CN1300642C - Toner composition for developing electrostatic latent image - Google Patents

Abstract

The present invention relates to a toner composition for developing electrostatic latent images, comprising at least a binder resin, a colorant, and a charge control agent, for use in an image forming method having an image fixing device for fixing a toner image on a recording medium by flash light, wherein the toner composition has a characteristic of generating benzene at a concentration of 60 μg/g or less when heated at 330° C. for 90 seconds. The present invention also provides a toner composition for developing electrostatic latent images, which has a long filter life or does not require a filter.

Description

Toner composition for developing electrostatic latent image

technical field

The present invention relates to a developing powder (hereinafter referred to as a toner composition) for developing an electrostatic latent image in electrophotography, and in particular to a laser for flash-fixing an object to be printed at a high temperature. A toner composition for electrostatic latent images suitable for beam printers or LED printers.

technical background

The electrophotography method consists of a charging process of supplying a uniform electrostatic charge to a photoreceptor using a photoconductive substance, an exposure process of irradiating light to form an electrostatic latent image, and a developing process of electrostatically adhering toner to the latent image, The copying process of copying onto the toner image support, the fixing process of fixing the toner image to the toner image support by means of pressure, momentary flashing, etc., removing the unreplicated toner remaining on the photoreceptor The cleaning process of the photoreceptor and the destaticizing process of removing the electrostatic charge on the photoreceptor to return to the initial state are composed, and an image can be obtained by repeating these processes.

The pressure fixing method, which is one of the fixing methods in electrophotographic printers, has the advantages of being able to work immediately, power consumption is small because a heater is not used as a heat source, and there is no risk of fire in the fixing part. However, Since there are disadvantages such as poor image fixability, obvious image gloss and thus low quality, generally speaking, the fixing method using heat fixing method is advantageous. Among the heating and fixing methods, there are known contact heating and fixing methods using hot rollers for fixing, non-contact heating and fixing methods using flash flashes for fixing, and heating oven fixing that uses electric heaters to pass through them in a heating atmosphere. Non-contact heat fixing method.

The present invention relates to fixing by flash, which is representative of the non-contact heat fixing method. The flash fixing method is to irradiate the visible image of the toner with the emission spectrum of a xenon lamp or a halogen lamp in a short time of milliseconds or less, and use the A method in which the toner is melted and softened by radiant heat and then fixed to a toner support (JP-A-7-107605) has the following advantages.

(1) Since it is non-contact fixing, the sharpness of the image at the time of development is not deteriorated.

(2) There is no waiting time after the power is turned on, and it can be started quickly.

(3) Even if recording paper or the like gets stuck in the fuser due to system shutdown, no fire will occur.

(4) Good fixability regardless of the kind of toner support (material of recording paper, crease paper, thick paper, etc.).

(5) Only the toner of the character portion which is black itself is heated, so there is no heat shrinkage of the recording paper, etc., the transportability of the printing paper is good, and high-speed printing is possible.

However, since the flash fixing method is a non-contact heating method, the rate of escape of energy to the surroundings is high, and in addition, since it is intermittent energy irradiation, the specific thermal efficiency of fixing with a heat roller is not good. In other words, it is a fixing method that consumes a lot of power. In addition, the flash fixing method also has the following problem: due to the rapid irradiation of high-energy flash in an extremely short period of time, the surface temperature of the toner composition reaches a high temperature of several hundred degrees in an instant, and a part of the toner The additives of the composition of the agent decompose into gases emitting foul odors, or produce such decomposition products as harmful gases.

In printers using the flash fixing method, in general, in order to remove the generation of decomposition products during flash fixing, in the flash fixing part, a device that absorbs these decomposition products and passes them through a filter such as activated carbon to adsorb and capture harmful gases is used. method. However, there are problems in that a filter is required and the running cost increases due to the shortened exchange life of the filter.

The present invention was invented in order to solve these problems, and the purpose is to provide a method of suppressing the occurrence of decomposition products in a printer using flash fixing method so that the filter is no longer used, or the replacement life of the filter is changed. A toner composition for developing an electrostatic latent image that has the problem of increased running costs caused by shortness and the like.

disclosure of invention

The present invention relates to a method for fixing a toner composition, the method is characterized in that, when flash-fixing a toner composition composed of at least a binder resin, a colorant and a charge control agent, A charge control agent selected from the group consisting of ammonium salts, triphenylmethane-based compounds, or nigrosin-based compounds heated in vacuum at a temperature of 100°C to 250°C and a vacuum degree of 0.2MPa or lower.

In addition, the present invention also relates to a toner composition for developing an electrostatic latent image, wherein, in the toner composition composed of at least a binder resin, a colorant and a charge control agent, it is characterized in that the The concentration of benzene generated at 90 seconds was 60 μg/g or less.

A brief description of the drawings

Fig. 1 is a schematic sectional view showing the image generating apparatus of the present invention.

FIG. 2 is a schematic sectional view showing a fixing device of the present invention.

FIG. 3 shows distribution of radiant energy generated by the image fixing device of the embodiment of FIG. 2 on a recording medium.

Fig. 4 is a schematic sectional view showing an embodiment of the fixing device of the present invention.

Fig. 5 is a schematic sectional view showing an embodiment of the image fixing device of the present invention.

Fig. 6 is an embodiment of the present invention viewed from the side of the recording medium.

Symbol Description

1: Photosensitive drum 2: Charger 3: Exposure device

4: Developing device 5: Transfer charger 6: Recording media

7: Fuser 8: Cleaning brush 9: Xenon lamp (flash light source)

10: Toner 11: Reflective plate 12: Glass plate

13: Chassis 14: Halogen lamp 15: Limiting body

16: Exhaust port 17: Housing

Best Mode for Carrying Out the Invention

When the toner composition of the present invention is heated at 330° C. for 90 seconds, the concentration of benzene generated is 60 μg/g or less, preferably 40 μg/g or less. When the concentration of benzene exceeds 60 μg/g, it is necessary to take measures such as strengthening the smoke removal filter.

Here, although attention is paid to the decomposition products that determine the necessity and life of the filter, the generation of benzene as a decomposition product will become a problem from the viewpoint of legal management. As a method of measuring the amount of benzene produced, there is a method of operating the printer and collecting the exhaust gas generated thereby to quantify it. However, there are problems of sampling and factors other than toner. It is less than the preferable characteristic as a toner. The inventors of the present invention continued to study the conditions of practical reproducibility, and found that the amount of benzene generated by heating at 330°C for 90 seconds can be used as a criterion for judging the quality of toner. If the toner is below g, the life of the filter can be greatly extended.

Here, when the flash voltage related to the flash energy was changed, the generation of benzene was confirmed at the commonly used voltage of 1850V, and it was found that the amount of benzene generation was greatly reduced when the voltage was lowered to 1750V. Although it is estimated that the toner during flash fixing is exposed to high temperature instantaneously, when the voltage condition is indirectly estimated using a characteristic substance whose decomposition temperature is known, it can be known that the decomposition time takes around 330°C corresponding to the conditions. That is, if the benzene generation amount of the toner is evaluated under the condition of 90 seconds, which is sufficient to decompose the characteristic substance at 330° C., it is found that there is a good relationship between the evaluation result and the amount of benzene generated from the actual printer. Relationship.

As the method for measuring the amount of benzene produced, it does not matter what method is used as long as the amount of benzene produced at 330°C for 90 seconds can be measured. For example, put a few 10 mg of a sample into a glass container with an internal volume of 20 ml. , and after nitrogen substitution, it was sealed, heated in an electric furnace at 330° C. for 90 seconds, and 0.5 ml of the gas phase in the glass container was injected into a gas chromatograph to study the amount of benzene produced. Although the test conditions of the gas chromatograph to be used are given here, it is not necessary to ask the method as long as it is a method that can quantify benzene with good reproducibility. For example, the following conditions can be used for measurement.

Gas Chromatography Conditions Column: SPB-1S 0.32mm×60mm

Carrier Gas : He

Column temperature: 50°C→280°C (10°C/min)

Detector: FID

Injection volume: 0.5ml

As for the means to achieve such a production amount, although there are various means, the inventors of the present invention have conducted in-depth studies on the cause of benzene generation, and found the following fact: the generation of this benzene is caused by the commonly used nigrosine. The charge control agent of the system is decomposed by light energy of flash fixing to generate benzene. Therefore, it is preferable to adopt the following method.

(1) Removal of benzene-generating substances in nigrosine-based charge control agents

As a result of studying the mechanism of benzene generation in the nigrosin-based charge control agent, it was found that benzene generated by decomposition of the main component and benzene generated from impurities contained in the charge control agent exist. Therefore, although the method of removing impurities by vacuum heat treatment can be mentioned as the method of removing impurities, and the method of cleaning with organic solvents such as ethanol, etc., but in terms of the ease of the process, vacuum heating The method of processing is preferred.

(2) Use a charge control agent that does not generate benzene

As such a charge control agent, it is preferable to use a quaternary ammonium salt or a triphenylmethane-based compound charge control agent.

In the case of using quaternary ammonium salts, it is difficult to impart good chargeability to the toner. In addition, in the case of using triphenylmethane-based compound-based charge control agents, when the fixing temperature is high, the charge control agent decomposes The method of removing the benzene-generating substance in the nigrosine-based charge control agent is more preferable in view of the phenomenon that the periphery of the printed characters is stained.

Here, when a quaternary ammonium salt is used as the charge control agent, it is preferable that the anion of the quaternary ammonium salt is an inorganic anion containing a molybdenum or tungsten atom. Specific examples of inorganic anions include molybdic acid, tungstic acid, phosphomolybdic acid, silicomomolybdic acid, phosphotungstic acid, silicotungstic acid, phosphotungstomolybdic acid, silicomotungstomolybdic acid, chromomolybdic acid, and the like.

Specific examples of such a quaternary ammonium salt include TP-302 and 415 produced by Hodogaya Chemical Co., Ltd., and the like.

The amount of the quaternary ammonium salt added is preferably 0.1 to 5 parts by weight relative to 100 parts by weight of the toner composition. If it is less than 0.1 parts by weight, it is impossible to impart sufficient chargeability to the toner, and if it exceeds 5 parts by weight, the charge control agent is more expensive than other components, so the cost will increase.

When a triphenylmethane-based charge control agent is used as the charge control agent, examples of the triphenylmethane charge control agent include C.I.Solvent Blue 66, 124, C.I.PigmentBlue 61, 56, 19, 18, etc., and it is preferable to use C.I. Solvent Blue 124. Specific examples of such a triphenylmethane-based charge control agent include "Copy Blue" PR and "Brilliant Blue Base" SM produced by Hoechst, and "BASF Alikali Blue" NBD 6165DLD produced by BASF Japan.

The added amount of the triphenylmethane-based charge control agent is preferably 0.1 to 5 parts by weight relative to 100 parts by weight of the toner composition. If it is less than 0.1 parts by weight, it is impossible to impart sufficient chargeability to the toner, and if it exceeds 5 parts by weight, the cost will increase because the charge control agent is more expensive than other components.

In addition, in the method of performing vacuum heat treatment on the nigrosine-based charge control agent, it is preferable to carry out the vacuum heat treatment at a vacuum degree of 100°C to 250°C, and 0.2MPa or less, preferably at 100°C or higher. The vacuum heat treatment is carried out at 250° C. or lower and a vacuum degree of 0.05 MPa or lower, more preferably at 130° C. to 220° C. and a vacuum degree of 0.03 MPa or lower.

It is unpredictable to suppress the generation of benzene at the time of flash fixing by such treatment. This is because if a charge control agent such as a nigrosine compound generates benzene by thermal decomposition of itself, it is impossible to remove the source of benzene by vacuum heat treatment or the like. The present invention was conceived by paying attention to the fact that the source of benzene generation is not the charge control agent itself.

If the heating temperature is less than 100°C, it is impossible to suppress the generation of decomposition products, and there will be no effect of prolonging the life of the filter. In the case of exceeding 250°C, the decomposition of the charge control agent itself begins, and it loses its role as a charge control agent. The electrification endowment function. In the case where the degree of vacuum is higher than 0.2Mpa, a long time for vacuum heat treatment is required in order to produce an effect, which is not practical. The content of the nigrosine-based charge control agent is preferably 0.1 to 5% by weight, more preferably 0.5 to 2% by weight, based on the entire toner composition.

In addition, in the method of washing and treating the nigrosine-based charge control agent with an organic solvent, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, acetone, methyl ethyl ketone, etc., can be mentioned as organic solvents. , methyl isobutyl ketone, ketones such as hexanone, aromatics such as toluene and xylene, etc., are preferably cleaned with alcohols.

As a specific method of the cleaning treatment, there is mentioned a method of repeatedly washing the nigrosine-based charge control agent with an organic solvent in several times at normal temperature.

The toner composition of the present invention is composed of at least a binder resin, a colorant, and a charge control agent, and these compositions will now be described.

As the binder resin contained in the toner composition in the present invention, known binder resins can be used, for example, polystyrene homopolymer, styrene-isobutylene copolymer, styrene-butadiene copolymer , acrylonitrile-butadiene-styrene copolymer, styrene-acrylic acid copolymer, styrene-methyl methacrylate copolymer, styrene-n-butyl methacrylate copolymer, styrene-methacrylic acid Styrene copolymers such as glycidyl ester copolymers, acrylic homopolymers or copolymers such as polymethyl methacrylate, polyethyl methacrylate, poly-n-butyl methacrylate, polyglycidyl methacrylate, etc. Polyester resins such as polyethylene terephthalate, fumaric acid/etherified biphenyl polyester, cross-linked polyester formed from polyhydric alcohol and/or polycarboxylic acid, epoxy resin, etc. Among them, polyester-based resins are suitable in order to reduce odors generated by thermal decomposition during flash fixing.

Although not particularly limited, it is preferable that 80 mol% or more of the acid components of the polyester resin be composed of phthalic acid-based dicarboxylic acids, and 80 mol% or more of the alcohol components be A polyester resin obtained from an alcohol component composed of bisphenol A alkylene epoxide adduct. In addition, considering fixability, the softening point is preferably 80 to 130°C, the glass transition point (Tg) is preferably 55 to 70°C, and the temperature at which the melt viscosity is 10,000 centipoise measured by a flow meter is preferably 90 to 130°C. At 135° C., the number average molecular weight of the molecular weight distribution of the polyester resin is 2,500 to 4,500, and the weight average molecular weight is 7,000 to 130,000.

As the colorant contained in the toner composition in the present invention, well-known colorants can also be used, for example, in addition to carbon black such as furnace black, acetylene black, channel black, etc., ferromagnetic fine particles, such as , Magnetite particle powder can be used. In addition, ferromagnetic fine particles and carbon black can also be used as a black coloring agent in combination. Among these colorants, dispersion in the binder resin of carbon black is important for the charging stability of the toner, and a dispersant may be used together if necessary. The content of carbon black is preferably 1 to 10 parts by weight relative to 100 parts by weight of the toner composition. When it is less than 1 part by weight, the hiding power of the adhesive resin is insufficient, and sufficient image density cannot be obtained. On the other hand, in the case of exceeding 10 parts by weight, although it is preferable to increase the hiding power of the image to be formed and to increase the image density, on the contrary, it depends on the carbon black formed in the toner. If the chain structure of the toner particles becomes excessively conductive, the insulation will be lost, and the chargeability of the toner will be reduced. As a result, the image density will decrease, and white paper staining or toner scattering will increase.

In the toner composition of the present invention, inorganic fine particles and organic fine particles having an average particle diameter of 0.005 to 1.0 μm may be added as a fluidity improver as needed. As the inorganic fine particles, fine particles of silica, titania, alumina and the like can be used. In particular, hydrophobically treated silica fine particles are preferable in order to securely obtain high fluidity. As the organic microparticles, resin microparticles such as polyvinylidene fluoride particles, polymethyl methacrylate, fluorine-containing resins, and silicone resins can be used.

The average particle diameter of the toner composition of the present invention is preferably 4 to 20 microns, more preferably 6 to 12 microns. When the average particle size of the toner is less than 4 microns, it is difficult to produce by the conventional kneading and pulverizing method, so the product yield is significantly reduced, and when it exceeds 20 microns, fine lines will be generated. The problem of poor reproducibility.

The toner composition used in the present invention can be produced using a well-known method. That is, after preliminarily mixing the toner composition of the binder resin, the colorant, the charge control agent, and the dispersing auxiliary agent added if necessary, for example, with a super mixer, uniformly mix it with a 2-screw extruder. After dispersion, melting, kneading, fine pulverization with a jet mill, and classification with an air classifier, the desired toner composition can be obtained.

The toner composition of the present invention can be used as a two-component developer after being mixed with a carrier. In addition, when the toner composition contains a magnetic substance, it can be used as a one-component developer for developing an electrostatic latent image as it is. The carrier is composed of metals such as iron, manganese, cobalt, nickel, chromium, etc., or magnetic materials such as cobalt dioxide, ferric oxide, ferric oxide, etc. metal oxides or ferrite. Ferrite is a A material represented by the general formula MFe ₂ O ₄ (M is Mn, Co, Mg, Zn or Cu) can be used. In addition, when the carrier is formed of a metal, it is preferable to form an oxide film in advance in order to prevent oxidation of the surface of the carrier. In addition, in addition to the magnetite and ferrite carriers that have made magnetite particles and ferrite particles into particles, it is also possible to disperse magnetite particles or ferrite particles and a charge control agent. to the so-called resinous carrier throughout the resin. In addition, the carrier may be coated with the same resin as that contained in the toner composition or a different resin for the purpose of improving the charging characteristics of the surface of the carrier.

The particle diameter of the carrier is generally 20 to 200 microns, but it is preferable to use a small particle diameter of 20 to 60 microns because good printing density can be obtained. The method of measuring the particle size of the carrier is measured with a laser diffraction particle size distribution measuring machine SALD-200J (manufactured by Shimadzu Corporation).

The two-component developer can be produced by mixing the toner composition and the above-mentioned carrier. The compounding ratio of the toner composition is usually about 5 to 30% by weight relative to the total amount of the toner composition and carrier, but this compounding ratio depends on the kind of carrier or the chargeability and developing properties of the toner used. The ways are very different. Since the specific surface area of the carrier increases as the carrier particle size decreases, the toner blending ratio is generally made larger. In the case where the toner concentration in the developer is too low, the image density will become light, or a so-called carrier over phenomenon in which the carrier adheres to the photoreceptor tends to occur. On the other hand, when the toner concentration is too high, the pollution inside and outside the printer due to white paper stains on the background of the image or toner scattering becomes conspicuous. Determined after printing evaluation with a printer.

The toner composition for developing an electrostatic latent image of the present invention is used in an image fixing device for fixing a toner image on a recording medium by flashing light. More preferably, it is used in an image fixing device characterized by the following: between the above-mentioned light source and the recording medium, there is a device that partially restricts the radiant energy emitted from the light source that flashes and should be imparted to the toner image on the recording medium. Restricted body. In addition, it is preferable to use an image fixing device characterized in that a restricting body that partially restricts radiant energy is provided on a part of the outer wall of the light source of the flash.

Furthermore, in the image fixing device of the present invention, the above-mentioned restricting body preferably has a property of reflecting, scattering or refracting radiant energy from the above-mentioned light source.

In the image fixing device of the present invention, the above-mentioned limiting body preferably can strongly limit the radiant energy irradiated to the partial area of the recording medium, and weakly limit the radiant energy irradiated to the partial area of the recording medium; if no limiting body is used, the former is At least a portion of the region to which high radioactivity is to be applied, which is at least a portion of the region to which weak radioactivity is to be applied.

Furthermore, in the image fixing apparatus of the present invention, it is preferable to include preheating means for preheating the recording medium before imparting radiation energy to the toner image by the light source.

In the present invention, the so-called "limiting radiation energy" refers to the method of placing a limiting body between the radiation energy generating part of the flash light source and the conveying path of the recording medium, so that the radiation energy can be absorbed, reflected, scattered or refracted, so that In the absence of the restrictor, the radiation energy imparted to the recording medium or a specific portion of the toner image thereon (in many cases, the portion with the highest energy density) is partially reduced. However, the radiation energy shielded by the restricting body is preferably imparted to other parts of the recording medium by means of reflection, scattering or refraction. In this way, the distribution of the radiant energy to be imparted to the recording medium or the toner thereon in the transport direction can be made uniform. Furthermore, the limiting body can also be located on or near the surface of the light source.

In the present invention, any recording medium may be used as long as it is used for fixing a toner image. In many cases, thin sheets of paper, plastic film, cloth, metal plate, etc. are preferable. If paper or plastic film is used, since there is a possibility of deformation due to excessive heating, or deterioration such as burning, it is a suitable application object of the present invention that can minimize energy density.

A typical image forming method used in the toner composition of the present invention and an outline of an electrophotographic printer (image forming apparatus) will be described with reference to FIG. 1 . In the electrophotographic printer, a toner image is formed on the photosensitive drum 1 . First, the photosensitive drum 1 is uniformly charged by the charger 2 . Next, exposure is spatially selectively performed by an exposure device 3 equipped with an LED array or a laser beam according to an image to be formed. The latent image formed on the photosensitive drum 1 is developed with a developer by the developing device 4 to form a toner image on the photosensitive drum 1 . The similarly developed toner image is transferred onto the recording medium 6 by the transfer charger 5 . The recording medium 6 is melted and fixed by the fuser 7 while being transported at a constant speed.

The toner image that has not been transferred to the recording medium is removed by the cleaning brush 8 with a negative bias applied to the toner, and the original state is returned.

Figures 2 and 3 illustrate the restriction body. FIG. 2 is an explanatory diagram illustrating the fixing unit 7 in detail. In the fixing unit, a flash light source 9 is irradiated with radiant energy for fixing the toner image 10 on the recording medium 6 by photothermal conversion. As the flash light source, xenon lamp, neon lamp, argon lamp, krypton lamp and the like can be used. In order to effectively utilize the radiant energy from the radiant light source, a reflector 11 is provided on the rear portion of the flash light source. In addition, a glass plate 12 and a cabinet 13 may be included in order to constitute a fixing device. The radiant energy irradiated from the flash light source 9 is combined with the component reflected from the back reflection plate 11, passes through the glass plate 12, and irradiates the toner image 10 already formed on the recording medium 6. The irradiated radiation energy is selectively absorbed by the toner image 10, and the toner is heated and melted to be fixed on the recording medium 6. As shown in FIG. 3, the radiation energy distribution on the recording medium 6 is usually the highest at the portion directly below the flash light source 9, and is known to have a nearly Gaussian distribution when the radiation energy is not limited as in the present invention.

Then, the restricting body 14 is arranged so as to be located in the middle of the flash light source 9 and the recording medium 6, and to be located on the shortest distance between the flash light source 9 and the recording medium 6. In this way, the restrictor 14 can be arranged on the optical path of the portion on the recording medium 6 where the highest radiant energy is irradiated, and the radiant energy irradiated from the flash light source 9 can be partially reduced. By applying this effect, the peak value of the high radiant energy generated directly under the flash light source 9 can be reduced, and as shown in FIG. 3 , the distribution of radiant energy can be made uniform.

Furthermore, by making the restricting body 14 non-absorbing light, that is, making it diffuse or reflective, it can be expected that the radiant energy originally concentrated directly below the flash light source 9 will be transferred to the surrounding area. In addition, since light is not absorbed, the restriction body 14 generates little heat due to the absorption of radiant energy, and a stable effect can be expected. As a material from which such an effect can be expected, a metal mesh, a grid, or a chromium vapor-deposited film can be considered as the reflective member. In the case of nets and grids, stainless steel is preferred in terms of heat and weather resistance. As the diffusion member, a heat-resistant optical diffusion plate or the like can be considered. As an optical diffuser, ground glass with a roughened glass surface can be considered. In addition, a cylindrical prism can be considered as a refracting member. In addition, when a chromium vapor-deposited film or an optical diffusion plate is used as the restricting body 14, the restricting body 14 and the glass plate 12 may be integrally formed.

In addition, a relatively uniform radiation energy distribution can be obtained by changing the limiting rate of the radiation energy with respect to the conveyance direction of the recording medium 6 . That is, the closer to the flash light source 9 , the higher the radiant energy, the stronger the restriction on the restricting body 14 is. Specifically, in the case of metal meshes and grids, the density of the mesh should be increased toward the central portion and decreased toward the peripheral portion. In the case of a chromium vapor-deposited film, it can be realized by increasing the amount of vapor-deposited metal toward the central portion and decreasing the amount of vapor-deposited metal toward the peripheral portion.

In FIG. 3 , examples of the distribution of radiant energy on the recording medium 6 are shown in the case of the restriction body 14 and the case of no restriction body. It can be seen from the figure that when there is a limiting body 14, a relatively uniform radiation energy distribution can be obtained.

Glass plate 12, in order to prevent from the paper dust or toner itself that recording medium produces, or the gas that produces from toner etc. pollutes flash light source 9 and reflecting plate 11, is preferably between flash light source 9 and recording medium 6 . In addition, it is preferable to provide the restrictor 14 on the side of the flash light source of the glass plate 12 to prevent contamination of the restrictor 14 by the toner 10 and the like.

In addition, as shown in FIG. 4, the restricting body 14 may also be formed on the outer wall of the flash light source. Since it is integrated with the flash light source, it has the advantage of simplifying the device.

Hereinafter, examples of the present invention will be specifically described, but the present invention is not limited by these examples.

Example

Reference Example 1 (Details of Fixing Device)

The outline of an electrophotographic printer (image forming apparatus) including a fixing device and a fixing method used for fixing the toner composition for an electrostatic latent image of the present invention will be described with reference to FIG. 1 . In the electrophotographic printer, a toner image is formed on the photosensitive drum 1 . First, the photosensitive drum 1 is uniformly charged by the charger 2 . Next, exposure is spatially and selectively performed according to an image to be formed using an exposure device 3 equipped with an LED array or a laser beam. The latent image formed on the photosensitive drum 1 is developed by a developing device 4 using toner to form a toner image on the photosensitive drum 1 . The toner image thus developed is transferred onto the recording medium 6 by the transfer charger 5 . While conveying the recording medium 6 at a constant speed, it is melt-fixed by the fixing device 7 shown in the above-mentioned embodiment.

An embodiment of a fixing device and a fixing method of the present invention will be described with reference to FIG. 1 . In the present embodiment, the toner image on the recording medium is fixed on the recording medium with the halogen lamp 15 and the flash light source 9 that produce the radiant heat energy of the far-infrared rays with the peak wavelength of energy in the vicinity of 2 to 5 microns as the main component. on the front part inside the device. The halogen lamp 15 is continuously turned on to preheat the recording medium 6 and the toner image 10 . By preheating, moisture that is often contained when the recording medium is paper or the like is removed to a certain extent, and the entire recording medium 6 is preheated. Because far infrared rays can be absorbed not only by the toner image, but also can be efficiently absorbed by the recording medium 2, the modulation caused by the radiant energy given by the flash light source 9 that is absorbed efficiently by the toner image is suppressed afterwards. With the generation of a temperature difference between the toner image and the recording medium, stronger fixing can be achieved. In other words, even if the radiant energy of the flash light source 9 is relatively low, it can play an auxiliary role such that good fixing performance can be obtained. In addition, an exhaust port 16 is provided at the inner rear portion of the fuser for absorbing odor or gas generated from toner at the time of fixing.

A xenon lamp is used as the flash light source 9 . The dimensions of the xenon lamp in this embodiment are: a diameter of about 15 mm, a length of the light-emitting part of about 425 mm, a rated voltage of 1850 V, and a rated energy of 343 J. The energy generated by the flash light source 9 is preferably more than 200J. The xenon lamp was turned on at a cycle of 6.6 Hz as the recording medium 6 was transported (about 225 mm/sec). That is, on the recording medium 6, the xenon lamps are turned on at intervals of about 34 mm.

A regulating body 14 is provided between the flash light source 9 and the transport path of the recording medium 6 . As the restrictor 14, a grid-shaped restrictor obtained by processing a 0.1 mm-thick stainless steel plate (width 14 mm, length 441 mm) by etching was used. Fig. 5 shows the fixing unit when viewed from the recording medium side. The limiting body 14 is composed of 11 lines with a width of 0.1 mm parallel to the longitudinal direction of the flash light source 9 (a direction substantially perpendicular to the transport direction of the recording medium 2 ), and a plurality of oblique lines connected to them. The 11 lines parallel to the longitudinal direction of the flash light source 9 are arranged such that the density is high at the portion directly below the flash light source 9 , and the density becomes lower toward the peripheral portion. While multiple slash lines are connected with parallel lines, they also have the effect of increasing the limit.

These stainless steel restrictors 14 having a mesh structure are placed on the upper portion of the glass plate 12, just below the flash light source 9, and are fixed by sandwiching both ends between the glass plate 12 and the cabinet 17.

Using the image forming apparatus of the example having such a constitution, experiments were conducted with the following toners.

Reference example 2 (manufacture of standard carrier)

Polyester resin (“(Tuftone)” TTR-2, manufactured by Kao Co., Ltd.) 24% by weight

Magnetic body (EPT-1000, manufactured by Toda Kogyo Co., Ltd. 74% by weight

Charge control agent ("Bontron" S-34; produced by Orient Chemical Co., Ltd.) 1% by weight

Paraffin (LUVAX-1151; produced by Nippon Seikasha Co., Ltd.) 1% by weight

After the above ingredients were sufficiently mixed, melt kneading was carried out using a 2-screw extruder (PCM-30; manufactured by Ikegai Corporation). After cooling the kneaded material, use a coarse pulverizer (UG-210KGS; produced by Penglai Iron Works) to coarsely pulverize it into a size of 2 mmΦ, and put it in a medium pulverizer ("finemill" FM-300N; produced by Japan Pneumatic Industry). After being pulverized in progress, it was classified with a micro pulverizer ("Separator" DS-5UR; produced by Pneumatic Industries, Japan) to obtain a resin carrier with a weight average particle diameter of 50 micrometers.

Reference example 3

"Bontron" N-01 produced by Orient Chemical Co., Ltd. was treated at 190° C. under vacuum heating at 0.01 MPa for 6 hours to produce a charge control agent A.

Reference example 4

"Bontron" N-01 produced by Orient Chemical Co., Ltd. was treated at 160° C. under vacuum heating at 0.02 MPa for 12 hours to produce a charge control agent B.

Reference example 5

"Bontron" N-01 produced by Orient Chemical Co., Ltd. was treated at 90° C. under vacuum heating at 0.01 MPa for 6 hours to produce a charge control agent C.

Reference example 6

"Bontron" N-01 produced by Orient Chemical Co., Ltd. was treated at 160° C. under vacuum heating at 0.02 MPa for 6 hours to prepare the charge control agent D.

Reference example 7

Charge control agent E was prepared by washing 10 g of "Bontron" N-01 produced by Orient Chemical Co., Ltd. with 100 g of methanol (special grade reagent, produced by Nacalai Tesque Co., Ltd.) three times.

Example 1

A toner was produced with the following ingredients.

[toner components]

Polyester resin (“Tuftone” TTR-2, manufactured by Kao Corporation) 60% by weight

Polyester resin (“Tuftone” TTR-5, manufactured by Kao Corporation) 16% by weight

Magnetic body (EPT-1000, produced by Toda Kogyo Co., Ltd. 20% by weight

Carbon black (manufactured by Cabot; "Regal" "330R) 2% by weight

Charge control agent A of reference example 3 2% by weight

After fully mixing the above ingredients, melt kneading was carried out with a 2-axis extruder (PCM-30; produced by Ikegai Co., Ltd.), and then a jet mill (PJM-100; produced by Pneumatic Industry Co., Ltd. of Japan) was used. After fine pulverization, classification was carried out with an air classifier (A-12; manufactured by Alpine Co., Ltd.) to obtain a toner having a weight average particle diameter of 8 micrometers. In addition, in order to improve the fluidity of the toner, 1.2% by weight of hydrophobic silica particles (produced by Hoechst Japan Co., Ltd.; HVK-2150) was added to the toner, and then a super mixer (SMV-20; produced by Kawada Co., Ltd.) ) to adjust the toner by mixing to obtain a positively chargeable toner.

The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 9 μg/g.

Next, the developer was adjusted by blending the toner at 10% by weight and the resin carrier produced in Reference Example 2 at 90% by weight, and printed an image with the LED printer shown in Reference Example 1, and Image quality evaluation was performed. In this printer, a filter with an amount of activated carbon of 300 g is used. Good images were obtained both initially and after printing 900,000 characters. In addition, the amount of benzene in the exhaust gas passing through the filter at the initial stage and after printing 900,000 characters was also measured, and there was no significant difference between 1 ppb and the ambient atmospheric level, and it was below the atmospheric fluctuation level (0.3 ppb).

The measurement of benzene is carried out by individual trapping method (carbotrap 400) to collect the gas passing through the 1L filter, set the trap tube on the thermal detachment unit (TDU), and perform thermal detachment ~ GC-FID method, GC/MS method analyze.

Example 2

In the composition of Example 1, a toner was prepared in the same manner except that the charge control agent B was used instead of the charge control agent A. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 14 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. Good images were obtained both initially and after printing 900,000 characters. In addition, the amount of benzene in the exhaust gas passing through the filter at the initial stage and after printing 900,000 characters was also measured, and there was no significant difference between 1ppb and the ambient atmospheric level, and the atmospheric fluctuation level was below (0.3ppb).

Comparative example 1

A toner was prepared in the same manner as in Example 1, except that the charge control agent A of Reference Example 3 was replaced with "Bontron" N-01 which was an untreated nigrosine-based charge control agent. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 100 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. As a result of printing, good images were obtained. However, when the amount of benzene in the exhaust gas is measured, it is 9 ppb, which is higher than the atmospheric level (1 ppb), and a filter is required. Therefore, when printing with a filter with an amount of activated carbon of 300g, although there is no significant difference between the initial stage and the ambient air level of 1ppb, the amount of benzene in the exhaust gas after printing 600,000 characters after passing through the filter It is 2ppb, which is larger than the atmospheric fluctuation level, and it is necessary to replace the filter.

Comparative example 2

A toner was produced in the same manner as in Example 1, except that the charge control agent A of Reference Example 3 was replaced with "Bontron" N-13 which was an untreated nigrosine-based charge control agent. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 150 μg/g. Using this toner, a developer was produced in the same manner as in Example 1. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. As a result of printing, good images were obtained. However, when measuring the amount of benzene in the exhaust gas, 10.5 ppb is higher than the atmospheric level (1 ppb), and a filter is required. Therefore, when printing with a filter with an amount of activated carbon of 300g, although there is no significant difference between the initial stage and the ambient air level of 1ppb, the amount of benzene in the exhaust gas after printing 600,000 characters after passing through the filter It is 2ppb, which is larger than the atmospheric fluctuation level, and it is necessary to replace the filter.

Comparative example 3

A toner was prepared in the same manner as in Example 1 except that the charge control agent C was used instead of the charge control agent A. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 74 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. Good images were obtained at the initial stage and after printing 700,000 words. However, the amount of benzene in the exhaust gas passing through the filter after printing 700,000 characters was 2 ppb, which was significantly different from the atmospheric fluctuation level (0.3 ppb), and it was necessary to replace the filter.

Example 3

A toner was prepared in the same manner as in Example 1, except that the charge control agent D was used instead of the charge control agent A. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 32 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. Good images were obtained both initially and after printing 900,000 characters. In addition, the amount of benzene in the exhaust gas passing through the filter at the initial stage and after printing 900,000 characters was also measured, and there was no significant difference between 1ppb and the ambient atmospheric level, and the atmospheric fluctuation level was below (0.3ppb).

Example 4

A toner was produced in the same manner as in Example 1, except that the charge control agent E was used instead of the charge control agent A. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 36 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 1, and image quality was evaluated. Good images were obtained both initially and after printing 900,000 characters. In addition, the amount of benzene in the exhaust gas passing through the filter at the initial stage and after printing 900,000 characters was also measured, and there was no significant difference between 1ppb and the ambient atmospheric level, and the atmospheric fluctuation level was below (0.3ppb).

Example 5

Toners were manufactured with the following ingredients.

[toner ingredient]

Polyester resin (“Tuftone” TTR-2, manufactured by Kao Corporation) 60% by weight

Polyester resin (“Tuftone” TTR-5, manufactured by Kao Corporation) 16% by weight

Magnetic body (EPT-1000, produced by Toda Kogyo Co., Ltd.) 20% by weight

Carbon black (manufactured by Cabot; "Regal" 330R) 2% by weight

Triphenylmethane charge control agent ("Copy Blue" PR,

Manufactured by Hoechst Company) 2% by weight.

After the above-mentioned ingredients were fully mixed, after melt kneading was carried out with a 2-axis extruder (PCM-30; produced by Ikegai Co., Ltd.), micronization was carried out with a jet mill pulverizer (PJM-100; produced by Japan Pneumatic Industry). After pulverization, classification was performed with an air classifier (A-12; manufactured by Alpine Co., Ltd.) to obtain a toner having a weight average particle diameter of 8 µm. In addition, in order to improve the fluidity of the toner, 1.2% by weight of hydrophobic silica particles (produced by Hoechst Japan Co., Ltd.; HVK-2150) was added to the toner, and then a super mixer (SMV-20; produced by Kawada Co., Ltd.) ) to adjust the toner by mixing to obtain a positively chargeable toner.

The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 2 μg/g.

Next, the toner was blended in an amount of 10% by weight, and the resin carrier manufactured in Reference Example 2 was blended in an amount of 90% by weight to prepare a developer, and an image was printed with the LED printer shown in Reference Example 1, and the drawing was carried out. Evaluation of image quality. Printing was performed without a filter in this printer. As a result of printing, good images were obtained. In addition, the amount of benzene in the exhaust gas was also measured, and there was no significant difference between 1 ppb and the surrounding atmospheric level, and it was below the atmospheric fluctuation level (0.3 ppb).

The measurement of benzene is carried out by individual trapping method (carbotrap 400) to collect the gas passing through the 1L filter, set the trap tube on the thermal detachment unit (TDU), and perform thermal detachment ~ GC-FID method, GC/MS method analyze.

Example 6

A toner was produced in the same manner as in Example 5, except that "Copy Blue", which is a triphenylmethane-based charge control agent, was used instead of "Brilliant Blue Base" SM (manufactured by Hoechst). The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 4 μg/g. Using this toner, a developer was produced in the same manner as in Example 5. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 5, and the image quality was evaluated. As a result of printing, good images were obtained. In addition, the amount of benzene in the exhaust gas was also measured, and there was no significant difference between 1 ppb and the ambient atmospheric level, and the atmospheric fluctuation level was below (0.3 ppb).

Example 7

A toner was produced with the following ingredients.

[toner ingredient]

Polyester resin (“Tuftone” TTR-2, manufactured by Kao Corporation) 60% by weight

Polyester resin (“Tuftone” TTR-5, manufactured by Kao Corporation) 16% by weight

Magnetic body (EPT-1000, produced by Toda Kogyo Co., Ltd.) 20% by weight

Carbon black (manufactured by Cabot; "Regal" 330R) 2% by weight

Charge control agent of quaternary ammonium salt (TP-302, Hodogaya Chemical Co., Ltd. produces 2% by weight

After the above-mentioned ingredients were fully mixed, after melt kneading was carried out with a 2-axis extruder (PCM-30; produced by Ikegai Co., Ltd.), micronization was carried out with a jet mill pulverizer (PJM-100; produced by Japan Pneumatic Industry). After pulverization, classification was performed with an air classifier (A-12; manufactured by Alpine Co., Ltd.) to obtain a toner having a weight average particle diameter of 8 µm. In addition, in order to improve the fluidity of the toner, 1.2% by weight of hydrophobic silica particles (manufactured by Hoechst Japan Co., Ltd.; HVK-2150) was added to the toner, and then mixed with a super mixer (SMV-20; produced by Kawada Corporation) ) to adjust the toner by mixing to obtain a positively chargeable toner. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 4 μg/g.

Next, the developer was adjusted by blending the toner at 10% by weight and the resin carrier produced in Reference Example 2 at 90% by weight, and printed an image with the LED printer shown in Reference Example 1, and Image quality evaluation was performed. In this printer, image printing is performed without using a filter. As a result of printing, good images were obtained. In addition, the amount of benzene in the exhaust gas was also measured, but there was no significant difference from the ambient air level of 1 ppb, and it was below the atmospheric fluctuation level (0.3 ppb).

The measurement of the amount of benzene is collected by the individual trapping method (Carbotrap 400), and the part of the gas passing through the 1L filter is collected, and the trapping tube is installed on the thermal detachment unit (TDU), and the thermal detachment ~ GC-FID method, GC/MS method is used. analyze.

Example 8

A toner was produced in the same manner except that TP-415 (manufactured by Hodogaya Chemical Co., Ltd.) was used instead of "TP-302" as the charge control agent of the quaternary ammonium salt of Example 7. The benzene generation amount of this toner when heat-treated at 330° C. for 90 seconds was 2 μg/g. Using this toner, a developer was prepared in the same manner. Using this developer, an image was printed with the LED printer shown in Reference Example 1 in the same manner as in Example 7, and image quality was evaluated. As a result of printing, good images were obtained. In addition, the amount of benzene in the exhaust gas was also measured, and there was no significant difference between 1 ppb and the surrounding atmospheric level, and it was below the atmospheric fluctuation level (0.3 ppb).

Possibility of industrial use

As described above, with the present invention, since either the exchange life of the filter can be extended, or the filter can be eliminated, the running cost of the printer can be reduced.

Claims (8)

1, a kind of toner composition for developing electrostatic latent image that in flash fusing, uses, at least by adhering resin, colorant and charged controlling agent constitute, it is characterized in that: the generation concentration of the benzene that produce after 90 seconds 330 ℃ of heating is below 60 μ g/g, wherein, adhering resin is a polyester based resin, charged controlling agent is the nigrosine based compound, quaternary ammonium salt or triphenylmethane based compound, the nigrosine based compound is under the temperature below 250 ℃ more than 100 ℃, and under the vacuum tightness below the 0.2MPa, having carried out the nigrosine based compound of vacuum heating treatment, the negative ion that contains in the quaternary ammonium salt is an inorganic anion.

2, the described toner composition for developing electrostatic latent image that uses in flash fusing of claim 1, it is characterized in that: the generation concentration of benzene is below 40 μ g/g.

3, the described toner composition for developing electrostatic latent image that uses in flash fusing of claim 1, it is characterized in that: toner is a Positively chargeable.

4, the described toner composition for developing electrostatic latent image that uses in flash fusing of claim 1, it is characterized in that: during vacuum heating treatment, vacuum tightness is below 0.05MPa.

5, the described toner composition for developing electrostatic latent image that uses in flash fusing of claim 1, it is characterized in that: during vacuum heating treatment, vacuum tightness is below 0.03MPa.

6, a kind of fixation method of method for producing toner and toner, it is characterized in that: make at least by adhering resin, the method for producing toner and toner that colorant and charged controlling agent constitute carries out when the flash fusing, the charged controlling agent that adopts is from quaternary ammonium salt, the triphenylmethane based compound, perhaps select in the group that the nigrosine based compound constitutes, the generation concentration of the benzene that toner produces after 90 seconds 330 ℃ of heating is below 60 μ g/g, wherein, adhering resin is a polyester based resin, the nigrosine based compound is under the temperature below 250 ℃ more than 100 ℃, and under the vacuum tightness below the 0.2MPa, having carried out the nigrosine based compound of vacuum heating treatment, the negative ion that contains in the quaternary ammonium salt is an inorganic anion.

7, the fixation method of the described method for producing toner and toner of claim 6 is characterized in that: during vacuum heating treatment, vacuum tightness is below 0.05MPa.

8, the fixation method of the described method for producing toner and toner of claim 6 is characterized in that: during vacuum heating treatment, vacuum tightness is below 0.03MPa.

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