JP6987655B2 - toner - Google Patents

Description

The present invention relates to toner used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and a toner jet method.

In recent years, there has been a demand for higher speed, higher image quality, and lower running cost of the electrophotographic method. Therefore, it is necessary to use a highly durable drum with a suppressed scraping rate as the photosensitive drum, and a more stable cleaning system is required accordingly.
When a high-durability drum is used, the cleaning property becomes strict because the surface of the photosensitive drum is not refreshed, so that the discharge product is not removed and the friction coefficient increases. Therefore, the cleaning blade becomes unstable and the toner easily slips through. In addition, the adhesiveness of the drum surface increases, and it becomes difficult for the toner to be completely scraped off by the cleaning blade portion, and cleaning defects are likely to occur.
In order to improve this, it has been proposed to use an inorganic fine powder of perovskite-type crystals having a substantially cubic and / or rectangular parallelepiped particle shape as an external additive for the toner (Patent Document 1). According to this, since the particle shape is roughly a cube and / or a rectangular parallelepiped, the contact area with the surface of the photosensitive drum can be increased, excellent abrasiveness can be exhibited, and discharge products can be effectively removed.
However, in recent years, as the image quality has been improved, it has become necessary to reduce the particle size and increase the circularity of the toner, and more stable cleaning performance is required.

Japanese Unexamined Patent Publication No. 2010-21124

An object of the present invention is to provide a toner that solves the above problems. Specifically, it is to provide a toner that can obtain excellent cleaning property for a long period of time even in a recent electrophotographic system having strict cleaning property.

The present invention is a toner having toner particles containing a binder resin and a colorant, and strontium titanate particles.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner before the toner is washed with water, the peak A1 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B1 that exists in the range of 80 nm or more and 300 nm or less.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner after the toner is washed with water, the peak A2 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B2 that exists in the range of 80 nm or more and 300 nm or less.
When the height of the peak A1 is HA1, the height of the peak A2 is HA2, the height of the peak B1 is HB1, and the height of the peak B2 is HB2.
70 ≦ (HA2 / HA1) × 100 ≦ 90
20 ≦ (HB2 / HB1) × 100 ≦ 50
With respect to toner characterized by satisfying.

According to the present invention, it is possible to provide a toner that can stably obtain a high-quality image by realizing excellent cleaning properties even after long-term use.

It is a schematic diagram of the apparatus suitable for the surface treatment of toner particles.

Hereinafter, embodiments for carrying out the present invention will be described in detail.

The toner of the present invention is a toner having toner particles containing a binder resin and a colorant, and strontium titanate particles.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner before the toner is washed with water, the peak A1 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B1 that exists in the range of 80 nm or more and 300 nm or less.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner after the toner is washed with water, the peak A2 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B2 that exists in the range of 80 nm or more and 300 nm or less.
When the height of the peak A1 is HA1, the height of the peak A2 is HA2, the height of the peak B1 is HB1, and the height of the peak B2 is HB2.
70 ≦ (HA2 / HA1) × 100 ≦ 90
20 ≦ (HB2 / HB1) × 100 ≦ 50
It is characterized by satisfying.

By using such a toner of the present invention, stable cleaning performance can be exhibited from beginning to end even in a situation where cleaning is severe, which is the problem.

The present inventors presume the mechanism by which this effect is exhibited as follows.

We believe that strontium titanate particles can alleviate local charge concentration due to the dielectric constant and volume resistivity peculiar to the material. Silica particles are generally added to the surface of the toner to impart charge or fluidity, but the silica particles have a high resistance and have a characteristic of accumulating charges. Then, it becomes easy to form a place where the electric charge is locally concentrated, the electrostatic adhesive force increases, and it becomes difficult to peel it off from the surface of the photosensitive drum. This also applies to the surface of the toner base, and if the surface of the toner base has a local charge, the base itself has a high resistance, so that the charge is stored and the adhesive force is increased. However, when strontium titanate intervenes in this charge concentration portion, charge transfer is performed by the action of its dielectric constant and volume resistivity, and charge concentration is suppressed.

In order to effectively exhibit this effect, strontium titanate particles are preferably finely dispersed, and for that purpose, the particle size is preferably 10 nm or more and 60 nm or less. It is considered that a retention layer due to toner exists downstream of the nip portion of the cleaning blade, and that the toner circulates there, the toner rubs against each other, and the charge concentration due to the strontium titanate particles is relaxed. At the same time, it is thought that the charge on the surface of the photosensitive drum will be relaxed. Further, in order to effectively exhibit the action, it is necessary that the strontium titanate particles having a particle size of 10 nm or more and 60 nm or less are firmly attached to the toner surface. If it seems that the toner is easily peeled off from the toner surface at the retention layer portion, the above-mentioned action and effect cannot be expected. Therefore, the relationship between the height HA1 of the peak A1 having a particle size in the range of 10 nm or more and 60 nm or less before the washing with water and the height HA2 of the peak A2 after washing with water is 70 ≦ (HA2 / HA1) × 100 ≦ 90. There must be. If it is less than 70, it will be separated from the toner surface and the expected charge concentration will not be relaxed. On the contrary, when it exceeds 90, since it is necessary to adhere the strontium titanate particles considerably strongly, it may be embedded from the beginning and may be embedded too much with low printing durability, and the above-mentioned effect may not be exhibited.

On the other hand, the action of strontium titanate having a particle size of 80 nm or more and 300 nm or less is derived by the presence of a blocking layer mainly composed of an external additive downstream of the cleaning blade. It has been experimentally found that strontium titanate particles have the effect of adsorbing discharge products and removing the discharge products on the surface of the photosensitive drum. For that purpose, it is necessary to have a large amount in the blocking layer portion, and the particle size is preferably 80 nm or more and 300 nm. If it is less than 80 nm, the probability of slipping through the cleaning blade increases, and the amount of accumulation in the blocking layer portion decreases. Further, by setting the particle size to 80 nm or more and 300 nm, the polishing power is also exhibited, and the effect of removing the discharge product is also exhibited. On the contrary, if it exceeds 300 nm, the polishing force becomes too strong and the surface of the photosensitive drum may be scratched. Since strontium titanate particles having a particle size of 80 nm or more and 300 nm or less are expected to have polishing power, it is preferable that the particle shape is roughly a cube and / or a rectangular parallelepiped. Further, strontium titanate having a particle size of 80 nm or more and 300 nm or less needs to be in a state of being easily separated from the toner surface to some extent. Therefore, the relationship between the height HB1 of the peak B1 having a particle size in the range of 80 nm or more and 300 nm or less before the washing with water and the height HB2 of the peak B2 after washing with water is 20 ≦ (HB2 / HB1) × 100 ≦ 50. There must be. If it exceeds 50, the number of strontium titanate particles peeled off from the toner surface is reduced and the particles do not sufficiently accumulate in the blocking layer. On the other hand, if it is less than 20, the toner is peeled off too much from the surface of the toner, and the toner is lost because it adheres to the developing carrier before reaching the cleaning nip.

The dielectric constant of the strontium titanate particles is preferably 25 pF / m or more and 100 pF / m or less, and the volume resistivity is preferably 2.0 × 10 ⁹ Ω · cm or more and 2.0 × 10 ¹² Ω · cm or less. By setting it in this range, a better effect can be expected.

The content of the strontium titanate particles A having a particle size of 10 nm or more and 60 nm or less in the toner is preferably 0.5% by mass or more and 20.0% by mass or less. Within this range, an excellent charge mitigation effect can be obtained. If it exceeds 20% by mass, it is not preferable because it causes adverse effects such as deterioration of fixability and contamination of members.

The content of the strontium titanate particles B having a particle size of 80 nm or more and 300 nm or less in the toner is preferably 0.1% by mass or more and 15.0% by mass or less. Within this range, excellent adsorption / polishing action is exhibited. If it exceeds 15% by mass, it is not preferable because it causes adverse effects such as deterioration of fixability and contamination of members.

[Strontium titanate particles]
The strontium titanate particles of the present invention can be obtained, for example, by a normal pressure heating reaction method. At this time, a mineral acid deflated product of a hydrolyzate of the titanium compound is used as the titanium oxide source, and a water-soluble acidic strontium compound is used as the strontium oxide source. It can be produced by a method of reacting the mixed solution with an alkaline aqueous solution at 60 ° C. or higher while adding an alkaline aqueous solution, and then treating with an acid.

(Atmospheric pressure heating reaction method)
As the titanium oxide source, a mineral acid defoliated product of a hydrolyzate of a titanium compound is used. _{Preferably, metatitanic acid having an SO 3} content of 1.0% by mass or less, preferably 0.5% by mass or less obtained by the sulfuric acid method is solved by adjusting the pH to 0.8 to 1.5 with hydrochloric acid. A glued one can be used. If the SO ₃ content in metatitanic acid exceeds 1.0% by mass, gluing does not proceed, which is not preferable.

As the strontium oxide source, metal nitrate, hydrochloride and the like can be used, and for example, strontium nitrate and strontium chloride can be used. As the alkaline aqueous solution, caustic alkali can be used, but the sodium hydroxide aqueous solution is particularly preferable.

Factors that affect the particle size of the obtained strontium titanate particles in the above-mentioned production method include the mixing ratio of the titanium oxide source and the strontium oxide source at the time of the reaction, the concentration of the titanium oxide source at the initial stage of the reaction, and the addition of an alkaline aqueous solution. The temperature and the addition rate of the above can be mentioned, and can be appropriately adjusted in order to obtain the desired particle size and particle size distribution. In addition, it is preferable to prevent the mixing of carbon dioxide gas by reacting in a nitrogen gas atmosphere in order to prevent the formation of carbon dioxide in the reaction process.

In the above-mentioned production method, factors that affect the dielectric constant of the obtained strontium titanate particles include conditions / operations that disrupt the particle crystallinity. In particular, in order to obtain particles having a low dielectric constant even with strontium titanate as in the present invention, it is preferable to perform an operation of giving energy that disturbs crystal growth in a state where the concentration of the reaction solution is increased. As a method, for example, microbubbles with nitrogen may be added to the crystal growth step.

The mixing ratio of the titanium oxide source and the strontium oxide source during the reaction is preferably 0.9 or more and 1.4 or less, and more preferably 1.05 or more and 1.20 or less in _{terms of the molar ratio of SrO / TiO 2.} When the SrO / TiO ₂ molar ratio is 1 or less, not only the metal titanate but also unreacted titanium oxide is likely to remain in the reaction product. Since the strontium oxide source has a relatively high solubility in water, while the titanium oxide source has a low solubility in water, when the SrO / TiO ₂ molar ratio is 1 or less, the reaction product is not only the metal titanate. Unreacted titanium oxide tends to remain. The concentration of the titanium oxide source at the initial stage of the reaction is preferably 0.05 mol / L or more and 1.3 mol / L or less, preferably 0.08 mol / L or more and 1.0 mol / L or less as _{TiO 2.}

When the temperature at which the alkaline aqueous solution is added is 100 ° C. or higher, a pressure vessel such as an autoclave is required, and a practically range of 60 ° C. to 100 ° C. is appropriate. As for the addition rate of the alkaline aqueous solution, the slower the addition rate, the larger the particle size of metal titanate particles can be obtained, and the faster the addition rate, the smaller the metal titanate particle size can be obtained. The appropriate addition rate of the alkaline aqueous solution is 0.001 equivalent / h or more and 1.2 equivalents / h or less, preferably 0.002 equivalents / h or more and 1.1 equivalents / h or less with respect to the charged raw material. It can be adjusted as appropriate according to the particle size.

(Acid treatment)
In the production method of the present invention, it is preferable to further acid-treat the metal titanate particles obtained by the atmospheric heating reaction. _{When the mixing ratio of the titanium oxide source and the strontium oxide source exceeds 1.0 in the molar ratio of SrO / TiO 2} when the titanium acid metal particles are synthesized by performing the atmospheric heating reaction, it remains after the reaction is completed. An unreacted metal source other than titanium reacts with carbon dioxide in the air to generate impurities such as metal carbonate. Further, if impurities such as metal carbonate remain on the surface, the organic surface treatment agent cannot be uniformly coated due to the influence of the impurities when performing the organic surface treatment for imparting hydrophobicity. Therefore, after adding the alkaline aqueous solution, it is preferable to perform acid treatment in order to remove the unreacted metal source.

In the acid treatment, it is preferable to adjust the pH to 2.5 or more and 7.0 or less, more preferably 4.5 or more and 6.0 or less by using hydrochloric acid. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. It is not preferable to use sulfuric acid because metal sulfate having low solubility in water is generated.

For mixing the toner particles and the strontium titanate particles, known mixers such as Henshell mixer, Mechanohybrid (manufactured by Nippon Coke Co., Ltd.), Supermixer, Nobilta (manufactured by Hosokawa Micron Co., Ltd.) can be used, and the apparatus is particularly limited. It's not something.

[Silica particles]
In addition to the strontium titanate particles described above, the toner of the present invention may contain other inorganic fine particles as necessary for adjusting the charge amount and fluidity.

As the inorganic fine particles used in the present invention, conventionally known inorganic fine particles such as titanium oxide, silica, and alumina are used, but silica is preferable. Examples of the silica fine particles include wet silica such as a precipitation method and a sol-gel method, and dry silica such as an explosive combustion method and a fumed method, but dry silica is more preferable because of ease of shape control.

Dry silica is made from a silicon halogen compound or the like. Silicon tetrachloride is used as the silicon halogen compound, but silanes such as methyltrichlorosilane and trichlorosilane can be used alone, or silicon tetrachloride and silanes can be mixed as a raw material.

After the raw material is vaporized, the desired silica is obtained by a so-called flame hydrolysis reaction, which reacts with water generated as an intermediate in an oxyhydrogen flame. For example, it utilizes the pyrolysis oxidation reaction of silicon tetrachloride gas in oxygen and hydrogen, and the reaction formula is as follows.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

Hereinafter, an example of producing the dry silica used in the present invention will be described.

After supplying oxygen gas to the burner and igniting the ignition burner, hydrogen gas was supplied to the burner to form a flame, and silicon tetrachloride, which is a raw material, was added to the burner to gasify it. Next, a flame hydrolysis reaction was carried out, and the produced silica powder was recovered.

The average particle size and shape can be arbitrarily adjusted by appropriately changing the silicon tetrachloride flow rate, oxygen gas supply flow rate, hydrogen gas supply flow rate, and silica residence time in flame.

<Other inorganic fine particles>
The toner of the present invention may further contain inorganic fine particles such as titanium oxide and aluminum oxide, if necessary. The inorganic fine particles may be internally added to the toner particles or may be mixed with the toner particles as an external additive. It is preferable that these inorganic fine particles are used in an amount of 0.1 part by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the toner particles. A known mixer such as a Henschel mixer can be used for mixing the toner particles with other inorganic fine particles.

<Bundling resin>
The binder resin used in the toner of the present invention needs to contain a polyester resin as a main component. The monomers used in the polyester unit of the polyester resin include polyvalent alcohol (divalent or trivalent or higher alcohol), polyvalent carboxylic acid (divalent or trivalent or higher carboxylic acid), its acid anhydride or its lower grade. Alkyl esters are used. Here, when producing a branched polymer, it is effective to partially crosslink in the molecule of the binder resin, and for that purpose, it is preferable to use a polyfunctional compound having a valence of 3 or more. Therefore, it is preferable that the raw material monomer of the polyester unit contains a carboxylic acid having a valence of trivalent or higher, an acid anhydride thereof or a lower alkyl ester thereof, and / or an alcohol having a valence of trivalent or higher.

As the polyhydric alcohol monomer used in the polyester unit of the polyester resin, the following polyhydric alcohol monomers can be used.

The divalent alcohol component includes ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, and 1, 6-Hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydride bisphenol A, bisphenol represented by the formula (A) and derivatives thereof;

（式中、Ｒはエチレンまたはプロピレン基であり、ｘ及びｙはそれぞれ０以上の整数であり、かつ、ｘ＋ｙの平均値は０以上１０以下である。）
式（Ｂ）で示されるジオール類；

(In the formula, R is an ethylene or propylene group, x and y are integers of 0 or more, and the average value of x + y is 0 or more and 10 or less.)
Diols represented by the formula (B);

が挙げられる。

Can be mentioned.

Examples of the trihydric or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. , 1,2,5-pentantriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene Can be mentioned. Of these, glycerol, trimethylolpropane, and pentaerythritol are preferably used. These divalent alcohols and trihydric or higher alcohols can be used alone or in combination of two or more.

The following polyvalent carboxylic acid monomers can be used as the polyvalent carboxylic acid monomer used in the polyester unit of the polyester resin.

Examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebatic acid, azelaic acid and malonic acid. n-dodecenyl 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, anhydrides of these acids and Examples thereof include these lower alkyl esters. Of these, maleic acid, fumaric acid, terephthalic acid, and n-dodecenyl succinic acid are preferably used.

Examples of the trivalent or higher carboxylic acid, its acid anhydride or its lower alkyl ester include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalentricarboxylic acid and 1,2,4-naphthalenetricarboxylic acid. , 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra ( Methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimeric acid, acid anhydrides thereof or lower alkyl esters thereof. Of these, 1,2,4-benzenetricarboxylic acid, that is, trimellitic acid or a derivative thereof is preferably used because it is inexpensive and reaction control is easy. These divalent carboxylic acids and the like and trivalent or higher carboxylic acids can be used alone or in combination of two or more.

If the main component is a polyester resin, a hybrid resin containing another resin component may be used. For example, a hybrid resin of a polyester resin and a vinyl-based resin can be mentioned. As a method for obtaining a reaction product of a vinyl-based resin or a vinyl-based copolymerization unit and a polyester resin such as a hybrid resin, a monomer component capable of reacting with each of the vinyl-based resin, the vinyl-based copolymerization unit and the polyester resin is included. A method of polymerizing one or both of the resins in the presence of the polymer is preferable.

For example, among the monomers constituting the polyester resin component, those capable of reacting with the vinyl-based copolymer include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Be done. Among the monomers constituting the vinyl-based copolymer component, those capable of reacting with the polyester resin component include those having a carboxyl group or a hydroxy group, acrylic acid or methacrylic acid esters.

Further, in the present invention, if the polyester resin is the main component of the binder resin, various resin compounds conventionally known as the binder resin can be used in combination in addition to the vinyl-based resin described above. Examples of such resin compounds include phenol resin, natural resin modified phenol resin, natural resin modified malein resin, acrylic resin, methacrylic resin, polyvinyl acetate resin, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, and epoxy. Examples thereof include resins, xylene resins, polyvinyl butyral, terpene resins, kumaloinden resins, petroleum-based resins and the like.

Further, the peak molecular weight of the binder resin A of the present invention is preferably 5000 or more and 13000 or less from the viewpoint of low temperature fixability and hot offset resistance. Further, the acid value of the binder resin of the present invention is preferably 10 mgKOH / g or less from the viewpoint of charge stability in a high temperature and high humidity environment.

Further, the binder resin of the present invention may be used by mixing the low molecular weight binder resin E and the high molecular weight binder resin D. The content ratio (D / E) of the high molecular weight binder resin D and the low molecular weight binder resin E is 10/90 or more and 60/40 or less on a mass basis from the viewpoint of low temperature fixability and hot offset resistance. Is preferable.

The peak molecular weight of the high molecular weight binder resin D is preferably 10,000 or more and 20,000 or less from the viewpoint of hot offset resistance. Further, the acid value of the high molecular weight binder resin is preferably 15 mgKOH / g or more and 30 mgKOH / g or less from the viewpoint of charge stability in a high temperature and high humidity environment.

The number average molecular weight of the low molecular weight binder resin E is preferably 1500 or more and 3500 or less from the viewpoint of low temperature fixability. Further, the acid value of the low molecular weight binder resin is preferably 10 mgKOH / g or less from the viewpoint of charge stability in a high temperature and high humidity environment.

<Other binding resins>
As the binder resin used for the toner of the present invention, the following polymers other than the above-mentioned binder resin are used for the purpose of improving pigment dispersibility, charge stability and blocking resistance of the toner. It is also possible to add in an amount that does not impair the effect of the invention.

Examples of other resins used for the toner binding resin of the present invention include the following resins. Monopolymers of styrene such as polystyrene, poly-p-chlorstyrene, polyvinyltoluene and its substitution products; styrene-p-chlorstyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene -Acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chlormethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Stylized polymers such as copolymers, styrene-vinyl methyl ketone copolymers, styrene-acrylonitrile-inden copolymers; polyvinyl chloride, phenolic resins, naturally modified phenolic resins, natural resin modified maleic acid resins, acrylic resins , Methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, kumaron-inden resin, petroleum resin and the like.

Further, the following crystalline polyester resin may be added to the toner particles of the present invention for the purpose of promoting the plastic effect of the toner and improving the low temperature fixability.

The crystalline polyester used in the toner of the present invention contains a monomer composition containing, as main components, an aliphatic diol having 2 or more and 22 or less carbon atoms and an aliphatic dicarboxylic acid having 2 or more and 22 or less carbon atoms. Examples are those obtained by conducting a condensation reaction.

The aliphatic diol having 2 or more and 22 or less carbon atoms (more preferably 6 or more and 12 or less carbon atoms) is not particularly limited, but is preferably a chain-like (more preferably linear) aliphatic diol, for example. , Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,4-butadiene glycol, trimethylene glycol, tetramethylene glycol, Examples thereof include pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol and neopentyl glycol. Among these, ethylene glycol, diethylene glycol, 1,4-butanediol, and linear aliphatics such as 1,6-hexanediol, α, ω-diol are preferably exemplified.

Of the above alcohol components, preferably 50% by mass or more, more preferably 70% by mass or more is an alcohol selected from an aliphatic diol having 2 or more and 22 or less carbon atoms.

In the present invention, a polyhydric alcohol monomer other than the above aliphatic diol can also be used. Examples of the dihydric alcohol monomer among the polyhydric alcohol monomers include aromatic alcohols such as polyoxyethylene glycol A and polyoxypropylene glycol A; 1,4-cyclohexanedimethanol and the like. Among the polyhydric alcohol monomers, the trihydric or higher polyhydric alcohol monomer includes aromatic alcohols such as 1,3,5-trihydroxymethylbenzene; pentaerythritol, dipentaerythritol, and tripentaerythritol. , 1,2,4-Butantriol, 1,2,5-Pentantriol, Glycerin, 2-Methylpropantriol, 2-Methyl-1,2,4-Butantriol, Trimethylolethane, Trimethylolpropane and other fats Triol alcohol and the like can be mentioned.

Further, in the present invention, monovalent alcohol may be used to the extent that the characteristics of the crystalline polyester are not impaired. Examples of the monohydric alcohol include monofunctionals such as n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, lauryl alcohol, 2-ethylhexanol, decanol, cyclohexanol, benzyl alcohol, and dodecyl alcohol. Examples include sex alcohol.

On the other hand, the aliphatic dicarboxylic acid having 2 or more and 22 or less carbon atoms (more preferably 6 or more and 12 or less carbon atoms) is not particularly limited, but is a chain (more preferably linear) aliphatic dicarboxylic acid. Is preferable. Specific examples include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, glutaconic acid, azelaic acid, sebacic acid, nonandicarboxylic acid, decandicarboxylic acid, undecandicarboxylic acid, and dodecandicarboxylic acid. Examples thereof include maleic acid, fumaric acid, mesaconic acid, citraconic acid and itaconic acid, and those obtained by hydrolyzing these acid anhydrides or lower alkyl esters are also included.

In the present invention, of the above carboxylic acid components, preferably 50% by mass or more, more preferably 70% by mass or more is a carboxylic acid selected from an aliphatic dicarboxylic acid having 2 or more and 22 or less carbon atoms.

In the present invention, a polyvalent carboxylic acid other than the aliphatic dicarboxylic acid having 2 or more and 22 or less carbon atoms can also be used. Among other polyvalent carboxylic acid monomers, the divalent carboxylic acid includes aromatic carboxylic acids such as isophthalic acid and terephthalic acid; aliphatic carboxylic acids of n-dodecylsuccinic acid and n-dodecenylsuccinic acid; cyclohexanedicarboxylic acids. Examples thereof include alicyclic carboxylic acids such as acids, and these acid anhydrides or lower alkyl esters are also included. Among other carboxylic acid monomers, the trivalent or higher polyvalent carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimeritic acid), 2,5,7-naphthalenetricarboxylic acid, and 1,2. Aromatic carboxylic acids such as 2,4-naphthalenetricarboxylic acid and pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxy-2-methyl-2 Examples thereof include aliphatic carboxylic acids such as methylenecarboxypropane and the like, and derivatives such as acid anhydrides or lower alkyl esters thereof are also included.

Further, in the present invention, a monovalent carboxylic acid may be contained to such an extent that the characteristics of the crystalline polyester are not impaired. Examples of the monovalent carboxylic acid include naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid and dodecanoic acid. Examples include monocarboxylic acids such as stearate.

The crystalline polyester in the present invention can be produced according to a conventional polyester synthetic method. For example, it is desired to carry out an esterification reaction or a transesterification reaction between the carboxylic acid monomer and the alcohol monomer described above, and then carry out a polycondensation reaction under reduced pressure or by introducing nitrogen gas according to a conventional method. Crystalline polyester can be obtained.

The esterification or transesterification reaction can be carried out using a usual esterification catalyst or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate and magnesium acetate, if necessary.

Further, the polycondensation reaction can be carried out using a usual polymerization catalyst, for example, a known catalyst such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide and the like. .. The polymerization temperature and the amount of catalyst are not particularly limited and may be appropriately determined.

In the esterification or transesterification reaction or polycondensation reaction, all the monomers are charged in a batch to increase the strength of the obtained crystalline polyester, or the divalent monomer is first reacted to reduce the low molecular weight component. After that, a method such as adding a monomer having a valence of 3 or more and reacting may be used.

<Colorant>
Examples of the colorant that can be contained in the toner include the following.

Examples of the black colorant include carbon black; a color toned black using a yellow colorant, a magenta colorant, and a cyan colorant. The pigment may be used alone as the colorant, but it is more preferable to improve the sharpness by using the dye and the pigment in combination from the viewpoint of the image quality of the full-color image.

Examples of the magenta toner pigment include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 146, 147, 150, 163, 184, 202, 206, 207, 209, 238, 269, 282; C.I. I. Pigment Violet 19; C.I. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of the magenta toner dye include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121; C.I. I. Disperse thread 9; C.I. I. Solvent Violet 8, 13, 14, 21, 27; C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40; C.I. I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of the cyan toner pigment include the following. C. I. Pigment Blue 2, 3, 15: 2, 15: 3, 15: 4, 16, 17; C.I. I. Bat Blue 6; C.I. I. Acid blue 45, a copper phthalocyanine pigment in which 1 to 5 phthalimide methyl groups are substituted in the phthalocyanine skeleton.

As the dye for cyan toner, C.I. I. There is Solvent Blue 70.

Examples of the pigment for yellow toner include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185; C.I. I. Bat Yellow 1, 3, 20.

Examples of the dye for yellow toner include C.I. I. There is Solvent Yellow 162.

The amount of the colorant used is preferably 0.1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin.

<Developer>
The toner of the present invention can also be used as a one-component developer, but in order to further improve dot reproducibility, it is possible to mix it with a magnetic carrier and use it as a two-component developer for long-term stable images. Is preferable in that

Examples of the magnetic carrier include iron powder whose surface is oxidized, unoxidized iron powder, and metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, chromium, and rare earth. A magnetic material-dispersed resin carrier (so-called resin carrier) containing a magnetic material such as alloy particles, oxide particles, and ferrite, or a magnetic material and a binder resin that holds the magnetic material in a dispersed state, and the like are generally known. You can use things.

When the toner of the present invention is mixed with a magnetic carrier and used as a two-component developer, the carrier mixing ratio at that time is preferably 2% by mass or more and 15% by mass or less as the toner concentration in the two-component developer. When it is 4% by mass or more and 13% by mass or less, good results are usually obtained.

<Manufacturing method>
As a method for producing the toner particles, any conventionally known method such as a melt-kneading method, an emulsification phase inversion method, a suspension polymerization method, and an emulsification / aggregation method may be used. From the viewpoint of finely dispersing the colorant particles in the amorphous resin, a melt-kneading method is preferable in which the binder resin, the resin composition, and the crystalline polyester are melt-kneaded, the kneaded product is cooled, and then pulverized and classified. ..

Hereinafter, the toner manufacturing procedure in the melt-kneading method will be described.

In the raw material mixing step, as materials constituting the toner particles, for example, a binder resin and wax, a colorant, and if necessary, other components such as a charge control agent are weighed and blended in a predetermined amount and mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

Next, the mixed materials are melt-kneaded to disperse wax and the like in the binder resin. In the melt-kneading process, a batch-type kneader such as a pressure kneader or a Bambary mixer or a continuous-type kneader can be used, and a single-screw or twin-screw extruder has become the mainstream because of its superiority in continuous production. ing. For example, KTK type twin-screw extruder (manufactured by Kobe Steel), TEM type twin-screw extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikekai Iron Works), twin-screw extruder (manufactured by Kay-Cee). ), Co-kneader (manufactured by Bus Co., Ltd.), Kneedex (manufactured by Nippon Coke Industries Co., Ltd.), etc. Further, the resin composition obtained by melt-kneading may be rolled with two rolls or the like and cooled with water or the like in the cooling step.

Then, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step. In the crushing process, after coarse crushing with a crusher such as a crusher, a hammer mill, or a feather mill, further, for example, a cryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), a super rotor (manufactured by Nisshin Engineering Co., Ltd.), a turbo mill. (Made by Turbo Industries) or a fine crusher using the air jet method.

After that, if necessary, classification such as inertial classification type elbow jet (manufactured by Nittetsu Mining Co., Ltd.), centrifugal force classification method turboplex (manufactured by Hosokawa Micron), TSP separator (manufactured by Hosokawa Micron), faculty (manufactured by Hosokawa Micron) Classify using a machine or a sieving machine to obtain a classified product (toner particles).

It is preferable that the weight average diameter of the toner particles is 4.0 μm or more and 8.0 μm or less because the effect of the external additive of the present invention can be sufficiently obtained.

Further, the circularity of the toner particles may be increased by applying a mechanical impact force to the particles or performing a heat treatment with hot air or the like. For example, toner can be obtained by performing surface treatment with hot air using the surface treatment apparatus shown in FIG. 1 and classifying the toner as necessary.

The mixture quantitatively supplied by the raw material quantitative supply means 1 is guided to the introduction pipe 3 installed on the vertical line of the raw material supply means by the compressed gas adjusted by the compressed gas adjusting means 2. The mixture that has passed through the introduction pipe is uniformly dispersed by the conical protrusion-shaped member 4 provided in the central portion of the raw material supply means, and is guided to the supply pipe 5 in eight directions spreading radially to perform heat treatment. Guided by.

At this time, the flow of the mixture supplied to the processing chamber is regulated by the regulating means 9 for regulating the flow of the mixture provided in the processing chamber. Therefore, the mixture supplied to the treatment chamber is heat-treated while swirling in the treatment chamber, and then cooled.

The heat for heat-treating the supplied mixture is supplied from the hot air supply means 7, distributed by the distribution member 12, and introduced by spirally swirling the hot air into the processing chamber by the swirling member 13 for swirling the hot air. Will be done. As its configuration, the swirling member 13 for swirling the hot air has a plurality of blades, and the swirling of the hot air can be controlled by the number and the angle thereof. The temperature of the hot air supplied to the processing chamber at the outlet of the hot air supply means 7 is preferably 100 ° C. or higher and 300 ° C. or lower, and more preferably 130 ° C. or higher and 170 ° C. or lower. If the temperature at the outlet of the hot air supply means is within the above range, it is possible to uniformly sphericalize the toner particles while preventing fusion and coalescence of the toner particles due to overheating of the mixture. Become. The circularity at this time is preferably 0.955 or more and 0.980 or less. The hot air is supplied from the hot air supply means outlet 11.

Further, the heat-treated heat-treated toner particles are cooled by the cold air supplied from the cold air supply means 8, and the temperature supplied from the cold air supply means 8 is preferably −20 ° C. to 30 ° C. When the temperature of the cold air is within the above range, the heat-treated toner particles can be efficiently cooled, and the heat-treated toner particles are prevented from being fused or coalesced without impeding the uniform spheroidizing treatment of the mixture. be able to. The absolute water content of the cold air ^{is preferably 0.5 g / m 3} or more and 15.0 g / m ³ or less.

Next, the cooled heat-treated toner particles are recovered by the recovery means 10 at the lower end of the processing chamber. A blower (not shown) is provided at the tip of the collecting means, and the blower is sucked and conveyed by the blower (not shown).

Further, the powder particle supply port 14 is provided so that the swirling direction of the supplied mixture and the swirling direction of the hot air are in the same direction, and the recovery means 10 of the surface treatment device is a swirling powder particle. It is provided on the outer peripheral portion of the processing chamber so as to maintain the turning direction. Further, the cold air supplied from the cold air supply means 8 is configured to be supplied horizontally and tangentially from the outer peripheral portion of the apparatus to the peripheral surface of the processing chamber. The swirling direction of the toner particles before heat treatment supplied from the powder supply port, the swirling direction of the cold air supplied from the cold air supply means, and the swirling direction of the hot air supplied from the hot air supply means are all in the same direction. Therefore, turbulent flow does not occur in the processing chamber, the swirling flow in the apparatus is strengthened, a strong centrifugal force is applied to the toner particles before heat treatment, and the dispersibility of the toner particles before heat treatment is further improved, so that the number of coalesced particles is small. , Heat-treated toner particles having a uniform shape can be obtained.

If necessary, an external additive selected by the above-mentioned production method is added to the toner particles and mixed (externally added). Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauta mixer, a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.) and the like.

The methods for measuring various physical properties of toner and raw materials will be described below.

<Calculation of average particle size of inorganic fine particles>
The number average particle size of the strontium titanate particles and the silica particles is calculated from an image of the toner surface taken by a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation). The image shooting conditions of S-4800 are as follows.

(1) Sample preparation A thin layer of conductive paste is applied to a sample table (aluminum sample table 15 mm x 6 mm), and toner is sprayed on it. Further air blow to remove excess toner from the sample table and allow it to dry sufficiently. Set the sample table on the sample holder and adjust the sample table height to 36 mm with the sample height gauge.

(2) Setting of S-4800 observation conditions The number average diameter is calculated using the image obtained by observing the backscattered electron image of S-4800. When measuring the coverage, elemental analysis is performed in advance by an energy dispersive X-ray analyzer (EDAX), and particles other than silicon compound fine particles on the toner surface are excluded before the measurement. Inject liquid nitrogen into the anti-contamination trap attached to the mirror body of S-4800 until it overflows, and leave it for 30 minutes. Start the "PC-SEM" of S-4800 and perform flushing (cleaning of the FE chip which is an electron source). Click the acceleration voltage display part of the control panel on the screen and press the [Flushing] button to open the flushing execution dialog. Confirm that the flushing intensity is 2, and execute. Confirm that the emission current due to flushing is 20 to 40 μA. Insert the sample holder into the sample chamber of the S-4800 mirror. Press [Origin] on the control panel to move the sample holder to the observation position.

Click the acceleration voltage display to open the HV setting dialog, and set the acceleration voltage to [1.1 kV] and the emission current to [20 μA]. In the [Basic] tab of the operation panel, set the signal selection to [SE], select [Top (U)] and [+ BSE] for the SE detector, and select [+ BSE] in the selection box to the right of [+ BSE]. L. A. 100] is selected to set the mode for observing with a backscattered electron image. Similarly, in the [Basic] tab of the operation panel, set the probe current of the electro-optical system condition block to [Normal], the focal mode to [UHR], and the WD to [4.5 mm]. Press the [ON] button on the acceleration voltage display of the control panel to apply the acceleration voltage.

(3) Focus adjustment Rotate the focus knob [COARSE] on the operation panel and adjust the aperture alignment when the focus is reached to some extent. Click [Align] on the control panel to display the alignment dialog, and select [Beam]. Rotate the STIGMA / ALIGNMENT knobs (X, Y) on the control panel to move the displayed beam to the center of the concentric circles. Next, select [Aperture] and turn the STIGMA / ALIGNMENT knobs (X, Y) one by one to stop the movement of the image or adjust it to the minimum movement. Close the aperture dialog and focus with autofocus. After that, the magnification is set to 80,000 (80k) times, the focus is adjusted using the focus knob and the STIGMA / ALIGNMENT knob in the same manner as above, and the focus is adjusted again by autofocus. Repeat this operation again to focus. Here, if the tilt angle of the observation surface is large, the measurement accuracy of the coverage tends to be low, so by selecting the one that focuses on the entire observation surface at the same time when adjusting the focus, select the one with the least inclination of the surface. And analyze.

(4) Image saving Perform brightness adjustment in ABC mode, take a picture with a size of 640 x 480 pixels, and save it. The following analysis is performed using this image file. One photograph is taken for each toner, and an image is obtained for at least 25 particles of toner.

(5) Image analysis The particle size of at least 500 inorganic fine particles on the toner surface is measured to obtain the number average particle size. In the present invention, the image analysis software Image-Pro Plus ver. Using 5.0, the number average diameter is calculated by binarizing the image obtained by the above method.

<Measurement method of peaks A1, B1, A2, B2 of strontium titanate particles on the toner surface>
Number of primary particles of strontium titanate particles on the toner surface Peaks A1, B1, A2, and B2 in the number distribution of the average particle size were determined by observing the strontium titanate particles on the toner surface. The observation magnification was appropriately adjusted according to the size of the strontium titanate particles, but the major axis of at least 500 strontium titanate particles was measured in a field magnified up to 200,000 times, and the number distribution of the measured major axis (the number distribution of the major axis was measured. When the abundance ratio (number%) is shown on the vertical axis and the particle size is shown on the horizontal axis, the peak having a particle size in the range of 10 nm or more and 60 nm or less is A1, and the peak having a particle size in the range of 80 nm or more and 300 nm or less is B1. And said. A2 and B2 were determined by making similar observations on the toner after washing with water. In addition, HB1 and HB2 were calculated from the number distribution of the inorganic fine particles obtained by observing the toner surface.

<Washing method>
In the present invention, the washing treatment was carried out as follows. Contaminone N (nonionic surfactant, anionic surfactant, organic builder), which is a surfactant, is dissolved in an aqueous solution of sucrose in which 20.7 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) is dissolved in 10.3 g of ion-exchanged water. Neutral detergent for cleaning precision measuring instruments with pH 7 consisting of 6 cc and 30 cc glass vial (for example, VCV-30 manufactured by Nichiden Rika Glass Co., Ltd., outer diameter: 35 mm, height: 70 mm) And mix well to prepare a dispersion. 1.0 g of toner is added to this vial, and the mixture is allowed to stand until the toner naturally settles to prepare a pretreatment dispersion. This dispersion was shaken with a shaker (YS-8D type: manufactured by Yayoi Co., Ltd.) at a shaking speed of 200 rpm for 5 minutes to remove the inorganic fine particles from the surface of the toner particles. The toner in which the inorganic fine particles remain and the desorbed inorganic fine particles are separated by using a centrifuge. The centrifugation step was performed at 3700 rpm for 30 minutes. Toner with residual inorganic fine particles was collected by suction filtration and dried to obtain toner after separation of the inorganic fine particles.

<Measurement of permittivity>
After calibration at frequencies of 1 kHz and 1 MHz using a 284 A precision LCR meter (manufactured by Hewlett-Packard), the complex permittivity at a frequency of 1 MHz was measured. A load of 39200 kPa (400 kg / cm ² ) is applied to the strontium titanate particles to be measured for 5 minutes to form a disk-shaped measurement sample having a diameter of 25 mm and a thickness of 1 mm or less (preferably 0.5 to 0.9 mm). This measurement sample was mounted on ARES (manufactured by Leometric Scientific FE) equipped with a permittivity measuring jig (electrode) having a diameter of 25 mm, and 0.49 N (50 g) in an atmosphere at a temperature of 25 ° C. It is obtained by measuring at a frequency of 1 MHz under the load of.

<Measurement of volume resistivity>
The volume resistivity of the strontium titanate particles is measured as follows. As a device, a 6517 type electrometer / high resistance system manufactured by Keithley Instruments is used. An electrode having a diameter of 25 mm is connected, strontium titanate particles are placed between the electrodes so that the thickness is about 0.5 mm, and the distance between the electrodes is measured with a load of about 2.0 N applied.

The resistance value when a voltage of 1,000 V is applied to the strontium titanate particles for 1 minute is measured, and the volume resistivity is calculated using the following formula.
Volume resistivity (Ω ・ cm) = R × L
R: Resistance value (Ω)
L: Distance between electrodes (cm)

<Measurement method of weight average molecular weight of resin>
The molecular weight distribution of the THF-soluble component of the resin was measured by gel permeation chromatography (GPC) as follows.

First, the toner was dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. The obtained solution was then filtered through a solvent-resistant membrane filter "Maesholidisk" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of the component soluble in THF was about 0.8% by mass. This sample solution was used for measurement under the following conditions.
Equipment: HLC8120 GPC (detector: RI) (manufactured by Tosoh Corporation)
Column: 7 stations of Shodex KF-801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK)
Eluent: Tetrahydrofuran (THF)
Flow velocity: 1.0 ml / min
Oven temperature: 40.0 ° C
Sample injection amount: 0.10 ml

In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade names "TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-" 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Toso Co., Ltd.) was used.

<Measuring method of weight average particle size (D4) of toner particles>
The weight average particle size (D4) of the toner particles is measured with a precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter) equipped with a 100 μm aperture tube by the pore electric resistance method. Measurement data is measured with 25,000 effective measurement channels using the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter) for setting conditions and analyzing measurement data. Was analyzed and calculated.

As the electrolytic aqueous solution used for the measurement, one in which special grade sodium chloride is dissolved in ion-exchanged water so that the concentration becomes about 1% by mass, for example, "ISOTON II" (manufactured by Beckman Coulter) can be used.

Before performing the measurement and analysis, the dedicated software was set as follows.

On the "Change standard measurement method (SOM) screen" of the dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value to "Standard particles 10.0 μm" (Beckman Coulter). The value obtained by using (manufactured by the company) was set. By pressing the threshold / noise level measurement button, the threshold and noise level were automatically set. Further, the current was set to 1600 μA, the gain was set to 2, the electrolytic solution was set to ISOTON II, and the flash of the aperture tube after the measurement was checked.

In the "pulse to particle size conversion setting screen" of the dedicated software, the bin spacing was set to logarithmic particle size, the particle size bin was set to 256 particle size bins, and the particle size range was set to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic aqueous solution was placed in a 250 ml round bottom beaker made of glass exclusively for Multisizer 3, set on a sample stand, and the stirrer rod was stirred counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube were removed in advance by the "aperture flash" function of the analysis software.
(2) Approximately 30 ml of the electrolytic aqueous solution is placed in a 100 ml flat-bottomed beaker made of glass, and "Contaminone N" (nonionic surfactant, anionic surfactant, organic builder) is used as a dispersant in the electrolytic aqueous solution for precise measurement of pH 7. Approximately 0.3 ml of a diluted solution prepared by diluting a 10% by mass aqueous solution of a neutral detergent for washing a vessel, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water 3 times by mass was added.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and are installed in the water tank of the ultrasonic disperser "Ultrasonic Dispension System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water was added, and about 2 ml of the Contaminone N was added into the water tank.
(4) The beaker of (2) was set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser was operated. Then, the height position of the beaker was adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker was maximized.
(5) With the electrolytic aqueous solution in the beaker of (4) being irradiated with ultrasonic waves, about 10 mg of toner was added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing was continued for another 60 seconds. For ultrasonic dispersion, the water temperature in the water tank was appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) The electrolyte aqueous solution of (5) in which toner was dispersed was dropped onto the round bottom beaker of (1) installed in the sample stand, and the measured concentration was adjusted to about 5%. .. Then, the measurement was performed until the number of measured particles reached 50,000.
(7) The measurement data was analyzed by the dedicated software attached to the apparatus, and the weight average particle size (D4) was calculated. The "average diameter" of the analysis / volume statistical value (arithmetic mean) screen when the graph / volume% was set by the dedicated software was set to the weight average particle size (D4).

<Measuring method of average circularity of toner particles>
The average circularity of the toner was measured by a flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.

The measurement principle of the flow-type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) is to capture a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is sent to the flat sheath flow cell by the sample suction syringe. The sample sent into the flat sheath flow is sandwiched between the sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and the flowing particles can be photographed as a still image. Moreover, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, and the captured image has 512 pixels × 512 pixels in one field, and is image-processed at an image processing resolution of 0.37 × 0.37 μm per pixel, and the contour of each particle image is processed. Extraction is performed, and the projected area and peripheral length of the particle image are measured.

Next, the projected area S and the perimeter L of each particle image are obtained. Using the area S and the perimeter L, the diameter equivalent to a circle and the circularity are obtained. The circular equivalent diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity is the value obtained by dividing the peripheral length of the circle obtained from the circular equivalent diameter by the peripheral length of the particle projected image. It is defined and calculated by the following formula.
Circularity C = 2 × (π × S) ^1/2 / L

When the particle image is a perfect circle, the circularity becomes 1.000, and the greater the degree of unevenness on the outer circumference of the particle image, the smaller the circularity.

After calculating the circularity of each particle, the range of circularity 0.2 to 1.0 is divided into 800 channels, and the average value is calculated using the center value of each channel as a representative value to calculate the average circularity.

As a specific measurement method, 0.02 g of a surfactant, preferably sodium dodecylbenzene sulfonate, as a dispersant is added to 20 ml of ion-exchanged water, 0.02 g of a measurement sample is added, an oscillation frequency of 50 kHz, and electrical. A tabletop ultrasonic cleaner with an output of 150 W (for example, "VS-150" (manufactured by Vervocreer Co., Ltd.) was used for dispersion treatment for 2 minutes to prepare a dispersion liquid for measurement. It is appropriately cooled so that the temperature of the above temperature is 10 ° C. or higher and 40 ° C. or lower.

The flow-type particle image analyzer equipped with a standard objective lens (10x) was used for the measurement, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion prepared according to the above procedure is introduced into the flow type particle image analyzer, 3000 toner particles are measured in the total count mode in the HPF measurement mode, and the binarization threshold at the time of particle analysis is set to 85%. The analysis particle size was limited to a circle equivalent diameter of 2.00 μm or more and 200.00 μm or less, and the average circularity of the toner was determined.

In the measurement, automatic focus adjustment is performed using standard latex particles (for example, 5200A manufactured by Duke Scientific is diluted with ion-exchanged water) before the start of the measurement. After that, it is preferable to perform focus adjustment every two hours from the start of measurement.

In the embodiment of the present application, a flow type particle image analyzer issued by Sysmex Corporation is used, and the diameter of the analyzed particle is limited to 2.00 μm or more and 200.00 μm or less in equivalent circle diameter. Measured under the measurement and analysis conditions when the calibration certificate was received.

<Measurement of resin glass transition temperature (Tg)>
The glass transition temperature of the resin is measured according to ASTM D3418-82 using a differential scanning calorimeter analyzer "Q2000" (manufactured by TA Instruments).

The melting point of indium and zinc is used for temperature correction of the device detection unit, and the heat of fusion of indium is used for the correction of calorific value.

Specifically, about 5 mg of the resin is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rise rate is 10 ° C./min within the measurement range of 30 to 200 ° C. Make a measurement with. The temperature is once raised to 180 ° C. and held for 10 minutes, then lowered to 30 ° C., and then the temperature is raised again. In this second temperature rise process, a specific heat change is obtained in the temperature range of 30 to 100 ° C. The intersection of the line at the midpoint of the baseline before and after the specific heat change at this time and the differential thermal curve is defined as the glass transition temperature (Tg) of the resin.

Although the basic configuration and features of the present invention have been described above, the present invention will be specifically described below based on Examples. However, the present invention is not limited thereto.

<Production example of strontium titanate particles 1>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then the pH was neutralized to 5.8 with hydrochloric acid and washed with filtered water. Water was added to the washed cake to make _{a slurry of TIO 2} of 1.5 mol / L, and then hydrochloric acid was added to adjust the pH to 1.5 for deflocculation treatment.

Desulfurized and deglutinized metatitanium acid _{was collected as TIO 2} and placed in a 3 L reaction vessel. An aqueous solution of strontium chloride was added to the deflated metatitanium acid slurry so as to have a SrO / TiO ₂ molar ratio of 1.15, and then the TiO ₂ concentration was adjusted to 0.8 mol / L. Next, after heating to 90 ° C. with stirring and mixing, 444 mL of a 10N sodium hydroxide aqueous solution was added over 50 minutes while performing microbabbling of nitrogen gas at 600 ml / min, and then 200 ml of microbabbling of nitrogen gas was added. Stirring was carried out at 95 ° C. for 1 hour while carrying out at / min.

Then, the reaction slurry was stirred while flowing cooling water at 10 ° C. on the jacket of the reaction vessel, rapidly cooled to 15 ° C., hydrochloric acid was added until the pH reached 2.0, and stirring was continued for 1 hour. After decantation washing of the obtained precipitate, 6N hydrochloric acid was added to adjust the pH to 2.0, 8.0% by mass of n-octylethoxysilane was added to the solid content, and the mixture was stirred for 18 hours. The particles were neutralized with a 4N aqueous sodium hydroxide solution, stirred for 2 hours, filtered and separated, and dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 1. The average primary particle size calculated on the basis of the number by electron microscope observation was 35 nm. The physical characteristics are shown in Table 1.

<Production example of strontium titanate particles 2-7>
Strontium titanate particles 2 to 7 were produced by changing the reaction temperature, the charging concentration, and the cooling rate by the same production method as for the particles 1. The physical characteristics are shown in Table 1.

<Production example of strontium titanate particles 8 to 12>
The hydrous titanium slurry obtained by hydrolyzing an aqueous solution of titanyl sulfate was washed with an aqueous alkaline solution. Next, hydrochloric acid was added to the hydroxide-containing titanium slurry to adjust the pH to 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.5, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

To the hydrated titanium hydroxide, added 0.97-fold molar amount of _{Sr (OH) 2 · 8H 2} O were placed in a SUS reaction vessel was replaced with nitrogen gas. Further, distilled water was added so as to be 0.1 to 2.0 mol / liter in terms of _{SrTiO 3.}

The dispersion liquid, oxygen gas, and propane gas were sprayed from a fine particle spray nozzle into an 80 L combustion reaction tank and burned, and then collected through a filter to obtain fine particles. Pure water was added to the obtained fine particles to form a slurry, 6N hydrochloric acid was added to adjust the pH to 2.0, 7.0% by mass of n-octylethoxysilane was added to the solid content, and the mixture was stirred for 18 hours. .. The mixture was neutralized with a 4N aqueous sodium hydroxide solution, stirred for 2 hours, filtered and separated, and dried in the air at 120 ° C. for 8 hours to obtain powders 8 to 12. Table 1 shows the physical characteristics of the powders 8 to 12.

<Production example of silica fine particles 1>
After supplying oxygen gas to the burner and igniting the ignition burner, hydrogen gas was supplied to the burner to form a flame, and silicon tetrachloride, which is a raw material, was added to the burner to gasify it to obtain silica fine particles. .. The obtained silica fine particles were transferred to an electric furnace, spread in a thin layer, and then heat-treated at 900 ° C. for sintering. As a specific method, it was prepared with reference to the description of JP-A-2002-3213. Then, as a hydrophobic treatment, a surface treatment was performed with hexamethyldisilazane to obtain silica fine particles 1. Table 1 shows the physical characteristics of the silica fine particles 1.

<Production example of silica fine particles 2>
Silica fine particles 2 were obtained by adjusting the amount of silicon tetrachloride, the amount of oxygen gas, the amount of hydrogen gas, the silica concentration, the residence time, the sintering conditions, and the surface treatment agent with reference to the description of JP-A-2002-3213. Table 2 shows the physical characteristics of the silica fine particles 2.

<Production example of binder resin A>
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 72.0 parts by mass (0.20 mol; 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 28.0 parts by mass (0.17 mol; 100.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed in a cooling tube, a stirrer, a nitrogen introduction tube, and a reaction vessel equipped with a thermocouple. Next, the inside of the flask was replaced with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 4 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180 ° C., and returned to atmospheric pressure (first reaction step).
Trimellitic anhydride: 1.3 parts by mass (0.01 mol; 4.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 1 hour while maintaining the temperature at 180 ° C., ASTM D36. After confirming that the softening point measured according to −86 reached 120 ° C., the temperature was lowered to stop the reaction (second reaction step), and a binder resin A having Tg = 57 ° C. was obtained.

<Toner manufacturing example 1>
-Bundling resin A 100 parts by mass-Wax (Fischer-Tropsch wax, melting point 90 ° C) 5 parts by mass-C. I. Pigment Blue 15:35 parts by mass The raw materials shown in the above formulation are mixed using a Henshell mixer (FM-75 type, manufactured by Mitsui Mine Co., Ltd.) at a rotation speed of 20 s ^-1 and a rotation time of 5 min, and then the temperature is 125. The mixture was kneaded with a twin-screw kneader (PCM-30 type, manufactured by Ikekai Co., Ltd.) set at ° C. The obtained kneaded product was cooled and coarsely pulverized to 1 mm or less with a hammer mill to obtain a coarsely crushed product. The obtained coarse crushed product was finely pulverized with a mechanical crusher (T-250, manufactured by Turbo Industries, Ltd.). Further, classification was performed using a rotary classifier (F-300, manufactured by Hosokawa Micron Co., Ltd.) to obtain toner particles. The operating conditions of the rotary classifier (F-300, manufactured by Hosokawa Micron Co., Ltd.) were that the classifying rotor rotation speed was 150.0 s ^-1 and the distributed rotor rotation speed was 125.0 s ^-1 . The obtained toner matrix particles 1 had a weight average particle size (D4) of 5.4 μm.

・ Toner matrix particles 1 100 parts by mass ・ Silica fine particles 1 1.0 parts by mass Using a Henshell mixer (FM-10C type, manufactured by Mitsui Mine Co., Ltd.), the raw materials shown in the above formulation are rotated at 50s ^-1 (3000 rpm). ), The mixture was mixed with a rotation time of 2 min. After that, heat treatment was performed by the surface treatment apparatus shown in FIG. 1 to obtain toner particles 1. The operating conditions are feed amount = 5 kg / hr, hot air temperature = 220 ° C., hot air flow rate = 6 m ³ / min. , Cold air temperature = 5 ° C., Cold air flow rate = 4 m ³ / min. , Cold air absolute moisture content = 3 g / m ³ , blower air volume = 20 m ³ / min. , Injection air flow rate = 1m ³ / min. And said. The obtained toner particles 1 had a weight average particle diameter (D4) of 5.5 μm. The average circularity was 0.965.

・ Toner particles 1 100 parts by mass ・ Silica fine particles 1 1.0 part by mass ・ Silica fine particles 2 1.0 part by mass ・ Strontium titanate fine particles 1 1.0 part by mass Henshell mixer (FM-10C type) ^{, Mitsui Mine Co., Ltd., and mixed at a rotation speed of 58s -1} (3500 rpm) and a rotation time of 2 min as the first-stage external particles. After that, 1.0 part by mass of strontium titanate fine particles 10 was added as the second stage external addition, and using a Henchel mixer (FM-10C type, manufactured by Mitsui Mine Co., Ltd.), the rotation speed was 67s ^-1 (4000 rpm) and the rotation time. Mixing was performed for 1 min to obtain toner 1.

The toner 1 had an average circularity of 0.965 and a weight average particle size (D4) of 5.5 μm. The outline of the obtained toner 1 is shown in Table 3, and the physical properties are shown in Tables 4-1 and 4-2.

<Toner Production Examples 2 to 22>
As shown in Table 3, the same procedure as in Toner Production Example 1 was carried out except that the type of the inorganic fine powder, the number of copies added, and the external addition time were changed. The outline of the toners 2 to 22 is shown in Table 3, and the physical properties are shown in Tables 4-1 and 4-2.

<Manufacturing example of magnetic core particles>
Step 1 (Weighing / mixing step):
・ Fe ₂ O ₃ 60.2% by mass
・ MnCO ₃ 33.9% by mass
・ Mg (OH) ₂ 4.8% by mass
・ SrCO ₃ 1.1% by mass
The ferrite raw material was weighed so as to be. Then, it was pulverized and mixed for 2 hours with a dry ball mill using a zirconia (φ10 mm) ball.

Step 2 (temporary firing step):
After crushing and mixing, it was fired in the air at 1000 ° C. for 3 hours using a burner type firing furnace to prepare calcined ferrite. The composition of ferrite is as follows.
(MnO) _a (MgO) _b (SrO) _c (Fe ₂ O ₃ ) _{d In the} above formula, a = 0.39, b = 0.11, c = 0.01, d = 0.50.

Step 3 (crushing step):
After crushing to about 0.5 mm with a crusher, 30 parts by mass of water was added to 100 parts by mass of calcined ferrite using a zirconia (φ10 mm) ball, and the mixture was crushed with a wet ball mill for 2 hours.

The slurry was pulverized with a wet bead mill using zirconia beads (φ1.0 mm) for 4 hours to obtain a ferrite slurry.

Step 4 (granulation step):
To 100 parts by mass of calcined ferrite as a binder, 2.0 parts by mass of polyvinyl alcohol was added to the ferrite slurry, and the particles were granulated into spherical particles of about 36 μm by a spray dryer (manufacturer: Okawara Kakoki).

Step 5 (main firing step):
In order to control the firing atmosphere, firing was performed at 1150 ° C. for 4 hours in a nitrogen atmosphere (oxygen concentration 1.00% by volume or less) in an electric furnace.

Step 6 (sorting step):
After crushing the agglomerated particles, the coarse particles were removed by sieving with a sieve having a mesh size of 250 μm to obtain magnetic core particles.

<Manufacturing example of coated resin>
-Cyclohexyl methacrylate monomer 26.8 parts by mass-Methyl methacrylate monomer 0.2 parts by mass-Methyl methacrylate macromonomer 8.4 parts by mass (macromonomer with a weight average molecular weight of 5000 having a methacryloyl group at one end)
・ Toluene 31.3 parts by mass ・ Methyl ethyl ketone 31.3 parts by mass Add the above materials to a four-port separable flask equipped with a reflux condenser, a thermometer, a nitrogen introduction tube and a stirrer, and introduce nitrogen gas. The atmosphere was sufficiently nitrogen. Then, the mixture was heated to 80 ° C., 2.0 parts by mass of azobisisobutyronitrile was added, and the mixture was refluxed for 5 hours for polymerization. Hexane was injected into the obtained reaction product to precipitate and precipitate a copolymer, and the precipitate was filtered off and then vacuum dried to obtain a coated resin.

<Magnetic carrier 1 manufacturing example>
・ Coat resin 20.0% by mass
・ Toluene 80.0% by mass
The above materials were dispersed and mixed with a bead mill to obtain a resin liquid.

100 parts by mass of the magnetic core particles were charged into the Nautamixer, and further, the resin liquid was charged into the Nautamixer so as to be 2.0 parts by mass as a resin component. The mixture was heated to a temperature of 70 ° C. under reduced pressure, mixed at 100 rpm, and the solvent was removed and the coating operation was performed over 4 hours. Then, the obtained sample was transferred to a Julia mixer, heat-treated at a temperature of 100 ° C. for 2 hours under a nitrogen atmosphere, and then classified with a sieve having an opening of 70 μm to obtain a magnetic carrier 1. The volume distribution standard 50% particle size (D50) of the obtained magnetic carrier was 38.2 μm.

^{With the above toners 1 to 22 and the magnetic carrier 1, 0.5 s -1} and rotation time 5 min with a V-type mixer (V-10 type: Tokuju Seisakusho Co., Ltd.) so that the toner concentration becomes 8.0% by mass. The two-component developer 1 to 22 were obtained. Details are shown in Table 5.

[Example 1]
As an image forming apparatus, a Canon digital commercial printing printer imageRUNNER ADVANCE C5560 remodeling machine was used, and a two-component developer 1 was placed in a developer at the cyan position to evaluate the cleaning property.

Here, the amount of discharge current in the primary charging step was set to 100 μA (the definition of discharge current is described in JP-A-2009-128842). The photosensitive drum used has a taper wear amount of 0.5 mg (the method for measuring the taper wear amount is described in JP-A-2009-128842), and the surface of the photosensitive drum has Rz = 1.0 μm and Sm = 50 μm. used. The surface roughness of the photosensitive drum was measured as follows using a contact type surface roughness measuring machine (trade name: Surfcoder SE3500, manufactured by Kosaka Laboratory Co., Ltd.).

Detector: R2μm, 0.7mN diamond needle, filter: 2CR, cutoff value:
0.8 mm, measurement length: 2.5 mm, feed speed: 0.1 mm, JIS standard B0601
The data of the 10-point average roughness Rz defined in 1 was processed. Further, the average interval Sm of the unevenness of the surface is an arithmetic mean value obtained from the following formula measured under the same conditions.

Examples of the roughening means for controlling the surface shape of the photosensitive drum include, but are not limited to, a polishing sheet and a ejection grind.

The conditions for evaluating the cleanability were as follows.

<Cleaning evaluation conditions>
Environment 15 ℃ 10%
Cleaning blade setting angle 20 °
Amount placed on the photosensitive drum 0.3 to 0.4 mg / cm ²
Toner charge amount 35 to 50 μC / g
Under the above conditions, untransferred toner equivalent to 10 sheets of A3 was supplied to the cleaning blade at a process speed of 260 mm / sec and then bet-stopped, and the amount of toner that slipped through the cleaning blade was measured. The amount of slip-through toner was estimated from the reflection density using X Rite.

The linear pressure of the cleaning blade with respect to the photosensitive drum was 12 gf / cm (11.76 N / m) and 8 gf / cm (7.84 N / m).

The evaluation criteria are as follows. The evaluation results are shown in Table 6.

Linear pressure 12gf / cm
A: Less than 0.010 (very good)
B: 0.010 or more and less than 0.015 (good)
C: 0.015 or more and less than 0.020 (a level that does not cause any problem in the present invention)
D: 0.020 or more (not acceptable in the present invention)
Linear pressure 8gf / cm
A: Less than 0.015 (very good)
B: 0.015 or more and less than 0.030 (good)
C: 0.030 or more and less than 0.050 (a level that does not cause any problem in the present invention)
D: 0.050 or more (not acceptable in the present invention)

[Examples 2 to 14 and Comparative Examples 1 to 8]
The evaluation was carried out in the same manner as in Example 1 except that the two-component developer 2 to 24 was used. The evaluation results are shown in Table 6.

1. 1. Raw material fixed quantity supply means, 2. Compressed gas flow rate adjusting means, 3. Introductory tube, 4. Protruding member, 5. Supply pipe, 6. Processing room, 7. Hot air supply means, 8. Cold air supply means, 9. Regulatory means, 10. Collection means, 11. Hot air supply means outlet, 12. Distributor, 13. Swivel member, 14. Powder particle supply port

Claims (3)

Toner particles containing a binder resin and a colorant, and toner having strontium titanate particles.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner before the toner is washed with water, the peak A1 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B1 that exists in the range of 80 nm or more and 300 nm or less.
In the number distribution of the number average particle size of the primary particles of the strontium titanate particles in the toner after the toner is washed with water, the peak A2 having a particle size in the range of 10 nm or more and 60 nm or less and the particle size are There is a peak B2 that exists in the range of 80 nm or more and 300 nm or less.
When the height of the peak A1 is HA1, the height of the peak A2 is HA2, the height of the peak B1 is HB1, and the height of the peak B2 is HB2.
70 ≦ (HA2 / HA1) × 100 ≦ 90
20 ≦ (HB2 / HB1) × 100 ≦ 50
Toner characterized by satisfying. The strontium titanate particles have a dielectric constant of 25 pF / m or more and 100 pF / m or less and a volume resistivity of 2.0 × 10 ⁹ Ω · cm or more in the measurement of the dielectric constant at 25 ° C. and 1 MHz. The toner according to claim 1, which is 0 × 10 ^{12 Ω · cm or less.} The toner according to claim 1 or 2 , wherein the weight average particle size of the toner particles is 4.0 μm or more and 8.0 μm or less.

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