JPH08314181A - Electrophotographic toner - Google Patents

Abstract

PURPOSE: To obtain a toner fixable at a low fixing temp., not causing any problem on anti-offsetting property and shelf stability in practical use and excellent in fixing strength to transfer paper by incorporating Fischer-Tropsch wax derived from natural gas. CONSTITUTION: This electrophotographic toner contains Fischer-Tropsch wax derived from natural gas. The wax is produced by the Fischer-Tropsch's process using natural gas as starting material and it is wax hydrocarbon synthesized by the catalytic hydrogenation of CO. The wax is structurally straight chain paraffin wax with few methyl branches. Since the wax has a lower m.p. than PP wax, it is excellent in low-temp. fixability and excellent also in shelf stability. Because of a low penetration of <=2, the wax does not deteriorate the flowability of a toner when incorporated into the toner and it does not cause any problem on triboelectric chargeability, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner, and more particularly to an electrophotographic toner used in a copying machine or a printer adopting a heat roll fixing system.

[0002]

2. Description of the Related Art In recent years, with the spread of copying machines and printers using the electrophotographic method, the energy saving (power consumption) is mainly aimed at spreading to the home and multifunction of copying machines or printers. Speed reduction for the purpose of popularization in the so-called gray area located at the boundary between the printing machine and the copying machine, or to simplify the heat fixing roll to reduce the machine cost, for example, low roll. Pressure is desired. In addition, copiers equipped with a double-sided copy function and an automatic document feeder have become widespread along with the sophistication of copiers. Therefore, electrophotographic toner used in copiers and printers has a low fixing temperature and offset resistance. There is a demand for an electrophotographic toner that is excellent in fixing property and has excellent fixing strength on a transfer paper in order to prevent stains during double-sided copying and stains in an automatic document feeder.

Conventionally, attempts have been made to satisfy the above requirements by improving the molecular weight and the molecular weight distribution of the binder resin as described below. Specifically, attempts have been made to lower the fixing temperature by using a resin having a low molecular weight as the binder resin. However, by using a low molecular weight binder resin, it was possible to achieve the purpose of lowering the melting point of the toner, but at the same time, the melt viscosity is also reduced, which causes the phenomenon that the toner adheres to the heat fixing roll. There is a new problem that the offset phenomenon occurs. In order to prevent the occurrence of this offset phenomenon, a method has been used in which the low molecular weight region and the high molecular weight region of the molecular weight distribution of the binder resin are widened or the polymer portion is crosslinked. However, in order for the toner to have sufficient low temperature fixability by these methods, the glass transition temperature of the binder resin had to be lowered in anticipation of the anchor effect on the transfer paper. However, simply lowering the glass transition temperature of the binder resin lowers the melting start temperature of the toner, and the toner starts to melt near room temperature, resulting in a new problem that storage stability is impaired.
Also, if a large amount of low molecular weight resin in the binder resin is blended,
The toner itself becomes fragile and easily crushed by mechanical friction or the like, which causes a problem that the transfer paper is soiled during double-sided copying and the automatic document feeder is contaminated. There is also a method of incorporating a release agent such as low molecular weight polypropylene in order to prevent the offset phenomenon. However, the commercially available low molecular weight polypropylene has a melting point of 135 to 145 ° C., and when the low molecular weight polypropylene is contained in the toner and fixed at a low fixing temperature, the effect of preventing the offset phenomenon is sufficiently obtained. As a result, offset occurs and the melting point of the toner becomes high, so that there is a problem that sufficient fixing strength on the transfer paper cannot be obtained. It is also possible to blend a toner with Fischer-Tropsch wax made from coal.
No. 73554. However, although such a toner is effective in preventing offset, it has a problem in storage stability of the toner in a high temperature atmosphere.

[0004]

The object of the present invention is that fixing can be carried out at a low fixing temperature, practically no problem occurs in non-offset property and storage stability, and the fixing strength to transfer paper is excellent. To provide a toner for electrophotography.

[0005]

SUMMARY OF THE INVENTION The present invention is an electrophotographic toner containing a natural gas type Fischer-Tropsch wax.

The present invention will be described in detail below. The natural gas type Fischer-Tropsch wax applied to the toner for electrophotography of the present invention is produced by the Fischer-Tropsch method using natural gas as a raw material, and is a wax-like carbonization synthesized by catalytic hydrogenation of carbon monoxide. It is hydrogen. And structurally, it is a linear paraffin wax with few methyl branches. As such natural gas type Fischer-Tropsch wax, trade names: FT-100, FT-0030, FT-0 manufactured by Nippon Seiro Co., Ltd.
050, FT-0070, FT-0165, FT-11
55, FT-60S, etc. are on the market. The natural gas type Fischer-Tropsch wax preferably has a melting point of 85 to 100 ° C. as measured by a differential scanning calorimeter (hereinafter abbreviated as DSC). When the melting point is lower than 85 ° C., the storage stability of the toner is apt to cause a problem and the fluidity is apt to deteriorate. On the other hand, if the temperature is higher than 100 ° C., the effect of lowering the melting start temperature of the toner is small, and it becomes difficult to obtain the low temperature fixing property of the toner. The natural gas-based Fischer-Tropsch wax preferably has a penetration of 2 or less at 25 ° C. measured by JIS K-2235, and when it is more than 2, the fluidity tends to be poor when it is made into a toner, and the storage stability is high. And problems of triboelectricity with carrier particles and the like tend to occur. The content of the natural gas type Fischer-Tropsch wax in the electrophotographic toner is
It is preferably 1 to 20% by weight based on the total toner. 1
If it is less than wt%, the releasability of the electrophotographic toner is insufficient and the high temperature offset resistance tends to be insufficient. Further, since there is little effect of lowering the melting start temperature of the toner, it is difficult to obtain sufficient fixing strength on the transfer paper when fixing at a low fixing temperature. On the other hand, if it is more than 20% by weight, the compatibility with the binder resin is poor and the dispersion of the wax is likely to be poor, and the high-temperature offset resistance is likely to be poor due to the detachment of the wax alone during pulverization, which is not preferable.

Next, materials other than the natural gas type Fischer-Tropsch wax which constitutes the toner for electrophotography of the present invention, that is, the binder resin, the colorant and the like will be described. As the binder resin used in the present invention, polystyrene resin, polyacrylic acid ester resin, styrene-acrylic acid ester copolymer resin, styrene-methacrylic acid ester copolymer resin, polyvinyl chloride, polyvinyl acetate,
Polyvinylidene chloride, phenol resin, epoxy resin,
Examples include polyester resins. Further, as the colorant, carbon black, nigrosine dye, aniline blue, chalco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate and mixtures thereof, etc. Can be mentioned. It is necessary that these colorants be contained in a sufficient ratio so that a visible image having a sufficient density is formed. Usually, the ratio is about 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin. To be done.

The electrophotographic toner of the present invention includes the above-mentioned natural gas type Fischer-Tropsch wax, binder resin and colorant, and other toner components such as a charge control agent,
The particles are those in which a release agent, a magnetic material, etc. are appropriately dispersed and contained, and the average particle diameter thereof is in the range of 5 to 20 μm. A toner for electrophotography may be formed by adding and mixing a fluidity improver made of fine silica powder or the like to the particles thus obtained. The electrophotographic toner of the present invention is a one-component toner which is mixed with a carrier composed of iron powder, ferrite, granulated magnetite, resin fine powder containing magnetic powder, etc. without mixing with a two-component developer or carrier. It may be used as a developer.

[0009]

[Function] Polypropylene wax (melting point: 135 to 145 ° C.) which has been generally used for toners for electrophotography.
Was excellent in high temperature offset resistance, but was unsuitable for fixing at low temperature because of its high molecular weight and melting point. Therefore, in order to lower the melting start temperature of the toner, it has been proposed to add a low melting point wax having a low melting point and exhibiting sharp melting behavior. However, petroleum-based paraffin wax and low-melting point microcrystalline wax containing isoparaffin, naphthene, aromatic, etc., which have been conventionally known as low-melting wax, have a problem in storage stability as a toner because of their low molecular weight. Further, since the petroleum paraffin wax and the microcrystalline wax have a large penetration of 5 or more, when they become fine powder like toner, the powder fluidity is lowered and the image characteristics are likely to be adversely affected. The natural gas Fischer-Tropsch wax applied to the present invention has a low melting point as compared with polypropylene wax and thus has excellent low-temperature fixability, and has a very low melting point component as compared with existing petroleum-based and coal-based paraffin waxes, and thus is preserved. Since it has excellent stability and a small penetration of 2 or less, the fluidity is not hindered when it is made into a toner, and there is no problem in triboelectricity. Further, compared to the conventional Fischer-Tropsch wax synthesized by taking out the water gas from coal by the Fischer-Tropsch method, the natural gas Fischer-Tropsch wax not only satisfies the prevention of offset to the heat fixing roll and the storage stability of the toner at the same time, Since natural gas is used as a raw material, it has an advantage that toner can be supplied at low cost.

[0010]

EXAMPLES The present invention will be described below based on examples. In the examples, “part” means “part by weight”. Example 1 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Embodiment 2 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Embodiment 3 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Embodiment 4 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Example 5 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Example 6 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

Comparative Example 1 Instead of the natural gas type Fischer-Tropsch wax of Example 2, a commercially available polypropylene wax (manufactured by Sanyo Kasei Co., Ltd., trade name: Viscol 550P, melting point 140 ° C.)
A comparative electrophotographic toner was obtained in the same manner as in Example 2 except that 6 parts of was mixed.

Comparative Example 2 Petroleum-based paraffin wax (made by Nippon Seiro Co., Ltd.) was used in place of the natural gas-based Fischer-Tropsch wax of Example 2.
Product name: No. A comparative electrophotographic toner was obtained in the same manner as in Example 2 except that 6 parts of 155 having a melting point of 70 ° C. and a penetration of 15) were used.

Comparative Example 3 Petroleum-based paraffin wax (made by Nippon Seiro Co., Ltd.) was used in place of the natural gas-based Fischer-Tropsch wax of Example 2.
Product name: HNP-0190 Melting point 87 ° C, Penetration 6) 6
A comparative electrophotographic toner was obtained in the same manner as in Example 2 except that parts were used.

Comparative Example 4 6 parts of a coal-based Fischer-Tropsch wax (trade name: H1 having a melting point of 80 ° C. and 107 ° C., a penetration of 1) manufactured by Sazol in place of the natural gas-based Fischer-Tropsch wax of Example 2 Example 2 except that
A comparative electrophotographic toner was obtained in the same manner as in.

Next, the following items were tested for each of the electrophotographic toners obtained in the above Examples and Comparative Examples. (1) Non-offset temperature region and non-offset temperature range First, 4 parts of each electrophotographic toner and a non-coated ferrite carrier (trade name: FL-102 manufactured by Powder Tech Co., Ltd.)
0) 96 parts were mixed to prepare a two-component developer. Then, using the developer, a commercially available copying machine (trade name: SF-9800 manufactured by Sharp Corporation) was used to vertically transfer 2c onto A4 transfer paper.
A plurality of band-shaped unfixed images each having a size of m and a width of 5 cm were prepared. Then, a fixing machine in which a heat fixing roll having a surface layer made of Teflon and a pressure fixing roll having a surface layer made of silicone rubber are paired and rotated, the roll pressure is 1 Kg / cm ² and the roll speed is 50 mm / sec. And the surface temperature of the heat fixing roll is changed stepwise,
At each surface temperature, the toner image on the transfer paper having the unfixed image was fixed. At this time, it was observed whether or not the toner was smeared in the blank area, and the temperature region in which the toner was not smeared was set as the non-offset temperature region. Further, the difference between the maximum value and the minimum value in the non-offset temperature region was defined as the non-offset temperature width.

(2) Fixing Strength The surface temperature of the heat fixing roll of the fixing device was set to 130 ° C., and the toner image on the transfer paper on which the unfixed image was formed was fixed. Then, the image density of the formed fixed image is measured by a reflection densitometer (trade name: RD-91, manufactured by Macbeth Co.).
4), the fixed image was rubbed with a cotton pad, and the image density was measured in the same manner. The fixing strength was calculated from the obtained measured value by the following formula and used as an index of low energy fixing property. Fixing strength (%) = (image density of fixed image after rubbing / image density of fixed image before rubbing) × 100

(3) Fluidity The apparent density was measured according to JIS K5101 as an index showing the fluidity of the toner. (4) Storage stability 20 g of the toner was put in a polyethylene bottle having a volume of 150 cc and stored in a constant temperature bath at 50 ° C. for 24 hours. After allowing to cool to room temperature, the toner is taken out of the bottle, the fusion state (blocking) between the toner particles is observed, and those in which fusion does not occur at all are marked with a circle, and fusion occurs and causes practical problems of the toner. Was marked with x. Table 1 shows the test results of the above items.

[0023]

[Table 1]

As is clear from the test results in Table 1, the non-offset temperature region of the electrophotographic toner of the present invention does not cause an offset from a low temperature to a high temperature, and has a temperature range of 7%.
It was confirmed that a practically sufficient range of 0 to 85 ° C was maintained. Further, it was confirmed that the fixing strength at the fixing temperature of 130 ° C. was 80% or more and there was no problem in practical use. It was also confirmed that there were no problems in fluidity and storage stability. On the other hand, in Comparative Example 1, the low-temperature non-offset temperature was high, and the fixing strength was as low as 66%. Further, in Comparative Example 2, the non-offset temperature width was as narrow as 55 ° C., the apparent density due to the fluidity was also small, and there was a problem in storage stability. Further, in Comparative Examples 3 and 4, it was confirmed in the storage stability test that toner fusion occurred and there was a problem.

Further, a commercially available copying machine (trade name: manufactured by Toshiba Corp.) using the developer in each of the above-mentioned examples (1) is used.
BD-3801) was subjected to a continuous copy test up to 10,000 sheets, and the results are shown in Table 2. As a result, in all of the electrophotographic toners of Examples 1 to 5 of the present invention, it was confirmed that there were no problems in image density, fog in the non-image area, and triboelectric charge amount. The continuously copied original is A4 with a black portion of 6%, the image density is a reflection densitometer RD-914 manufactured by Macbeth, the fog is a color difference meter manufactured by Nippon Denshoku Co., and the triboelectric charge is Toshiba Chemical. A blow-off triboelectric charge measuring device manufactured by the same company was used.

[0026]

[Table 2]

[0027]

The electrophotographic toner of the present invention is capable of fixing at a low temperature while maintaining a sufficient non-offset temperature region, has excellent fixing strength and storage stability, and has a sufficient image density. The effect is that it is possible to obtain one. Therefore, when the electrophotographic toner of the present invention is applied to a copying machine, a printer, or the like, power consumption can be reduced, and the effect of lowering the machine cost by lowering the roll pressure and increasing the copying speed can be achieved.

[Procedure amendment]

[Submission date] June 26, 1996

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

The present invention will be described in detail below. The natural gas type Fischer-Tropsch wax applied to the toner for electrophotography of the present invention is produced by the Fischer-Tropsch method using natural gas as a raw material, and is a wax-like carbonization synthesized by catalytic hydrogenation of carbon monoxide. It is hydrogen. And structurally, it is a linear paraffin wax with few methyl branches. Examples of such natural gas-based Fischer-Tropsch wax include Shell M
Product name of DS company: FT-100, FT-0030, F
T-0050, FT-0070, FT-0165, FT
-1155 and FT-60S are on the market. The natural gas type Fischer-Tropsch wax has a melting point of 85 to 10 by a differential scanning calorimeter (hereinafter abbreviated as DSC).
Those at 0 ° C. are preferred. When the melting point is lower than 85 ° C., the storage stability of the toner is apt to cause a problem and the fluidity is apt to deteriorate. On the other hand, if the temperature is higher than 100 ° C., the effect of lowering the melting start temperature of the toner is small, and it becomes difficult to obtain the low temperature fixing property of the toner. The natural gas-based Fischer-Tropsch wax preferably has a penetration of 2 or less at 25 ° C. measured by JIS K-2235, and when it is more than 2, the fluidity tends to be poor when it is made into a toner, and the storage stability is high. And problems of triboelectricity with carrier particles and the like tend to occur. The content of the natural gas type Fischer-Tropsch wax in the electrophotographic toner is preferably 1 to 20% by weight based on the total toner. If it is less than 1% by weight, the releasability of the electrophotographic toner is insufficient and the high temperature offset resistance tends to be insufficient.
Further, since there is little effect of lowering the melting start temperature of the toner, it is difficult to obtain sufficient fixing strength on the transfer paper when fixing at a low fixing temperature. On the other hand, if it is more than 20% by weight, the compatibility with the binder resin is poor and the dispersion of the wax is likely to be poor, and the high-temperature offset resistance is likely to be poor due to the detachment of the wax alone during pulverization, which is not preferable.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Function] Polypropylene wax (melting point: 135 to 145 ° C.) which has been generally used for toners for electrophotography.
Was excellent in high temperature offset resistance, but was unsuitable for fixing at low temperature because of its high molecular weight and melting point. Therefore, in order to lower the melting start temperature of the toner, it has been proposed to add a low melting point wax having a low melting point and exhibiting sharp melting behavior. However, petroleum-based paraffin wax and low-melting point microcrystalline wax containing isoparaffin, naphthene, aromatic, etc., which have been conventionally known as low-melting wax, have a problem in storage stability as a toner because of their low molecular weight. Further, since the petroleum paraffin wax and the microcrystalline wax have a large penetration of 5 or more, when they become fine powder like toner, the powder fluidity is lowered and the image characteristics are likely to be adversely affected. The natural gas-based Fischer-Tropsch wax applied to the present invention has a lower melting point than polypropylene wax and therefore has excellent low-temperature fixability, and is compatible with existing petroleum-based paraffin.
Compared to fin wax, it has a very low melting point component and has excellent storage stability. At the same time, it has a penetrability of 2 or less, so its fluidity is not hindered when it is made into a toner, and there is no problem with frictional electrification. Does not occur. In addition, the conventional method of extracting water gas from coal and synthesizing it by the Fischer-Tropsch method
Compared to coal-based Fischer-Tropsch wax, natural gas-based Fischer-Tropsch wax not only satisfies offset prevention on the heat fixing roll and storage stability of toner at the same time, but also has the advantage that toner can be supplied at low cost because it uses natural gas as a raw material. Have.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

EXAMPLES The present invention will be described below based on examples. In the examples, “part” means “part by weight”. Example 1 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

Embodiment 2 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Embodiment 3 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

Embodiment 4 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Example 5 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

Example 6 The raw materials having the above blending ratios are mixed with a super mixer, hot melt kneaded with a twin-screw kneader, pulverized with a jet mill, and then classified with a dry air stream classifier to obtain an average particle diameter of 10
Particles of μm were obtained. Then, 100 parts of the particles and hydrophobic silica (trade name: Cabosil TS-53 manufactured by Cabot Corporation)
0.3 parts of 0) was stirred for 1 minute in a Henschel mixer, and hydrophobic silica was adhered to the surface of the particles to obtain the electrophotographic toner of the present invention.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Further, a commercially available copying machine (trade name: manufactured by Toshiba Corp.) using the developer in each of the above-mentioned examples (1) is used.
BD-38 10 ) was subjected to a continuous copy test up to 10,000 sheets, and the results are shown in Table 2. As a result, in all of the electrophotographic toners of Examples 1 to 6 of the present invention, it was confirmed that there were no problems in image density, fog in non-image areas, and triboelectric charge amount. The continuously copied original was A4 with a black portion of 6%, the image density was a reflection densitometer RD-914 manufactured by Macbeth, and the fog was a color difference meter- Z-1001DP manufactured by Nippon Denshoku Co., Ltd. The amount is a blow-off triboelectric charge measuring device manufactured by Toshiba Chemical Co.
TB-200 was used.

Claims (4)

[Claims] 1. A toner for electrophotography, comprising a natural gas type Fischer-Tropsch wax. 2. The melting point of natural gas Fischer-Tropsch wax measured by a differential scanning calorimeter is 85 to 100 ° C.
The electrophotographic toner according to claim 1, wherein 3. The toner for electrophotography according to claim 1, wherein the penetration of the natural gas Fischer-Tropsch wax at 25 ° C. is 2 or less. 4. The toner for electrophotography according to claim 1, wherein the content of the natural gas type Fischer-Tropsch wax is 1 to 20% by weight based on the total toner.