JPH04338970A - Electrophotographic dry developer - Google Patents

Abstract

PURPOSE:To provide an electrophotographic dry developer emitting no foul odor in a copying machine and at the time of fixing. CONSTITUTION:Fine powder surface-treated with perfume or fine powder of activated carbon, inorg. gel or zeolite is added or stuck to toner particles based on a resin binder and a colorant to obtain an electrophotographic dry developer. Since this developer emits no foul odor in a copying machine and at the time of fixing or adsorbs or decomposes an unpleasant smell, a worker does not feel unpleasant and working environment is improved.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to improvements in electrophotographic dry developers.

0002

[Prior Art] As a conventional electrophotographic method, US Pat.
Various methods are described in Japanese Patent Publication No. 97691, Japanese Patent Publication No. 49-23910, Japanese Patent Publication No. 43-24748, etc., but generally a photoconductive substance is used and electricity is applied to the photoreceptor by various means. This process forms a latent image, then develops the latent image using toner, transfers the powder image to paper or the like as required, and then fixes it by heating or solvent vapor to obtain a copy.

[0003] Methods for developing electrical latent images are broadly divided into liquid development methods using a developer in which various pigments and dyes are finely dispersed in an insulating organic liquid, cascade methods, magnetic brush methods, and powder cloud methods. There is a so-called dry development method that uses toner in which a colorant such as carbon black is dispersed in natural or synthetic resin, and there is also a one-component developer consisting only of toner, toner, iron powder, ferrite, etc.
It is divided into two-component developers that are used in combination with carrier materials such as glass beads.

[0004] A general method for manufacturing toner for dry development involves premixing a thermoplastic resin, a colorant, a charge control agent, and other additives as necessary, and then applying this mixture to a heating roll, a heating kneader, or an extruder. The resulting agglomerates are melted and kneaded using a ruder or the like, and the resulting agglomerates are pulverized using a mechanical pulverizing means such as a jet mill or an I-type mill, and then classified to produce toner having a desired particle size.

However, the toners produced by these conventional techniques have the following problems.

First, since the thermoplastic resin, which is the main raw material of the toner, is mainly a high molecular weight substance obtained by polymerization, residual monomers exist.

[0007] This residual monomer has a significant odor, especially in the case of vinyl polymers which are widely and generally used as binder resins. Further, even if the amount of residual monomer is extremely small, a bad odor is generated during heating during fixing.

[0008] The occurrence of bad odor due to this heating occurs not only during fixing, but also when the toner is stored in the copying machine for replenishment, the temperature inside the copying machine rises due to the heat generated by the optical system and fixing section. Occur.

[0009] In order to solve these drawbacks, various proposals have been made as shown below.

(1) Japanese Patent Application Laid-Open No. 48-65945 discloses a method in which a fragrance is added to the toner and then kneaded. (2) Japanese Patent Application Laid-Open No. 52-113737 discloses a method in which a fine powder of a fragrance is mixed into a toner. , the method of holding this on the toner surface is (3
) JP-A No. 62-141567 proposes a method of adding a micro-encapsulated fragrance to a toner, and (4) JP-A No. 62-210474 proposes a method of sealing a fragrance in a toner. .

[0011] In the method (1), fragrances are generally very unstable chemically, so stirring and heat during kneading may cause
It decomposes or evaporates, and a satisfactory effect cannot be obtained. Method (2) has been proposed to solve this problem, but when used, for example, as a two-component developer, the perfume fine powder migrates to the carrier side, and a sufficient effect cannot be expected. In addition, (3) and (4) are both effective because the fragrance is ejected to the outside by the pressure and heat during fixing, but they are not effective against bad odors generated due to temperature rise in the copying atmosphere.

The present invention aims to solve these problems, and its purpose is to provide a dry developer for electrophotography that does not generate bad odor in a copying machine or during fixing.

[0013]

[Means for Solving the Problems] The present invention provides an electrophotographic dry method characterized by containing toner particles whose main components are a binder resin and a colorant, and a fine powder whose surface is treated with a fragrance. It is a developer.

The present invention also provides an electrophotographic dry developer characterized in that it contains toner particles containing a binder resin and a colorant as main components, and a fine powder selected from activated carbon, inorganic gel, and zeolite.

It is preferable to mix the toner particles and each of the above-mentioned fine powders in advance, but it is also preferable to have the fine powders adhere to the surface of the toner particles. Examples of adhesion include those in which the fine powder is adhered to the surface of the base particle via an adhesive, or those in which a part of the fine powder is embedded in the toner surface. The fixing method includes a method of providing a thin adhesive layer on the surface of the toner base particles and adhering the fine powder to this, or a method of pushing the fine powder onto the surface of the base particles with strong force, such as mechanical impact force. There is. It is preferable to employ the latter method in terms of manufacturability and toner properties.

Examples of the binder resin used in the present invention include polystyrene, chloropolystyrene, and polystyrene.
α-Stylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer , styrene-acrylate copolymer, (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-
(phenyl acrylate copolymer, etc.), styrene-methacrylate ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate) styrenic resins (unipolymers or copolymers containing styrene or styrene substitutes), styrene-α-methyl chloroacrylate copolymers, styrene-acrylonitrile-acrylic acid ester copolymers, chlorinated Vinyl resin, styrene-vinyl acetate copolymer,
Rosin-modified maleic acid resin, phenyl resin, epoxy resin, polyester resin, low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc. However, these resins are not limited to single use, but can also be used in combination of two or more types.

[0017] The manufacturing method for these is also not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

[0018] The base toner particles of the present invention may contain various colorants as required, and specifically include carbon black, nigrosine dye, aniline blue, ultramarine blue, phthalocyanine blue, chrome yellow,
Malachite green, rose bengal, etc. can be used alone or in combination. The amount of the colorant added is 1 to 30 parts by weight, preferably 5 to 15 parts by weight, per 100 parts by weight of the resin component.

Further, magnetic substances such as triiron tetroxide and ferrite powder may be added.

The base toner particles of the present invention are obtained by a known method, for example, by thoroughly mixing a thermoplastic resin, a colorant, etc., then kneading with a pressure kneader, heated twin rolls, extruder, etc., and then cooling. Obtained by solidifying, crushing, and classifying.

[0021] As the fragrance, any substance that emits an aroma can be used, but specifically, the following substances are available.

(1) Benzyl benzoate (almost odorless, somewhat balsam-like) (2) Cinnamyl alcohol (hyacinth-like) (3) Cyclopentadecanolide (jako-like) (4)
Diphenyl ether (geranium-like, rose-like) (
5) Tonalid (fruit-like) (6) β-naphthyl alkyl ether (fruit-like)

[
0023

[Chemical formula 1]

(7) Heliotropin=piperonal (
Helotrope flower) (8) Methyl N-methylanthranilate (fruit)
(9) L-Menthol (10) Isoamyl salicylate (11) Geraniol (Rose) (12) L-Carvone (Spearmint oil) (13) Undecylenaldehyde (Rose, Citrus) ) (14) Eugenol (15) Isoamyl invalerate (fruit) (16) Anisaldehyde (Yamasako) (17) Geranyl acetate (
(rose scent) (18) Cinnamyl acetate (flower scent)

[0025]

[Case 2]

(19) Terpinyl acetate (like lavender) (20) Dimethylbenzylcarbinyl acetate (like lilac, like lily) (21) pt-butyl-α-methylhydrocinnamic aldehyde (like like lily) ) (22) Citral (like lemon) (23) Cyclamenaldehyde (like cyclamen) These substances may be used alone or in combination of two or more. As the fine powder whose surface is treated with perfume, known materials that have been widely used can be used, for example,
Examples include silicon oxide, titanium oxide, aluminum oxide, silicon carbide, silicon nitride, barium titanate, and the like.

[0027] The surface of the fine powder can be treated with a perfume by dissolving the perfume in alcohol or the like, immersing the fine powder in it, and then evaporating the alcohol or the like.

The amount of the fine powder surface-treated with these fragrances added to the base toner particles is 1
0.1 to 10.0 parts by weight,
Preferably it is 0.3 to 3.0 parts by weight. Further, various mixers can be used to mix the base toner particles and the fine powder whose surface has been treated with these fragrances.

Activated carbon is produced by activating (increasing the surface area, ie, increasing the number of micropores) wood, coconut shell, palm kernel shell, coal, tar, bone, and other substances that can be carbonized.

The deodorizing mechanism of activated carbon is that odor substances are trapped within the micropores created by the activation operation, and the performance of activated carbon is determined by the state of the micropores created by the activation operation.

[0031] The specific surface area of activated carbon is 500 to 2000 m2
/g (BET method) can be used. These activated carbons are finely pulverized by a pulverizer such as a jet pulverizer, and the particle size is 5.0μ or less, preferably 0.01 to 2.0μ.
It is.

The amount of activated carbon fine powder added to the base particles is 0.1 to 10.0 parts by weight, preferably 0.3 to 3.0 parts by weight, per 100 parts by weight of the base particles. Moreover, various mixers can be used to mix the base particles and the activated carbon fine powder.

[0033] As the inorganic gel, SiO2/Al2O
A fine powder of 3.ZnO.Li2O.Ag+ is used. This SiO2・Al2O3・ZnO・Li2O・Ag+
Fine powder is fine particles with a large surface area that contain metal ions produced by a hydrolysis method, and deodorizes odors by simultaneously adsorbing and oxidizing them.

[0034]SiO2・Al2O3・ZnO・Li2O
- The average particle diameter of Ag+ primary particles is preferably 1.0 μm or less. SiO2・Al2O3・Z for base toner particles
The amount of nO.Li2O.Ag+fine powder added is 0.1 to 10.0 parts by weight, preferably 0.3 to 5.0 parts by weight, based on 100 parts by weight of the base toner particles. Various mixers can be used to mix these particles.

Zeolites come in both natural and synthetic forms, and have cavities and pores that are not found in other minerals due to their unique crystal structure. Normally, this part contains a large amount of crystallized water,
Zeolite can be easily removed by heating and depressurizing, and in its dehydrated state, zeolite can adsorb substances that enter its pores from the outside, and this function serves as a deodorizer. These zeolites are finely pulverized using a pulverizer such as a jet pulverizer.
The particle size is 5.0 μm or less, preferably 0.01 to 2.0 μm.
It is 0μ.

[0036] The method of fixing the fine zeolite powder to the surface of the base particles is to place the fine zeolite powder and the base particles in an airtight container equipped with a rotating body, and apply mechanical impact energy such as impact force or friction force due to high-speed rotation. There are methods to make it stick. The amount of zeolite fine powder added to the base particles is 0.1 to 15 parts by weight per 100 parts by weight of the base particles.
．． 0 parts by weight, preferably 0.5 to 5.0 parts by weight.

[0037]

[Examples] Next, the present invention will be explained with reference to Examples and Comparative Examples.

Example 1 Styrene-n-butyl methacrylate copolymer
88.0 parts by weight Quaternary ammonium salt
2.0 parts by weight Carbon black (#4
4: Made by Mitsubishi Kasei) 10.
A formulation containing 0 parts by weight or more was kneaded using an extruder to obtain base toner particles having a volume average particle diameter of 10 μm.

Next, titanium oxide (P-25: Nippon Aerosil) was immersed in a 3% alcohol solution of benzyl benzoate, and the alcohol was evaporated to obtain fine titanium oxide powder whose surface had been treated with benzyl benzoate. A developer (toner) of the present invention was obtained by mixing 2 parts by weight of surface-treated titanium oxide with 98 parts by weight of the base toner particles in a mixer. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and a copying machine (FT-48 manufactured by Ricoh Co., Ltd.) was used.
20), 1000 sheets were continuously copied. 300 g of replenishment toner was set in the copying machine. At this time, a sensory test was conducted by 20 monitors.

Comparative Example 1 In Example 1, a developer (toner) using P-25 which was not treated with benzyl benzoate was prepared and the same test as in Example 1 was conducted.

[0041] The results are summarized in Table 1.

Note that there was no difference in the images after copying 1000 sheets between Example 1 and Comparative Example 1.

[0043]

[Table 1]

Example 2 Unsaturated polyester resin 88.0 parts by weight Nigrosine dye 2.0 parts by weight Carbon black (#44) 10.0 parts by weight or more was kneaded using an extruder.
Base toner particles having a volume average particle diameter of 10 μm were obtained.

Next, aluminum oxide (Mechanox UB-10, manufactured by Uemura Industries) was immersed in a 5% alcohol solution of l-menthol, and the alcohol was evaporated to obtain fine aluminum oxide powder surface-treated with l-menthol. .

A developer (toner) of the present invention was obtained by mixing 5 parts by weight of surface-treated aluminum oxide with 95 parts by weight of the base toner particles in a mixer.

Comparative Example 2 For comparison, a developer (toner) made of Mechanox UB-10 which was not treated with l-menthol was also prepared.

The same test as in Example 1 was conducted using the toners obtained in Example 2 and Comparative Example 2 above. The results are shown in Table 2. Note that there was no difference in the images after copying 1000 sheets between Example 2 and Comparative Example 2.

[0049]

[Table 2]

Example 3 and Comparative Example 3 Base toner particles and surface-treated fine titanium oxide powder were obtained in the same manner as in Example 1. This base toner particle 20
0g and 1.0g of titanium oxide fine powder surface-treated with benzyl benzoate were placed in a sealed container with a diameter of 50cm and a rotating blade installed inside, and the rotation speed of the rotating blade was set to 5000 r.
pm, the container temperature was maintained at 45° C., and the operation was continued for 5 minutes to obtain the developer (toner) of the present invention. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and 1000 sheets were continuously copied using a copying machine (FT-4820 manufactured by Ricoh). 300 g of replenishment toner was set in the copying machine. At this time, a sensory test was conducted by 20 monitors. For comparison, a developer (toner) made of P-25 which was not treated with benzyl benzoate was also prepared (Comparative Example 3) and the same test was conducted.

[0051]

[Table 3]

Example 4 and Comparative Example 4 In the same manner as in Example 2, base toner particles and surface-treated aluminum oxide fine powder were obtained. 200 g of the base toner particles and 2.0 g of fine aluminum oxide powder whose surface had been treated with l-menthol were fixed in the same manner as in Example 3. However, the rotation speed of the rotating blade is 400
The developer (toner) of the present invention was obtained at 0 rpm and at a container temperature of 35°C. For comparison, a developer (toner) made of Mechanox UB-10 which was not treated with l-menthol was also prepared (Comparative Example 4). These two types of developers (toners) were tested in the same manner as in Example 3.

[0053]

[Table 4]

Example 5 and Comparative Example 5 Base toner particles were obtained in the same manner as in Example 1. A developer (toner) of the present invention was obtained by mixing 95.0 parts by weight of the base toner particles with 5.0 parts by weight of activated carbon fine powder pulverized to 1.0 μm using a jet pulverizer using a mixer. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and a copying machine (FT-482 manufactured by Ricoh Co., Ltd.) was used.
0), 1000 sheets were continuously copied. At this time 2
A sensory test was conducted with 0 monitors. Also, for comparison, a developer without the addition of activated carbon fine powder (Comparative Example 5)
I also created one and conducted a similar test.

[0055]

[Table 5]

Example 6 and Comparative Example 6 Toner formulation Styrene/2-ethylhexyl acrylate/
n-Butyl methacrylate copolymer 86.0 parts by weight Low molecular weight polypropylene
3.0 parts by weight Nigrosine dye
1.0 parts by weight carbon black

10.0 parts by weight The above formulation was kneaded using an extruder to obtain base toner particles having a volume average particle diameter of 10 μm. To 97.0 parts by weight of the base toner particles, 3.
0 parts by weight were mixed in a mixer to obtain a developer (toner) of the present invention. Using this toner, 100
A series of 0 copies were made, and an odor sensory test was conducted by 20 monitors. For comparison, a developer (toner) (Comparative Example 6) to which no activated carbon fine powder was added was also prepared and the same test was conducted.

[0057]

[Table 6]

Example 7 and Comparative Example 7 Base toner particles were obtained in the same manner as in Example 1. 200g of the base toner particles and 5g of activated carbon fine powder crushed to 1.0μ with a jet pulverizer were placed in a sealed container with a diameter of 50cm and a rotating blade installed inside, the rotation speed of the rotating blade was set at 5000 rpm, and the temperature of the container was set at 45°C. The developer (toner) of the present invention was obtained by maintaining the temperature at A developer was prepared using this toner (carrier: 100μ ferrite carrier), and a copying machine (FT-4820 manufactured by Ricoh) was used to create a developer.
000 copies were made continuously. At this time, a sensory test was conducted by 20 monitors. Also, for comparison, a developer (toner) without the addition of activated carbon fine powder (Comparative Example 7)
I also created one and conducted a similar test.

[0059]

[Table 7]

Example 8 and Comparative Example 8 Base toner particles were obtained in the same manner as in Example 7. 200 g of the base toner particles and 2 g of activated carbon fine powder ground to 0.7 μm using a jet grinder were subjected to a fixation treatment in the same manner as in Example 7. However, the rotation speed of the rotating blade is 4000
The developer (toner) of the present invention was obtained at rpm and container temperature of 40°C. Using this toner, 1000 copies were made continuously in the same manner as in Example 7, and a sensory odor test was conducted by 20 monitors. For comparison, a developer (toner) (Comparative Example 8) to which no activated carbon fine powder was added was also prepared and the same test was conducted.

[0061]

[Table 8]

Example 9 and Comparative Example 9 Base toner particles were obtained in the same manner as in Example 1. For 96 parts by weight of the base toner particles, SiO2, Al2O3,
ZnO・Li2O・Ag+fine powder (primary particle average particle size 1
．． 0μ or less) were mixed in a mixer to obtain a developer toner of the present invention. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and 1000 sheets were continuously copied using a copying machine (FT-4820 manufactured by Ricoh). 300 g of replenishment toner was set in the copying machine. At this time, a sensory test was conducted by 20 monitors. Also, for comparison, SiO2・Al2O3・Zn
O・Li2O・Ag+Toner without the addition of fine powder (
Comparative Example 9) In other words, the base toner particles were also subjected to the same test.

[0063]

[Table 9]

There was no difference in the images after copying 1000 sheets between Example 9 and Comparative Example 9.

Example 10 and Comparative Example 10 Base toner particles were obtained in the same manner as in Example 2. This base toner particle 9
For 9 parts by weight, SiO2・Al2O3・ZnO・Li
2O・Ag+fine powder (primary particle average particle size 1.0μ or less)
1 part by weight was mixed in a mixer to obtain a developer (toner) of the present invention. Also, for comparison, SiO2・Al2O3・
A toner without the addition of ZnO.Li2O.Ag+fine powder (Comparative Example 10), ie, base toner particles, is also tested. A test similar to that in Example 10 was conducted using these two types of toner.

[0066]

[Table 10]

[0067] The images after copying 1000 sheets are Example 10,
There was no difference in Comparative Example 10.

Example 11 and Comparative Example 11 Base toner particles were obtained in the same manner as in Example 1. This base toner particle
200g and SiO2, Al2O3, ZnO, Li2O
・Pour 4 g of Ag + fine particles into a sealed container with a diameter of 50 cm and a rotating blade installed inside, and rotate the rotating blade at 5000 rotations.
The rpm and container temperature were maintained at 45° C., and the operation was continued for 5 minutes to obtain a developer (toner) of the present invention. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and 1000 sheets were continuously copied using a copying machine (FT-4820 manufactured by Ricoh). 300 g of replenishment toner was set in the copying machine. At this time, a sensory test was conducted by 20 monitors. Also, for comparison, SiO2・Al2O
3.ZnO.Li2O.Ag+Toner to which no fine powder was added (Comparative Example 11), ie, base toner particles, was also subjected to the same test.

[0069]

[Table 11]

[0070] The images after copying 1000 sheets are Example 11,
There was no difference in Comparative Example 11.

Example 12 and Comparative Example 12 Base toner particles were obtained in the same manner as in Example 2. This base toner particle 2
00g and SiO2・Al2O3・ZnO・Li2O・
2 g of Ag+fine particles were fixed in the same manner as in Example 11. However, the rotation speed of the rotating blade is 4000 rpm.
m, the temperature of the container was 35° C., and a developer (toner) of the present invention was obtained. Also, for comparison, SiO2・Al2O3・Z
A toner without the addition of nO.Li2O.Ag+fine powder (Comparative Example 12), ie, base toner particles, is also tested. A test similar to that in Example 11 was conducted using these two types of toner.

[0072]

[Table 12]

[0073] The images after copying 1000 sheets are Example 12,
There was no difference in Comparative Example 12.

Example 13 and Comparative Example 13 Base toner particles were obtained in the same manner as in Example 1. This base toner particle
200g and 5g of zeolite fine powder crushed to 1.0μ with a jet crusher were placed in a sealed container with a diameter of 50cm and a rotating blade installed inside, and the rotation speed of the rotating blade was set to 5000.
rpm, keep the container temperature at 45°C, run for 5 minutes,
A developer (toner) of the present invention was obtained. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and a 100μ
Continuous copying of 0 sheets was performed. At this time, a sensory test was conducted by 20 monitors. For comparison, a toner (Comparative Example 13) to which no zeolite fine powder was added was also prepared, and the same test was conducted.

[0075]

[Table 13]

Example 14 and Comparative Example 14 Base toner particles were obtained in the same manner as in Example 6. This base toner particle
A fixation treatment was performed in the same manner as in Example 1 using 200 g and 2 g of zeolite fine powder crushed to 0.7 μm using a jet crusher. However, the rotation speed of the rotating blade is 4000 rpm.
m, the temperature of the container was 40° C., and a developer (toner) of the present invention was obtained. Using this toner, 100
A series of 0 copies were made, and an odor sensory test was conducted by 20 monitors. For comparison, a developer (toner) (Comparative Example 14) to which no zeolite fine powder was added was also prepared and the same test was conducted.

[0077]

[Table 14]

Example 15 and Comparative Example 15 Base toner particles were obtained in the same manner as in Example 1. This base toner particle 9
A developer (toner) of the present invention was obtained by mixing 5.0 parts by weight of zeolite fine powder pulverized to 1.0 μm with a jet pulverizer in a mixer. A developer was prepared using this toner (carrier: 100μ ferrite carrier), and 1000 sheets were continuously copied using a copying machine (FT-4820 manufactured by Ricoh). At this time, a sensory test was conducted by 20 monitors. Also, for comparison, a toner without the addition of zeolite fine powder (Comparative Example 15)
I also created and ran a similar test.

[0079]

[Table 15]

Example 16 and Comparative Example 16 Base toner particles were obtained in the same manner as in Example 2. This base toner particle 9
To 7.0 parts by weight, 3.0 parts by weight of fine zeolite powder ground to 0.7 μm using a jet pulverizer was mixed in a mixer to obtain the toner of the present invention. Using this toner, 1000 sheets were continuously copied in the same manner as in Example 1, and an odor sensory test was conducted by 20 monitors. For comparison, a developer (toner) (Comparative Example 16) to which no zeolite fine powder was added was also prepared and the same test was conducted.

[0081]

[Table 16]

[0082]

Effects of the Invention The developer of the present invention emits a unique pleasant aroma or absorbs unpleasant odors in the copying machine or during fixing.
Since it decomposes, there is no unpleasant odor, the working environment in the office is improved, and the copied images are not adversely affected.

Claims (4)

[Claims] 1. An electrophotographic dry developer comprising toner particles whose main components are a binder resin and a colorant, and a fine powder whose surface is treated with a fragrance. 2. The electrophotographic dry developer according to claim 1, wherein fine powder is adhered to toner particles. 3. An electrophotographic dry developer comprising toner particles containing a binder resin and a colorant as main components, and a fine powder selected from activated carbon, inorganic gel, and zeolite. 4. The electrophotographic dry developer according to claim 3, wherein fine particles selected from activated carbon, inorganic gel, and zeolite are fixed to the toner particles.