JP2856494B2 - Toner and image forming method - Google Patents

Description

The present invention relates to a toner and an image forming method applied to an electrophotographic method, an electrostatic recording method, an electrostatic printing method and the like, and more particularly, to a method containing a wax. And an image forming method using the toner.

[Conventional technology]

A toner used for electrophotography or the like is usually formed by dispersing and containing a colorant in a binder resin made of a thermoplastic resin.

As the binder resin, a polyester resin is advantageously used.

On the other hand, in order to improve the fixing characteristics of the toner, it is effective to include wax in the binder resin.

[Problems to be solved by the invention]

However, when the dispersibility of the wax in the polyester resin is too good, the domain of the wax becomes too small, and the amount of the wax exposed on the surface of the toner particles is reduced. As a result, an offset phenomenon and a winding phenomenon occur. Therefore, sufficient fixing characteristics are not exhibited.

On the other hand, if the dispersibility of the wax in the polyester resin is too poor, the domain of the wax becomes excessively large, and the amount of the wax exposed on the surface of the toner particles increases. As a result, the physical adhesion of the toner decreases. As a result, a problem arises that the developing property is reduced and the image density is reduced.

This problem can be alleviated to some extent by adding and mixing inorganic fine particles such as hydrophobic silica fine particles from outside the toner particles. However, when an image is formed by a two-component non-contact development method using a thin layer forming member pressed against a developer carrier, toner particles are formed by the thin layer forming member when a thin layer is formed. Due to considerable pressure, the improvement effect is likely to be impaired due to separation and burial of the inorganic fine particles. Therefore, when forming images many times, the physical adhesion of the toner to the developer carrier increases. As a result, the image density is greatly reduced.

A first object of the present invention is to provide a toner having excellent durability.

A second object of the present invention is to provide an offset phenomenon and a winding phenomenon when an image is formed by applying a two-component non-contact developing method using a thin layer forming member pressed against a surface of a developer carrier. It is an object of the present invention to provide an image forming method which can achieve good fixing without causing the problem and can form an image having a high image density even when forming an image many times.

[Means for solving the problem]

In order to achieve the above object, the present inventor has conducted intensive studies and found that at least an average particle diameter containing a binder resin composed of a polyester resin having a particle diameter of 4 to 10 μm and a mixture obtained by mixing wax. , A binder resin and a toner material composed of a colorant are preliminarily mixed and melt-kneaded, and the average value of the domain volume of the wax is 5 to 20 μm.
By producing a kneaded material having a m of ³ and using a toner obtained by pulverizing the kneaded material, the wax domain in the toner particles is in a suitable range, and as a result, both the fixing property and the developing property are sufficient. And found that the toner had excellent durability, thereby completing the present invention.

That is, the toner of the present invention is a kneaded material in which at least a binder resin composed of a polyester resin, a wax, and a toner material composed of a colorant are melt-kneaded, and the average value of the domain volume of the wax is 5 to 20 μm ³ . Is produced by pulverizing the kneaded product.

The image forming method of the present invention is a method for forming an image by applying a two-component non-contact developing method using a thin layer forming member disposed in pressure contact with the surface of a developer transporting carrier. It is characterized by using the above toner.

[Action]

The toner material is melt-kneaded to produce a kneaded product having an average value of the domain volume of the wax of 5 to 20 μm ³ , and in the toner obtained by pulverizing the kneaded product, the amount of the wax exposed on the surface of the toner particles is reduced. The amount is not too large or too small and is in a suitable range. Therefore, a toner having excellent durability can be obtained.

When a two-component non-contact developing method using a thin layer forming member with this toner is applied, the effect of improving the fixing characteristics by the wax is remarkably exhibited, and the physical adhesion caused by the wax is also improved. There is no possibility that the developing property is deteriorated by the adhesion, and as a result, an image having a high image density can be stably formed many times without the offset phenomenon and the winding phenomenon.

[Specific description of configuration]

 Hereinafter, the configuration of the present invention will be specifically described.

In the toner of the present invention, a polyester resin is used as the binder resin. The polyester resin is obtained by polycondensation of an alcohol component and an acid component. In particular, the polyester resin contains 40 to 60 mol% of etherified diphenols as an alcohol component, and a di- or higher carboxylic acid as an acid component. And a polyester resin synthesized using a monomer having a divalent carboxylic acid content of 70 to 95 mol% in the acid component, which is 40 to 60 mol%.

Examples of the etherified diphenols include polyoxyethylenated bisphenol A and polyoxypropylene-modified bisphenol A.

Other alcohol components include ethylene glycol, diethylene glycol, triethylene glycol,
1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol,
1,4-butenediol, polyoxypropane (2.2) -2,
Examples thereof include diols such as 2-bis (4-hydroxyphenyl) propane, 1,4-bis (hydroxymethyl) cyclohexane, bisphenol A, and hydrogenated bisphenol A.

Examples of the divalent carboxylic acid include maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, and malonic acid. And anhydrides or lower alkyl esters of these acids, dimers of linoleic acid, and other divalent organic acid monomers.

Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,3,5-benzenetricarboxylic acid, 1,2,4
-Cyclohexanetricarboxylic acid, 1,2,5-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxylic acid Carboxyl-2-methyl-2
-Methylenecarboxypropane, tetra (methylenecarboxy) methane, 1,2,7,8-octanetetracarboxylic acid, empoletrimeric acid, anhydrides of these acids, and others.

The toner of the present invention contains wax as an essential component. Specifically, polyolefin wax such as low molecular weight polypropylene and low molecular weight polyethylene, fatty acid ester wax, higher fatty acid wax, higher alcohol wax, paraffin wax, acid amide wax and the like can be used.

The softening point of wax (JIS K 2531) is 100-160
It is preferably in the range of ° C.

The mixing ratio of the wax is preferably 1 to 10 parts by weight based on 100 parts by weight of the polyester resin as the binder resin.

Examples of the colorant used in the toner include carbon black, chrome yellow, Dupont oil red, quinoline yellow, phthalocyanine blue, and malachite green oxalate. The amount of the colorant is usually in the range of 0.1 to 20 parts by weight based on 100 parts by weight of the polyester resin as the binder resin.

Further, the toner may further contain an additive such as a charge control agent, if necessary.

In the toner of the present invention, the average value of the domain volume of the wax needs to be 5 to 20 μm ³ in the kneaded product obtained by melting and kneading the toner material. When the average value of the domain volume of the wax is in such a range, the effect of improving the fixing properties is sufficiently exhibited by the wax, and the developing property is not likely to be reduced by the physical adhesive force caused by the wax.

Such a toner can be manufactured, for example, as follows.

<Production Example 1 of Toner> A polyester resin as a binder resin is pulverized by a jet mill or the like to produce resin particles having an average particle diameter of 4 to 10 μm.

The above resin particles and wax particles are stirred and mixed by a Henschel mixer or the like to produce a preliminary mixture.

In this pre-mixing, with respect to the large-diameter wax particles having an average particle diameter of 5 times or more of the resin particles, the surfaces of the wax particles are coated with the resin particles due to triboelectric charging between the resin particles and the wax particles. The dispersibility of the wax in the binder resin is improved. However, with respect to small-sized wax particles having an average particle size less than 5 times that of the resin particles, since the particle size of the wax particles and the resin particles is close to each other, the surface thereof is difficult to be covered with the resin particles, and as a result, the dispersion proceeds excessively. Is suppressed. That is, the dispersibility of the large-diameter wax particles is improved, and the dispersibility of the small-diameter wax particles does not proceed excessively, so that the domain volume of the wax can be set to a suitable range.

Next, a toner material composed of a polyester resin as a binder resin, the above-mentioned premix, a colorant, and other additives used as necessary is premixed with a Henschel mixer or the like, and is mixed with a biaxial extruder or the like. After melt-kneading, the mixture is pulverized and classified by an air-flow type pulverizer and the like to produce a toner having an average particle size of about 7 to 16 μm.

In order to further improve the fluidity of the toner, it is preferable to add and mix inorganic fine particles such as hydrophobic silica, titanium oxide, and alumina. The amount of the inorganic fine particles added is 0.
1 to 1% by weight is preferred.

<Production Example 2 of Toner> A toner material including a polyester resin as a binder resin, a wax, a colorant, and other additives used as necessary is preliminarily mixed by a Henschel mixer or the like, and then biaxially mixed. After melt-kneading with a mold extruder or the like, the mixture is pulverized by a jet mill or the like to produce colored particles having an average particle size of 4 to 10 μm.

The colored particles and the wax particles are stirred and mixed by a Henschel mixer or the like to produce a preliminary mixture.

In this pre-mixing, as in Production Example 1, the dispersibility of large-diameter wax particles is improved, and the dispersion of small-diameter wax particles does not proceed excessively. Can be set to

Next, a polyester resin as a binder resin,
A toner material comprising the above pre-mixture, a colorant, and other additives used as needed is pre-mixed by a Henschel mixer or the like, melt-kneaded by a twin-screw extruder or the like, and then subjected to an air-flow type pulverizer. Crushed by, etc.
After classification, a toner having an average particle size of about 7 to 16 μm is manufactured.

Further, in order to further improve the fluidity of the toner, it is preferable to add and mix the same inorganic fine particles as in Production Example 1 from outside.

As described above, when the average value of the domain volume of the wax in the kneaded material is excessively large, the developability is reduced and the image density is reduced. On the other hand, when the average value of the domain volume is too small, the offset phenomenon and the winding phenomenon are likely to occur.

In the present invention, the average value of the domain volume of the wax in the kneaded material means that the kneaded material is formed into a plate shape, and 20 or more thin sections are formed from the plate-shaped kneaded material. The average value when the domain volume of wax is measured based on a photograph taken with a microscope and obtained.

The two-component developer used in the image forming method of the present invention is formed by mixing the above toner and a carrier. As such a carrier, for example, a coated carrier obtained by coating the surface of magnetic particles such as ferrite with a resin can be preferably used.

In the image forming method of the present invention, using the two-component developer described above, an image is formed by applying a two-component non-contact developing method using a thin layer forming member pressed against the surface of the developer carrier. To form

As the developer carrying carrier, a carrier constituted by a developing sleeve made of a rigid member and a magnet fixed inside the developing sleeve is preferable.

As the thin layer forming member, a member constituted by a magnet fixed inside the developer carrier is preferable.

The thin layer forming member is preferably a rod-shaped member that is pressed against the surface of the developing sleeve at a position facing the magnet fixed inside the developer carrier. And
The pressing portion of the thin layer forming member with the developer transporting carrier is made of a material having rigidity and magnetism, and has a radius of curvature of the pressing portion.
Preferably it is 0.5 to 15 mm. Here, “having rigidity” means that the rigidity is 10 ⁴ kg / cm ² or more.

The material constituting the surface of the developing sleeve can be selected from non-magnetic stainless steel, aluminum, hard resin, glass, ceramics, and the like.

In addition, as a constituent material of the thin layer forming member, SUS416, SU
It can be selected from magnetic stainless steel such as 430, an iron alloy, a hard resin containing magnetic powder, and the like.

The pressing force of the thin layer forming member against the developing sleeve is 1 to 15 gf
/ mm is good. When the pressing force is too small, the regulating force of the developer amount is reduced, so that stable regulation becomes difficult. on the other hand,
When the pressing force is excessive, the load on the developer increases, so that the adhesion of the developer to the thin layer forming member increases, and it is difficult to stably regulate the developer.

FIG. 1 shows an example of the configuration of a developing device suitable for carrying out a two-component non-contact developing method using a thin layer forming member disposed in pressure contact with the surface of a developer carrying carrier.

The magnet body 2 constituting the developer transport carrier 1 is fixed inside the developer transport carrier 1, and N poles and S poles are alternately arranged on the outer periphery thereof.

Developing sleeve 3 constituting the surface of developer carrier 1
Is made of rigid non-magnetic stainless steel and is rotated in the direction of the arrow.

The thin layer forming member 4 has a columnar rod shape with a cross-sectional radius of curvature of, for example, 3 mm, and is made of magnetic stainless steel (SUS416) which is a material having rigidity and magnetism.

The thin layer forming member 4 is disposed at a position facing the magnet body 2 in a state of being pressed against the developing sleeve 3, and regulates a supply amount of the developer carried on the developing sleeve 3 to the developing area 5. Things.

The thin layer forming member 4 is subjected to a grinding process so as to have a surface roughness of 0.5 S, and has no surface coating. In addition, you may provide a surface coating as needed.

The thin layer forming member 4 is restricted from moving laterally by the holder 7 attached to the housing 6, and is pressed by the nonlinear elastic member 14 made of urethane rubber-like elastic material such as urethane foam. Further, the thin layer forming member 4 may be pressed by a spring material or the like. The pressing force is preferably in the range of 1 to 15 gf / mm.

In FIG. 1, reference numeral 8 denotes an image forming body, 9 denotes a first stirring member, 10 denotes a second stirring member, 11 denotes a supply roller, 12 denotes a scraper, and 13 denotes a stirring partition plate.

In this developing device, the toner in the container is separated by a first stirring member 9 rotating in the direction of the arrow and a second stirring member 10 rotating so as to overlap each other in the opposite direction.
After being sufficiently stirred and mixed with the carrier, the toner is carried to the surface of the developing sleeve 3 by the supply roller 11. That is, the first stirring member 9 and the second stirring member 10 are screw-shaped members having a left-handed spiral excess rotating in mutually opposite arrow directions, and are driven by the thrust of the second stirring member 10 on the back side. The toner and the carrier conveyed to the first stirring member 9 sequentially move over the stirring partition plate 13 whose upper edge is inclined downward in the depth direction in FIG. 1 and move toward the first stirring member 9 side by the thrust. The sponge-like developer is conveyed and frictionally charged by the stirring and mixing action of the toner and the carrier during that time to form a sponge-like developer. Attaches in layers.

When the developer adhered on the developing sleeve 3 passes between the thin layer forming member 4 and the thin layer forming member 4, a developer layer having a uniform thickness of, for example, 100 to 450 μm is formed. Is supplied to the development area 5 and is subjected to development.

The size of the minimum gap D _{sd in} the developing region 5 is larger than the thickness of the supplied developer layer, and an oscillating electric field is formed in the developing region 5.

Since both the developing sleeve 3 and the thin layer forming member 4 are made of stainless steel, a thin layer can be formed stably and durability is improved.

〔Example〕

Hereinafter, Examples of the present invention will be described together with Comparative Examples,
The present invention is not limited to these embodiments. In the following, “parts” means “parts by weight”.

<Example 1> [Production of polyester resin A] Polyoxyethylenated bisphenol A 15 mol% Polyoxypropyleneated bisphenol A 35 mol% terephthalic acid 32.5 mol% n-dodecenyl succinic anhydride 5 mol% trimellitic acid 12.5 mol% Polyester resin A was produced by condensation polymerization of the above monomers.

[Production of Resin Particles] The polyester resin A was pulverized by a jet mill to produce resin particles A having an average particle size of 8 μm.

(Preparation of premix)

The above resin particles A 10 parts wax (Viscol 660P, low molecular weight polypropylene,
Preliminary mixture A was manufactured by stirring and mixing 10 parts or more of the materials with a Henschel mixer for 5 minutes.

[Production of toner]

97 parts of the polyester resin A, 6 parts of the pre-mixture A, 6 parts of carbon black, 10 parts of carbon black or more were preliminarily mixed with a Henschel mixer, melt-kneaded with a twin-screw extruder or the like, and pulverized and classified with a pneumatic pulverizer and classifier. Average particle size is 11μm
Was produced.

The average value of the domain volume of the wax in the kneaded product after the melt-kneading was 6 μm ³ .

To the above powder, hydrophobic silica fine particles (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) were further added and mixed from the outside at a ratio of 0.3% by weight to prepare a toner A.

(Two-component developer)

The toner A and the carrier were mixed to produce a two-component developer having a toner concentration of 5% by weight.

The carrier used was on the surface of the ferrite particles.
It is a carrier provided with a coating layer of styrene / methyl methacrylate copolymer resin.

(Image formation)

Actual image forming a copy image through a process of developing an electrostatic latent image on a photoreceptor with the above-described two-component developer using an image forming apparatus incorporating a developing device having the configuration shown in FIG. Tested.

[Evaluation]

The following items were evaluated. The results are as shown in Table 1.

[Trap generation temperature and offset generation temperature]

5c width only on the leading edge of the fixing paper
A m-solid unfixed toner image is formed, and then a test is performed to fix the unfixed toner image from the leading side of the fixing paper by changing the fixing temperature with a heat roller fixing device. Was measured. The heat roller fixing device used was PFA (tetrafluoroethylene /
It consists of an upper roller having a coating layer of perfluoroalkyl vinyl ether copolymer) and a lower roller having a coating layer of silicone rubber. The load of the upper roller is 1.5 kg / cm, and the linear velocity is the winding temperature. Was set to 140 mm / s in the measurement of, and 40 mm / s in the measurement of the offset generation temperature.

[Copy image density]

The relative density of the copy image was measured using a Konica Corporation's Sacciditometer.

<Example 2> [Production of colored particles] 100 parts of polyester resin A of Example 1 wax (Viscol 660P, low molecular weight polypropylene,
4 parts Carbon black 10 parts The above materials were preliminarily mixed with a Henschel mixer, melted and kneaded with a twin-screw extruder or the like, pulverized with a jet mill, and colored particles A having an average particle diameter of 6 μm.
Was manufactured.

(Preparation of premix)

The above colored particles A 10 parts wax (Viscol 660P, low molecular weight polypropylene,
Preliminary mixture B was manufactured by stirring and mixing 10 parts or more of the materials for 5 minutes using a Henschel mixer.

[Production of toner]

100 parts of the polyester resin A of Example 1 Preliminary mixture B 8 parts Carbon black 10 parts The above materials were preliminarily mixed with a Henschel mixer, melted and kneaded with a twin-screw extruder or the like, and pulverized and classified with a pneumatic pulverizer and classifier. And the average particle size is 10 μm
Was produced.

The average value of the domain volume of the wax in the kneaded product after the melt-kneading was 18 μm ³ .

To the above powder, hydrophobic silica fine particles (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) were externally added and mixed at a ratio of 0.3% by weight to prepare a toner B.

(Two-component developer)

A two-component developer was manufactured in the same manner as in Example 1 except that the toner B was used.

(Image formation)

A copy image was formed in the same manner as in Example 1 except that the above two-component developer was used.

[Evaluation]

 The same items as in Example 1 were evaluated.

<Example 3> [Production of polyester resin B] Polyoxyethylenated bisphenol A 15 mol% Polyoxypropyleneated bisphenol A 35 mol% Terephthalic acid 20 mol% Fumaric acid 25 mol% Trimellitic acid 5 mol% or more The polymer was polycondensed to produce a polyester resin B.

[Production of Colored Particles] The classified fine powder generated when producing toner B in Example 2 is referred to as colored particles B. The average particle size of the colored particles B was 5 μm.

(Preparation of premix)

The above colored particles B 20 parts wax (Viscol 660P, low molecular weight polypropylene,
Preliminary mixture C was produced by stirring and mixing 10 parts or more of the materials with a Henschel mixer for 5 minutes.

[Production of toner]

The above polyester resin B 100 parts Preliminary mixture C 12 parts Carbon black 10 parts The above materials were preliminarily mixed by a Henschel mixer, then melt-kneaded by a twin-screw extruder, pulverized and classified by an air-flow type pulverizer and classified. A powder having a particle size of 10 μm was produced.

The average value of the domain volume of the wax in the kneaded product after the melt-kneading was 10 μm ³ .

To the above powder, hydrophobic silica fine particles (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) were externally added and mixed at a ratio of 0.3% by weight to prepare a toner C.

(Two-component developer)

A two-component developer was manufactured in the same manner as in Example 1 except that the toner C was used.

(Image formation)

A copy image was formed in the same manner as in Example 1 except that the above two-component developer was used.

[Evaluation]

 The same items as in Example 1 were evaluated.

<Comparative Example 1> 100 parts of the polyester resin A of Example 1 wax (Viscol 660P, low molecular weight polypropylene,
4 parts Carbon black 10 parts The above materials were pre-mixed with a Henschel mixer, melted and kneaded with a twin-screw extruder, pulverized and classified with an air-flow type pulverizer and classifier to obtain an average particle size. A 10 μm powder was produced.

The average value of the domain volume of the wax in the kneaded product after the melt-kneading was 30 μm ³ .

Hydrophobic silica fine particles (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) were further added to the above powder from the outside at a ratio of 0.3% by weight, and a comparative toner a was manufactured.

(Two-component developer)

A two-component developer was manufactured in the same manner as in Example 1 except that the toner a was used.

(Image formation)

A copy image was formed in the same manner as in Example 1 except that the above two-component developer was used.

[Evaluation]

 The same items as in Example 1 were evaluated.

<Comparative Example 2> 100 parts of polyester resin B of Example 3 4 parts of wax (polyethylene wax) 10 parts of carbon black The above materials were premixed with a Henschel mixer, then melt-kneaded with a twin-screw extruder, and pulverized by air current. The powder was pulverized and classified by a classifier to produce a powder having an average particle size of 10 μm.

The average value of the domain volume of the wax in the kneaded product after the melt kneading was 2 μm ³ .

To the above powder, hydrophobic silica fine particles (Aerosil R-972, manufactured by Nippon Aerosil Co., Ltd.) were further added and mixed from the outside at a ratio of 0.3% by weight to prepare a comparative toner b.

(Two-component developer)

A two-component developer was manufactured in the same manner as in Example 1, except that the toner b was used.

(Image formation)

A copy image was formed in the same manner as in Example 1 except that the above two-component developer was used.

[Evaluation]

 The same items as in Example 1 were evaluated.

As is clear from the above examples, according to the toner of the present invention, an image is formed by applying a two-component non-contact developing method using a thin layer forming member pressed against the surface of a developer carrying carrier. In doing so, good fixing can be achieved without offset phenomenon and winding phenomenon,
Even when an image is formed many times, an image having a high image density can be formed.

On the other hand, in the toner of Comparative Example 1, the average value of the domain volume of the wax in the kneaded material was excessively large.
After 5000 copies, the image density was considerably reduced.

In the toner of Comparative Example 2, since the average value of the domain volume of the wax in the kneaded material was too small, both the offset resistance and the winding resistance were inferior.

〔The invention's effect〕

As described in detail above, according to the toner of the present invention, a kneaded material having an average value of wax domain volume of 5 to 20 μm ³ is produced by melting and kneading the toner material, and the kneaded material is pulverized. Therefore, the amount of wax exposed on the surface of the toner particles is in a suitable range, and the durability of the toner is significantly improved.

According to the image forming method of the present invention, since the two-component non-contact developing method using the thin layer forming member pressed and arranged on the surface of the developer carrying carrier using the toner is applied, the fixing by the wax is performed. The effect of improving the characteristics is remarkably exhibited, and there is no possibility that the developability will be reduced due to the physical adhesion force caused by the wax, and the image with high image density is stable many times without the offset phenomenon and the winding phenomenon Can be formed.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of a developing device that can be used for carrying out the image forming method of the present invention. DESCRIPTION OF SYMBOLS 1 ... Developer conveyance carrier, 2 ... Magnet body 3 ... Developing sleeve, 4 ... Thin layer forming member 5 ... Developing area, 6 ... Housing 7 ... Holder, 8 ... Image forming body 9 ... First stirring member, 10 Second stirring member 11 Supply roller 12, Scraper 13 Stirring partition plate 14, Nonlinear elastic member

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/08 G03G 9/087

Claims (2)

(57) [Claims] 1. A toner material comprising a binder resin, a colorant and a mixture obtained by mixing at least particles having an average particle size of 4 to 10 μm and containing a binder resin comprising a polyester resin and a wax. Mix, melt-knead, average wax domain volume is 5-20μ
toners produced a kneaded material which is m ^3, characterized in that it is obtained by pulverizing the kneaded product. 2. A toner constituting a developer when an image is formed by applying a two-component non-contact developing method using a thin layer forming member disposed in pressure contact with the surface of a developer carrying carrier. An image forming method, comprising using the toner described in (1).