine particles B1 were dispersed and adhered to the toner material component droplets. As described above, the acrylic resin fine particles B1 cause aggregation but are loosened by shearing, which is important for uniform adhesion to the toner surface.

-Preparation of emulsion or dispersion-
150 parts of the aqueous medium phase is put in a container, and stirred at a rotational speed of 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). The mixture was added and mixed for 10 minutes to prepare an emulsified dispersion (emulsified slurry).

-Removal of organic solvent-
100 parts of the emulsified slurry was charged into a flask equipped with a degassing pipe, a stirrer, and a thermometer, and the solvent was removed under reduced pressure at 30 ° C. for 12 hours while stirring at a stirring peripheral speed of 20 m / min. .

-Washing-
After filtering the whole amount of the solvent removal slurry under reduced pressure, 300 parts of ion exchange water was added to the filter cake, mixed and redispersed (at 12,000 rpm for 10 minutes) with a TK homomixer, and then filtered. To the obtained filter cake, 300 parts of ion exchange water was added, mixed with a TK homomixer (at 12,000 rpm for 10 minutes) and then filtered three times. The conductivity of the redispersed slurry was When it became 0.1 μS / cm or more and 10 μS / cm or less, a cleaning slurry was obtained.

-Heat treatment-
In a flask equipped with a stirrer and a thermometer, the obtained washing slurry was stirred at 50 ° C. for 60 minutes while stirring at a stirring peripheral speed of 20 m / min. After filtration.

-Drying-
The obtained filter cake was dried at 45 ° C. for 48 hours with a forward air dryer and sieved with a mesh having a mesh size of 75 μm to obtain toner base particles a having a volume average particle size of 5.2 μm.
Scanning electron micrographs of the obtained toner base particles a are shown in FIGS. 10A and 10B. In the toner base particles 5 shown in FIGS. 10A and 10B, a shell layer 2 (white portion) formed of acrylic resin fine particles is formed around the core particles 4, and further, styrene-acrylic resin fine particles are formed outside the shell layer. 3 (black part) has adhered.

-External treatment-
To 100 parts of toner base particles a, 0.6 part of hydrophobic silica having an average particle diameter of 100 nm, 1.0 part of titanium oxide having an average particle diameter of 20 nm, and 0.8 fine particles of hydrophobic silica having an average particle diameter of 15 nm The toner was mixed with a Henschel mixer.
The content of the acrylic resin fine particles (content of the shell layer) in the toner a was 4.0% by mass.
Further, the content of the styrene-acrylic resin fine particles in the toner a was 2.0 mass%.

<Evaluation>
A developer was prepared using the obtained toner and subjected to the following evaluation. The results are shown in Table 7.

<< Career preparation >>
A specific example of manufacturing the carrier used for the actual toner evaluation will be described. The carrier used in the present invention is not limited to these examples.
-Career-
Acrylic resin solution (solid content 50% by mass) 21.0 parts Guanamin solution (solid content 70% by mass) 6.4 parts Alumina particles [0.3 μm, specific resistance 10 ¹⁴ (Ω · cm)] 7.6 parts Silicone resin Solution 65.0 parts [Solid content 23% by mass (SR2410: manufactured by Toray Dow Corning Silicone)]
Aminosilane 1.0 part [Solid content 100% by mass (SH6020: manufactured by Toray Dow Corning Silicone)]
Toluene 60 parts Butyl cellosolve 60 parts The carrier raw material was dispersed with a homomixer for 10 minutes to obtain a coating film forming solution of acrylic resin and silicone resin containing alumina particles. Firing ferrite powder [(MgO) _1.8 (MnO) _49.5 (Fe ₂ O ₃ ) _48.0 : average particle size; 25 μm] as the core material is coated with the coating film forming solution on the surface of the core material. The coated ferrite powder was obtained by applying with a Spira coater (Okada Seiko Co., Ltd.) to a thickness of 15 μm and drying. The obtained coated ferrite powder was fired in an electric furnace at 150 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve having an aperture of 106 μm to obtain a carrier. The measurement of the binder resin film thickness was performed by observing the cross section of the carrier with a transmission electron microscope so that the coating film covering the carrier surface could be observed. Thus, carrier A having a weight average particle diameter of 35 μm was obtained.

<< Preparation of two-component developer >>
Using toner a and carrier A, 7 parts of toner with respect to 100 parts of carrier were uniformly mixed and charged using a type of tumbler mixer in which the container was rolled and stirred to prepare a two-component developer a.

<< Transfer efficiency (%) >>
Using an evaluation machine modified from Fuji Xerox's DocuColor 8,000 Digital Press and tuned to a linear speed of 162 mm / sec and a transfer time of 40 msec, the developer is A4 size and the toner adhesion amount is 0.6 mg / cm ^2. A running test was performed to output a solid pattern as a test image. At the initial stage of the test image and after output of 100K (100,000 sheets), the transfer efficiency in the primary transfer was determined by the following formula (3), and the transfer efficiency in the secondary transfer was determined by the following formula (4). The evaluation criteria are as follows.
Primary transfer efficiency (%) = (amount of toner transferred onto intermediate transfer member / amount of toner developed on electrophotographic photosensitive member) × 100 (3)
Secondary transfer efficiency (%) = (amount of toner transferred onto intermediate transfer body−amount of residual toner on intermediate transfer body / amount of toner transferred onto intermediate transfer body) × 100 (4)
As the evaluation criteria, an average value of the primary transfer efficiency and the secondary transfer efficiency was calculated and evaluated according to the following criteria.
◎: 90% or more ○: 85% or more and less than 90% △: 80% or more and less than 85% ×: less than 80%

<< Fixing temperature limit >>
The fixing unit of the full color multifunction machine Imagio NeoC600Pro manufactured by Ricoh Co., Ltd. was modified, and the fixing device with adjustable temperature and linear speed was used to transfer plain paper and cardboard (type 6000 <70W> made by Ricoh Co., Ltd.) The image was fixed on a copy printing paper <135>) with a solid image and a toner adhesion amount of 0.85 ± 0.1 mg / cm ² . The fixing roll temperature at which the residual ratio of the image density after rubbing the fixed image with a pad becomes 70% or more was determined as the minimum fixing temperature.
The evaluation criteria are as follows.
◎: Less than 100 ° C ○: 100 ° C or more and less than 110 ° C △: 110 ° C or more and less than 120 ° C ×: 120 ° C or more

(Example 2)
<Manufacture of toner b>
In Example 1, a toner b was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B2.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
The acrylic resin fine particles B2 used for the toner b are not compatible with the binder resin and exhibit high swellability because there are few cross-linked structures. Further, when the acrylic resin fine particles B2 were added to the aqueous medium phase and observed with an optical microscope, an aggregate of several hundred μm was observed. When the aqueous medium phase was stirred at 8,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), it was confirmed by an optical microscope that the aggregates were loosened and could be dispersed into small aggregates of several μm.
Therefore, it was expected that the acrylic resin fine particles B2 were dispersed and adhered to the droplets of the toner material component even in the emulsification step of the toner material. The toner b using the acrylic resin fine particles B2 is slightly inferior to the toner a in transfer efficiency, but can sufficiently achieve the problem at the minimum fixing temperature.

Example 3
<Manufacture of toner c>
A toner c was obtained in the same manner as in Example 1 except that the acrylic resin fine particle water dispersion B1 was replaced with the acrylic resin fine particle water dispersion B3 in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
The acrylic resin fine particles B3 used for the toner c are not compatible with the binder resin, but have a much cross-linked structure, so that the swelling property is inferior to that of the acrylic resin fine particles B1. Further, when the acrylic resin fine particles B3 were added to the aqueous medium phase and observed with an optical microscope, an aggregate of several hundred μm was observed. When the aqueous medium phase was stirred at 8,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), it was confirmed by an optical microscope that the aggregates were loosened and could be dispersed into small aggregates of several μm.
Accordingly, it was expected that the acrylic resin fine particles B3 were dispersed and adhered to the droplets of the toner material component even in the emulsification step of the toner material. The toner c using the acrylic resin fine particles B3 can sufficiently achieve the problems in the transfer efficiency and the minimum fixing temperature.

Example 4
<Manufacture of toner d>
In Example 1, a toner d was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B4.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
The acrylic resin fine particles B4 used for the toner d are not compatible with the binder resin and exhibit high swellability because there are few cross-linked structures. Further, when the acrylic resin fine particles B4 were added to the aqueous medium phase and observed with an optical microscope, an aggregate of several hundred μm was observed. When the aqueous medium phase was stirred at 8,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), it was confirmed by an optical microscope that the aggregates were loosened and could be dispersed into small aggregates of several μm.
Therefore, it was expected that the acrylic resin fine particles B4 were dispersed and adhered to the droplets of the toner material component even in the emulsification step of the toner material. The toner d using the acrylic resin fine particles B4 has a transfer efficiency slightly lower than that of the toners a, b, and c, but can sufficiently achieve the problem at the minimum fixing temperature.

(Example 5)
<Manufacture of toner e>
In Example 1, a toner e was obtained in the same manner as in Example 1, except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A2.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
Since the difference between the acid value of the acrylic resin fine particles and the acid value of the core particle resin is smaller than that of the toner a, the adhesion of the acrylic resin fine particles is slightly weak and the transfer efficiency is inferior to that of the toner a. The problem could be sufficiently achieved at the lower limit temperature.

(Example 6)
<Manufacture of toner f>
In Example 1, a toner f was obtained in the same manner as in Example 1, except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A3.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
Since the difference between the acid value of the acrylic resin fine particles and the acid value of the resin of the core particles is larger than that of the toner a, the adhesion of the acrylic resin fine particles is strong, and the problems can be sufficiently achieved in the transfer efficiency and the minimum fixing temperature. It was.

(Example 7)
<Manufacture of toner g>
A toner g was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A4.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the volume average particle size of the styrene-acrylic resin fine particles, the coverage of the styrene-acrylic resin fine particles has increased, so the lower limit of the fixing temperature is slightly inferior to that of the toner a, but the transfer efficiency is not sufficient. It was achievable.

(Example 8)
<Manufacture of toner h>
In Example 1, a toner h was obtained in the same manner as in Example 1, except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A5.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the volume average particle size of the styrene-acrylic resin fine particles, the coverage of the styrene-acrylic resin fine particles is reduced, so that the transfer efficiency is slightly inferior to that of the toner a. It was achievable.

Example 9
<Manufacture of toner i>
A toner i was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A6.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the pH of the styrene-acrylic resin fine particle aqueous dispersion, agglomeration occurred when added to the aqueous medium phase. It was confirmed by an optical microscope that the aggregates were loosened when stirred at 8,000 rpm and could be dispersed in small aggregates of several μm. As a result, the transfer efficiency and the lower limit fixing temperature of the toner i are at the same level as the toner a, and the problem can be sufficiently achieved.

(Example 10)
<Manufacture of toner j>
In Example 1, a toner j was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A7.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the pH of the styrene-acrylic resin fine particle aqueous dispersion, aggregation when added to the aqueous medium phase was suppressed, and a desired shell layer was easily formed. Accordingly, the transfer efficiency and the lower limit fixing temperature of toner j are at the same level as toner a, and the problem can be sufficiently achieved.

(Example 11)
<Manufacture of toner k>
In Example 1, a toner k was obtained in the same manner as in Example 1, except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A8.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the electrical conductivity of the styrene-acrylic resin fine particle aqueous dispersion, agglomeration occurred when added to the aqueous medium phase. It was confirmed by an optical microscope that the aggregates were loosened when stirred at a rotational speed of 8,000 rpm and could be dispersed in small aggregates of several μm. As a result, the transfer efficiency and the lower limit fixing temperature of toner k are equivalent to those of toner a, and the problem can be sufficiently achieved.

(Example 12)
<Manufacture of toner 1>
In Example 1, a toner 1 was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A9.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the electrical conductivity of the styrene-acrylic resin fine particle aqueous dispersion, aggregation when added to the aqueous medium phase was suppressed, and a desired shell layer was easily formed. As a result, the transfer efficiency and the lower limit fixing temperature of the toner 1 are the same as those of the toner a, and the problem can be sufficiently achieved.

(Example 13)
<Manufacture of toner m>
In Example 1, a toner m was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B5.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the acid value of the acrylic resin fine particles, the difference between the acid value of the core particles with the unmodified polyester resin and the acid value of the styrene-acrylic resin fine particles become large, and the acrylic resin fine particles of the unmodified polyester resin The adhesion to became stronger. The problems can be sufficiently achieved in the transfer efficiency and the minimum fixing temperature.

(Example 14)
<Manufacture of toner n>
In Example 1, a toner n was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B6.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the acid value of the acrylic resin fine particles, the difference between the acid value of the core particles with the unmodified polyester resin and the acid value of the styrene-acrylic resin fine particles are reduced, and the acrylic resin fine particles of the unmodified polyester resin are reduced. However, although the transfer efficiency was inferior to that of the toner a, the problem could be sufficiently achieved at the minimum fixing temperature.

(Example 15)
<Manufacture of toner o>
In Example 1, a toner o was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B7.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the volume average particle size of the acrylic resin fine particles, the coverage of the acrylic resin fine particles is increased, so that the lower limit of the fixing temperature is slightly inferior to that of the toner a, but the transfer efficiency can sufficiently achieve the problem. there were.

(Example 16)
<Manufacture of toner p>
In Example 1, a toner p was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B8.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the volume average particle size, the coverage of the acrylic resin fine particles was lowered, so that the transfer efficiency was slightly inferior to that of the toner a, but the fixing minimum temperature could sufficiently achieve the problem.

(Example 17)
<Manufacture of toner q>
A toner q was obtained in the same manner as in Example 1 except that the acrylic resin fine particle water dispersion B1 was replaced with the acrylic resin fine particle water dispersion B9 in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the pH of the acrylic resin fine particle aqueous dispersion, aggregation occurred when added to the aqueous medium phase. The aqueous medium phase was rotated at a rotational speed of 8, using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). It was confirmed by an optical microscope that the aggregates were loosened when stirred at 000 rpm and could be dispersed in small aggregates of several μm. As a result, the transfer efficiency and the lower limit fixing temperature of toner q are equivalent to those of toner a, and the problem can be sufficiently achieved.

(Example 18)
<Manufacture of toner r>
In Example 1, a toner r was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B10.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the pH of the acrylic resin fine particle aqueous dispersion, aggregation when added to the aqueous medium phase was suppressed, and a desired shell layer was easily formed. Thus, the transfer efficiency and the lower limit fixing temperature of the toner r are at the same level as the toner a, and the problem can be sufficiently achieved.

(Example 19)
<Manufacture of toner s>
In Example 1, a toner s was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B11.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the electrical conductivity of the acrylic resin fine particle aqueous dispersion, agglomeration occurred when added to the aqueous medium phase. The aqueous medium phase was rotated using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.). It was confirmed by an optical microscope that the aggregates were loosened when stirred at 8,000 rpm and could be dispersed in small aggregates of several μm. Accordingly, the transfer efficiency and the lower limit fixing temperature of the toner s are at the same level as those of the toner a, and the problem can be sufficiently achieved.

(Example 20)
<Manufacture of toner t>
A toner t was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B12 in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the electrical conductivity of the acrylic resin fine particle aqueous dispersion, aggregation when added to the aqueous medium phase was suppressed, and a desired shell layer was easily formed. Accordingly, the transfer efficiency and the lower limit fixing temperature of the toner t are at the same level as the toner a, and the problem can be sufficiently achieved.

(Example 21)
<Manufacture of toner u>
A toner u was obtained in the same manner as in Example 1 except that the unmodified polyester resin 1 was replaced with the unmodified polyester resin 2 in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By lowering the acid value of the unmodified polyester resin, the difference in acid value with the acrylic resin fine particles present on the outer side is reduced, and the adhesion of the acrylic resin fine particles to the polyester resin is weakened. Although it was inferior to the above, the problem could be sufficiently achieved in both the upper and lower fixing temperatures.

(Example 22)
<Manufacture of toner v>
A toner v was obtained in the same manner as in Example 1 except that the unmodified polyester resin 1 was replaced with the unmodified polyester resin 3 in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the acid value of the unmodified polyester resin, the difference in acid value with the acrylic resin present on the outer side increased, and the adhesion of the resin fine particles to the polyester resin became stronger. The problems could be sufficiently achieved in both the transfer efficiency and the fixing upper and lower limit temperatures.

(Example 23)
<Manufacture of toner w>
In Example 1, toner w was obtained in the same manner as in Example 1 except that the amount of the acrylic resin fine particle dispersion B1 was changed from 50 parts by mass to 75 parts by mass.
The content of the acrylic resin fine particles in the toner w (content of the shell layer) was 6.0% by mass.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the content of the acrylic resin fine particles, the thickness of the shell layer was increased and the low-temperature fixability was slightly inferior, but it was at a level that could sufficiently achieve the problem. Further, the storage stability was superior to that of Example 1.

(Example 24)
<Manufacture of toner x>
In Example 1, toner x was obtained in the same manner as in Example 1 except that the amount of the acrylic resin fine particle dispersion B1 was changed from 50 parts by mass to 25 parts by mass.
The content of the acrylic resin fine particles in the toner x (the content of the shell layer) was 2.0% by mass.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the content of the acrylic resin fine particles, the thickness of the shell layer was reduced and the storage stability was slightly inferior, but it was at a level that could sufficiently achieve the problem. Further, the low-temperature fixability was superior to that of Example 1.

(Example 25)
<Manufacture of toner y>
In Example 1, a toner y was obtained in the same manner as in Example 1 except that the amount of the styrene-acrylic resin fine particle dispersion A1 was changed from 25 parts by mass to 50 parts by mass.
The content of styrene-acrylic resin fine particles in the toner y was 4.0% by mass.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By increasing the content of the styrene-acrylic resin fine particles, the granulation property and the low-temperature fixability were slightly inferior, but were at a level at which the problem could be sufficiently achieved. Further, the storage stability was superior to that of Example 1.

(Example 26)
<Manufacture of toner z>
In Example 1, a toner z was obtained in the same manner as in Example 1 except that the amount of the styrene-acrylic resin fine particle dispersion A1 was changed from 25 parts by mass to 15 parts by mass.
The content of styrene-acrylic resin fine particles in the toner z was 1.2% by mass.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By reducing the content of the styrene-acrylic resin fine particles, the granulation property and storage stability were slightly inferior, but it was at a level at which the problem could be sufficiently achieved. Further, the low-temperature fixability was superior to that of Example 1.

(Comparative Example 1)
<Manufacture of toner a '>
In Example 1, a toner a ′ was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A10.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
Since the difference between the acid value of the acrylic resin fine particles and the acid value of the resin of the core particles is remarkably smaller than that of the toner a, the acrylic resin fine particles are not sufficiently adhered to the core particles, and the granulation property is remarkably deteriorated. I couldn't.

(Comparative Example 2)
<Manufacture of toner b '>
In Example 1, a toner b ′ was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A11.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the volume average particle size of the styrene-acrylic resin fine particles, the styrene-acrylic resin fine particles did not sufficiently adhere to the toner surface, and the granulation property was significantly deteriorated, so that the toner could not be formed. .

(Comparative Example 3)
<Manufacture of toner c '>
In Example 1, a toner c ′ was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A12.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly lowering the pH of the styrene-acrylic resin fine particle aqueous dispersion, aggregation was significant when added to the aqueous medium phase, and toner could not be formed.

(Comparative Example 4)
<Manufacture of toner d '>
In Example 1, a toner d ′ was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A13.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
When the pH of the styrene-acrylic resin fine particle aqueous dispersion was remarkably increased, the aqueous dispersion was not stable, and aggregates were formed before the addition to the aqueous medium phase, making it impossible to form a toner.

(Comparative Example 5)
<Manufacture of toner e '>
In Example 1, a toner e ′ was obtained in the same manner as in Example 1, except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A14.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly lowering the electrical conductivity of the styrene-acrylic resin fine particle aqueous dispersion, it is not stable as an aqueous dispersion, and aggregates are formed at the stage prior to addition to the aqueous medium phase and cannot be converted into a toner. It was.

(Comparative Example 6)
<Manufacture of toner f '>
In Example 1, a toner f ′ was obtained in the same manner as in Example 1 except that the styrene-acrylic resin fine particle aqueous dispersion A1 was replaced with the styrene-acrylic resin fine particle aqueous dispersion A15.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the electrical conductivity of the styrene-acrylic resin fine particle aqueous dispersion, it is not stable as an aqueous dispersion, and aggregates are formed at the stage prior to addition to the aqueous medium phase, and cannot be converted into a toner. It was.

(Comparative Example 7)
<Manufacture of toner g '>
In Example 1, a toner g ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B13.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the acid value of the acrylic resin fine particles, the difference in acid value from the polyester resin present on the inner side is reduced, so that the acrylic resin fine particles do not adhere sufficiently to the toner surface, resulting in an improvement in transfer efficiency. I couldn't. The upper and lower fixing temperatures were sufficient to achieve the task.
Further, scanning electron micrographs of the obtained toner base particles are shown in FIGS. 11A and 11B. In the toner base particles 5 shown in FIGS. 11A and 11B, acrylic resin fine particles (white portions) are aggregated and adhered around the core particles 4, and no shell layer is formed. Reference numeral 3 denotes styrene-acrylic resin fine particles.

(Comparative Example 8)
<Manufacture of toner h '>
In Example 1, a toner h ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B14.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By making the volume average particle size of the acrylic resin fine particles remarkably large, the acrylic resin fine particles did not sufficiently adhere to the toner surface, and the granulation property was remarkably deteriorated, so that the toner could not be formed.

(Comparative Example 9)
<Manufacture of toner i '>
In Example 1, a toner i ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B15.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly lowering the pH of the acrylic resin fine particle aqueous dispersion, aggregation becomes significant when added to the aqueous medium phase, and a uniform shell layer cannot be formed on the toner surface, resulting in an improvement in transfer efficiency. There wasn't. The upper and lower fixing temperatures were sufficient to achieve the task.

(Comparative Example 10)
<Manufacture of toner j '>
In Example 1, a toner j ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B16.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the pH of the acrylic resin fine particle aqueous dispersion, it was not stable as an aqueous dispersion, and aggregates were formed before addition to the aqueous medium phase, so a uniform shell layer could not be formed. The effect of improving the transfer efficiency was not obtained. The upper and lower fixing temperatures were sufficient to achieve the task.

(Comparative Example 11)
<Manufacture of toner k '>
In Example 1, a toner k ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B17.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly lowering the electrical conductivity of the acrylic resin fine particle aqueous dispersion, agglomeration becomes significant when added to the aqueous medium phase, a uniform shell layer cannot be formed on the toner surface, and the transfer efficiency is improved. It was not obtained. The upper and lower fixing temperatures were sufficient to achieve the task.

(Comparative Example 12)
<Production of Toner l '>
In Example 1, a toner l ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B18.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the electrical conductivity of the acrylic resin fine particle aqueous dispersion, it was not stable as an aqueous dispersion, and aggregates were formed before addition to the aqueous medium phase, so a uniform shell layer could be formed. The transfer efficiency could not be improved. The upper and lower fixing temperatures were sufficient to achieve the task.

(Comparative Example 13)
<Manufacture of toner m '>
A toner m ′ was obtained in the same manner as in Example 1 except that the unmodified polyester resin 1 was replaced with the unmodified polyester resin 4 (acid value was 5 mg KOH / g).
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly lowering the acid value of the unmodified polyester resin, the difference in acid value with the acrylic resin present on the outer side becomes smaller, the acrylic resin fine particles do not adhere sufficiently to the polyester resin, and the granulation property The toner deteriorated significantly and could not be converted into toner.

(Comparative Example 14)
<Manufacture of toner n '>
In Example 1, a toner n ′ was obtained in the same manner as in Example 1 except that the unmodified polyester resin 1 was replaced with the unmodified polyester resin 5 (acid value: 50 mgKOH / g).
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
When the acid value of the unmodified polyester resin was remarkably increased, the granulation property was deteriorated and the toner could not be formed.

(Comparative Example 15)
<Manufacture of toner o '>
A toner o ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particles were not used in Example 1.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
The minimum fixing temperature was sufficient to achieve the problem, but the effect of improving transfer efficiency was not obtained.

(Comparative Example 16)
<Manufacture of toner p '>
In Example 1, a toner P ′ was obtained in the same manner as in Example 1 except that styrene-acrylic resin fine particles were not used.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By not using the styrene-acrylic resin fine particles, the granulation property was remarkably deteriorated and could not be converted into a toner.

(Comparative Example 17)
<Manufacture of toner q '>
In Example 1, a toner q ′ was obtained in the same manner as in Example 1 except that the acrylic resin fine particle aqueous dispersion B1 was replaced with the acrylic resin fine particle aqueous dispersion B19.
The obtained toner was evaluated in the same manner as in Example 1. The results are shown in Table 7.
By significantly increasing the pH of the acrylic resin fine particle aqueous dispersion, it was not stable as an aqueous dispersion, and aggregates were formed before addition to the aqueous medium phase, so a uniform shell layer could not be formed. The effect of improving the transfer efficiency was not obtained. The upper and lower fixing temperatures were sufficient to achieve the task.

  Table 4 shows the physical properties of the styrene-acrylic resin fine particle aqueous dispersion A used in Examples 1 to 26 and Comparative Examples 1 to 17.

  Table 5 shows the physical properties of the acrylic resin fine particle aqueous dispersion B used in Examples 1 to 26 and Comparative Examples 1 to 17.

Table 6 shows the results of the uniformity and granulation property of the resin fine particles in the toners of Examples 1 to 26 and Comparative Examples 1 to 17.
In addition, the evaluation method of uniformity and granulation property is shown below.

<Uniformity of styrene-acrylic resin fine particles>
The cross section of the toner was observed and evaluated according to the following evaluation criteria.
A: A layer of styrene-acrylic resin fine particles is uniformly formed. ○: An agglomerate is present slightly, but a layer of styrene-acrylic resin fine particles is formed almost uniformly. There is unevenness and the uniformity of the layer made of styrene-acrylic resin fine particles is inferior. ×: The layer made of styrene-acrylic resin fine particles is not formed at all.

<Uniformity of acrylic resin fine particles>
The cross section of the toner was observed and evaluated according to the following evaluation criteria.
◎: Shell layer is uniformly formed ○: Some aggregates are present, but shell layers are formed almost uniformly △: Many aggregates are present or uneven, and the shell layer is uniform Inferior ×: Shell layer is not formed at all

<Granulation>
The toner was produced under the same granulation conditions as those for producing the toner a having a volume average particle diameter of 5.2 μm, and evaluated according to the following evaluation criteria.
A: The volume average particle diameter of the toner is within 5.2 ± 0.1 μm (5.1 μm to 5.3 μm), and the granulation property is very good. ○: The volume average particle diameter of the toner is 5.2. It exceeds ± 0.1 μm and is within 0.3 μm (4.9 μm or more and less than 5.1 μm or more than 5.3 μm and 5.5 μm or less), and the granulation property is good.
Δ: The volume average particle size of the toner is more than 5.2 ± 0.3 μm and within 0.5 μm (4.7 μm or more and less than 4.9 μm or more than 5.5 μm and 5.7 μm or less), and the granulation property is Somewhat inferior.
X: The volume average particle diameter of the toner exceeds 5.2 ± 0.5 μm (less than 4.7 μm or exceeds 5.7 μm), or the granulation property is inferior or not granulated.

In the table, “*” indicates that evaluation could not be performed because granulation could not be performed.

In addition, "-" in a table | surface shows that it was not able to evaluate since it could not be granulated.

DESCRIPTION OF SYMBOLS 1 Toner 2 Shell layer 3 Styrene-acryl resin fine particle 4 Core particle 5 Toner base particle 50 Intermediate transfer body 51 Roller 52 Manual feed tray 53 Manual feed path 55 Switching claw 56 Discharge roller 57 Discharge tray 58 Corona charger 59 Charger 60 Cleaning Equipment (cleaning blade)
61 Developing Device 62 Transfer Charging Device 63 Photoconductor Cleaning Device 64 Static Eliminator 70 Static Eliminating Lamp 80 Transfer Roller 90 Cleaning Device 95 Recording Paper 100, 100A, 100B, 100C Image Forming Device 110 Belt Type Fixing Device 120 Tandem Type Developer 120Bk, 120C , 120M, 120Y Image writing unit 130 Document table 130Bk, 130C, 130M, 130Y Image forming unit 140 Paper feed unit 142a, 142b Paper feed roller 143 Paper bank 144 Paper feed cassette 145a, 145b Separation roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copying device main body 200 Paper feed table 200Bk, 200C, 200M, 200Y Developing device 215Bk, 215C, 215M, 215Y Charging device 220 Intermediate transfer belt 230Bk 230C, 230M, 230Y Primary transfer device 241, 242, 243 Conductive roller 300 Scanner 300Bk, 300C, 300M, 300Y Cleaning device 400 Automatic document feeder 500 Roller charging device 501 Charging roller 502 Core metal 503 Conductive rubber layer 505 Photosensitive Body 510 brush type charging device 511 fur brush roller 513 brush unit 514 power source 515 photoconductor 600 developing device 601 developing sleeve 602 power source 603 developing unit 604 photoconductor 605 toner 700 fixing device 710 heating roller 720 fixing roller 730 endless belt-like fixing belt 731 Base 732 Heat generation layer 733 Intermediate layer 734 Release layer 740 Pressure roller 741 Core metal 742 Elastic member 760 Induction heating means 761 Excitation coil 762 Coil guide plate 763 Excitation coil core 764 Excitation coil core support member 770 Recording medium 800 Process cartridge 801 Photoconductor 802 Charging means 803 Development means 804 Developer 805 Development roller 806 Cleaning means

Japanese Patent Application Laid-Open No. 07-209952 JP 2000-077551 Japanese Patent No. 3640918 Japanese Patent Laid-Open No. 06-250439 JP 2001-0666820 A Japanese Patent No. 3692929 JP 2006-293273 A

Claims (7)

Core particles containing a binder resin;
A shell layer formed of acrylic resin fine particles on the surface of the core particles;
Styrene-acrylic resin fine particles are present outside the shell layer,
The acid value of the styrene-acrylic resin fine particles is 150 mgKOH / g to 250 mgKOH / g,
The volume average particle diameter of the styrene-acrylic resin fine particles is 10 nm to 50 nm,
The acid value of the acrylic resin fine particles is 0 mgKOH / g to 20 mgKOH / g,
The volume average particle diameter of the acrylic resin fine particles is 30 nm to 200 nm,
The binder resin contains an unmodified polyester resin having an acid value of 10 mgKOH / g to 30 mgKOH / g,
The ζ potential (X) of the 10% by mass aqueous dispersion of the acrylic resin fine particles satisfies the following formula (1):
A toner wherein the ζ potential (Y) of a 10% by mass aqueous dispersion of styrene-acrylic resin fine particles satisfies the following formula (2).
−90 mV ≦ ζ potential (X) ≦ −60 mV (1)
−60 mV ≦ ζ potential (Y) ≦ −30 mV (2)   The toner according to claim 1, wherein the binder resin contains an unmodified polyester resin having an acid value of 10 mgKOH / g to 17 mgKOH / g.   The toner according to claim 1, wherein the acrylic resin fine particles are resin fine particles of a crosslinked resin containing at least one of acrylic acid ester and methacrylic acid ester as a constituent component and not containing styrene as a constituent component. A step of preparing an oil phase in which at least a binder resin is dissolved or dispersed in an organic solvent, a step of preparing an aqueous phase containing styrene-acrylic resin fine particles, and dispersing the oil phase in the aqueous phase. A method for producing a toner, comprising a step of preparing an emulsification or dispersion, and a step of removing an organic solvent contained in the emulsification or dispersion.
In the step of preparing the emulsification or dispersion, when the oil phase is dispersed in the water phase , the water phase contains acrylic resin fine particles,
The formed toner has core particles containing the binder resin, a shell layer formed of the acrylic resin fine particles on the surface of the core particles, and the styrene-acrylic resin fine particles outside the shell layer. ,
The binder resin contains an unmodified polyester resin having an acid value of 10 mgKOH / g to 30 mgKOH / g,
The volume average particle size of the styrene-acrylic resin fine particles is 10 nm to 50 nm, the acid value is 150 mgKOH / g to 250 mgKOH / g,
The pH of the 10% by mass aqueous dispersion of the styrene-acrylic resin fine particles is 2.0 to 4.0, and the electrical conductivity is 0.5 mS / cm to 1.5 mS / cm,
The volume average particle diameter of the acrylic resin fine particles is 30 nm to 200 nm, the acid value is 0 mgKOH / g to 20 mgKOH / g,
The pH of a 10% by mass aqueous dispersion of the acrylic resin fine particles is 1.5 to 4.0, and the electrical conductivity is 1.0 mS / cm to 2.5 mS / cm. Production method.   The method for producing a toner according to claim 4, wherein the pH of the 10% by mass aqueous dispersion of the acrylic resin fine particles is 1.5 to 3.4. A charging step for charging the surface of the electrophotographic photosensitive member; an exposure step for exposing the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the electrophotographic photosensitive member; and a step formed on the electrophotographic photosensitive member. A developing process for developing the electrostatic latent image with toner to form a toner image, a primary transfer process for transferring the toner image onto an intermediate transfer member, and a toner image transferred to the intermediate transfer member on a recording medium. A secondary transfer step of transferring, and a cleaning step of removing toner remaining on the surface of the electrophotographic photosensitive member,
The full-color image forming method, wherein the toner is the toner according to claim 1. A process cartridge having at least an electrophotographic photosensitive member and developing means for developing an electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and detachable from the image forming apparatus. ,
The process cartridge according to claim 1, wherein the toner is the toner according to claim 1.