DE69837641T2 - TONER COMPOSITION FOR THE DISPERSION OF ELECTROSTATIC IMAGES - Google Patents

Description

The The present invention relates to a powdery developer (hereinafter called toner composition) for development electrostatically latent images in electrophotography, especially a toner composition for the development of electrostatic latent images, which are for a Laser beam printer or an LED printer is suitable in which flash fixation on the high-speed printed material.

The Electrophotographic process includes a charge phase in which a uniform electrostatic charge on a photosensitive body using a photoconductive Transfer material is an imaging phase in which the exposure and the formation an electrostatic latent image, a development phase, in the toner electrostatically on the area of the latent image is attached, a transfer phase, in which transfer a toner image carrier is a fixing phase in which the toner image by pressure, heat or Flash, etc. is fixed on the toner image carrier, a cleaning phase, in the not transferred Toner remaining on the photosensitive body is removed, and a discharge phase in which the electrostatic charge is on the photosensitive body is dismantled and this is brought back to its original state, wherein prints are obtained by repeating these phases.

Cold pressure fixing, this is one of the fixing methods used by electrophotographic printers has the advantage that an immediate start-up is possible, the power consumption is low, since no heater as a heat source is used and not the risk of burning the fixing area However, there are also disadvantages, such as that the pressure-fixing properties are inferior and have a visible print gloss as well as low quality so that, in general, the use of heat fixing systems is more advantageous. As such, heat fixing systems are contact heat fixing systems based on hot roller fixing and non-contact heat fixing systems based on fixation by flash or oven fixation through the passage through the heated atmosphere of an electric heater known.

• (1) Da es sich um kontaktfreies Fixieren handelt, kommt es zu keiner Verschlechterung der Druckauflösung zum Zeitpunkt der Entwicklung.
• (2) Es gibt keine Wartezeit nach dem Einschalten der Stromversorgung, und ein "Schnellstart" ist möglich.
• (3) Auch wenn es aufgrund eines Systemfehlers zu Aufzeichnungspapierstau in dem Fixiersystem kommt, entstehen keine Papierverbrennungen.
• (4) Unabhängig von der Art des Tonerträgers (Qualität des Aufzeichnungspapiers, Haftpapier, dickes Papier etc.) werden gute Fixiereigenschaften erzielt.
• (5) Da nur der Toner, der Schwarzbereiche umfasst, erhitzt wird, läuft das Aufzeichnungspapier oder dergleichen aufgrund der Wärme nur in geringem Maße ein, die Papierzuführeigenschaften sind hervorragend, und Hochgeschwindigkeitsdrucken ist möglich.

The present invention relates to flash-fixing, which is a typical non-contact heat-fixing system, and in the flash-fixing system, the visible toner image is exposed to the emission spectrum of, for example, a xenon or halogen lamp for a short time in the millisecond range so that the toner softens and shrinks Radiant heat is melted and fixed on the toner carrier ( JP-A-07-107805 ), this method having the following advantages:

• (1) Since it is non-contact fixing, there is no deterioration of the printing resolution at the time of development.
• (2) There is no waiting time after the power is turned on, and a "quick start" is possible.
• (3) Even if a recording error occurs in the fuser due to a system error, paper burns will not occur.
• (4) Regardless of the kind of the toner carrier (quality of the recording paper, adhesive paper, thick paper, etc.), good fixing properties are obtained.
• (5) Since only the toner comprising black areas is heated, the recording paper or the like is inferior due to the heat, the paper feed properties are excellent, and high-speed printing is possible.

There however, the flash fixation system includes non-contact heat fixation the extent of Energy loss to the environment considerably and, since it is Flashing light energy is the thermal efficiency in comparison for heat roller fixation inadequate. In other words it is a fixation system with high energy consumption. Furthermore is the problem of decomposed materials in flash fixing systems, because the surface temperature the toner composition due to exposure to a sudden High energy lightning without delay a high temperature of several hundred degrees in a very short time achieved and some additives of the toner composition decomposes or gasified, causing an unpleasant odor or to the formation of toxic gases.

in the Generally, in flash fixation system printers for removal of the decomposed materials at the time of flash fixation in the flash fixation area applied a method in which the decomposition products are recovered be passed through an activated carbon filter or the like and the toxic gases are adsorbed and collected. however In this context, there is the problem of increased operating costs, because a filter is used and the life of this filter shortened becomes.

The present invention has therefore been made to solve the aforementioned problems and provides a Toner composition for developing electrostatic latent images, wherein by preventing the formation of the decomposition products in a printer that uses a flash fixing system, a filter is no longer required or the problem of higher operating costs due to the shortened life of the filter is solved.

US-A-4539284 . JP-A-08-179549 . JP-A-07-110596 and JP-A-07-191492 each disclose a toner composition comprising a binder resin, a colorant and a charge control agent. In the composition off US-A-4539284 when the charge control agent is a quaternary ammonium salt, while the charge control agent is in the composition JP-A-08-179549 Nigrosine, a quaternary ammonium salt or a Triphenylmethanfarbstoff can be. Reveal in a similar way JP-A-07-110596 and JP-A-07-191492 each flash-fixing toner in which the charge control agent is a nigrosine dye.

If but a quaternary one Ammonium salt is used, it is difficult, the toner good charge properties and when a triphenyl type charge control agent is used, the charge control agent, if the fixation occurs at high temperatures, decomposes, and the pressure environments get dirty. When a known charge control agent of the Nigrosin type are used, as more comprehensive below explained is formed, gases.

The The present invention provides a toner composition for development electrostatic latent images as used in flash fixation is prepared, which is characterized in that in a toner composition, the at least one binder resin, a colorant and a charge control agent of the nigrosin type, by heating the toner for 90 seconds at 330 ° C benzene concentration is not more than 60 μg / g.

The The present invention also provides a method of manufacture a charge control agent of the nigrosine type prepared thereby characterized in that a compound of the nigrosin type in a Temperature of at least 100 ° C, but not more than 250 ° C, and vacuum-heat-treated at a vacuum of 0.2 MPa or less to provide the nigrosine type charge control agent becomes.

Brief explanation of the drawings

1 : A schematic longitudinal sectional view showing a printer apparatus for the application of a toner composition of the present invention.

2 Fig. 10 is a schematic cross-sectional view showing a fixing device for fixing a toner composition of the present invention.

3 : A graph showing the radiation energy distribution on the recording material with respect to the in 2 shown pressure fixing device shows.

4 Fig. 3 is a schematic cross-sectional view showing an alternative embodiment of the fixing device for fixing a toner composition of the present invention.

5 Fig. 10 is a schematic cross-sectional view showing another embodiment of the pressure fixing device for fixing a toner composition of the present invention.

6 : A view of a practical example of a pressure fixing device for fixing a toner composition of the present invention as viewed from the recording medium side.

1

photosensitive drum

2

loader

3

imaging device

4

developing device

5

Transfer charger

6

recording medium

7

fixing

8th

cleaning brush

9

Xenon lamp (Flash light source)

10

toner

11

reflector

12

glass plate

13

casing

14

halogen lamp

15

damper

16

exhaust hole

17

outer casing

Now become preferred embodiment of the present invention.

The Toner composition of the present invention produced when 90 seconds at 330 ° C heat treated is, a benzene concentration of not more than 60 ug / g and preferably of not more than 40 μg / g. When the concentration of benzene formed is more than 60 μg / g Activities, such as. an improvement of the smoke filter required.

In Regard to the decomposition products, the need for a filter and determine its lifespan, in terms of legal Controls only the formation of benzene as a decomposition product Problem. To determine the amount of benzene formed is the printer operated, and the exhaust gases formed by this collected and subjected to a quantitative analysis, however the sampling difficult and there are difficulties, such as e.g. the influence of factors other than the toner, which is why the preferred properties for a toner has not yet been detected. The inventors of the present Invention have ongoing investigations in terms of practical and reproducible conditions and found that by the 90-second Heating to 330 ° C benzene formed the basis for the assessment of suitability of the toner forms, and the inventors have also found that The life of the filter can be significantly extended if one Toner is used, in which the amount of benzene formed no longer as 60 μg / g is.

When the lightning voltage, which correlates with the flash energy, varies was, it was found that the formation of benzene in the ordinary applied voltage of 1850 V was observed that the formation of benzene, however, when lowered to 1750 V, much lower was. It is concluded that the toner at the time of lightning fixation is exposed directly to a high temperature, and when the Conditions at that particular voltage value then indirectly below Use of an indicator material with known decomposition temperature were evaluated, it was found that these decomposition conditions corresponded to a certain period of time at about 330 ° C. Accordingly, if the amount of benzene formed by the toner is under conditions of 90 s, sufficient for the decomposition of the indicator material, evaluated at 330 ° C, it was found that a good relationship between the evaluation result and the actually formed by the printer Benzene amount existed.

Any method of measurement may be used, provided that it can measure the amount of benzene formed at 330 ° C in 90 seconds; For example, a few tens of mg of the sample is placed in a glass container with an inner capacity of 20 ml and, after cleaning, sealed with nitrogen and heated to 330 ° C in an electric furnace for 90 seconds. 0.5 ml of the gas phase in the container is injected into a gas chromatograph and the amount of benzene formed is determined. The gas chromatographic measurement conditions used here are given, but any method which enables the quantitative determination of benzene with good reproducibility can be used. Accordingly, a measurement under the following conditions is possible. GC conditions: Pillar: SPB-1 S 0.32 × 60 mm Carrier gas: He Column temperature: 50 ° C → 280 ° C (10 ° C / mm) Detector: FID injected amount: 0.5 ml

Various ways of achieving such a level of formation may be considered, however, the inventors of the present invention have laboriously investigated the reasons for the formation of benzene, by which they have shown that this formation of benzene occurs Nigrosin type charge control agents, which are commonly used generally, degrade when exposed to light energy by flash fixation to form benzene. Thus, according to the present invention, benzene-forming material is removed from the charge control agents of the nigrosine type.

By the investigation of the mechanism of benzene formation by charge control agents of the nigrosin type it was found that in addition to the benzene, the formed by the decomposition of the main component, also benzene is present, due to impurities in the charge control agent is formed. examples for Process for removing these impurities is a process in which the contaminants are removed by a vacuum heat treatment, and a method in which a purification with an organic Solvent, such as. Alcohol, performed in view of the simplicity of the process the vacuum heat treatment is to be preferred.

at the vacuum heat treatment process is a compound of the nigrosine type at a temperature of at least 100 ° C, but less than 250 ° C, and a vacuum of 0.2 MPa or less of a vacuum heat treatment subjected to a vacuum heat treatment at a temperature of at least 100 ° C, but less than 250 ° C, and a Vacuum of 0.05 MPa or less is preferred and a vacuum heat at a temperature of at least 130 ° C, but less than 220 ° C, and a Vacuum of 0.03 MPa or less is more preferable.

The Prevention of benzene formation at the time of lightning fixation by such a treatment could not be predicted. The This is because if the benzene is decomposed by the thermal decomposition of the Charge control agent, for example, the compound of the nigrosine type itself, is formed, it is unimaginable that the source Benzene formation can be eliminated by a vacuum heat treatment can. The invention was first used in this application the realization conceivable that the charge control agent itself is not the source of benzene formation.

If the heating temperature is less than 100 ° C, it is not possible the Prevent formation of decomposition products, and there is none Effect on the extension the life of the filter while at a temperature of more than 250 ° C, the decomposition of the charge control agent itself used and lost the charge function as a charge control agent goes. If the vacuum is more than 0.2 MPa, it is a long vacuum heat treatment time necessary to make an impact and that is impractical. In addition, the salary is of the charge control agent of the nigrosine type is preferably 0.1 to 5% by weight with respect to the total toner composition and still more preferably 0.5 to 2% by weight.

at the method in which charge control agents of the nigrosine type Cleaning treatment using an organic solvent may be subjected to the organic solvent for example, alcohols, e.g. Methanol, ethanol, propanol, Isopropanol and butanol, ketones, e.g. Acetone, methyl ethyl ketone, Methyl isobutyl ketone and hexanone, as well as aromatic substances, such as e.g. Toluene and xylene, but with a cleaning treatment using alcohol is preferable.

One example for an actual one Method of implementation The cleaning treatment is the process by which the cleaning at room temperature using the charge control agent of the Nigrosin type multiple amount of an organic solvent carried out and repeated several times.

The Toner composition of the present invention comprises at least a binder resin, a coloring agent and a charge control agent, and these components are now explained.

Known Binder resins can than that in the toner composition of the present invention contained binder resin can be used, the following examples cited can be: Polystyrene homopolymer; Styrene copolymers, e.g. Styrene-isobutylene copolymer, Styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, Styrene-acrylic copolymer, styrene-methyl methacrylate copolymer, styrene-n-butyl methacrylate copolymer and styrene-glycidyl methacrylate copolymer; Acrylic homopolymers and copolymers, e.g. Polymethylmethacrylate, polyethylmethacrylate, Poly-n-butyl methacrylate and polyglycidyl methacrylate; Polyester resins, e.g. polyethylene terephthalate, Polyester on fumaric / etherified Diphenyl-based and crosslinked polyesters based on polyvalent Alcohols and / or polycarboxylic acids and Epoxy resins. Of these, polyester resins are ideal for reduction caused by the decomposition at the time of flash fixing Odor suitable.

Although the polyester resin is not particularly limited, it is preferable a polyester resin obtained from an acid component, wherein preferably at least 80 mol% of the polyester resin acid component a dicarboxylic acid of the phthalic acid type and at least 80 mol% of the alcohol component is a bisphenol A-alkylene oxide adduct are. Furthermore is under consideration the fixation properties of the softening point preferably in Range from 80 to 130 ° C, the glass transition temperature (Tg) in the range of 55 to 70 ° C and the Temperature at which the melt viscosity determined by a continuity tester is 10 Pa · s (10,000 Centipoise), in the range of 90 to 135 ° C, and in view of the molecular weight distribution of polyester is the number average molecular weight is suitably 2500 to 4500 and the weight average molecular weight is 7,000 to 130,000.

When used in the toner composition of the present invention dye can known colorants used, such as furnace black, carbon black, Channel black or other types of soot can ferromagnetic fine particles, such as e.g. fine magnetite powder used become. It is also possible Mixtures of ferromagnetic fine particles and carbon black as black dye use. For these colorants is the dispersion of the carbon black in the binder resin in terms of toner charge stability, and if necessary it is possible also to use a dispersant. In addition, the carbon black content is preferably 1 to 10 parts by weight per 100 parts by weight of the toner composition. Less than 1 part by weight is the masking performance of the binder resin not sufficient, and it can not achieve sufficient print density become. On the other hand, if the content is more than 10 parts by weight, what although to increase the masking performance of the applied pressure and the print density is desirable can be the toner particles due to the formed in these Carbon chain structure over electrically conductive, causing impaired the insulating properties and the toner charge properties are lowered, which leads to the print density is lowered and it causes an increased background contamination and toner scattering is coming.

Possibly can to the toner composition of the present invention as an agent to increase the flowability inorganic fine particles or organic fine particles having a average particle size of 0.005 up to 1.0 μm be added. As inorganic particles, fine particles may be exemplified Silica, titania or alumina. In particular, silica fine particles undergoing treatment for Have been subjected to hydrophobicity, are to be preferred in this respect, as reliable a high flowability can be obtained. Furthermore can as organic particles, for example, polyvinylidene fluoride particles or resin fine particles of polymethylmethacrylate, fluoropolymers or Silicone resins are used.

The average particle size of the toner composition of the present invention preferably 4 to 20 μm, where 6 to 12 microns even more preferred. When the mean particle size of the toner less than 4 μm is, is the production by conventional Kneading and pulverization process difficult, and the product yield is significantly reduced while at a particle size of more than 20 μm Problems, such as a poorer reproducibility of fine lines, occur.

The The toner composition used in the present invention may by conventionally known methods are produced. That means that it is possible the desired Toner composition, for example by premixing binder resin, dye, Charge control agent and, optionally, a dispersion aid etc. using a super mixer, followed by the uniform Dispersion, melting and kneading in a twin-screw extruder, followed by fine pulverization with a jet mill which particle size classification is used of wind power classification takes place.

The toner composition of the present invention can be used as a two-component developer by mixing with a carrier. In addition, the toner composition, when comprising a magnetic substance, may also be used as it is as a one-component developer for developing an electrostatic latent image. The carrier comprises, for example, a magnetic material, such as a metal such as iron, manganese, cobalt, nickel or chromium, a metal oxide such as chromium dioxide, hematite or magnetite or ferrite. Ferrite is a material represented by the general formula MFe ₂ O ₄ (where M = Mn, Co, Mg, Zn or Cu). Now, if the support is made of a metal material, it is preferable to form an oxide coating to prevent the oxidation of the support surface. In addition, besides the use of a magnetite or ferrite carrier in which magnetite or ferrite fine particles are granulated, it is possible to use a carrier of the so-called binder type in which magnetite or ferrite fine particles and a charge control agent are dispersed in a resin. In turn, with the aim of improving the charge properties on the support surface, a coating with the same resin, the contained in the toner composition, or performed with another resin.

In With regard to the particle size of the carrier generally a carrier with a particle size of 20 up to 200 μm used, wherein the use of a carrier with a smaller particle size of 20 up to 60 μm for the Achieving a good print density is preferable. Measurements of Particle size of the carrier were made using a laser light scattering analysis device for particle size measurements, Model SALD-2000J (manufactured by Shimadzu Corporation).

One Two-component developer is by mixing the aforementioned carrier made with the toner composition. The mixing ratio of Toner composition is usually 5-30% by weight based on the total amount of toner composition plus carrier, wherein but this in large Measures of the differences between the types of carriers, the charge characteristics the used toner and the development system is dependent. The specific surface of the carrier increases, the smaller the particle size of the carrier, whereby the toner mixing ratio in Generally increased can be. When the toner concentration in the developer is too low is, the printing density decreases, or there is a tendency that the carrier on the photosensitive body liable, that is it comes to so-called "carrier-over". If the toner concentration On the other hand, it is too high, it comes to significant pressure background contamination and contamination of the interior and exterior of the printer due to toner scattering, why the appropriate Tonermischverhältnis by an actual Print rating is determined by the printer.

The Toner composition of the present invention for development of electrostatic latent images is in a Druckfixiervorrichtung used the toner image using flash on a recording medium fixed. More preferably, it becomes in a pressure fixing device inserted, which is characterized in that between the flash light source and the recording medium is provided with a damper the radiant energy emitted by the flash light source, the the toner image is to be applied to the recording medium locally attenuates. Preferably a pressure fixing device is used which is characterized is that on a part of the outer wall the flash source a damper is provided, which locally attenuates the radiation energy.

Besides that is the aforementioned damper in the pressure fixing device of the present invention having the Property provided by the light source mentioned above can reflect, scatter or bend outgoing radiant energy.

at the aforementioned damper in the pressure fixing device of the present invention also preferably a damper, the radiation energy in at least part of the area on the recording material attenuates, was applied to the high radiation energy, and the the radiation energy in at least part of the area on the Recording medium to which without the attenuation of the radiant energy through the damper low radiation energy would be applied, dampens to a slight extent.

In addition, will in the pressure fixing device of the present invention preferably a preheating agent provided with the aforementioned recording medium before Application of the radiation energy by the aforementioned light source preheats to the toner image.

In of the present invention means "dampens the radiant energy ", that radiant energy by the arrangement of a damper between the flash light source, the radiation energy generating area is absorbed and the recording material feed route is reflected, scattered or diffracted and, in comparison with cases, in which no damper exists, leading to a partial reduction to a specific region on the recording material (mostly the region in which the energy density the highest is) or a toner image applied thereto radiant energy comes. Preferably, the arrangement is such that the intercepted by the damper Radiation energy by reflection, scattering or refraction on other areas is applied to the recording material. That way is it is possible the distribution of the on the recording medium or the toner on it applied radiation energy in the feed direction uniform to design. Furthermore can the damper also at or near the surface be provided to the light source.

In the present invention, the recording medium may be any material on which the toner image can be fixed. In most cases, material in web form, such as paper, plastic film, fabric or metal plates, is preferably used. For paper or a plastic As a consequence of excessive heating, distortion and decomposition, such as scorching, may occur, which is why these materials are suitable materials for use in the present invention in which maximum energy density can be reduced.

A typical method of printing formation using the toner composition of the present invention and the features of the electrophotographic printer (printing apparatus) will be described with reference to FIG 1 explained. In the electrophotographic printer, a toner image is formed on the photosensitive drum 1 educated. First, the photosensitive drum 1 using the charger 2 uniformly loaded. Then, using the imaging device 3 provided with an LED array or a laser beam, a spatially selective imaging in accordance with the desired pressure to be formed. That on the photosensitive drum 1 produced latent image is using a developing device 4 developed by a developer, and a toner image is printed on the photosensitive drum 1 educated. Through a transfer charger 5 The developed toner image is applied to the recording medium 6 transfer. While the recording medium 6 is fed at a constant speed, the melting and fixing is carried out using a fixing device 7 ,

Toner image that has not been transferred to the recording medium is cleaned with a cleaning brush 8th to which a negative voltage has been applied with respect to the toner, and the drum is returned to its original state.

The damper is now referring to 2 and 3 explained. 2 shows in detail the fixing device 7 , In the fixing device, the toner image becomes 10 that on the recording medium 6 is a radiation of radiant energy by a flash light source 9 subjected to fixation by a light-to-heat conversion effect. As the flash light source, for example, a xenon lamp, a neon lamp, an argon lamp or a krypton lamp can be used. To efficiently use the radiant energy emanating from the flash light source, it becomes a reflector 11 behind the flash light source. In addition to this will be a glass plate 12 and a housing 13 used for the construction of the fixing device. The from the flash source 9 Outgoing radiant energy occurs together with the through the reflector 11 reflected component through the glass plate te 12 through and illuminates the toner image 10 that already on the recording medium 6 is trained. The radiated radiant energy is through the toner image 10 is selectively absorbed so that the toner is heated and melts and on the recording medium 6 is fixed. As in 3 As shown, the radiation energy distribution on the recording medium is usually in the area immediately under the flash light source 9 is highest, and if, as in the case of the present invention, there are no restrictions on radiant energy, it is known to form a shape that approximates the Gaussian distribution.

A damper 14 is therefore between the flash source 9 and the recording medium 6 and is also positioned so that it is positioned where the distance between the flash source 9 and the recording medium 6 is the shortest. This makes it possible for the damper 14 on the path of the light rays to position the area with the highest radiant energy on the recording medium 6 Irradiate, eliminating the flash from the source 9 outgoing radiant energy is locally lowered. This has the effect of being able to reduce the peak of the high radiant energy typically produced directly under the flash source and, as in 3 represented, it is possible thereby to achieve a more uniform radiation energy distribution.

In addition, by using a damper 14 that does not absorb the light, but can scatter or reflect it, a transfer of radiant energy that would otherwise be directly under the flash source 9 is expected to be expected in the surrounding areas. In addition, because the light is not absorbed, only a slight warming of the damper occurs 14 by the absorption of the radiant energy, whereby a stable effect can be expected. As examples of materials in which such a stable effect can be expected, in the case of reflective materials, metal nets or grids and vapor-deposited chrome films may be considered. Stainless steel is preferably used for the mesh or grid in terms of heat and weather resistance. As the scattering material, a heat-resistant optical diffusion plate may be considered. Frosted glass with a roughened glass surface can be used as an optical scattering plate. In addition, a cylindrical lens can be used as a diffractive material. If a vapor-deposited chrome film or an optical diffusion plate as a damper 14 is used, the damper can 14 also in one piece with the glass plate 12 be educated.

In addition, it is possible by varying the radiation energy restriction factor in the Zu direction of the recording medium 6 to achieve a uniform radiation energy distribution. That means the damper 14 provided with the property that it is with increasing proximity to the flash source 9 and the more it lies in the region of highest radiant energy density, becomes increasingly restrictive. When using a metal net or grid, the mesh density is increased toward the central area as it is lowered towards the edge areas. In the case of vapor deposition of chromium, the same effect can be achieved by increasing the amount of evaporated metal in the direction of the center and lowering it in the direction of the edge regions.

3 shows the radiation energy distribution on the recording medium 6 if a damper 14 is present and if no damper 14 is available. It is clear that in the presence of a damper 14 a more uniform radiation energy distribution can be achieved.

Preferably, a glass plate 12 between the flash source 9 and the recording medium 6 arranged to prevent the paper dust or toner formed by the recording medium or gas formed by the toner or the like, the flash light source 9 and the reflector 11 contaminate. Preferably, a damper 14 at the side of the flash light source 9 the glass plate 12 provided as this contamination of the damper 14 through the toner 10 etc. can prevent.

As in 4 shown, the damper can 14 also on the outside wall of the flash light source 9 be arranged. Because he is using the flash source 9 can be formed in one piece, this has the advantage that the device can be made simpler.

below is based on examples of the present invention provides a more specific explanation, wherein however, the invention is not limited to these examples.

Examples

Reference Example 1 (Details of Fixing Device)

With reference to 1 The main features of an electrophotographic printer (printing apparatus) including the fixing device and the fixing method used for fixing the toner composition for developing electrostatic latent images according to the present invention will be explained. In an electrophotographic printer, the toner image on a photosensitive drum 1 educated. First, the photosensitive drum 1 using the charger 2 uniformly loaded. Then, using the imaging device 3 provided with an LED array or a laser beam, a spatially selective imaging in accordance with the desired pressure to be formed. That on the photosensitive drum 1 produced latent image is using a developing device 4 developed by a toner, and a toner image is formed on the photosensitive drum 1 educated. Through a transfer charger 5 The developed toner image is applied to the recording medium 6 transfer. While the recording medium 6 is fed at a constant speed, the melting and fixing is carried out using the fixing device 7 as described in the above embodiment.

A practical example of the fixing device and the fixing method of the present invention will now be described 1 explained. In this example, a toner image is formed using a halogen lamp 15 which emits heat radiation energy in which the main component is long-wavelength infrared light having a maximum energy wavelength in the range of 2 to 5 μm and positioned forward inside the fixing device, and a flash light source 9 fixed on the recording medium. The halogen lamp 15 shines through and warms the recording medium 6 and the toner image 10 in front. By this preheating, the moisture which, when the recording medium is paper, may be eliminated to some extent, and the entire recording medium 6 is preheated. The long-wave infrared radiation becomes not only by the toner image but also by the recording medium 6 effectively absorbed, whereby the consequent emergence of a temperature difference between the toner image and the recording medium due to it by the flash light source 9 emitted radiant energy, which is effectively absorbed by the toner image, is prevented, whereby a firmer fixation is made possible. In other words, this radiation also fulfills an additional role, even if the radiation energy of the flash light source 9 is comparatively low, a good fixing performance is achieved. In addition, at the rear inside the fixing device becomes an exhaust hole 16 for the absorption of unpleasant odors or gases formed by the toner at the time of fixation.

A xenon lamp is used as a flash source 9 used. The outer dimensions of the xenon lamp in this example correspond to a diameter of about 15 mm and a length of about 425 mm in the light emitting area, wherein the printed nominal voltage 1850 V and the nominal energy 343 J was. The by the flash light source 9 The energy generated is preferably at least 200 J. This xenon lamp flashed in a 6.6-Hz interval, in accordance with the supply of the recording medium 6 (at about 225 mm / s). In other words, the xenon lamp flashed on the recording medium at intervals of about 34 mm 6 ,

A damper 14 was between the flash source 9 and the feeding route of the recording medium 6 provided. It became a grid-shaped damper 14 used, which was prepared by the etching of a 0.1 mm thick stainless steel sheet (width: 14 mm, length: 441 mm). 5 shows the damper seen from the side of the recording medium from. This damper 14 included 11 0.1 mm wide wires parallel to the longitudinal direction of the flash light source 9 were (the direction substantially at right angles to the feeding direction of the recording material 6 runs), and several oblique wires connected thereto. The 11 wires, which are parallel to the longitudinal direction of the flash light source 9 were arranged so that their arrangement density in the area directly below the flash source 9 lay, was denser and decreased to the outside. The multiple oblique wires serve to connect the parallel wires together and to increase the restriction amount.

The damper 14 with this stainless steel network construction will be on the glass plate 12 immediately under the flash light source 9 arranged, and its two ends are fastened by placing it between the glass plate 12 and the outer casing 17 be pushed.

Tests were carried out by using a pressure forming apparatus having this structure and using the following toners. Reference Example 2 (Preparation of Standard Carrier) Polyester resin ("Tuftone" TTR-2, manufactured by Kao Corporation) 24% by weight magnetic material (EPT-1000, manufactured by Toda Kogyosha) 74% by weight Charge Control Agent ("Bontron" S-34, manufactured by Orient Kagakusha) 1% by weight Wax (Luvax-1151, made by Nippon Seiro Co.) 1% by weight

To careful Melting of the aforementioned components was carried out by melting and kneading using a twin-screw extruder (PCM-30, manufactured by Ikegai Corporation). After cooling the kneaded material, it was using a coarse pulverizer (UG-210KGS, manufactured by Horai Tekkosho) to a pass of 2 mm roughly pulverized, after which this powder with a Mittelpulverisierer ("Finemill" FM-300N, manufactured by Nippon Pneumatic Mfg Co.), after which using a fine pulverizer ("Separator" DS-5UR, manufactured by Nippon Pneumatic Mfg Co.) and a resin carrier having a weight average Particle size of 50 microns obtained has been.

Reference Example 3

"Bontron" -N 01, made from Orient Kagakusha, was heated by heating under a 0.01 MPa vacuum for 6 hours at 190 ° C treated to generate the charge control agent A.

Reference Example 4

"Bontron" N-01, made from Orient Kagakusha, was heated for 12 hours by heating under a 0.02 MPa vacuum at 160 ° C treated to generate the charge control agent B.

Reference Example 5

"Bontron" N-01, made from Orient Kagakusha, was heated by heating under a 0.01 MPa vacuum for 6 hours at 90 ° C treated to generate the charge control agent C.

Reference Example 6

"Bontron" N-01, made from Orient Kagakusha, was heated for 6 hours by heating under a 0.02 MPa vacuum at 160 ° C treated to generate the charge control agent D.

Reference Example 7

10 g "Bontron" N-01 from Orient Kagakusha, was prepared 3 times with 100 g of methanol (reaction grade washed by Nacalai Tesque) while the methanol was changed to charge the charge control agent E. produce.

example 1

Toner was produced using the following components. [Toner Composition] Polyester resin ("Tuftone" TTR-2, manufactured by Kao Corporation) 60% by weight Polyester resin ("Tuftone" TTR-5, manufactured by Kao Corporation) 1.6% by weight magnetic material (EPT-1000, manufactured by Toda Kogyosha) 20% by weight Carbon black (manufactured by Cabot Corp., "Regal" 330 R) 2% by weight Charge control agent A from Reference Example 3 2% by weight

To the careful one Mixing of the above components was carried out by melting and kneading using a twin-screw extruder (PCM-30, manufactured by Ikegai Corporation), followed by fine pulverization with a jet mill pulverizer (PJM-100, manufactured by Nippon Pneumatic Mfg Co.), after which the Classification using a Windkraftklassierers (A-12, manufactured by Alpine-sha) and a toner having a weight average Particle size of 8 microns obtained has been. Furthermore were used to increase the flowability of the toner 1.2% by weight, based on the toner, of hydrophobic silica fine particles (manufactured by Hoechst Japan, HVK-2150), after which the Blending to produce the toner with a super mixer (SMV-20, made by Kawadasha) and a positively charging Toner was obtained.

The Amount of at the 90-second heat treatment this toner at 330 ° C benzene formed was 9 μg / g.

Then became a developer by mixing 90% by weight of that in Reference Example 2 prepared resin carrier with 10 wt .-% of this toner produced, and the printing was carried out under Use of the LED printer described in Reference Example 1, which an evaluation of print quality carried out has been. This printer used a filter that weighs 300 g Activated carbon included. At the beginning and after 900,000 printouts were get good prints. Furthermore was the amount of benzene in the exhaust gases after they pass through the filter measured initially and after 900,000 prints, but with no significant difference in terms of content in the surrounding the atmosphere of 1 ppb, and this was less than the level of volatility in the the atmosphere (0.3 ppb).

The Measurements of the amount of benzene were carried out as follows: 1 l Gas from the filter passage area was recovered using the solids capture procedure (Carbotrap 400) was collected, then the collection tube in a thermal desorption unit (TDE) placed, and an analysis by thermal desorption using the GC-FID, GC / MS method was carried out.

Example 2

Toner was produced in the same manner as in Example 1 except that the charge control agent B was used in place of the charge control agent A in the toner composition. The amount of benzene formed by the 90-second heat treatment of this toner at 330 ° C was 14 μg / g. Developer was produced in the same way using this toner. Using this developer was printed in the same manner as in Example 1 using the printer described in Reference Example 1, and a Evaluation of print quality was performed. At the beginning and after 900.000 prints good printouts were obtained. In addition, the amount of benzene in the exhaust gases after passing through the filter was measured initially and after 900,000 prints, but there was no significant difference in the surrounding atmosphere content of 1 ppb and less than the fluctuation amount in the atmosphere (0 , 3 ppb).

Comparative Example 1

toner was generated in the same manner as in Example 1, except that instead of the charge control agent A from Reference Example 3 "Bontron" N-01, an untreated one Charge control agent of the nigrosine type was used. By the 90-second heat treatment this toner at 330 ° C The amount of benzene formed was 100 μg / g. Developer was used in the same manner as in Example 1 this toner generates. Using this developer was on the same manner as in Example 1 using the reference example 1 printer was printed, and an evaluation of the print quality was carried out. By printing good prints were obtained. As, however the amount of benzene in the exhaust gas was measured to be 9 ppb more than the content in the atmosphere (1 ppb), and it was clear that the use of a filter was required. In the episode became the printing process using 300 g of activated carbon as a filter, but while initially no significant difference in terms of salary in the surrounding atmosphere of 1 ppb, the amount of benzene was after 600,000 prints in the exhaust after passing through the filter with 2 ppb higher than the degree of fluctuation in the atmosphere, why the filter had to be replaced.

Comparative Example 2

toner was generated in the same manner as in Example 1, except that instead of the charge control agent A from Reference Example 3 "Bontron" N-13, an untreated one Charge control agent of the nigrosine type was used. By the 90-second heat treatment this toner at 330 ° C The amount of benzene formed was 150 μg / g. Developer was used in the same manner as in Example 1 this toner generates. Using this developer was on the same manner as in Example 1 using the reference example 1 printer was printed, and an evaluation of the print quality was carried out. By printing good prints were obtained. As, however the amount of benzene in the exhaust gas was measured to be 10.5 ppb more than the content in the atmosphere (1 ppb), and it was clear that the use of a filter was required. In the episode became the printing process using 300 g of activated carbon as a filter, but while initially no significant difference in terms of salary in the surrounding atmosphere of 1 ppb, the amount of benzene was after 600,000 prints in the exhaust after passing through the filter with 2 ppb higher than the degree of fluctuation in the atmosphere, why the filter had to be replaced.

Comparative Example 3

toner was generated in the same manner as in Example 1, except that instead of the charge control agent A in the toner composition, the charge control agent C was used. The result of the 90-second heat treatment of this toner at 330 ° C The amount of benzene formed was 74 μg / g. Developer was the same way using this toner generated. Using this developer was done the same way as in Example 1 using the described in Reference Example 1 Printer was printed, and a print quality rating was carried out. By printing, initially and after 700,000 prints were good Printouts are obtained. However, as the amount of benzene in the exhaust gas after passing through the filter after 700,000 prints was measured, the amount of benzene was 2 ppb in terms of the degree of fluctuation in the the atmosphere (0.3 ppb) considerably, why the filter had to be replaced.

Example 3

Toner was produced in the same manner as in Example 1 except that the charge control agent D was used in place of the charge control agent A in the toner composition. The amount of benzene formed by heat-treating this toner at 330 ° C for 90 seconds was 32 μg / g. Developer was produced in the same way using this toner. Using this developer was printed in the same manner as in Example 1 using the printer described in Reference Example 1, and evaluation of print quality was carried out. At the beginning and after 900.000 prints good printouts were obtained. In addition, the amount of benzene in the exhaust gases was measured after passing through the filter at the beginning and after 900,000 prints, but with no significant difference with respect to the Content in the ambient atmosphere of 1 ppb was less than the fluctuation amount in the atmosphere (0.3 ppb).

Example 4

toner was generated in the same manner as in Example 1, except that instead of the charge control agent A in the toner composition, the charge control agent E was used. The result of the 90-second heat treatment of this toner at 330 ° C The amount of benzene formed was 36 μg / g. Developer was the same way using this toner generated. Using this developer was done the same way as in Example 1 using the described in Reference Example 1 Printer was printed, and a print quality rating was carried out. At the beginning and after 900.000 prints good printouts were obtained. Furthermore was the amount of benzene in the exhaust gases after they pass through the filter measured initially and after 900,000 prints, but with no significant difference in terms of content in the surrounding the atmosphere of 1 ppb, and this was less than the level of volatility in the the atmosphere (0.3 ppb).

Industrial Applicability

Under The use of the toner of the present invention is as above explains possible, extend the period before the filter needs to be replaced or not to use a filter, which makes it possible to lower the operating costs of the printer.

Claims (9)

A toner composition for developing electrostatic latent images as used in flash fixing comprising at least a binder resin, a colorant and a nigrosine type charge control agent, characterized in that the benzene concentration produced by heating the toner at 330 ° C for 90 seconds does not exceed 60 μg / g. A toner composition according to claim 1, wherein the produced Benzene concentration is not more than 40 micrograms / g. A toner composition according to claim 1 or claim 2, wherein the binder resin is a polyester resin. Toner composition according to one of the preceding Claims, wherein the charge control agent is a nigrosine type compound is that at a temperature of at least 100 ° C, but not above 250 ° C, at a of vacuum vacuum-heat-treated of 0.2 MPa or less has been. A toner composition according to claim 4, wherein the vacuum heat treatment at a vacuum quality of 0.05 MPa or less has been. A toner composition according to claim 5, wherein the vacuum heat treatment at a temperature of at least 130 ° C, but not above 220 ° C, at a of vacuum of 0.03 MPa or less. Process for the preparation of a charge control agent of the nigrosine type with heating of the toner for 90 seconds at 330 ° C produced benzene concentration of not more than 60 μg / g, thereby characterized in that a compound of the nigrosine type at a temperature of at least 100 ° C, but not above 250 ° C, at one of vacuum vacuum-heat-treated of 0.2 MPa or less to provide the nigrosine type charge control agent becomes. The method of claim 7, wherein the vacuum quality is 0.05 MPa or less. A method according to claim 8, wherein the heat treatment at a temperature of at least 130 ° C, but not above 220 ° C, at a of vacuum of 0.03 MPa or less.