JPH05313403A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To provide a toner showing enough fixing performance without causing offset development even in a heater roller fixing method without supplying an offset preventing liquid such as silicone oil by adding a polypropylene wax having specified mol.wt. and volatile component to the toner. CONSTITUTION:This toner contains at least a resin, coloring agent, and polypropylene wax having 3000-10000 number average mol.wt. by vaper pressure osmotic method and <=0.5% volatile component. The resin component is preferably a styrene resin, satd. or unsatd. polyester resin and epoxy resin. As for the coloring agent, any proper pigments or dyes can be used without special limits, and for example, titanium oxide, zinc oxide, etc., are used according to the color of the toner in a single or mixed state. By specifying the volatile component of the wax to <=0.5%, good stability for charges of the toner and toner density in the a developer is obtd., and good picture stability and good state for splashing of the toner are obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing toner used for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic recording method or the like.

[0002]

2. Description of the Related Art In a developing process, a developer used in an electronic copying machine or the like is once attached to an image carrier such as a photoconductor on which an electrostatic charge image is formed, and then a photoconductor is used in a transferring process. After being transferred from the sheet to the transfer sheet, it is fixed on the copy sheet surface in the fixing step. At that time, as a developer for developing the electrostatic charge image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer (magnetic toner or Non-magnetic toner) is known. As the toner contained in the developer, there is a positively chargeable toner, and conventionally, as the toner imparting the positively chargeable toner chargeability, a charging agent such as a nigrosine dye, a quaternary ammonium salt or the like is added to the toner. A coating agent or the like that imparts a predetermined chargeability to a control agent or a carrier is known, while a charge control agent such as a metal-containing azo dye or an inorganic oxide such as fine powder silica is known to impart a negative chargeability. , And carrier coating agents are known.

Further, as a method for fixing on the copy paper surface in the fixing step, there are an open fixing method, a flash fixing method, a pressure fixing method, a heating roller fixing method and the like, but in an electrophotographic copying machine or the like, a heating roller is generally used. A fixing method is used. This method has extremely good thermal efficiency in fusing the surface of the roller and the image of the sheet to be fixed onto the sheet to be fixed, and can perform fixing at a high speed. It is extremely effective as a fixing method at times. However, in this method, since the toner image and the surface of the fixing roller are in pressure contact with each other in a heat-melted state, a part of the toner image is not adhered to the surface of the fixing roller and is transferred, and is retransferred to the next sheet to be fixed. Offset development may occur and stain the fixed sheet. Conventionally, as a method that does not cause offset development of toner and does not supply an offset prevention liquid such as silicon oil to the surface of the fixing roller, for example, a material having excellent releasability from toner such as fluorine resin on the roller surface. And a method of incorporating an olefinic wax such as low molecular weight polypropylene or low molecular weight polyethylene into the toner, as described in JP-A-52-3304, JP-B-60-17109, JP-B-57-52574, and JP-B-58-58664. And so on.

[0004]

However, conventional toners containing olefinic waxes are not always sufficiently satisfactory in terms of image quality stability during continuous long-term copying and printing, and developer durability performance. It wasn't something. For example, when copying with a two-component developer composed of a toner and a carrier, a toner using an olefin wax whose molecular weight is too low has an excellent effect of preventing offset development in fixing, but the fluidity of the toner is low. If the deterioration deteriorates, the streak on the black solid part becomes noticeable and the front or rear end of the black part becomes noticeable, resulting in poor copy image quality.Furthermore, the toner component does not adhere to the photoconductor during continuous copying. Copying is likely to cause defects, and the toner unevenly distributed in the developer deteriorates the chargeability of the toner charging, resulting in large image changes and instability. There was a problem that caused defects. Further, a toner using an olefin wax having an excessively high molecular weight cannot obtain a sufficient effect for preventing offset development in fixing, and therefore, if the amount of the olefin wax added is too large, the same problem as described above may occur. It was

As a result of intensive studies to solve the above problems, the present inventors have found that by adding a polypropylene wax having a specific molecular weight and a volatile component to the toner, the image quality is good, the image density is sufficient, and the stability is stable. The present invention has been accomplished by finding that an excellent toner can be obtained. That is, an object of the present invention is to provide a toner for developing an electrostatic charge image, which has excellent image quality, less deterioration in image quality over time, and excellent charging characteristics. Another object of the present invention is to provide an electrostatic charge image developing toner having high image density, good stability, less toner scattering, less image stain such as fog, and excellent life stability. .. Another object of the present invention is to develop an electrostatic charge image showing sufficient fixing performance without causing offset development even when toner is fixed by a heating roller fixing method in which an offset preventing liquid such as silicon oil is not supplied. To provide toner.

[0006]

The object of the present invention is, at least, a polypropylene wax having at least a resin, a colorant and a number average molecular weight of 3,000 to 10,000 by a vapor pressure osmometry and a volatile content of 0.5% or less. Is easily achieved by a toner for electrostatic charge development. As the resin component that can be used in the present invention, various known types suitable for toners for developing electrostatic images can be used. For example, polystyrene, chloropolystyrene, poly-α-
Methylstyrene, styrene-chlorostyrene copolymer,
Styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-
Vinyl acetate copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer And styrene-phenyl acrylate copolymer), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer and styrene- Phenyl methacrylate, etc.), styrene-α-chloromethyl acrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, and other styrene-based resins (styrene or styrene-substituted homopolymer or copolymer) Combined), vinyl chloride resin, rosin-modified maleic acid Fat, phenol resin, epoxy resin, polyester resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, polycarbonate resin, etc. However, as a particularly preferable resin for use in the present invention, a styrene resin,
Examples thereof include saturated or unsaturated polyester resin and epoxy resin. More preferably, the styrene resin is good.

Considering durability such as copy image stability and stability of fixing performance when a toner and a developer are continuously copied and used, a styrene resin is a low molecular weight polymer or a high molecular weight polymer. It is more preferable to use the molecular weight design. The low molecular weight polymer is a styrene-based copolymer containing 50 to 100 parts by weight of styrene and 50 to 0 parts by weight of an acrylic component as a monomer unit. The high-molecular weight polymer is a styrene-based copolymer containing 40 to 90 parts by weight of styrene and 60 to 10 parts by weight of an acrylic component as a monomer unit. What gives an acrylic component is a so-called acrylic monomer, and specific examples thereof include acrylic acid alkyl ester and methacrylic acid alkyl ester such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, Ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, lauryl methacrylate,
Stearyl methacrylate and the like, especially acrylic acid n-
Butyl, ethylhexyl acrylate, n-methacrylic acid
Butyl and lauryl methacrylate are preferred.

[0008] The low molecular weight combination has a molecular weight peak (Lp) of 3,000 to 80,000 in the GPC chromatogram.
It is more preferable to have at least one or more in 4000 to 50000. The low-molecular weight polymer has a molecular weight peak Lp of less than 3000, and the fixability is good, but the toner is likely to cause spent and miniaturization in the developing machine.
The image quality becomes poor and the life of the developer is deteriorated. In addition, the spent toner of which the molecular weight peak Lp is higher than 80,000,
Although miniaturization is unlikely to occur, the fixability becomes poor in the low temperature region, and the cold offset temperature also becomes poor, which is not preferable. The high molecular weight polymer is composed of (1) non-crosslinked high molecular weight component or (2) crosslinked component.

(1) In the case of non-crosslinked high molecular weight component The styrene-based copolymer has a molecular weight peak (Hp) of the high molecular weight substance in the GPC chromatogram of 100,000 to 1
More preferably 500,000 to 200,000 to 1200
Those having at least one in 000 are preferable. When the molecular weight peak Hp of the high molecular weight compound is lower than 100,000, the fixability is good, but hot offset is likely to occur and the usable fixing temperature range is narrowed, which is not preferable. Further, when the molecular weight peak Hp exceeds 1500000, the hot offset resistance is good, but the fixability in the low temperature region becomes poor and the lower limit fixing temperature rises, which is not preferable.

(2) Amount of cross-linked high-molecular weight component To obtain a cross-linked high-molecular weight component, a cross-linking agent of a constituent monomer is included as a constituent component, and the cross-linking agent amount is 0.01.
Is preferably 2 to 2% by weight, more preferably 0.02 to 1% by weight. The cross-linking agent is a compound mainly having two or more polymerizable double bonds, for example, divinylbenzene,
Aromatic divinyl compounds such as divinylnaphthalene, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol
Examples include dimethacrylate, diethylenic carboxylic acid esters such as 1,6-hexanediol / diacrylate aryl / methacrylate, N, N divinyl aniline, divinyl ether, and divinyl sulfide. Divinylbenzene, ethylene glycol dimethacrylate, 1,
6-hexanediol diacrylate is preferably used. Crosslinked high molecular weight tetrahydrofuran (TH
F) The insoluble content is preferably 3 to 95% by weight, more preferably 5 to 90% by weight. When the THF insoluble content is lower than 3% by weight, hot offset is likely to occur and the usable fixing temperature range is narrowed, which is not preferable. On the other hand, if the THF insoluble content is higher than 95% by weight, the crosslink density becomes too high and the fixing becomes unsatisfactory. (The insoluble content is measured by filtration using Celite.)

The ratio of low molecular weight to high molecular weight is 8
0-40% by weight is preferred. When the ratio of the low molecular weight product exceeds 80 parts by weight, the fixability is good, but the hot offset resistance is deteriorated and the usable temperature range is narrowed, which is not preferable, and the obtained toner becomes brittle and becomes a toner for a carrier. When the toner is used for a long time, toner scattering and fog on a white background portion increase. When the ratio of the low molecular weight product is less than 40 parts by weight, the durability and hot offset resistance of the developer are good, but the fixability in the low temperature region deteriorates and the lower limit fixing temperature rises, which is not preferable.

The glass transition temperature of the styrene copolymer resin is preferably 50 ° C. or higher. When the glass transfer temperature is lower than 50 ° C., when the toner is left at a high temperature of 40 ° C. or higher for a long period of time, the toner agglomerates or the toner sticks, resulting in a problem in use. The flow softening temperature of the styrene-based copolymer resin may be appropriately selected in consideration of the fixing performance of the toner and the durability performance of the developer.
When fixing at a temperature of 20 ° C to 220 ° C, for example, 8
0-160 degreeC is preferable and 90-150 degreeC is suitable. In addition to the main resin, other sub resins may be used in combination, and the amount of the sub resin used is preferably 30% by weight or less based on the total amount of the resin. As the sub-resin, for example, a styrene-based copolymer resin having only one molecular weight peak,
A rosin-modified maleic resin, a phenol resin, a silicone resin, a ketone resin, an epoxy resin, a polyester resin, a xylene resin, and a polyvinyl butyral resin can be used alone or in combination of two or more.

The colorant used in the present invention is not particularly limited as long as it is conventionally used.
Any suitable pigment or dye can be used. For example, titanium oxide, zinc white, alumina white, calcium carbonate, navy blue, carbon black, phthalocyanine blue,
Phthalocyanine green, Hansa yellow G, Rhodamine-based cleansers, Chrome yellow, Quinacridone, Benzidine yellow, Rose Bengal, Triallylmethane-based dyes, Anthraquinone dyes, Monoazo and disazo-based cleansers, etc. Alternatively, they are mixed and used. The content of the colorant may be an amount sufficient to color the toner so that a visible image can be formed by development, and for example, it is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the resin.

The polypropylene wax used in the present invention has the following characteristics. The number average molecular weight (Mn) of the polypropylene wax is 3000 to 10000 as a value measured by a vapor pressure osmotic pressure method.
Is more preferable, and 4000 to 9000 is more preferable. When the number average molecular weight is less than 3,000, there is an effect of preventing fixing offset, but it is not preferable because the image quality such as brush streaks in the black solid portion of the toner and image defects is poor, and a high image density cannot be obtained stably. When the number average molecular weight is higher than 10,000, the image quality and image stability are excellent, but the effect of preventing offset during fixing cannot be sufficiently obtained, which is not preferable.

If the volatile content of the wax is higher than 0.5%, the toner charge amount is not stable during continuous copying, and especially the toner concentration change in the two-component developer is large, and thus the image concentration is stable. It is not preferable because the performance is poor, the fogging is large, and the toner scattering inside the copying machine is increased. When the volatile content is 0.5% or less, the toner blackout amount, the stability of the toner concentration in the developer are good, and the image stability and the toner scattering state are also good. The volatile content in the wax is 11
It was dried at 5 ° C. for 4 hours and determined as the weight loss before and after drying. The melting point of the wax is preferably 100 to 180 ° C., further 120 to 160, as determined from the peak position temperature of the endothermic pattern of thermal analysis (differential thermal analyzer, differential scanning calorimeter, etc.).
C is more preferred. With a high melting point of 180 ° C or higher,
Even if the toner is heated with a kneader or the like when heated, the wax is not sufficiently melted, the compatibility with the resin deteriorates, and the minimum fixing temperature of the toner deteriorates, which is not preferable. Those having a low melting point of 100 ° C. or less are not preferable because the shear of kneading is less likely to occur when the toner is manufactured by a kneader and the dispersibility of the colorant and other internal additives is deteriorated.

The content of the wax in the toner varies depending on the resin component used, the colorant, the fixing mechanism, etc., but in the heating roller fixing method, it is generally 0.5 to 10 parts by weight with respect to 100 parts by weight of the resin. Further, about 1 to 6 parts by weight is preferable, and if it is less than 0.5 to 10 parts by weight with respect to 0.5 parts by weight, the effect of preventing offset in fixing becomes small, and it exceeds 10 parts by weight. And the fluidity and chargeability of the toner are adversely affected, resulting in poor image quality and poor image stability, which is not preferable. In addition to the polypropylene wax, a small amount of polypropylene wax, polyethylene wax, paraffin wax, higher fatty acid, fatty acid amide, metal soap or the like having a different number average molecular weight (Mn) may be added if necessary. In addition, in order to adjust the chargeability of the toner, in the case of positively charged toner, a nigrosine dye,
Known charge control agents for quaternary ammonium salts, triaminotriphenylmethane compounds, imidazole compounds, metal-containing azo dyes for negatively chargeable toners, salicylic acid metal complexes and alkylsalicylic acid metal complexes An appropriate amount of charge control agent may be added. The addition amount is preferably about 0.05 to 10 parts by weight with respect to 100 parts by weight of the resin.

Further, the fluidity of the toner on the surface of the toner particles,
For the purpose of improving aggregation resistance, adjusting toner resistance, and controlling charge, fine powder of metal oxide such as titania, silica, alumina, magnetite, ferrite, and fine powder of organic material such as acrylic resin may be added alone or in a mixture. It is possible. The addition amount is preferably about 0.01 to 5 parts by weight with respect to 100 parts by weight of the toner particles. Further, when the toner of the present invention is used in a two-component developer, it may be used by mixing it with a magnetic carrier, and the content ratio of the carrier to the toner in the developer is 10%.
0: 1 to 10 parts by weight is preferable. As the magnetic carrier, conventionally known ones such as iron powder, ferrite powder, magnetite powder and magnetic resin carrier having an average particle diameter of about 20 to 200 μm can be used. In addition, known silicone resins, acrylic resins, fluorine resins, etc. on these surfaces,
Alternatively, those coated with a mixture of these resins can be preferably used.

The toner of the present invention can also be used as a magnetic one-component toner containing a magnetic substance such as magnetite which is a one-component developer without using a carrier, or a non-magnetic one-component toner containing no magnetic substance. .. As a method for producing toner particles, various conventionally used toner production methods can be applied. For example, as a general example, first, a resin, a colorant, a wax, a charge control agent and the like are uniformly mixed with a known mixer. The mixture may be dispersed and mixed, and then the mixture may be melt-kneaded by a closed kneader or a uniaxial or biaxial extruder, cooled, pulverized, and classified. In recent years, a single-screw or twin-screw extruder has been mainly used because of its superiority such as continuous production of kneaders. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd. A twin-screw extruder manufactured by CK, a PCM type twin-screw extruder manufactured by Ikegai Iron Works, a co-kneader manufactured by Bus Co. and the like are preferable. The average particle size of the toner is 3 to 20 μm.
Is preferred. When the toner is externally added, the classified toner and the external additive may be stirred and mixed with a high-speed stirrer or the like.

[0019]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, the term "parts" simply means "parts by weight". <Example 1>

[Table 1] Styrene / n-butyl acrylate copolymer resin 100 parts by weight (flow softening point 126 ° C, glass transition point 60 ° C) ・ Colorant carbon black MA-7 5 parts by weight (manufactured by Mitsubishi Kasei) ・ Low molecular weight Polypropylene a 2 parts by weight (Mn = 8000, volatile matter = 0.2%, melting point = 148 ° C.)-Charging control agent Bontron P51 2 parts by weight (Quaternary ammonium salt manufactured by Orient Chemical Co., Ltd.) was blended, and continuous biaxial extrusion was performed. Kneading, pulverizing and classifying using a machine, a black toner having an average particle size of 10 μm was obtained. To 100 parts of this black toner, 0.2 part of silica powder (R972 manufactured by Nippon Aerosil Co., Ltd.) was externally added using a Henschel mixer to obtain a toner A. 4 parts of the obtained toner A and an average particle size of 100 which was surface-coated with a resin containing methyl silicone
A stirring agent A was prepared by mixing 100 parts of a ferrite powder carrier of μm.

Next, regarding this developer A, an organic photoconductor is used as a tourist, a fixing device coats silicon rubber with a thin layer of Teflon resin, and a heater lamp is mounted inside the roller. It is composed of a pressure roller, fixing temperature is set to 190 ℃ without supplying release liquid such as silicone oil, and copy speed is 50 sheets /
Minute copier, temperature 23 ~ 25 ℃, humidity 50 ~ 6
A live-action test of 50,000 sheets was carried out under the condition of 0% RH. The replenishment toner used in the actual copying test is toner A having the same composition as the toner containing the developer.

As a result of the live-action test, 50,000 from the beginning
The charge amount of the developer and the toner concentration were stable until the number of sheets. The average blackness of the copy black area is good, and the image density is good, and the image density is high and stable, and there is no increase in fog that is a stain on the copy white area, and there is almost no contamination due to toner scattering inside the machine, and it is durable. The toner and developer have excellent properties. Further, the fixing roller was hardly stained, and neither the front side nor the back side of the fed paper was stained at all. The transition of the copy image data and the like at this time is shown in FIG.

<Example 2> Toner B and developer B were prepared in the same manner as in Example 1 except that the addition amount of the low molecular weight polypropylene a in Example 1 was changed to 5 parts. Was carried out. 5 from the beginning as a result of the live-action test
The charge amount of the developer and the toner concentration changed stably up to 50,000 sheets. The uniformity of the black portion of the copy and the lack thereof were almost good, but the image density was high and stable, and there was no increase in fog, which is a stain on the white portion of the copy, and there was also contamination due to toner scattering inside the machine. It was a toner and a developer with excellent durability. Further, the fixing roller was not stained at all, and neither the front side nor the backside of the fed paper was stained at all.

Example 3 A toner similar to Example 1 except that the low molecular weight polypropylene a of Example 1 was changed to 2 parts of b (Mn = 5000, volatile content = 0.3%, melting point = 148 ° C.). C and the developer C were prepared, and an actual copying test was performed on 50,000 sheets. As a result of the live-action test, 50000 from the beginning
The charge amount of the developer and the toner concentration were almost stable up to the 0th sheet. Further, the uniformity of the black portion of the copy, the lack of defects and the image density are high and almost stable, and the fog that is the stain on the white portion of the copy is lower than the initial level and is almost stable. The toner and the developer were excellent in durability with almost no contamination. Further, the fixing roller was not stained at all, and neither the front side nor the back side of the printed paper was stained. The transition of the copy image data etc. at this time is shown in FIG.

Comparative Example 1 The low molecular weight polypropylene a of Example 1 was c (Mn = 12,000, volatile matter = 0.3).
%, Melting point = 150 ° C.) Toner C and developer C were prepared in the same manner as in Example 1, except that the actual copying test was performed on 50,000 sheets. 5 from the beginning as a result of the live-action test
The charge amount of the developer tends to decrease from the middle up to 50,000 sheets, and the toner density tends to increase, and the image density increases as a copy image, resulting in an image with poor tonality and initial fogging. Was good but tended to deteriorate from the middle. In addition, in terms of copy image quality, a black streak had a streak or a chip, which was not preferable. Further, there was a considerable amount of contamination due to toner scattering inside the machine, which was a problematic level. It should be noted that the fixing roller was scarcely soiled, and neither the front side nor the backside of the fed paper was soiled at all.

Comparative Example 2 A toner was prepared in the same manner as in Example 1 except that 2 parts of d (Mn = 2100, volatile matter = 0.3%, melting point = 144 ° C.) was used for the low molecular weight polypropylene a of Example 1. D and developer D were prepared, and an actual copying test was performed on 50,000 sheets. As a result of the live-action test, 50,0 from the beginning
The amount of developer charge and toner concentration were stable up to 00 sheets, and the black portion of the copy was uniform and good, and the image density was high and almost stable, but fog was extremely high and at a problematic level. It was In addition, the fixing roller was markedly contaminated, and the front and back sides of the passed paper were contaminated during the actual shooting.

Comparative Example 3 A toner was prepared in the same manner as in Example 3 except that 2 parts of e (Mn = 5000, volatile content = 0.9%, melting point = 148 ° C.) was used for the low molecular weight polypropylene c of Example 3. E and developer E were prepared, and an actual copying test was performed on 50,000 sheets. As a result of the live-action test, 50,0 from the beginning
The charge amount of the developer tends to decrease a little from the middle until 00 sheets,
The toner density tended to increase, and the image density in the black portion of the copy gradually increased from the middle, resulting in an image with slightly poor tonality, and the fog was low at the beginning but deteriorated from the middle. Moreover, there was a considerable amount of pollution caused by toner scattering inside the machine, which was a problem. The fixing roller was not stained at all, and neither the front side nor the backside of the fed paper was stained. The transition of the copy image data and the like at this time is shown in FIG. <Comparative Example 4> Toner F and developing F were prepared in the same manner as in Example 1 except that the toner composition of Example 1 was changed to the following, and an actual copying test was performed on 50,000 sheets.

[0027]

[Table 2] Styrene / n-butyl acrylate copolymer resin 100 parts by weight (flow softening point 130 ° C, glass transition point 62 ° C) ・ Colorant carbon black MA-7 5 parts by weight (manufactured by Mitsubishi Kasei) ・ Low molecular weight Polypropylene a 2 parts by weight MM (Mn = 8000, volatile content = 0.2%, melting point = 148 ° C.), low molecular weight polyethylene (melting point = 127 ° C.), charge control agent Bontron P51 (Quaternary ammonium salt manufactured by Orient Chemical Co., Ltd.) As a result of the actual copying test, the charge amount of the developer and the toner concentration were stable from the initial stage to 50,000 sheets. The uniformity of the black portion of the copy, good chipping, and high image density are stable, and the fog, which is the stain on the white portion of the copy, is stable and much lower than the initial stage, and there is no contamination due to toner scattering inside the machine. None of them were toners and developers excellent in durability performance.

<Explanation of Words> Image Density: A value obtained by measuring a copy black portion with a Masbeth reflection densitometer. Vd = 500V means the photoconductor surface potential of 700V
Indicates that the bias potential is 200V and the developing potential is 500V. Vd = 300V means the photoconductor surface potential of 500V
Indicates that the bias potential is 300V. Fog: As for the stain on the white background portion of the copy, the whiteness of the Hunter (Wb) before and after the copying of the used paper was measured using a Nippon Densoku color difference meter, and the value obtained from the difference between the values before and after the measurement was taken as the fog.
The development potential Vd is 500V. Toner charge amount: The developer was sampled and measured with a Toshiba chemical blow-off charge amount measuring device. Toner concentration: The developer was sampled, the toner was removed, and the toner concentration was determined by gravimetric analysis.

[0029]

EFFECT OF THE INVENTION By using the electrostatic charge developing toner of the present invention, the toner charging property is good, the copy image quality, the image density, the fog and the like are good, and the copy image and the image quality change even during continuous copying. The present invention provides a great industrial advantage in that the heating roller is stable, and the heating roller is less contaminated and exhibits sufficient fixing performance.

[Brief description of drawings]

FIG. 1 Transition of copy image data and the like during continuous copying in Example 1

2 is a transition of copy image data and the like during continuous copying in Example 3. FIG.

FIG. 3 Transition of copy image data and the like during continuous copying in a comparative example

Claims (1)

[Claims] 1. A toner for developing an electrostatic charge image comprising at least a resin, a colorant, and a polypropylene wax having a number average molecular weight of 3,000 to 10,000 and a volatile content of 0.5% or less by a vapor pressure osmometry.