KR20050079638A - Positive charging magnetic torner composition - Google Patents

Abstract

The present invention relates to a one-component antistatic toner, in particular (i) magnetic magnetic toner particles comprising a positively charged charge control agent (ii) ancillary hydrophobic silica (iii) finely fluorinated organic powder and (iv) a tin content of 20 It relates to a one-component positive electrostatic toner containing fine metal oxide powder of about 80% by weight. The toner of the present invention has the advantage of extending drum life, reducing background contamination, and improving long-term reliability, and thus can be effectively used in an image developing apparatus.

Description

Electrostatic magnetic toner composition {POSITIVE CHARGING MAGNETIC TORNER COMPOSITION}

The present invention relates to a one-component antistatic toner, and more particularly, the present invention relates to an electrostatic magnetic toner composition that extends drum life, reduces background contamination, and improves long-term reliability.

In general, the dry developing method of electrophotography can be classified into two-component developing method using two-component developer including toner and carrier and one-component developing method using one-component developer including only toner without using carrier. The one-component developing method has the advantages of miniaturization, low cost, and easy maintenance. In recent years, copiers and printers using a one-component system have been widespread, and printing speed has been remarkably improved.

Unlike bicomponent toners in which carrier particles are included for the transport of toner particles, magnetic one-component toners have a great influence on the flow of toner particles themselves.

Non-magnetic one-component toner controls the adhesion thickness of the toner layer formed on the developing roller by applying pressure to the developing roller by using a blade made of metal or resin, and the two-component toner is frictionally charged with the carrier. Move the toner by

However, unlike the two-component toner, in the magnetic one-component developing system, the toner moves to the developing roller using the magnetic attraction force as the driving force. That is, the layer controlling member (doctor blade) contacts the developing roller, and the toner is charged by friction generated while the one-component toner passes between the doctor plate and the developing roller. The charged toner is present on the surface of the developing roller by the electrostatic force.

Charged toner is used to visualize an invisible image present on the drum surface in the form of a latent image. If the magnetic toner repeatedly contacts the surface of the organic drum (Organic Photo Conductor = OPC), which is manufactured by coating more than one layer of organic resin, wear occurs on the surface of the drum. Does not cause problems. Therefore, background contamination of the non-image portion is also increased, and the density of the image, i.e., black color, is also insufficient.

In the prior art, a method of using alumina particles together with high hardness silica used to impart fluidity of a toner to prevent burn contamination due to worn drum surface is disclosed in Japanese Patent Laid-Open No. 10-326028. have. Further, Japanese Laid-Open Patent Publication No. 11-153886 discloses a positively charged color toner containing a urethane-modified polyester resin as the binder resin of the toner.

However, since this method does not reduce the amount of hard silica used as a fluidizing agent or does not externally attach, it is not a very effective means of reducing the wear of the drum surface. In addition, even if the external amount is reduced too much, the fluidity is lowered and the cohesive force of the toner is too high, so that the transfer efficiency is lowered, so that the image density, that is, blackness, is lowered. Therefore, it is practical to simultaneously obtain a high image density and essentially prevent wear of the drum surface. It was extremely difficult.

Therefore, even after long-term radiation, the developing drum surface has less wear and not only increases drum life, but also has excellent charging characteristics, which can reduce background pollution and maintain high image density, thereby improving long-term reliability. More research on the need to provide has been called for.

The inventors of the present invention are trying to find a positively charged magnetic toner that extends drum life, reduces background contamination, and improves long-term reliability, while (i) magnetic magnetic toner particles, (ii) are opposed to the charges of the magnetic magnetic toner particles. A toner composition was developed comprising silica with charge, (iii) fine metal oxide powder containing tin, and (iv) fine fluorinated organic powder.

It is an object of the present invention to provide an electrostatic magnetic toner composition that extends drum life, reduces background contamination, and improves long term reliability.

Another object of the present invention is to provide a method of using the electrostatic magnetic one-component toner according to the present invention in an image forming apparatus including an organic photoconductor and forming an image in a non-contact manner.

In order to achieve the above object, the present invention

i) Magnetic magnetic toner particles comprising binder resin, magnetic body and charge control agent

ii) ancillary hydrophobic silica having a hydrophobized specific surface area of 80 to 200 m 2 / g

iii) fine powders of fluorinated organics and

iv) Provided is a one-component chargeable toner containing fine metal oxide powder having a tin oxide content of 20 to 80 wt%.

The magnetic magnetic toner particles include 20 to 80 parts by weight of the binder resin, 20 to 70 parts by weight of the magnetic body and 0.15 to 4 parts by weight of the charge control agent.

In the present invention, the average particle diameter of the magnetic toner particles is not particularly limited, but is preferably 5 to 30 µm. The magnetic toner particles can be produced by melt kneading pulverization, polymerization, or the like.

The binder resin used in the present invention may use a fixing resin known in the art, and in particular, polycondensation reaction of an alcohol component and a carboxylic acid component is preferable, and the binder resin is preferably contained in an amount of 20 to 80 parts by weight based on the magnetic magnetic toner particles. Do.

Examples of the alcohol component include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, cyclohexane dimethanol, xylene glycol, bisphenol A, bisphenol A ethylene oxide, and bisphenol A propylene. Divalent or more alcohol or alcohol derivatives, such as an oxide, sorbitol, or glycerin, can be used individually or in mixture. In addition, the carboxylic acid component is a divalent acid such as maleic acid, fumal, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, trimellitic acid, cyclopentane dicarboxylic acid, succinic anhydride, trimellitic anhydride or maleic anhydride. The above carboxylic acids, carboxylic acid derivatives or carboxylic anhydrides can be used alone or in combination.

Examples of the binder resin include acrylic ester polymers such as polyester, methyl polyacrylate, ethyl polyacrylate, butyl polyacrylate, polyethyl acrylate 2-ethylhexyl or polylauryl acrylate, methyl polymethacrylate, butyl polymethacrylate, poly Copolymer of methacrylic ester polymer acrylic ester and methacrylic acid ester, such as hexyl methacrylate, polyethyl methacrylate 2-ethyl hexyl, or poly methacrylate lauryl; styrene monomer with acrylic ester or methacrylic ester Copolymer Ethylene-based polymers such as polyvinyl acetate, polyvinyl propionate, polyvinyl acetate, polyethylene or polypropylene and copolymers thereof Styrene-based copolymer polyvinyl such as styrene butadiene copolymer, styrene isoprene copolymer or styrene maleic acid copolymer Ether poly Ketone carbonyl polyester polyurethane rubbers, polyamide epoxy resin, polyvinyl butyral Butch rosin-modified rosin phenol resin and the like, alone or mixed to be preferred to use, and it is particularly preferred to use a styrene butadiene copolymer.

As the magnetic body used in the present invention, ferromagnetic elements, alloys or mixtures thereof, granular magnetic components or acicular magnetic components can be used. Specific examples thereof include metal alloys or mixtures of iron metals such as magnetite, magnetite, hematite, ferrite, ferrite, cobalt, nickel or manganese and metals such as aluminum, copper, lead, magnesium, selenium, titanium, tungsten and vanadium. Alloy magnetic oxide and the like can be used. The magnetic body is preferably a fine powder having an average diameter of 1 μm or less, and preferably contained in an amount of 20 to 70 parts by weight based on the magnetic magnetic toner particles.

The charge control agent used in the present invention, such as quaternary ammonium salt phosphonium salts such as nigrosine tributylbellammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate which impart positive charge Onium salts and their lake pigments Triphenylmetal dyes and their lake pigments Metal salts of fatty acids Diorgano-oxidized tin compounds such as dibutylated tin, dioctyl oxide tin and dicyclohexyl oxide tin Dibutyl borate tin, dioctyl borate tin, dicy One or more selected from organoborate tin guanidine compounds and imidazole compounds such as chlorhexyl borate tin, etc. may be used in combination, and as the rake agent, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdate, tannic acid, Lauric acid, gallic acid, ferricyanic acid or ferrocyanic acid are used. In particular, the charge control agent of the present invention is preferably nigrosine or quaternary ammonium salt. The content of the charge control agent in the toner is not particularly limited, but is preferably included in an amount of 0.15 to 4 parts by weight based on the magnetic magnetic toner particles.

In addition, in order to prevent the offset of the magnetic toner particles, a release agent may be further included. Examples of the release agent include various waxes or low molecular weight olefin resins. Specifically, the olefin resins are preferably polypropylene, polyethylene, propylene ethylene copolymers, and more preferably polyethylene. . The release agent is preferably included in 0.05 to 5 parts by weight based on 100 parts by weight of the binder resin.

The secondary positively hydrophobic silica used in the present invention prevents nonuniformity of charging generated by agglomeration between toners, and serves to improve charge uniformity by spreading the toner evenly after passing through the doctor blade. It is preferable that the specific surface area of the said hydrophobic silica is 80-200 m <2> / g, More preferably, it is 100-150 m <2> / g.

In particular, the reason for using the positively charged hydrophobic silica is to give only positive fluidity to the positively charged magnetic toner particles. When the positively charged hydrophobic silica is used, the amine-containing coupling agent, which is mainly used to impart environmental stability and static charge, is humidity. It is sensitive to the long-term reliability of the toner, and the frictional charge amount of the toner itself increases, which also increases the electrostatic force attached to the drum surface. There is a problem in using for a long time because it falls.

When the specific surface area of the ancillary hydrophobic silica used in the present invention is less than 80 m 2 / g, the effect of imparting fluidity improvement to the toner is insufficient, and when a large number of solid images are outputted, image contamination may occur on the solid images. There is a problem, and when it exceeds 200 m2 / g, there is a problem in that the buried silica on the surface of the magnetic toner particles, the effect of imparting fluidity improvement to the toner is reduced.

The hydrophobic silica used in the present invention is included in an amount of 0.1 to 0.5 parts by weight based on 100 parts by weight of the magnetic toner particles. When the content of the hydrophobic silica is less than 0.1 parts by weight, the fluidity is insufficient, so that the toner migration to the layer control member is not smooth, and the image concentration becomes nonuniform. Since the triboelectric charging does not occur sufficiently, problems of background contamination and blackness (image concentration) decrease due to the reverse polarity toner occur.

The hydrophobization treatment of the silica particles can be carried out by applying or adhering a silane coupling agent or silicone oil to the silica particles.

The silane coupling agent is dimethyldichlorosilane, trimethylchlorosilane, methyltrichlorosilane, arylphenyldichlorosilane, benzyldimethylchlorosilane, bromine methyldimethylchlorosilane, P-chlorophenyltrichlorosilane, 3-chloropropyltrimethoxy , Vinyltriethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, or hexamethyldisiragen and the like can be used.

In addition, the hydrophobic treatment of silica with silicone oil may be used to reduce background contamination, such as dimethylsilicone oil, methylphenylsilicone oil, methylhydrogen silicone with a viscosity of 50 ?? 10000 cps (centipoises) at 25 ° C. Oil, alkyl modified silicone oil, alcohol modified silicone oil, epoxy modified silicone oil, phenol modified silicone oil, carboxy modified silicone oil, mercapto modified silicone oil, etc. can be used.

The method of hydrophobization by the silicone oil is not particularly limited as long as the silicone oil is adsorbed on the surface of the inorganic powder. Examples of the hydrophobic treatment by the silicone oil include a silica itself in a mixing bath, followed by stirring. There is a method of heating and drying for a predetermined time in the mixing tank while continuing to stir it.

The method of attaching the hydrophobic silica to the surface of the magnetic toner particles may be performed using a general stirrer such as a turbine type stirrer, a Henschel mixer or a super mixer, or an apparatus called a surface reformer, for example, Nara Hybridization Systems Co., Ltd. ) And the like. The hydrophobic silica on the surface of the magnetic toner particles may be attached to the magnetic toner particles in a weak adhesion state, or the hydrophobic silica may be fixed to the surface of the magnetic toner particles in a buried state.

In the present invention, the specific surface area of silica means the specific surface area measured by the BET (Brunauer, EmmettTeller) method, and the value can be measured by a commercially available high precision automatic gas adsorption device or the like. The above-described measuring device obtains the BET specific surface area (S, m 2 / g) by measuring the amount of gas adsorption necessary for forming a monolayer on the surface of the hydrophobic silica particles using an inert gas, particularly nitrogen gas, as the adsorption gas.

The fine fluorinated organic powder used in the present invention suppresses abrasion on the surface of the drum and at the same time increases the transfer efficiency of the toner, thereby maintaining a high image density even when used for a long time.

The fluorinated organic fine powder is a fluorine resin fine powder such as polyfluorovinylidene, polytetrafluoroethylene, etc. Fluorinated styrene-acrylic acid copolymer fine powder Fluorinated polyethylene fine powder Fluorinated acrylate polymer fine powder or copolymers thereof Can be used. The fluorination treatment method is not particularly limited and may be any conventional method.

The fine fluorinated organic powder preferably has an average particle diameter of 0.1 to 4.0 µm, more preferably 0.15 to 3.5 µm. If the average particle diameter is less than 0.1 μm, the fluorinated organic fine powder is insufficiently present on the surface of the magnetic toner particles, causing toner fusion under a high temperature environment. There is a problem that the separation occurs, and the fixing of the toner particles occurs.

The fine fluorinated organic powder is preferably included in an amount of 0.05 to 0.4 parts by weight, and more preferably 0.1 to 0.3 parts by weight, based on 100 parts by weight of the total amount of magnetic toner particles. If the content is less than 0.05 parts by weight, the formation of a fluorinated organic fine powder layer on the surface of the magnetic toner particles is insufficient, and it is difficult to suppress the occurrence of wear on the drum surface. When the content is more than 0.4 parts by weight, the fine fluorinated organic powder is separated from the surface of the magnetic toner particles. There is a problem that the background pollution occurs because the reverse polar toner is generated.

The fine metal oxide powder used in the present invention serves to remarkably improve drum contamination and drum wear, in which the toner is fused onto the drum surface when a large amount is output for a long period of time.

The fine metal oxide powder preferably has an average particle diameter of 50 nm to 500 nm, more preferably 60 nm to 300 nm. If the average particle diameter is less than 50 nm or more than 500 nm, there is a problem in that the improvement effect is reduced in terms of fluidity and durability.

The fine metal oxide powder includes 20 to 80 wt% of tin oxide, and preferably 25 to 70 wt%. When the tin oxide content is less than 20% by weight, the effect of removing the contamination of the drum is reduced, which may cause burn contamination. When the content exceeds 80% by weight, the frictional charging value is lowered, resulting in image unevenness. have. In the present invention, the fine metal oxide powder containing tin oxide includes, but is not limited to, titanium dioxide, aluminum oxide, zinc oxide, magnesium oxide, cerium oxide, iron oxide, or copper oxide containing tin oxide. Can

The fine metal oxide powder is preferably included in an amount of 0.05 to 0.5 parts by weight, and more preferably 0.1 to 0.4 parts by weight, based on 100 parts by weight of the total amount of magnetic toner particles. If the content is less than 0.05 parts by weight, image unevenness occurs due to drum contamination, and if it exceeds 0.5 parts by weight, drum wear occurs.

The present invention also provides a method of using the one-component antistatic toner according to the present invention in a non-contact image forming apparatus comprising an organic photoconductor. The image forming apparatus includes a conventional image forming apparatus including an organic photoconductor and forming an image in a non-contact manner.

An image forming apparatus to which the toner according to the present invention is applied includes a photoconductor photoconductor (photoconductive drum), a means for charging the photoconductor photoconductor surface, a means for forming an electrostatic latent image on the photoconductor photoconductor surface, a means for accommodating toner, and a toner And a means for developing an electrostatic latent image on the surface of the photoconductor photoconductor for supplying the toner image, and a means for transferring the toner image from the surface of the photoconductor photoconductor to the transfer material.

In the development method using one-component toner, the non-contact image forming method is mainly charged by frictional charging of the toner and the doctor blade (layer control member) and the sleeve (sleeve: developing roller surface layer) and the toner layer by the magnetic blade. Is formed. The toner layer thus formed is developed by applying a direct current and an alternating current bias to the latent image of the toner on the photoconductor surface. The non-contact image forming method has a feature of reducing non-image contamination.

On the other hand, in the contact image forming method, the toner and the doctor blade are subjected to frictional charging, and the toner layer is formed by the elastic blade. It is mainly characterized by solid images and wire reproducibility. On the other hand, the contact developing method has a disadvantage in that the formed toner layer is always in contact with the photoconductor surface, thereby promoting wear on the photoconductor surface (photoconductive drum surface) as compared with the noncontact developing method.

In the non-contact developing method, abrasion of the drum surface is caused by repeated contact with the photoconductive drum surface. The toner of the present invention reduces or suppresses the occurrence of such abrasion to provide high image density and clean image quality.

<Example 1>

1. Preparation of magnetic toner particles

48 parts by weight of styrene butadiene copolymer resin as binder resin, 45 parts by weight of iron oxide as magnetic material, 2 parts by weight of nigrosine as charge control agent, and 5 parts by weight of low molecular weight polyethylene having molecular weight 2000 as release agent were mixed with a Henschel mixer. This was melt kneaded at a temperature of 145 ° C. in a biaxial melt kneader, pulverized with a jet mill grinder, and classified in a wind classifier to prepare toner base particles having a volume average particle diameter of 9.1 μm.

2. Preparation of Single Component Antistatic Toner

0.1 parts by weight of ancillary hydrophobic silica having a specific surface area of 90 m2 / g hydrophobized with hexamethyldisilazane (abbreviated as "HMDS") with respect to 100 parts by weight of the magnetic toner particles, and polyfluorovinyl having an average particle diameter of 0.1 µm. At a composition ratio of 0.05 parts by weight of polyvinylidene fluoride (hereinafter referred to as “PVDF”) and 0.3 parts by weight of titanium oxide having an average particle diameter of 50 nm containing 45% of tin, the mixture was stirred and mixed for 5 minutes using a Henschel mixer to attach to the magnetic toner particle surface. One-component positive electrostatic toner was prepared.

<Example 2-89 and Comparative Example 1-32>

Using Hensel mixer at the composition ratio shown in Table 3, using an anionic hydrophobic silica hydrophobized by the method shown in Table 1, a fine metal oxide powder containing tin as shown in Table 2, and a fluorinated organic powder of polyfluorovinylidene (PVDF) as shown in Table 3 By stirring and mixing the particles for a minute on the surface of the magnetic toner particles, the one-component positive electrostatic toners of Examples 2 to 89 and Comparative Examples 1 to 32 were prepared.

In Table 1, the specific surface area is a value measured by the BET method.

Comparative Example 33

100 parts by weight of the prepared magnetic toner particles are positively charged silica treated with an amine coupling agent, 0.1 parts by weight of positively charged silica having a specific surface area of 100 m2 / g, and a PVDF 0.05 having an average particle diameter of 0.1 μm. At a composition ratio of 0.3 parts by weight of titanium oxide having an average particle diameter of 50 nm containing 45% by weight and tin, the mixture was stirred and mixed for 5 minutes using a Henschel mixer to prepare a one-component antistatic toner.

Experimental Example 1

Non-contact, magnetic one-component photocopiers (NP 3020, manufactured by Lotte Canon Co., Ltd.) of commercially available one-component antistatic toners prepared in Examples 1 to 89 and Comparative Examples 1 to 33 were used at room temperature and humidity. Up to 50,000 copies in an environment of 20 ° C., 55 ± 5% RH). The image concentration, background contamination occurrence and drum contamination was measured by the following method, and the results are shown in the following table.

1) Image Density (Black)

Solid area images were measured with Macbeth Reflectometer RD918. The image density value can be used in the present invention if it is 1.30 or more.

2) Background Pollution

The non-image was visually measured through an optical microscope.

(Circle): The background contamination phenomenon of an image was not recognized.

(Triangle | delta): The background contamination phenomenon of an image was partially confirmed.

X: The background pollution phenomenon of an image was confirmed clearly.

3) Contamination / wear of developing drum

After the toner was transferred onto the transfer paper, the drum was taken out of the copier and the drum surface was visually measured through an optical microscope.

○: Drum contamination is not confirmed.

△: drum contamination is partially confirmed

(Available because it does not appear in the image).

X: Drum contamination was clearly confirmed. (Appears as a drop in image density.)

From the above table, it was confirmed that the one-component positive electrostatic toners of Examples 1 to 89 had sufficient blackness with an image density (blackness) of 1.30 or more, and less background contamination of the image and contamination of the drum surface. . On the other hand, the magnetic toners of Comparative Examples 1 to 32 were found to have a problem in actual use due to severe drum contamination and background contamination of images. In addition, it was found that the magnetic toner of Comparative Example 33 using positive electrostatic silica had a high initial blackness but was unable to maintain blackness while copying about 10,000 sheets. As the number of copies increased by using the toner initially charged in a certain range at a time, it was found that the toner was not moved to the photoconductor surface and the blackness dropped as the toner portion charged in a certain range was used.

As mentioned above, the present invention has the advantage of extending drum life, reducing background contamination, and improving long-term reliability.

Claims (12)

a) magnetic toner particles comprising a binder resin, a magnetic substance and an antistatic charge control agent; b) ancillary hydrophobic silica having a hydrophobized specific surface area of 80 to 200 m 2 / g; c) fluorinated organic fine powder; And d) A one-component positive electrostatic toner comprising fine metal oxide powder having a tin content of 20 to 80 wt%. The method of claim 1, a) 100 parts by weight of magnetic toner particles b) 0.1 to 0.5 parts by weight of ancillary hydrophobic silica having a hydrophobized specific surface area of 80 to 20 m 2 / g c) 0.05 to 0.4 parts by weight of fine powders of fluorinated organics and d) One-component toner containing 0.05 to 0.5 parts by weight of fine metal oxide powder. The method of claim 2, The magnetic toner particles comprise 20 to 80 parts by weight of binder resin, 20 to 70 parts by weight of magnetic material and 0.15 to 4 parts by weight of charge control agent based on the total weight of magnetic toner particles. 2. The binder resin of claim 1, wherein the binder resin is a polycondensation reaction of an alcohol component and a carboxylic acid component, methyl polyacrylate, polyethyl acrylate, butyl polyacrylate, 2-ethylhexyl polyacrylate, lauryl polyacrylate, and poly meta. Methyl methacrylate, butyl poly methacrylate, polyhexyl methacrylate, polyethyl methacrylate 2-ethyl hexyl, poly methacrylate lauryl, copolymers of acrylic esters and methacrylic esters, styrene monomers and acrylic esters or Copolymers with methacrylic acid esters, polyvinyl acetate, polypropionate vinyl, polyvinylbutyrate, polyethylene, polypropylene, styrene butadiene copolymers, styrene isoprene copolymers, styrene maleic acid copolymers, polyvinyl ethers, polyvinyl ketones, Polyester, polyamide, polyurethane, rubber, epoxy resin, polyvinyl part A one-component toner, characterized in that at least one selected from the group consisting of chiral rosin, modified rosin and phenol resin. The magnetic material of claim 1, wherein the magnetic material is a metal such as iron oxide, cobalt, nickel, or manganese such as magnetite, magnetite, hematite, ferrite, and the like, and aluminum, copper, lead, magnesium, selenium, titanium, tungsten, vanadium A one-component toner, characterized in that at least one selected from the group consisting of a metal alloy or a mixture ferromagnetic alloy and a magnetic oxide. 2. The one-component toner according to claim 1, wherein the antistatic charge controlling agent is nigrosine or quaternary ammonium salt which imparts positive chargeability. The toner according to claim 1, wherein the toner particles are magnetic toner particles further comprising 0.05 to 5 parts by weight of a release agent based on 100 parts by weight of the magnetic toner particles. 2. The one-component toner of claim 1, wherein the magnetic toner particles have an average particle diameter of 5 to 30 mu m. The one-component toner according to claim 1, wherein the hydrophobized hydrophobic silica having a specific surface area of 80 to 200 m &lt; 2 &gt; / g is hydrophobized by applying and attaching a silane coupling agent or silicone oil to silica particles. According to claim 1, wherein the fluorinated organic fine powder is a fluorinated resin fine powder such as polyfluorovinylidene or polytetrafluoroethylene fluorinated styrene-acrylic acid copolymer fine powder fluorinated polyethylene fine powder fluorinated acrylate polymer fine powder or these One-component toner, characterized in that the copolymer fine powder. The toner according to claim 1, wherein the fine metal oxide powder is at least one selected from the group consisting of titanium dioxide, aluminum oxide, zinc oxide, magnesium oxide, cerium oxide, iron oxide, copper oxide and tin oxide. 12. A method of using the one-component antistatic toner according to any one of claims 1 to 11 in a non-contact image forming apparatus comprising an organic photoconductor.