JP4423336B2 - Image forming method - Google Patents

Description

  The present invention relates to an image forming method used in an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet method, and a toner used in the image forming method.

  Conventionally, many electrophotographic methods are known as described in Patent Documents 1, 2, and 3, but generally, a photoconductive substance is used and an electrophotographic material is electrically applied on a photoreceptor by various means. A latent image is formed, and then the latent image is developed with toner, and the toner image is transferred to a transfer material such as paper as necessary, and then fixed by heating, pressure, heating and pressurization, or solvent vapor. The toner remaining without being transferred onto the photoreceptor is cleaned by various methods, and the above-described steps are repeated.

  Further, a general full-color image forming method will be described. The photoconductor of the photoconductor drum is uniformly charged by a primary charger, and image exposure is performed by laser light modulated by a magenta image signal of an original. An electrostatic latent image is formed on the photosensitive drum, and the electrostatic latent image is developed by a magenta developer holding magenta toner to form a magenta toner image. Next, the magenta toner image developed on the photosensitive drum is transferred onto the transferred transfer material by a transfer charger.

  On the other hand, the photosensitive drum after the development of the electrostatic latent image is neutralized by a neutralizing charger, cleaned by a cleaning means, and then charged by a primary charger again. Similarly, a cyan toner image is obtained. The cyan toner image is transferred to the transfer material onto which the magenta toner image has been transferred, and the four color toner images are transferred to the transfer material in the same manner as yellow and black. The transfer material having the four color toner images is fixed by the action of heat and pressure by a fixing roller to form a full color image.

  In recent years, such a copying apparatus has started to be used not only as a general-purpose copying machine for copying an original document but also as a printer as an output of a computer or a personal copy for an individual. In addition to such fields represented by laser beam printers, the development of plain paper fax machines using basic engines is also rapidly developing. In particular, the demand for small offices and home offices has increased significantly. Accordingly, smaller and lighter, faster and higher image quality, higher reliability and lower cost, especially smaller, lighter and faster. There has been a strict search for cost reduction and cost reduction.

  From these backgrounds, the paper used for transfer materials recently has been widespread as recycled paper using recycled pulp obtained by deinking once used paper, and under such circumstances, it is required for toner. Performance is becoming more sophisticated, and there is a strong demand for improved toner performance, and image design that takes machine matching into consideration more than ever. In the case of a halftone part where the surface of the recycled paper has a large surface unevenness and a small amount of toner, the amount of heat supplied from the heating roller is less than that of conventional paper, and the fixing property on the low temperature side is severe. This becomes more remarkable when the surface of the heating roller is deteriorated after continuous paper feeding.

  In recent years, with the various copying needs, the demand for color copying is rapidly increasing, and in order to copy original color images more faithfully, higher image quality and higher resolution are desired.

  On the other hand, what is required of the toner is that it has good meltability and color mixing properties when heat is applied, and has a low softening point and a low melt viscosity and a high sharp melt property. Can be mentioned.

  However, such a toner with high sharp melt property generally has a high affinity with the fixing roller, and tends to be easily offset to the fixing roller at the time of fixing.

  Conventionally, for the purpose of preventing toner from adhering to the surface of the fixing roller, for example, the roller surface is formed of a material excellent in releasability with respect to the toner, such as silicone rubber or fluorine-based resin. In order to prevent such fatigue, the roller surface is coated with a thin film of a liquid having high releasability such as silicone oil and fluorine oil. However, this method is extremely effective in preventing toner offset. However, since a device for supplying the liquid for preventing offset is necessary, this method has a problem of miniaturization. The application of oil causes delamination between the layers constituting the fixing roller, resulting in an adverse effect of promoting the shortening of the life of the fixing roller.

  Transparency films that use an overhead projector (OHP) have been widely used as a transfer material for fixing toner images using these fixing devices in recent years. In particular, OHP has a low oil absorption capacity unlike paper, so that currently available copies can be obtained. OHP has an unavoidable sticky feeling due to oil application, and a great problem remains in the quality of the obtained image.

  In addition, there is a high possibility that silicone oil or the like evaporates due to heat, contaminates the inside of the machine, and causes problems such as processing of recovered oil. Therefore, instead of using a silicone oil supply device, instead of supplying an anti-offset liquid from the toner during heating, a method of adding releasability such as low molecular weight polyethylene and low molecular weight polypropylene to the toner was proposed. Has been. If a large amount of such an additive is added in order to obtain a sufficient effect, filming on the photoconductor and the surface of a toner carrier such as a carrier and a sleeve are contaminated, and the image is deteriorated, resulting in a problem. Therefore, a small amount of a release agent is added to the toner so as not to deteriorate the image, and a slightly releasable oil supply or offset toner is removed from the roll-up device using a member such as a web or a cleaning pad. A cleaning device is used in combination.

  However, considering the recent demands for miniaturization, weight reduction, and high reliability, it is necessary and preferable to remove even these auxiliary devices. Therefore, it can not be dealt with without further improvement in performance such as toner fixing property and offset resistance, and it is difficult to realize without further improvement in toner binder resin, release agent and the like.

  Further, particularly in the full-color field, when an OHP is used as a transfer material by including a release agent, the image of the fixed image is fixed due to high crystallization of the release agent or a difference in refractive index from the resin. The problem that transparency and haze will fall a little will arise.

  It is known to contain a wax as a release agent in a toner. For example, techniques are proposed in Patent Documents 4, 5, 6 and the like.

  In addition, it has been proposed that Patent Documents 7 to 16 contain waxes.

  Waxes are used to improve toner offset resistance at low and high temperatures, and to improve fixability at low temperatures. When exposed to heat due to a temperature rise or the like, the developability deteriorates, or when the toner is left for a long time, the wax migrates to the toner surface and the developability deteriorates.

  Conventional toners do not satisfy all of these aspects, causing some problems. For example, high-temperature offset resistance and developability are excellent, but low-temperature fixability is just one step away, low-temperature offset and low-temperature fixability are excellent, but blocking resistance is slightly inferior, and development is performed at a high temperature inside the machine. There was a bad effect such as lowering of the property, offset resistance at low temperature and high temperature was not compatible, and OHP transparency was extremely bad.

  In particular, regarding transparency of OHP, in order to suppress crystallization of the wax itself, a proposal to add a crystallization nucleating agent or the like to the wax (Patent Documents 17 and 18), or a wax having a small degree of crystallinity of the wax itself is used. (Patent Documents 19 and 20) and proposals for improving the surface smoothness of the toner layer after fixing by adding a material having good compatibility with the binder and lower melt viscosity than the binder. Is described in Patent Document 21 and the like.

  However, none of these are fully satisfied from the viewpoint of transparency and haze (cloudiness value) of OHP.

  There are cases where the fixing device is required for the problems of smaller and lighter, faster and higher image quality, higher reliability, and lower power consumption. In the case of a conventional heat roller type heating means, a large amount of energy is instantaneously required while applying a high pressure when performing image formation at a higher speed. Not only that, it also takes a wait time until the heat source reaches a predetermined temperature, so that improvement is required particularly in terms of high reliability and low power consumption.

  On the other hand, a fixing system using an electromagnetic induction heating method as described in Patent Documents 22 to 27 has been proposed.

  By the way, in this technical field, it is widely known to use a charge control agent in order to improve the chargeability of the toner. Examples of the negative chargeability include monoazo, salicylic acid, naphthoic acid, and dicarboxylic acid. Is mentioned. The charge control agent gives an appropriate amount of charge to the toner by frictional charging or the like, and has a great role in development, transfer, and fixing. However, none of the toners containing the charge control agent listed above is considered for the electromagnetic induction heating means fixing method. For example, Patent Documents 28 to 33 are available, but it cannot be said that the correspondence including the toner in the system design of the image forming apparatus using the heat fixing unit is not sufficient.

US Pat. No. 2,297,691 Japanese Patent Publication No.42-23910 Japanese Patent Publication No.43-24748 Japanese Patent Publication No.52-3304 Japanese Patent Publication No.52-3305 Japanese Unexamined Patent Publication No. 57-52574 Japanese Patent Laid-Open No. 3-50559 Japanese Patent Laid-Open No. 2-79860 JP-A-1-109359 Japanese Patent Laid-Open No. Sho 62-14166 JP-A-61-273554 JP 61-94062 A JP-A-61-138259 JP-A-60-252361 JP-A-60-252360 JP-A-60-217366 JP-A-4-149559 JP-A-4-107467 Japanese Patent Laid-Open No. 3-091108 Japanese Patent Laid-Open No. 3-24297 JP-A-3-212552 JP-A-8-6408 JP-A-8-137306 JP-A-8-17311 JP-A-8-179647 JP-A-9-160414 JP-A-9-292786 JP 63-33758 A Japanese Patent Laid-Open No. 2-190869 JP-A-2-230163 JP-A-4-347863 JP 61-238846 A JP-A-5-134437

  An object of the present invention is to provide an image forming method and a toner that can solve the above-mentioned problems.

  That is, an object of the present invention is to provide an image forming method capable of a quick start with a small wait time.

  An object of the present invention is to provide an image forming method and a toner excellent in low temperature offset resistance in a halftone portion.

  An object of the present invention is to provide an image forming method and a toner excellent in high temperature offset resistance in a halftone portion.

  An object of the present invention is to provide an image forming method and a toner with little difference in glossiness at the front and rear end portions of a fixed image.

  An object of the present invention is to provide an image forming method and a toner having good fixing properties.

  An object of the present invention is to provide an image forming method and a toner excellent in transparency of a full-color projection image of an OHP (overhead projector) in a halftone portion.

  An object of the present invention is to provide an image forming method and a toner excellent in transparency of a full color projection image of an OHP (overhead projector) in a solid portion.

The present invention relates to an image forming method in which a toner image on a transfer material is heated and pressed and fixed by a heating and pressing unit to form a fixed image on the transfer material.
The heating and pressing means is a heating and pressing means having a magnetic field generating means, a rotary heating member composed of two layers of a heat generating layer and a release layer that generate heat by electromagnetic induction, and a rotary pressure member.
The rotating heating member has a heating layer having a thickness of 1 to 200 μm, a release layer having a thickness of 1 to 100 μm and a surface pressure of 9000 to 500,000 N / m ² through the transfer material. The toner image is fixed at a fixing speed of 5 to 300 mm / sec while being pressed against the rotating heating member.
The toner forming the toner image is a toner containing at least a binder resin, a colorant, a release agent, and an oxycarboxylic acid, and a 0.1 mol / liter sodium hydroxide aqueous solution from 1 g of the toner The mass X (mg) of the oxycarboxylic acid extracted by, and the mass Y (mg) of the oxycarboxylic acid extracted by methanol,
Y / X = 1.05 to 3.00
X = 0.10 to 3.50
Satisfied with the relationship
The present invention relates to an image forming method, wherein the oxycarboxylic acid is a compound represented by the following formula (1).

  According to the present invention having the above-described configuration, a quick start with a small wait time is possible, and low-temperature fixability and high-temperature fixability can be improved. Furthermore, it is possible to provide an image with excellent transparency of a full-color projection image of an OHP (overhead projector) in a halftone part or a solid part.

  As a result of intensive studies, the present inventors have determined that in the above-described electromagnetic induction heating type fixing system, the toner composition is at least a binder resin, a colorant, a release agent, and an oxycarboxylic acid, and a strong alkaline property from 1 g of the toner. By defining the mass of the oxycarboxylic acid extracted with an aqueous solution, a technology that allows quick start and that has good fixability in the halftone part, which is not possible in the prior art, and the leading and trailing edges of the fixed image The present inventors have found a technique for improving transparency while forming a full-color image with little difference in glossiness of the part.

  In addition, by using the electromagnetic induction heating and fixing system described above, it was possible to obtain a good fixed image even when the conventional color toner has a large amount of toner while reducing power consumption.

  The electromagnetic induction heating means has a configuration in which the magnetic flux distribution of the exciting coil can be concentrated in the nip portion and the vicinity thereof while obtaining efficient heat generation, so that the nip portion can be rapidly heated and heat can be radiated. It is possible to obtain heat energy for heating the material to be heated efficiently and with high density by effectively using input power (input energy) with little loss, and by mutual pressure contact with the pressure member Low power consumption and shortened wait time (quick start) are possible due to the configuration that can sufficiently withstand a high load even when a sufficient nip is applied. Even with a large transfer material, the toner image can be sufficiently melted even for an image with a large amount of toner such as a full-color image, and good fixing properties can be obtained. Eteiru.

  The reason why the fixing property in the halftone part is good even with a transfer material having a large surface irregularity is that the amount of oxycarboxylic acid as in the present invention causes the toner surface to intervene with the oxycarboxylic acid. The electrostatic repulsive force of the oxycarboxylic acid on the mold release effect of the mold release agent itself in combination with the mold release agent while acting as a spacer between the layer and the heating part of the electromagnetic induction heating It is considered that the fixing effect on the high temperature side has been remarkably improved.

  The reason why the transparency of the full-color projection image of OHP in the halftone part is excellent is that the amount of oxycarboxylic acid as in the present invention is maintained, so that the amount of charge in the unexposed product can be kept higher than that of the conventional product. Since the amount of the external additive to be applied is small, it is considered that the scattered light of the light accompanying the external additive amount factor can be suppressed, and as a result, the transparency of the OHP projection image of the halftone portion is improved.

  Moreover, the reason why the transparency of the full color projection image of OHP in the solid portion is excellent is not because the oxycarboxylic acid exhibits a crystal growth inhibitory action in the combination of the oxycarboxylic acid and the release agent as in the present invention. I think.

  Originally, a crystal growth inhibitor is inhibited if it has a structure similar to that of the compound trying to inhibit crystal growth in the structure, but has a polar group or an aromatic group having a structure different from that of the compound. It is thought that the effect of. For example, in the case of paraffin wax, a compound having an alkyl group and a polar group or an aromatic group can be used.

  Specifically, when considered by replacing the present invention, Exemplified Compound Oxycarboxylic Acid 1-A and Exemplified Compound Release Agent No. In the case of the combination with No. 6, the tertiary butyl group of the oxycarboxylic acid and the long-chain alkyl group of the ester wax have the same structure, so that the conformation is easy and the carboxyl group of the oxycarboxylic acid has a polarity. It is thought that it acts as a crystal nucleating agent as a release agent.

  Hereinafter, the configuration of the toner of the present invention and the configuration of the image forming method will be described in sequence.

(1) Toner configuration:
As the oxycarboxylic acid, known compounds can be used, but from the viewpoint of charge imparting ability, compounds represented by the following formulas (1) and (2) are preferable, and in the present invention, the compounds are represented by formula (1). A compound is used.

［上記式（１）中、（Ａ）は下記の群より選ばれ、Ｘ₁は、水素原子、ナトリウム原子、カリウム原子、アンモニウム又は脂肪族アンモニウムを示す。］

[In the above formula (1), (A) is selected from the following group, and X ₁ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or aliphatic ammonium. ]

  Among the oxycarboxylic acids represented by the above formula (1), those preferably used in the present invention are oxycarboxylic acids having an aromatic ring, and monoalkyl aromatic oxycarboxylic acids or dialkyl aromatic oxycarboxylic acids. Is mentioned. In particular, salicylic acid, di-tert-butylsalicylic acid, alkylsalicylic acid represented by 5-tert-octylsalicylic acid, hydroxynaphthoic acid, and the like are easily used for the present invention because they can be easily fixed on the toner surface.

  Examples of typical specific compounds are listed below.

  In the present invention, the mass X (mg) of the oxycarboxylic acid extracted from 1 g of toner with a 0.1 mol / liter sodium hydroxide aqueous solution is preferably 0.10 to 20.0, more preferably 0.10 to 10. 15.0 is good. If it is less than 10 mg, the absolute value of the charge amount of the toner itself is low, so that there is a lot of background fog in the durability test, a good fixed image cannot be obtained, and a good full-color OHP image cannot be obtained. If it exceeds 20.0 mg, the fixing roller is contaminated during continuous paper feeding, and the high-temperature fixability deteriorates. Further, when the initial image is output after being left at high temperature and high humidity, the secondary color line portion is not scattered well, and a good full-color text chart cannot be produced.

  Further, the mass X of the oxycarboxylic acid extracted from 0.1 g / liter of the sodium hydroxide aqueous solution from 1 g of the toner and the mass Y (mg) of the oxycarboxylic acid extracted by methanol are Y / X = 1. 0.05 to 4.00 is preferable, and 1.05 to 3.00 is more preferable. When Y / X is less than 1.05, the toner charging characteristics are not improved, and when it exceeds 4.00, there may be a case where more oxycarboxylic acid is present inside the toner surface layer. From the viewpoint of charging, oxycarboxylic acid cannot be effectively used.

  The mass Y of oxycarboxylic acid extracted from 1 g of toner by methanol is the amount of oxycarboxylic acid present on the surface of the toner particles and the surface layer portion (near the surface) where methanol can permeate. The mass X of oxycarboxylic acid extracted from the inside by a 0.1 mol / liter sodium hydroxide aqueous solution means the amount of oxycarboxylic acid present on the surface of the toner particles.

  In the present invention, a conventionally known analysis method may be used for the amount of oxycarboxylic acid Y extracted from the toner with methanol and the amount of oxycarboxylic acid X extracted with a 0.1 mol / liter sodium hydroxide aqueous solution. I can do it. Specific examples are described below.

  50 ml each of 0.1 mol / liter aqueous sodium hydroxide solution containing methanol and 0.04 g of Contaminone N (manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant was prepared in separate containers, and 1 g of toner was put in each container. Weigh and add, stir at 50 rpm using a stirrer, and disperse uniformly. After the dispersion treatment for 3 hours, the mixture was filtered using a membrane filter (pore size: 0.45 μm), the absorption spectrum of the obtained filtrate was measured with a spectrophotometer, and the maximum value of the maximum absorption peak exhibited by oxycarboxylic acid Find the difference between and the baseline. From the obtained results, the oxycarboxylic acid amount X in the toner and the oxycarboxylic acid amount Y on the toner surface were calculated using a predetermined calibration curve. The absorption spectrum of oxycarboxylic acid appears in the range of 280 to 350 nm, for example.

  In the toner according to the present invention, the addition effect of oxycarboxylic acid present in the toner can be made efficient by producing a toner having particularly good circularity distribution.

In the toner according to the present invention, in the toner-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring apparatus, the toner equivalent circle average diameter D ₁ (μm) is 2 to 10 μm. And by controlling the particle shape of the toner so that the average circularity of the toner is 0.920 to 0.995 and the circularity standard deviation is less than 0.040, The charging characteristics are improved in a well-balanced manner, and at the same time, the oxidizing ability of the oxycarboxylic acid to the heating and pressurizing means and the surfactant-like behavior become appropriate, so that matching with the image forming apparatus is remarkably improved.

That is, by reducing the toner circle equivalent number average diameter D ₁ (μm) to 2 to 10 μm, the reproducibility in developing the contour portion of an image, particularly a character image or a line pattern, is improved. . Further, by controlling the average circularity of the circularity frequency distribution of the toner to 0.920 to 0.995, preferably 0.950 to 0.995, and more preferably 0.970 to 0.995, control is conventionally performed. The charging characteristics of the toner having a small particle diameter, which has been difficult, are greatly improved, and the developing ability for a low potential latent image is remarkably improved. In particular, the above-mentioned tendency is very effective when developing a digital microspot latent image or when forming a full-color image that is transferred many times using an intermediate transfer member, and also has good matching with an image forming apparatus. It will be something.

  Furthermore, the toner of the present invention has a developability by making the circularity standard deviation of the circularity frequency distribution of the toner less than 0.040, preferably less than 0.035, more preferably 0.015 or more and less than 0.035. The problem about can be greatly improved.

  Further, by setting the number of toner particles having an average circularity of less than 0.950 in the circularity frequency distribution to 15% by number or less, the development efficiency in the image formation becomes a sufficient level, and the image formation is also good.

  Control of the average circularity of the toner, the standard deviation of circularity, and the number of toners having a circularity of less than 0.950 can be controlled by the pH of the aqueous dispersion medium during the polymerization reaction in the production method of the toner by the polymerization method. .

  The circularity in the present invention is used as a simple method for quantitatively expressing the particle shape. In the present invention, the particle shape is measured using a flow particle image analyzer FPIA-1000 manufactured by Toa Medical Electronics. The circularity is obtained by the following formula. Furthermore, as shown by the following equation, a value obtained by dividing the total roundness of all the measured particles by the total number of particles is defined as the average circularity.

  Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define.

  In addition, “FPIA-1000”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity and the circularity standard deviation. Degrees of 0.400 to 1.000 at intervals of 0.010, 0.400 or more and less than 0.410, 0.410 or more and less than 0.420 ... 0.990 or more and less than 1.000 and 1.000 A calculation method is used in which the average circularity and the circularity standard deviation are calculated using the center value and frequency of the division points.

  Error between each value of average circularity and circularity standard deviation calculated by this calculation method and each value of average circularity and circularity standard deviation calculated by the above-described calculation formula that directly uses the circularity of each particle. Is very small and substantially negligible. Therefore, in the present invention, the circular shape of each particle described above is used for the reason of handling data such as a short calculation time and a simplified calculation formula. This calculation method is partially modified by using the concept of a calculation formula that directly uses the degree.

  The circularity in the present invention is an index indicating the degree of unevenness of particles, and is 1.000 when the particles are completely spherical, and the circularity becomes smaller as the surface shape becomes more complicated.

The equivalent circle diameter is
Equivalent circle diameter = (particle projected area / π) ^1/2 × 2
The circle-equivalent number average diameter (D1) represents the average value of the equivalent circle diameter of the toner based on the number, and the particle size (center value) at the division point i of the particle size distribution is di, When the frequency is fi, it is expressed as follows.

  Similarly, the standard deviation is expressed as follows.

  The division points of the particle size distribution in the present invention are as shown in the following table.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “UH-50 type” (manufactured by SMT Co., Ltd.) equipped with a 5φ titanium alloy chip as a vibrator is used, and a dispersion for measurement is performed using a dispersion treatment for 5 minutes. To do. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more.

  To measure the shape of the toner, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 or more toner particles are obtained. measure. After the measurement, using this data, the equivalent circle diameter of the toner, the circularity frequency distribution, and the like are obtained.

  As the binder resin of the toner used when the toner of the present invention is produced by the pulverization method, polystyrene; a styrene-substituted homopolymer such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene Polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene -Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile -Stins such as indene copolymers Emissions copolymer, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resins, polyester resins, polyamide resins, furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.

  As the main component of the binder resin, a styrene copolymer which is a copolymer of styrene and another vinyl monomer is preferable in terms of developability and fixability.

  The comonomer for the styrene monomer of the styrene copolymer includes acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methacrylic acid. Monocarboxylic acid having a double bond such as methyl acid, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a substituted product thereof; maleic acid, butyl maleate, methyl maleate, maleate Dicarboxylic acids having a double bond such as dimethyl acid and its substitutes; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene; Sulfonyl methyl ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

  The styrene copolymer is preferably crosslinked with a crosslinking agent such as divinylbenzene in order to widen the fixing temperature range of the toner and improve the offset resistance.

  As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a vinyl polymerizable monomer capable of radical polymerization is used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used. Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butyl. Styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p -Styrene derivatives such as phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2 -Ethylhexyl acrylate , Acrylic polymerizable monomers such as n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl Methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate Methacrylic polymerizable monomers such as dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl methyl ether Vinyl ether such as vinyl ethyl ether and vinyl isobutyl ether; vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol Dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, Examples include 2,2′-bis (4- (methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

  In the present invention, the above monofunctional polymerizable monomers are used alone or in combination of two or more, or the above monofunctional polymerizable monomers and polyfunctional polymerizable monomers are used in combination. To do. The polyfunctional polymerizable monomer can also be used as a crosslinking agent.

  As the polymerization initiator used in the polymerization of the polymerizable monomer described above, an oil-soluble initiator and / or a water-soluble initiator is used. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumylper Kisaido, t- butyl hydroperoxide, di -t- butyl peroxide, include peroxide initiators such as cumene hydroperoxide.

  Water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloric acid Examples include salts, azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

  In the present invention, in order to control the polymerization degree of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor or the like can be further added and used.

  As the crosslinking agent used in the toner of the present invention, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups. These are used alone or as a mixture.

  The release agent used in the toner of the present invention preferably has a weight average molecular weight (Mw) of 350 to 4000 and a number average molecular weight (Mn) of 200 to 4000, more preferably Mw of 400 to 3500, Mn. Is preferably 250 to 3500. When Mw is less than 350 and Mn is less than 200, the toner has low blocking resistance. When Mw exceeds 4000 and Mn exceeds 4000, the crystallinity of the release agent itself is developed, and the transparency of the fixed image is lowered.

  The releasing agent preferably has a melting point (temperature relative to the maximum endothermic peak of the DSC endothermic curve in the temperature range of 20 to 200 ° C.) of 30 to 120 ° C., more preferably 50 to 90 ° C. As the release agent, a wax in a solid state at room temperature is preferable, and a solid wax having a melting point of 40 to 100 ° C. is particularly preferable in terms of toner blocking resistance, durability of a large number of sheets, low-temperature fixability, and offset resistance.

  Examples of the wax include paraffin wax, polyolefin wax, microcrystalline wax, polymethylene wax such as Fischer-Tropsch wax, amide wax, higher fatty acid, long chain alcohol, ester wax, and derivatives thereof such as graft compounds and block compounds. These preferably have a sharp maximum endothermic peak in the DSC endothermic curve from which low molecular weight components have been removed.

  Examples of the wax preferably used include linear alkyl alcohols having 10 to 100 carbon atoms, linear fatty acids, linear acid amides, linear esters, and montan derivatives. Those from which impurities such as liquid fatty acids have been previously removed from these waxes are also preferred.

  Further, the wax preferably used is a low molecular weight alkylene polymer obtained by polymerizing alkylene with radical polymerization under high pressure or Ziegler catalyst or other catalyst under low pressure; alkylene obtained by thermally decomposing high molecular weight alkylene polymer Polymer: A low molecular weight alkylene polymer produced as a by-product in the polymerization of alkylene, separated and purified; a hydrocarbon polymer distillation residue obtained from a synthesis gas composed of carbon monoxide and hydrogen by the age method, or a distillation residue Examples include polymethylene wax obtained by extracting and fractionating specific components from a synthetic hydrocarbon obtained by hydrogenation. These waxes may contain an antioxidant.

  In order to improve the translucency of the fixed image, solid ester wax or solid ketone wax is preferable. More preferably, it is a solid ester wax, and those having a melting point of 50 to 90 ° C. are particularly good.

  Examples of the ester wax include those formed from the compounds represented by the following general formulas (I) to (V), but other types may be used.

（式中、ａ及びｂは０〜４迄の整数であり、ａ＋ｂは４である。Ｒ₁及びＲ₂は炭素数が１〜４０の有機基であり、Ｒ₁とＲ₂との炭素数差が３以上である。ｍ及びｎは０〜２５の整数であり、ｍとｎは同時に０になることはない。）

(In the formula, a and b are integers from 0 to 4 and a + b is 4. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and the number of carbon atoms of R ₁ and R _2. The difference is at least 3. m and n are integers from 0 to 25, and m and n cannot be 0 at the same time.)

（式中、ａ及びｂは０〜３の整数であり、ａ＋ｂは１〜３である。Ｒ₁及びＲ₂は炭素数が１〜４０の有機基であり、Ｒ₁とＲ₂との炭素数差が３以上である。Ｒ₃は水素原子、炭素数が１以上の有機基である。但し、ａ＋ｂ＝２のとき、Ｒ₃のどちらか一方は、炭素数が１以上の有機基である。ｋは１〜３の整数である。ｍ及びｎは０〜２５の整数であり、ｍとｎが同時に０になることはない。）

(In the formula, a and b are integers of 0 to 3, a + b is 1 to _3. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and carbons of R ₁ and R _2. The number difference is at least 3. R ₃ is a hydrogen atom and an organic group having 1 or more carbon atoms, provided that when a + b = 2, one of R ₃ is an organic group having 1 or more carbon atoms. (K is an integer of 1 to 3. m and n are integers of 0 to 25, and m and n are not 0 at the same time.)

（式中、Ｒ₁及びＲ₃は炭素数６〜３２を有する有機基であり、Ｒ₁とＲ₃は同じものであってもなくても良い。Ｒ₂は炭素数１〜２０を有する有機基を示す。）

(In the formula, R ₁ and R ₃ are organic groups having 6 to 32 carbon atoms, and R ₁ and R ₃ may or may not be the same. R ₂ is an organic group having 1 to 20 carbon atoms. Group.)

（式中、Ｒ₁及びＲ₂は炭素数６〜３２を有する有機基であり、Ｒ₁とＲ₃は同じものであってもなくてもよい。
Ｒ₂は−ＣＨ₂ＣＨ₂ＯＣ₆Ｈ₄ＯＣＨ₂ＣＨ₂−、

(In the formula, R ₁ and R ₂ are organic groups having 6 to 32 carbon atoms, and R ₁ and R ₃ may or may not be the same.
R ₂ represents —CH ₂ CH ₂ OC ₆ H ₄ OCH ₂ CH ₂ —,

（式中、ａは０〜４の整数であり、ｂは１〜４の整数であり、ａ＋ｂは４である。Ｒ₁は炭素数が１〜４０の有機基である。ｍ及びｎは０〜２５の整数であり、ｍとｎが同時に０になることはない。）

(Wherein, a is an integer of 0 to 4, b is an integer of 1 to 4, and a + b is 4. R ₁ is an organic group having 1 to 40 carbon atoms. M and n are 0. (It is an integer of ˜25, and m and n are not 0 at the same time.)

  The following are illustrated as an ester wax as a mold release agent which consists of ester compounds.

  Particularly preferably, an ester wax having one or more long chain ester portions having 10 or more carbon atoms is desired. When the releasing agent is an ester wax having an ester compound having the above structural formula, it exhibits good transparency and exhibits good fixability when incorporated in toner particles. After the release agent and the polar resin are dissolved in the polymerizable monomer, the polymerization reaction of the polymerizable monomer is advanced in a hydrogen medium, so that the charge amount of the obtained toner particles is large and appropriate. An excellent toner can be obtained which has a high speed until reaching the charge value and has little fluctuation in the frictional charge amount in the durability of a large number of sheets.

  The release agent is preferably used in an amount of 1 to 10 parts by mass with respect to 100 parts by mass of the binder resin when toner particles are produced by the melt-kneading pulverization method.

  When toner particles are directly generated using the polymerizable monomer composition, 5 to 40 parts by mass (more preferably 5 to 30 parts by mass) with respect to 100 parts by mass of the polymerizable monomer. As a result, 5 to 40 parts by mass (more preferably 5 to 30 parts by mass) of toner particles per 100 parts by mass of the binder resin produced from the polymerizable monomer may be contained in the toner particles.

  Compared to the dry toner manufacturing method, a large amount of release agent is generally used in the toner manufacturing method using the polymerization method compared to the dry toner manufacturing method by the melt kneading and pulverization method, because a large amount of release agent is easily contained in the toner particles by the polar resin. This is particularly effective for the effect of preventing offset during fixing.

  If the addition amount of the release agent is less than the lower limit, the effect of preventing offset tends to be lowered, and if the amount exceeds the upper limit, the anti-blocking effect is lowered and the anti-offset effect is liable to be adversely affected. Sleeve fusion is likely to occur, and when toner particles are produced by a polymerization method, toner particles having a wide particle size distribution tend to be produced.

  The release agent used in the present invention preferably has an (SP) value in the range of 7.6 to 10.5. A mold release agent having an SP value of less than 7.6 has poor compatibility with the polymerizable monomer or binder resin used, and as a result, it is difficult to obtain good dispersion in the binder resin, and many sheets At the time of copying or printing, the release agent is likely to adhere to the developing sleeve, and the charge amount of the toner is likely to change. In addition, the background fogging and the toner density fluctuation at the time of toner replenishment are likely to occur. When a release agent having an SP value exceeding 10.5 is used, blocking of the toner particles tends to occur when the toner is stored for a long time. Furthermore, since the compatibility with the binder resin is too good, it is difficult to form a sufficient release layer between the fixing member and the toner binder resin layer at the time of fixing, and an offset phenomenon is likely to occur.

  The solubility parameter (SP) value may be calculated by using the method of Fedors (Polym. Eng. Sci., 14 (2) 147 (1974)) utilizing the additivity of atomic groups.

  The release agent used in the present invention preferably has a melt viscosity at 135 ° C. of 1 to 300 mPa · S, more preferably 3 to 50 mPa · S. When the melt viscosity is lower than 1 mPa · S, when the toner layer is thinly coated on the developing sleeve with a coating blade or the like by the non-magnetic one-component developing method, the sleeve is likely to be contaminated by mechanical shearing force. In the two-component development method, when developing an electrostatic charge image using carrier particles and toner, the toner is liable to be damaged due to the shearing force between the toner and carrier particles, and the external additive is buried and the toner particles are crushed. Prone to occur. In the case where the melt viscosity exceeds 300 mPa · S, when the toner particles are produced using the polymerization method, the viscosity of the polymerizable monomer composition is increased, and the toner particles having a fine particle size with a sharp particle size distribution are obtained. Not easy to get.

  The melt viscosity of the release agent may be measured at 135 ° C. using a cone plate rotor (PK-1) with a AKE-VP VP-500.

  The mold release agent used in the present invention preferably has a hardness of 0.3 to 10.0, and more preferably Vickers hardness of 0.5 to 5.0. A more preferred Vickers hardness is 0.5 to 3.0.

  Toner containing a release agent with a Vickers hardness of less than 0.3 tends to be crushed in the cleaning process when copying or printing a large number of sheets, causing toner fusing on the surface of the photosensitive drum, resulting in black streaks on the image. It's easy to do. When a large number of fixed image samples are stored and stored, toner is transferred to the back surface, and show-through tends to occur.

  A toner containing a release agent having a Vickers hardness of more than 10.0 requires a pressing force more than necessary at the time of heat and pressure fixing even if it is a fixing means having a high thermal conductivity as in this case, and the life of the fixing device is long. It is not preferable in terms.

  An example of the hardness measurement of the release agent is a measurement method using a Shimadzu dynamic ultra-micro hardness meter (DUH-201). The measurement conditions were: Vickers hardness was determined by analyzing the dents on the sample held for 12 seconds after being displaced 10 μm at a loading speed of 9.67 mg per second under a 0.5 g load using a Vickers indenter. Ask. The sample is used by slowly cooling the molten sample and forming it into a 5 mm thick cylinder.

  As the colorant used in the toner of the present invention, carbon black, grafted carbon, magnetic material, or the like is used as a black colorant.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used as pigment systems. Specifically, C.I. I. Pigment Yellow 3, 7, 10, 12, 13, 14, 15, 17, 23, 24, 60, 62, 74, 75, 83, 93, 94, 95, 99, 100, 101, 104, 108, 109, 110 111, 117, 123, 128, 129, 138, 139, 147, 148, 150, 166, 168, 169, 177, 179, 180, 181, 183, 185, 191: 1, 191, 192, 193, 199 Etc. are preferably used. Examples of the dye system include C.I. I. Solvent Yellow 33, 56, 79, 82, 93, 112, 162, 163, C.I. I. Disperse Yellow 42, 64, 201, 211 etc. are mentioned.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254, C.I. I. Pigment violet 19 is particularly preferred.

  As the cyan colorant, phthalocyanine compounds such as copper, aluminum and zinc and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant of the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

  The toner of the present invention may be used in combination with a charge control agent.

  The following substances are used for controlling the toner to be negatively charged. For example, organometallic compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, resin charge control agents, and the like can be given.

  The following substances are used to control the toner to be positively charged. Modified products of nigrosine with nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and analogs thereof Onium salts such as phosphonium salts and their lake pigments, triphenylmethane dyes and their lake pigments (the rake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid Acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyls Borate, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate, resin charge control agent and the like. These can be used alone or in combination of two or more.

  The charge control agent is used in an amount of 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the binder resin.

  When the toner of the present invention is a polymerization toner, a condensation resin may be added.

  The condensation resin has a weight average molecular weight (Mw) of 6000 to 100,000, preferably 6500 to 85000, and more preferably 6500 to 45000.

  When the weight average molecular weight is less than 6000, as compared with those within the optimum range, the external additive on the surface of the toner particles tends to be buried due to durability in continuous paper passing, and the transferability tends to be lowered. When the weight average molecular weight exceeds 100,000, it takes much time to dissolve the condensation resin in the polymerizable monomer. Further, the viscosity of the polymerizable monomer composition increases, and it becomes difficult to obtain toner particles having a small particle size and a uniform particle size distribution.

  The condensation resin has a number average molecular weight (Mn) of 3000 to 80000, preferably 3500 to 60000, and more preferably 3500 to 12000. The condensed resin has a molecular weight distribution main peak value (Mp) in a gel permeation chromatogram (GPC) of 4500 to 40000, preferably 6000 to 30000, and more preferably 6000 to 20000. When it is out of the above range, the same tendency as in the case of the weight average molecular weight is exhibited.

  The condensation resin has a Mw / Mn of 1.2 to 3.0, more preferably 1.5 to 2.5. When Mw / Mn is less than 1.2, the durability and offset resistance of a large number of toners are reduced, and when it exceeds 3.0, in terms of low-temperature fixability, it is more than the range. Slightly inferior.

  The condensed resin has a glass transition point (Tg) of 50 to 125 ° C, preferably 50 to 95 ° C, and more preferably 55 to 90 ° C. When the glass transition point is lower than 50 ° C., the blocking resistance of the toner is lowered. When the glass transition point exceeds 125 ° C., the low temperature offset resistance of the toner decreases.

  The acid value (mgKOH / g) of the condensation resin is 0.1 to 35, preferably 3 to 35, more preferably 4 to 35, and still more preferably 5 to 30. When the acid value is less than 0.1, the toner charge amount rises slowly and fogging is likely to occur. When the acid value exceeds 35, the triboelectric charging characteristics of the toner after being left under high temperature and high humidity are likely to vary, and the image density is likely to vary during continuous paper feeding. Furthermore, when the acid value of the polar resin exceeds 35, the affinity between the polymers of the polar resin is increased, so that the polar resin is difficult to dissolve in the polymerizable monomer, and the uniform polymerizable monomer composition It takes time to prepare the product.

  The hydroxyl value (mgKOH / g) of the condensed resin is 0.2 to 50, preferably 5 to 50, more preferably 7 to 45. When the hydroxyl value is less than 0.2, the localization of the polar resin is less likely to occur on the surface of the polymerizable monomer composition particles in the aqueous medium as compared with those within the optimum range. When the hydroxyl value exceeds 50, the charge amount characteristic of the toner after standing under high temperature and high humidity tends to be slightly lower than that in the optimum range, and the image density tends to fluctuate during continuous paper feeding. .

  Examples of the condensation resin of the present invention include polyester, polycarbonate, phenol resin, epoxy resin, polyamide, and cellulose. More preferably, polyester is desired due to the variety of materials.

  Examples of the method for producing the condensation resin and the release agent include a synthesis method by an oxidation reaction, a synthesis from a carboxylic acid and a derivative thereof, an ester group introduction reaction represented by a Michael non-reaction, a carboxylic acid compound and an alcohol compound. It is produced by a method utilizing a dehydration condensation reaction from the above, a reaction from an acid halide and an alcohol compound, and a transesterification reaction. The catalyst may be a general acidic or alkaline catalyst used in the esterification reaction, such as zinc acetate or a titanium compound. Thereafter, it may be highly purified by a recrystallization method, a distillation method or the like.

  A particularly preferred production method of the condensation resin and the release agent is a dehydration condensation reaction from a carboxylic acid compound and an alcohol compound because of the versatility of raw materials and the ease of reaction.

  The composition of the condensation resin used in the present invention will be described below.

  Condensation-type resin WHEREIN: It is preferable that 45 to 55 mol% is an alcohol component among all the components, and 55 to 45 mol% is an acid component.

  As alcohol components, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexane Diol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, the following formula (I)

（式中、Ｒはエチレン又はプロピレン基を示し、ｘ，ｙはそれぞれ１以上の整数を示し、かつｘ＋ｙの平均値は２乃至１０を示す。）
で示されるビスフェノール誘導体、又は下記式（ロ）

(In the formula, R represents an ethylene or propylene group, x and y each represents an integer of 1 or more, and the average value of x + y represents 2 to 10.)
Or a bisphenol derivative represented by the following formula (b)

で示されるジオールの如きジオール類が挙げられる。

Diols such as the diol represented by

  Divalent carboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, diphenyl-P · P′-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane Benzene dicarboxylic acids such as P · P′-dicarboxylic acid, benzophenone-4,4′-dicarboxylic acid, 1,2-diphenoxyethane-P · P′-dicarboxylic acid or anhydrides thereof; succinic acid, adipic acid, sebacin Acids, azelaic acid, glutaric acid, cyclohexanedicarboxylic acid, triethylenedicarboxylic acid, alkyldicarboxylic acids such as malonic acid or anhydrides thereof, and succinic acid substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms or its Anhydrides such as fumaric acid, maleic acid, citraconic acid, itaconic acid Unsaturated dicarboxylic acids or anhydrides thereof, and the like.

  The alcohol component of the condensation resin particularly preferable in the practice of the present invention is a bisphenol derivative represented by the above formula (a), and the acid component is phthalic acid, terephthalic acid, isophthalic acid or its anhydride, succinic acid. , N-dodecenyl succinic acid or its anhydride, fumaric acid, maleic acid, maleic anhydride and the like dicarboxylic acids.

  The condensation resin can be obtained by synthesizing from a divalent dicarboxylic acid and a divalent diol. In some cases, a trivalent or higher polycarboxylic acid or polyol may be used in a small amount as long as it does not adversely affect the present invention.

  Trivalent or higher polycarboxylic acids include trimellitic acid, pyromellitic acid, cyclohexanetricarboxylic acids, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid Acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, 1,3-dicarboxyl-2-methyl-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2 , 7,8-octanetetracarboxylic acid and their anhydrides.

  Examples of the trivalent or higher polyol include sorbitol, 1,2,3,6-hexaneteitol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-methanetriol. Glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene.

  The additive for the purpose of improving various properties in the toner preferably has a particle size of 1/5 or less of the volume average diameter of the toner particles from the viewpoint of durability. The particle size of the additive means the average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for the purpose of imparting these characteristics, for example, the following are used.

  Examples of the fluidity-imparting agent include metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.) carbon black, carbon fluoride, and the like. Those subjected to hydrophobic treatment are more preferable.

  Abrasives include metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, barium sulfate, etc.) , Calcium carbonate, etc.).

  Examples of the lubricant include fluorine-based resin powders (such as vinylidene fluoride and polytetrafluoroethylene) and fatty acid metal salts (such as zinc stearate and calcium stearate).

  Examples of the charge controllable particles include metal oxides (such as tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide) and carbon black.

  These additives are used in an amount of 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles. These additives may be used alone or in combination.

  The toner of the present invention can be used as a toner for a one-component developer, and can also be used as a toner for a two-component developer having carrier particles. In the case of a magnetic toner in which a magnetic material is contained in toner particles, there is a method of conveying and charging the magnetic toner by using a magnet built in the developing sleeve. In the case of using a non-magnetic toner that does not contain a magnetic substance, there is a method in which a blade or a roller is used to forcibly frictionally charge with a developing sleeve, and the toner is deposited on the sleeve to be conveyed.

  When used as a two-component developer, a carrier is used as a developer together with the toner of the present invention. The magnetic carrier is composed of an element consisting of iron, copper, zinc, nickel, cobalt, manganese and chromium elements alone or in a composite ferrite state. The magnetic carrier has a spherical shape, a flat shape, or an indeterminate shape. Furthermore, it is preferable to control the fine structure (for example, surface irregularity) of the surface state of the magnetic carrier particles. Generally, a method is used in which magnetic carrier core particles are generated in advance by firing and granulating the above inorganic oxide, and then coated on a resin. From the viewpoint of reducing the load on the toner of the magnetic carrier, a method of obtaining a low-density dispersion carrier by kneading and classifying the inorganic oxide and the resin, and further kneading the inorganic oxide and the monomer directly. A method of obtaining a true spherical magnetic carrier by suspension polymerization in an aqueous medium can also be used.

  A coated carrier in which the surface of the carrier particles is coated with a resin is particularly preferable. As the method, a method in which a resin is dissolved or suspended in a solvent and applied and adhered to a carrier, or a method in which resin powder and carrier particles are simply mixed and adhered can be applied.

  The substance adhering to the carrier particle surface varies depending on the toner material. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, polyamide, polyvinyl butyral And aminoacrylate resins. These may be used alone or in plural.

The magnetic properties of the carrier are as follows. After magnetic saturation, the magnetization strength (σ _79.6 ) at a magnetic field strength of 79.6 kA / m (1000 oersted) needs to be 3.77 to 37.7 μWb / cm ³ . Further, in order to achieve higher image quality, it is preferably 12.6 to 31.4 Wb / cm ³ . When it is larger than 37.7 μWb / cm ^3, it becomes difficult to obtain a high-quality toner image. When it is less than 3.77 μWb / cm ³ , the magnetic binding force is also reduced, and carrier adhesion is likely to occur.

  The carrier shape is preferably such that SF-1 indicating the degree of roundness is 180 or less, and SF-2 indicating the degree of unevenness is 250 or less. SF-1 and SF-2 are defined by the following formulas and measured by LUZEX III manufactured by Nireco.

  The toner production method of the present invention will be described below.

  When the toner of the present invention is a pulverized toner, at least a binder resin, a colorant, a release agent and the oxycarboxylic acid of the present invention are kneaded using a pressure kneader, an extruder, a media disperser, or the like. A pulverization method in which toner particles are produced by uniformly dispersing, then colliding with a target under a mechanical or jet stream to finely pulverize to a desired toner particle size, and further sharpening the particle size distribution through a classification process There is a method for producing toner.

  When the toner of the present invention is a polymerization method, it is not particularly limited, but is described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842. A direct toner production method using a suspension polymerization method; a soap-free polymerization method, which is soluble in monomers and directly polymerized in the presence of a water-soluble polymerization initiator to produce toner particles Examples thereof include production of toner particles by an emulsion polymerization method. In addition, production of an interfacial polymerization method such as a microcapsule production method, an in situ polymerization method, a coacervation method, and the like can also be mentioned. Furthermore, as disclosed in JP-A-62-106473 and JP-A-63-186253, an interface association method for aggregating at least one kind of fine particles to obtain a desired particle size, etc. It is done.

  Particularly preferred is a suspension polymerization method in which small toner particles can be easily obtained. Furthermore, a seed polymerization method in which a monomer is further adsorbed to the obtained polymer particles and then polymerized using a polymerization initiator can be suitably used in the present invention. At this time, it is also possible to use a compound having polarity dispersed or dissolved in the monomer to be adsorbed. When suspension polymerization is used as a method for producing toner particles, the toner particles can be produced directly by the following production method. A monomer composition in which a low softening point substance such as wax, a colorant, a polymerization initiator, a crosslinking agent, and other additives are added to the monomer, and the monomer composition is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like. Is dispersed in an aqueous medium containing a dispersion stabilizer by a usual stirrer, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is carried out at a polymerization temperature of 40 ° C. or higher, usually 50 to 95 ° C. (preferably 55 to 85 ° C.). The temperature may be raised in the latter half of the polymerization reaction, and the pH may be changed as necessary. Further, in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, a part of the aqueous medium may be distilled off in the latter half of the reaction or after the completion of the reaction. After completion of the reaction, the produced toner particles are collected by washing and filtration and dried. The pH in the aqueous medium during granulation is not particularly limited.

  The number variation coefficient obtained by dividing the standard deviation of the number distribution by the number average diameter is 35% or less, preferably 30% or less.

  In the polymerization method, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition. Examples of the dispersant used include inorganic calcium oxide, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, Examples include calcium sulfate, barium sulfate, bentonite, silica, alumina, and sodium dodecyl sulfate. As the organic compound, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, carboxymethyl cellulose sodium salt, starch and the like are used. These dispersants or dispersion aids are preferably used in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Commercially available dispersants may be used as they are, but in order to obtain dispersed particles having a fine and uniform particle size, the inorganic compound can also be produced in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a preferred dispersant for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring. In order to make these dispersants fine, 0.001 to 0.1% by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

  The toner physical properties of the present invention other than those described above are shown below.

  The MELT INDEX value (MI value; g / 10 min) of the toner of the present invention is preferably 0.1 to 100. 1 to 80 is more preferable.

  When the MI value is less than 0.1, the toner is not sufficiently melted even at the fixing temperature, and the color developability of a color single color image is poor. When the MI value exceeds 100, toner agglomerates are likely to occur in the developer packing portion in the developing machine, and the external additives are also embedded in the toner surface, so that the transferability in durability deteriorates. A good fixed image cannot be obtained.

  The toner of the present invention preferably has a cohesion degree of 0.1 to 30%, more preferably 4 to 20%, mainly from the viewpoint of developability. When the toner cohesion is less than 0.1, the fluidity of the toner is high, but the leakage of the agent is likely to occur due to durability. When the toner aggregation is greater than 30, the fluidity of the toner is low, and the developer packing portion in the developing machine is low. Toner agglomerates are easily induced, resulting in poor transferability and no good fixed image.

  The toner of the present invention is preferably a toner having an SF-1 value of 100 to 160, more preferably 100 to 150, and still more preferably 100 to 125. When SF-1 exceeds 160, the spherical shape gradually approaches an indeterminate shape, and a decrease in transfer efficiency is recognized accordingly.

  A method for measuring toner raw materials and toner physical properties is shown below.

  “Molecular weight and molecular weight distribution of release agent” are measured by gel permeation chromatography (GPC) under the following conditions.

(GPC measurement conditions)
Apparatus: GPC-150C (Waters)
Column: GMH-MT 30 cm 2 series (manufactured by Tosoh Corporation)
Temperature: 135 ° C
Solvent: o-dichlorobenzene (0.1% ionol added)
Flow rate: 1.0 ml / min
Sample: 0.4 ml injection of 0.15% sample A molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used for calculating the molecular weight of the sample. Furthermore, it calculates by converting into polyethylene by the conversion formula derived from the Mark-Houwink viscosity formula.

  “Molecular weight and molecular weight distribution of toner and condensed resin by GPC” are measured by the following method.

The column is stabilized in a 40 ° C. heat chamber, and THF (tetrahydrofuran) as a solvent is allowed to flow through the column at this temperature at a flow rate of 1 ml per minute, and about 100 μl of a THF sample solution is injected and measured. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, one having a molecular weight of about 10 ^{2 to} 10 ⁷ manufactured by Tosoh Corporation or Showa Denko is used, and at least about 10 standard polystyrene samples are suitably used. is there. An RI (refractive index) detector is used as the detector. As the column, it is preferable to combine a plurality of commercially available polystyrene gel columns. Examples include combinations of TSKgel G1000H (H _XL ), G2000H (H _XL ), G3000H (H _XL ), G4000H (H _XL ), G5000H (H _XL ), G6000H (H _XL ), G7000H (H _XL ), and TSK guard column.

  The sample is prepared as follows.

  Place the sample in tetrahydrofuran (THF) and let it stand for several hours, then shake well and mix well with THF (until the sample is no longer united), and let stand for more than 12 hours. At this time, the standing time in THF is set to be 24 hours or longer. Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, for example, Mysori Disc H-25-5 manufactured by Tosoh Corporation, Excro Disc 25CR manufactured by Gelman Science Japan Co., Ltd., etc.) can be used. A sample of GPC is used. The sample concentration is adjusted so that the resin component is 0.5 to 5 mg / ml.

  “The melting point of the release agent and the glass transition point of the condensation resin” are determined by DSC measurement as follows.

  In DSC measurement, from the measurement principle, it is preferable to measure with a differential scanning calorimeter of high accuracy internal heat type input compensation type. For example, DSC-7 manufactured by Perkin Elmer can be used. The measurement method is performed according to ASTM D3418-82. The measurement is performed by using a DSC curve measured when the temperature is raised at a temperature rate of 10 ° C./min after raising and lowering temperature once and taking a previous history.

  The “acid value of the condensation resin” is determined as follows. Basic operation conforms to JIS-K0070.

  The number of mg of potassium hydroxide required to neutralize free fatty acids, resin acids, etc. contained in 1 g of the sample is called the acid value, and the test is conducted as follows.

(1) Reagent (a) Solvent ethyl ether-ethyl alcohol mixed solution (1 + 1 or 2 + 1) or benzene-ethyl alcohol mixed solution (1 + 1 or 2 + 1), these solutions were subjected to N / 10 hydroxylation using phenolphthalein as an indicator immediately before use. Neutralize with potassium ethyl alcohol solution.
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 10 potassium hydroxide-ethyl alcohol solution Dissolve 7.0 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. The standardization is performed according to JIS-K8006 (basic matters concerning titration during the reagent content test).

  (2) Operation Weigh correctly 1 to 20 g of sample, add 100 ml of solvent and a few drops of phenolphthalein solution as an indicator, and shake well until the sample is completely dissolved. In the case of a solid sample, dissolve it by heating on a water bath. After cooling, this is titrated with an N / 10 potassium hydroxide ethyl alcohol solution, and the end point of neutralization is defined as the time when the indicator is slightly red for 30 seconds.

  (3) Calculation formula The acid value is calculated by the following formula.

ここにＡ：酸価
Ｂ：Ｎ／１０水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／１０水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）

Where A: acid value B: N / 10 amount of potassium hydroxide ethyl alcohol solution used (ml)
f: Factor of N / 10 potassium hydroxide ethyl alcohol solution S: Sample (g)

  The “hydroxyl value of the condensation resin” is determined as follows. Basic operation conforms to JIS-K0070.

  When 1 g of a sample is acetylated by a prescribed method, the number of mg of potassium hydroxide required to neutralize acetic acid bonded to a hydroxyl group is referred to as a hydroxyl value, and the test is performed by the following reagents, operations and calculation formulas.

(1) Reagent (a) Acetylation reagent 25 g of acetic anhydride is placed in a 100 ml volumetric flask, pyridine is added to make a total volume of 100 ml, and shaken sufficiently (in some cases, pyridine may be added). The acetylating reagent should be kept away from moisture, carbon dioxide and acid vapors and stored in a brown bottle.
(B) Phenolphthalein solution 1 g of phenolphthalein is dissolved in 100 ml of ethyl alcohol (95 v / v%).
(C) N / 2 potassium hydroxide-ethyl alcohol solution Dissolve 35 g of potassium hydroxide in as little water as possible, add ethyl alcohol (95 v / v%) to 1 liter, leave it for 2 to 3 days, and filter. The orientation is performed according to JIS-K8006.

  (2) Operation 0.5-2.0 g of a sample is correctly weighed in a round bottom flask, and 5 ml of an acetylating reagent is correctly added thereto. Put a small funnel over the mouth of the flask and immerse the bottom of about 1 cm in a glycerin bath at 95-100 ° C. and heat. At this time, in order to prevent the temperature of the neck of the flask from rising due to the heat of the bath, a cardboard disc with a round hole in it is put on the base of the neck of the flask. After 1 hour, the flask is removed from the bath, and after cooling, 1 ml of water is added from the funnel and shaken to decompose acetic anhydride. In order to further complete the decomposition, the flask was again heated in a glycerin bath for 10 minutes, allowed to cool, and then the funnel and the wall of the flask were washed with 5 ml of ethyl alcohol, and N / 2 potassium hydroxide ethyl alcohol using a phenolphthalein solution as an indicator. Titrate with solution. A blank test is performed in parallel with the main test. In some cases, a KOH-THF solution may be used as an indicator.

  (3) Calculation formula The hydroxyl value is calculated by the following formula.

ここにＡ：水酸基価
Ｂ：空試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
Ｃ：本試験のＮ／２水酸化カリウムエチルアルコール溶液の使用量（ｍｌ）
ｆ：Ｎ／２水酸化カリウムエチルアルコール溶液のファクター
Ｓ：試料（ｇ）
Ｄ：酸価

Where A: hydroxyl value B: amount of N / 2 potassium hydroxide ethyl alcohol solution used in the blank test (ml)
C: Amount of use of N / 2 potassium hydroxide ethyl alcohol solution in this test (ml)
f: Factor of N / 2 potassium hydroxide ethyl alcohol solution S: Sample (g)
D: Acid value

  The measurement of “THF insoluble content of toner” of the present invention will be described.

  The THF-insoluble content indicates a mass ratio of a substance that is insoluble in the THF solvent in the toner. The THF-insoluble content is defined as a value measured as follows.

  About 1.0 g of the toner sample is weighed (W1 g), put into a cylindrical filter paper (for example, No. 86R manufactured by Toyo Filter Paper), passed through a Soxhlet extractor, extracted for 6 hours using 100 to 200 ml of THF as a solvent, and extracted with a THF solvent. After evaporating the soluble component, vacuum drying is performed at 100 ° C. for several hours, and the amount of the THF-soluble resin component is weighed (W2 g). The THF-insoluble matter in the toner can be obtained from the following formula.

  The method for measuring the “toner MI value” of the present invention is as follows. Using a melt indexer L203 type (manufactured by Takara Kogyo Co., Ltd.), a sample of 4.0 to 5.0 g is held at 125 degrees for 5 minutes, and then 98 N (10 kgf). The amount of elution is measured for 2 minutes, and the measured value is calculated by converting it to a 10-minute value.

  The “coagulation degree of toner” of the present invention is measured using a powder tester (manufactured by Hosokawa Micron Corporation) with a vibrating screen, 400 mesh (aperture 38 μm), 200 mesh (aperture 74 μm), 100 mesh (aperture 147 μm). ) Are stacked in the order of 400 mesh (aperture 38 μm), 200 mesh (aperture 74 μm), and 100 mesh (aperture 147 μm) so that the meshes are overlapped in the order of narrow opening, that is, 100 mesh is the top. set. Add the sample to the set 100 mesh (mesh 147 μm) sieve so that the input voltage to the shaking table is 15 V, and adjust the shaking table amplitude to be in the range of 60 to 90 μm. Vibration is applied for about 25 seconds, and then the mass of the sample remaining on each sieve is measured, and the degree of aggregation is obtained based on the following equation. The smaller the cohesion value, the higher the fluidity of the toner.

  In the present invention, the SF-1 indicating the shape factor is, for example, a sample of 100 toner images enlarged by a magnification of 500 times using FE-SEM (S-800) manufactured by Hitachi, Ltd. For example, an image analysis apparatus (Luxex III) manufactured by Nireco Corporation is introduced and analyzed, and a value calculated from the following equation is defined as a shape factor SF-1.

（式中、ＭＸＬＮＧはトナー粒子の絶対最大長を示し、ＡＲＥＡはトナー粒子の投影面積を示す）

(Where MXLNG indicates the absolute maximum length of the toner particles, and AREA indicates the projected area of the toner particles)

  The shape factor SF-1 indicates the degree of roundness of the toner particles.

(2) Image Forming Method / Apparatus One of the features of the present invention is an image forming method for forming a fixed image on a transfer material.

  An example of the image forming method of the present invention will be described more specifically with reference to FIG.

  FIG. 1 is a schematic configuration diagram of an example of an image forming apparatus. The image forming apparatus of this example is an electrophotographic printer.

  Reference numeral 101 denotes a photosensitive drum (image bearing member) made of an organic photosensitive member or an amorphous silicon photosensitive member, which is rotationally driven in a direction indicated by an arrow at a predetermined process speed (peripheral speed).

  The photosensitive drum 101 is uniformly charged with a predetermined polarity and potential by a charging device 102 such as a charging roller in the course of rotation.

  Next, the charged surface is subjected to a scanning exposure process of target image information by a laser beam 103 output from a laser optical box (laser scanner) 110. The laser optical box 110 outputs a laser beam 103 modulated (on / off) corresponding to a time-series electric digital pixel signal of target image information from an image signal generation device such as an image reading device (not shown), and rotates. An electrostatic latent image corresponding to target image information scanned and exposed on the surface of the photosensitive drum 101 is formed.

  Next, the electrostatic latent image is visualized as a toner image on the photosensitive drum 101 by the developing device 104 given an appropriate development potential difference to the electrostatic latent image.

  The toner image is transferred to the surface of a transfer material (recording material) P sent from a paper supply unit (not shown) at a predetermined timing in a transfer unit that is a contact nip portion between the photosensitive drum 101 and the transfer roller 106. To go. The transfer roller 106 transfers a toner image from the surface of the photosensitive drum 101 to the recording material P side by supplying a charge having a polarity opposite to that of the toner from the back surface of the recording material P.

  The recording material P that has passed through the transfer portion is separated from the surface of the photosensitive drum 101 and is introduced into an image heating device (fixing device) 100. It is discharged to a paper discharge tray (not shown). The fixing device 100 will be described in detail in “(3) Fixing device (heating means)”.

  After the toner image has been transferred to the recording material P, the photosensitive drum 101 is cleaned by the cleaner 107 after removal of adhering residues such as transfer residual toner and paper dust. The cleaner 107 is always kept in contact with the intermediate transfer drum 105.

  This example apparatus can also execute a print mode of a monocolor image other than black by using a monocolor toner as a toner to be filled in the cartridge. A double-sided image print mode or a multiple image print mode can also be executed. In the double-sided image print mode, the recording material P on which the first-side image has been printed exiting the fixing device 100 is turned upside down via a recirculation conveyance mechanism (not shown) and sent again to the transfer unit to be toner on the two sides. Upon receiving the image transfer, the image is again introduced into the fixing device 100 and undergoes a toner image fixing process on two sides, whereby a double-sided image print is output.

  In the multiple image print mode, the recording material P that has been printed on the first image from the fixing device 100 is sent to the transfer section again without being turned upside down via a recirculation conveyance mechanism (not shown), and the first image print is performed. A second image of the toner image is transferred to the finished surface, and the image is again introduced into the fixing device 100 and subjected to the second toner image fixing process, whereby a multiple image print is output.

  On the other hand, FIG. 2 is a schematic configuration diagram of another example of the image forming apparatus. The image forming apparatus of this example is an electrophotographic full color printer.

  Similar to FIG. 1, the photosensitive drum 101 is subjected to a uniform charging process with a predetermined polarity and potential by a charging device 102 such as a charging roller during its rotation.

  Next, the charged surface is subjected to a scanning exposure process of target image information by a laser beam 103 output from a laser optical box (laser scanner) 110. The laser optical box 110 outputs a laser beam 103 modulated (on / off) corresponding to a time-series electric digital pixel signal of target image information from an image signal generation device such as an image reading device (not shown), and rotates. An electrostatic latent image corresponding to target image information scanned and exposed on the surface of the photosensitive drum 101 is formed. Reference numeral 109 denotes a mirror that deflects the output laser light from the laser optical box 110 to the exposure position of the photosensitive drum 101.

  In the case of full-color image formation, scanning exposure / latent image formation is performed on a first color separation component image of a target full-color image, for example, a yellow component image, and the latent image is subjected to yellow development in the four-color developing device 104. The toner image is developed by the operation of the device 104Y. The toner image is transferred to the surface of the intermediate transfer drum 105 at the primary transfer portion T1 which is a contact portion (or proximity portion) between the photosensitive drum 101 and the intermediate transfer drum 105. The surface of the rotating photosensitive drum 101 after the transfer of the toner image to the surface of the intermediate transfer drum 105 is cleaned by the cleaner 107 after removal of adhered residues such as transfer residual toner.

  The process cycle of charging, scanning exposure, development, primary transfer, and cleaning as described above includes a second color separation component image (for example, a magenta component image, the magenta developer 104M is activated) of a target full color image, and a third color. An intermediate transfer body is sequentially executed for each color separation component image of the separation component image (for example, cyan component image, cyan developing device 104C is activated) and the fourth color separation component image (for example, black component image, black developing device 104BK is activated). Four color toner images, a yellow toner image, a magenta toner image, a cyan toner image, and a black toner image, are sequentially superimposed and transferred onto the surface of the drum 105, and a color toner image corresponding to the target full-color image is synthesized and formed. .

  The intermediate transfer drum 105 has a middle resistance elastic layer and a high resistance surface layer on a metal drum. The intermediate transfer drum 105 is in contact with or close to the photosensitive drum 101 at the same peripheral speed as the photosensitive drum 101. The toner image on the photosensitive drum 101 side is transferred to the surface side of the intermediate transfer drum 105 by a potential difference from the photosensitive drum 101 by applying a bias potential to the metal drum of the intermediate transfer drum 105.

  The color toner image synthesized and formed on the surface of the rotary intermediate transfer drum 105 is transferred to the secondary transfer portion T2 which is a contact nip portion between the rotary intermediate transfer drum 105 and the transfer roller 106. At T2, the image is transferred onto the surface of the recording material P fed from a paper supply unit (not shown) at a predetermined timing. The transfer roller 106 supplies a charge having a polarity opposite to that of the toner from the back surface of the recording material P, thereby sequentially transferring the combined color toner images sequentially from the surface of the intermediate transfer drum 105 to the recording material P side.

  The recording material P that has passed through the secondary transfer portion T2 is separated from the surface of the intermediate transfer drum 105 and introduced into an image heating device (fixing device) 100, and undergoes a heat fixing process for an unfixed toner image to form a color image. It is discharged as an object to a discharge tray (not shown) outside the machine. The fixing device 100 will be described in detail in “(2) Fixing device (heating means)”.

  After the color toner image is transferred to the recording material P, the rotating intermediate transfer drum 105 is cleaned by the cleaner 108 after removal of adhering residues such as transfer residual toner and paper dust. The cleaner 108 is normally held in a non-contact state with the intermediate transfer drum 105 and is in contact with the intermediate transfer drum 105 during the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P. Retained.

  Also, the transfer roller 106 is always held in a non-contact state with the intermediate transfer drum 105, and recording is performed on the intermediate transfer drum 105 during the secondary transfer of the color toner image from the intermediate transfer drum 105 to the recording material P. The contact state is maintained via the material P.

  This example apparatus can also execute a mono-color image print mode such as a monochrome image. A double-sided image print mode or a multiple image print mode can also be executed. In the double-sided image print mode, the recording material P on which the first-side image has been printed exiting the fixing device 100 is turned upside down via a recirculation conveyance mechanism (not shown) and sent again to the secondary transfer portion T2. Upon receipt of the toner image transfer to the surface, the image is again introduced into the fixing device 100 and undergoes toner image fixing processing for the two surfaces, whereby a double-sided image print is output.

  In the multiple image print mode, the recording material P after the first image printed out of the fixing device 100 is sent to the secondary transfer portion T2 again without being turned upside down via a recirculation conveyance mechanism (not shown). A second toner image transfer is received on the surface on which the first image has been printed, and the image is again introduced into the fixing device 100 and undergoes a second toner image fixing process, whereby a multiple image print is output.

In the image forming method of the present invention, the toner carrying amount on the recording material is preferably 0.05 to 0.80 dg / m ^{2 in} the case of monocolor such as magenta, cyan and yellow, and 0.1 to 0.7 dg / m ^2. m ² is more preferable.

If it is less than 0.05 dg / m ² , only a toner having a poor image density can be obtained even if the coloring power of the toner is increased. When it exceeds 0.80 dg / m ² , it is difficult to clearly express the effect of the present invention.

(3) Fixing device (heating means) 100
The fixing device which is one of the features of the present invention will be described in detail. However, the heating and fixing device of the present invention is not limited to the illustrated one, and for example, heating with a configuration in which an exciting coil portion is installed outside the belt. It may be a fixing device.

  3 is a schematic cross-sectional side view of the main part of the fixing device 100 of the electromagnetic induction heating method according to the present invention, FIG. 4 is a schematic front view of the main part, and FIG. 5 is a vertical front schematic view of the main part. Is.

  This example apparatus 100 is an apparatus of a pressure roller driving system and an electromagnetic induction heating system using a cylindrical electromagnetic induction heat generating belt, like the fixing device of FIG. Constituent members and parts common to the apparatus of FIG.

  The magnetic field generating means includes magnetic cores 17a, 17b and 17c and an excitation coil 18.

  The magnetic cores 17a, 17b, and 17c are members having high magnetic permeability, and are preferably made of a material used for a transformer core such as ferrite or permalloy, and more preferably ferrite having a low loss even at 100 kHz or more.

  As shown in FIG. 6, an excitation circuit 27 is connected to the power feeding units 18a and 18b. The excitation circuit 27 can generate a high frequency of 10 kHz to 500 kHz by a switching power supply.

  The exciting coil 18 generates an alternating magnetic flux by the alternating current (high-frequency current) supplied from the exciting circuit 27.

  Reference numerals 16a and 16b are saddle-shaped belt guide members having a substantially semicircular arc shape in cross section. The opening sides face each other to form a substantially cylindrical body, and the fixing belt 10 which is a cylindrical electromagnetic induction heating belt is loosened outwardly. It is fitted outside.

  The belt guide member 16a holds magnetic cores 17a, 17b and 17c as magnetic field generating means and an excitation coil 18 on the inner side.

  Further, as shown in FIG. 5, the belt guide member 16a is provided with a good heat conducting member 40 in the longitudinal direction in the drawing as opposed to the pressure roller 30 in the nip portion N and inside the fixing belt 10. It is.

In this example, aluminum is used for the good heat conductive member 40. The good heat conducting member 40 has a thermal conductivity k of k = 240 [W · m ⁻¹ · K ⁻¹ ] and a thickness of 1 [mm].

  Further, the good heat conducting member 40 is disposed outside the magnetic field so as not to be affected by the magnetic field generated from the exciting coil 18 and the magnetic cores 17a, 17b, and 17c as magnetic field generating means.

  Specifically, the good heat conducting member 40 is disposed at a position separating the magnetic core 17c from the exciting coil 18, and is located outside the magnetic path by the exciting coil 18 to affect the good heat conducting body 40. I am trying not to.

  Reference numeral 22 denotes a horizontally long pressurizing rigid stay disposed in contact with the inner surface flat portion of the belt guide member 16b.

  Reference numeral 19 denotes an insulating member for insulating the magnetic cores 17 a, 17 b, and 17 c and the exciting coil 18 from the pressurizing rigid stay 22.

  The flange members 23a and 23b are fitted around the left and right ends of the assembly of the belt guide members 16a and 16b, and are rotatably attached while fixing the left and right positions. When the fixing belt 10 is rotated, the end portions of the fixing belt 10 are attached. In response to this, it functions to regulate the displacement of the fixing belt along the length of the belt guide member.

  A pressure roller 30 serving as a rotary pressure member is composed of a core metal 30a and a heat-resistant / elastic material layer 30b made of silicone rubber, fluororubber, fluororesin or the like, which is formed and coated in a roller shape concentrically around the core metal. The two ends of the cored bar 30a are rotatably supported between the chassis side metal plates (not shown) of the apparatus.

  By pressing the pressure springs 25a and 25b between the both ends of the pressure rigid stay 22 and the spring receiving members 29a and 29b on the apparatus chassis side, a pressing force is applied to the pressure component stay 22. . As a result, the lower surface of the belt guide member 16a and the upper surface of the pressure roller 30 are pressed against each other with the fixing belt 10 interposed therebetween, so that a fixing nip portion N having a predetermined width is formed.

  The pressure roller 30 is rotationally driven by the driving means M in the direction indicated by the arrow. A rotational force acts on the fixing belt 10 by the frictional force between the pressure roller 30 and the outer surface of the fixing belt 10 by the pressure / rotation driving of the pressure roller 30, and the inner surface of the fixing belt 10 is in the fixing nip N. The belt guide members 16a and 16b are rotated around the outer periphery of the belt guide members 16a and 16b at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 30 in the direction indicated by the arrow while sliding in close contact with the lower surface of the good heat conducting member 40.

  In this case, in order to reduce the mutual sliding frictional force between the lower surface of the good heat conductive member 40 and the inner surface of the fixing belt 10 in the fixing nip portion N, the lower surface of the good heat conductive member 40 in the fixing nip portion N and the fixing belt 10. It is also possible to interpose a lubricant such as heat resistant grease between the inner surface and the lower surface of the good heat conductive member 40 with a lubricating member. This is because, when the surface heat-slidability is not good as in the case of using aluminum as the good heat conducting member 40 or the finishing process is simplified, the sliding fixing belt 10 is damaged and the fixing belt 10 is damaged. This prevents the durability of the resin from deteriorating.

  The good heat conducting member 40 has an effect of making the temperature distribution in the longitudinal direction uniform. For example, when small-size paper is passed, the heat amount of the non-sheet passing portion of the fixing belt 10 is transferred to the good heat conducting member 40. By heat conduction in the longitudinal direction of the good heat conducting member 40, the heat amount of the non-sheet passing portion is transferred to the small size sheet passing portion. Thereby, the effect of reducing the power consumption at the time of passing small-size paper is also obtained.

  Further, as shown in FIG. 6, convex rib portions 16e are formed on the curved surface of the belt guide member 16a at predetermined intervals along the length thereof, and the curved surface of the belt guide member 16a and the inner surface of the fixing belt 10 are formed. The rotational load on the fixing belt 10 is reduced by reducing the contact sliding resistance. Such a convex rib part can be similarly formed on the belt guide member 16b.

  FIG. 7 schematically shows how the alternating magnetic flux is generated. A magnetic flux C represents a part of the generated alternating magnetic flux. The alternating magnetic flux C guided to the magnetic cores 17a, 17b, and 17c is vortexed in the electromagnetic induction heating layer 1 of the fixing belt 10 between the magnetic cores 17a and 17b and between the magnetic cores 17a and 17c. Generate current. This eddy current causes Joule heat (eddy current loss) to be generated in the electromagnetic induction heat generating layer 1 by the specific resistance of the electromagnetic induction heat generating layer 1. The calorific value Q here is determined by the density of the magnetic flux passing through the electromagnetic induction heat generating layer 1, and shows a distribution as shown in the graph of FIG. In the graph of FIG. 7, the vertical axis indicates the circumferential position of the fixing belt 10 represented by an angle θ with the center of the magnetic core 17 a being 0, and the horizontal axis is the heat generation in the electromagnetic induction heating layer 1 of the fixing belt 10. The quantity Q is indicated. Here, when the maximum heat generation amount is Q, the heat generation region H is defined as a region where the heat generation amount is Q / e or more. This is a region where the amount of heat generated for fixing can be obtained.

  The temperature of the fixing nip portion N is controlled so that a predetermined temperature is maintained by controlling the current supply to the exciting coil 18 by a temperature control system including a temperature detection unit (not shown). Reference numeral 26 denotes a temperature sensor such as a thermistor for detecting the temperature of the fixing belt 10. In this example, the temperature of the fixing nip N is controlled based on the temperature information of the fixing belt 10 measured by the temperature sensor 26. Yes.

  Thus, the fixing belt 10 is rotated, and the electromagnetic induction heat generation of the fixing belt 10 is performed as described above by the power supply from the excitation circuit 27 to the excitation coil 18, and the fixing nip portion N rises to a predetermined temperature and the temperature is adjusted. In this state, the recording material P on which the unfixed toner image t conveyed from the image forming unit is formed has an image surface facing upward between the fixing belt 10 and the pressure roller 30 in the fixing nip N, that is, the fixing belt. The image is brought into close contact with the outer surface of the fixing belt 10 at the fixing nip portion N, and the fixing nip portion N is nipped and conveyed together with the fixing belt 10. In the process in which the recording material P is nipped and conveyed together with the fixing belt 10 through the fixing nip portion N, the fixing belt 10 is heated by electromagnetic induction heat generation, and the unfixed toner image t1 on the recording material P is heated and fixed. . When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the rotary fixing belt 10 and discharged and conveyed. The heat-fixed toner image t2 on the recording material is cooled to be a permanently fixed image after passing through the fixing nip portion.

  In this example, as shown in FIG. 3, a thermo switch 50, which is a temperature detection element, is used to cut off the power supply to the exciting coil 18 at the time of runaway at a position opposite to the heat generation area H (FIG. 6) of the fixing film 10. Is arranged.

  FIG. 8 is a circuit diagram of the safety circuit used in this example. The thermo switch 50, which is a temperature detection element, is connected in series with a + 24V DC power source and a relay switch 51. When the thermo switch 50 is turned off, the power supply to the relay switch 51 is cut off, the relay switch 51 operates, and the excitation is performed. The power supply to the exciting coil 18 is cut off by the power supply to the circuit 27 being cut off. The thermoswitch 50 was set to 220 ° C. OFF operation temperature.

  Further, the thermo switch 50 is disposed in a non-contact manner on the outer surface of the fixing film 10 so as to face the heat generation area H of the fixing film 10. The distance between the thermo switch 50 and the fixing film 10 was about 2 mm. Thereby, the fixing film 10 is not damaged by the contact of the thermo switch 50, and the deterioration of the fixed image due to durability can be prevented.

  According to this example, unlike the configuration in which the fixing nip N generates heat when the fixing device runs away due to a device failure, the fixing device stops with the paper sandwiched in the fixing nip N, and the exciting coil 18 Even when the power supply is continued and the fixing film 10 continues to generate heat, since the heat is not generated at the fixing nip portion N where the paper is sandwiched, the paper is not directly heated. Further, since the thermo switch 50 is disposed in the heat generating region H where the heat generation amount is large, when the thermo switch 50 senses 220 ° C. and the thermo switch is turned off, the relay switch 51 moves to the exciting coil 18. Is interrupted.

  According to this example, since the ignition temperature of the paper is around 400 ° C., the paper does not ignite, and the heat generation of the fixing film can be stopped.

  In addition to the thermoswitch, a thermal fuse can be used as the temperature detection element.

  In this example, oil application or cooling separation for preventing offset may be performed on the fixing device.

  Similarly, a method of driving the fixing roller by pressing the pressure roller in the direction of the rotation axis of the fixing roller by a mechanism using, for example, a spring in the direction of pressing and driving is also possible.

A) Excitation coil 18
The exciting coil 18 is a conductive wire (electric wire) that constitutes a coil (wire ring), which is a bundle of a plurality of thin copper wires each coated with an insulation coating (bundled wire). A coil is formed. In this example, the exciting coil 18 is formed by winding 10 turns.

  As the insulating coating, it is preferable to use a coating having heat resistance in consideration of heat conduction due to heat generation of the fixing belt 10. For example, a coating such as amideimide or polyimide may be used.

  The excitation coil 18 may improve the density by applying pressure from the outside.

  The shape of the exciting coil 18 is made to follow the curved surface of the heat generating layer as shown in FIG. In this example, the distance between the heat generating layer of the fixing belt and the exciting coil 18 is set to be about 2 mm.

  As the material of the exciting coil holding member 19, a material having excellent insulation and good heat resistance is preferable. For example, a phenol resin, a fluorine resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin, a PPS resin, a PFA resin, a PTFE resin, an FEP resin, an LCP resin, or the like may be selected.

  When the distances between the magnetic cores 17a, 17b, 17c and the exciting coil 18 and the heat generating layer of the fixing belt are as close as possible, the magnetic flux absorption efficiency is higher. If this distance exceeds 5 mm, the efficiency is significantly reduced. It should be within 5 mm. If the distance is within 5 mm, the distance between the heating layer of the fixing belt 10 and the exciting coil 18 does not have to be constant.

  With respect to the lead wires from the exciting coil holding member 19 of the exciting coil 18, that is, 18a and 18b (FIG. 6), an insulating coating is applied to the outside of the bundle wire on the part outside the exciting coil holding member 19.

B) Fixing belt 10
FIG. 9 is a schematic diagram of the layer structure of the fixing belt 10. The fixing belt 10 in FIG. 9A has a two-layer structure of a heat generating layer 1 made of a metal belt or the like as a base layer of the electromagnetic induction heat generating fixing belt 10 and a release layer 3 laminated on the outer surface thereof. is there. In the fixing belt 10 of FIG. 9B, an elastic layer 2 is provided between the heat generating layer 1 and the release layer 3. In addition, a primer layer (not shown) may be provided between each layer for adhesion between the heat generating layer 1 and the elastic layer 2 and adhesion between the elastic layer 2 and the release layer 3. In the fixing belt 10 having a substantially cylindrical shape, the heat generating layer 1 is on the inner surface side, and the release layer 3 is on the outer surface side. As described above, when an alternating magnetic flux acts on the heat generating layer 1, an eddy current is generated in the heat generating layer 1 and the heat generating layer 1 generates heat. The heat heats the fixing belt 10 through the elastic layer 2 and the release layer 3, and heats the recording material P as a material to be heated that is passed through the fixing nip N to heat and fix the toner image. .

a. Heat generation layer 1
The heat generating layer 1 may be a non-magnetic metal, but more preferably a ferromagnetic metal such as nickel, iron, magnetic stainless steel, cobalt-nickel alloy, etc., which absorbs magnetic flux.

The thickness is preferably thicker than the skin depth represented by the following formula and 200 μm or less. The skin depth σ [m] is the frequency f [Hz] of the excitation circuit, the magnetic permeability μ, and the specific resistance ρ [Ωm] σ = 503 × (ρ / fμ) ^1/2
It is expressed.

  This indicates the depth of absorption of electromagnetic waves used for electromagnetic induction, and the intensity of electromagnetic waves is 1 / e or less deeper than this, and conversely most energy is absorbed up to this depth. ing.

  The thickness of the heat generating layer 1 is preferably 1 to 200 μm. If the thickness of the heat generating layer 1 is less than 1 μm, most of the electromagnetic energy cannot be absorbed, resulting in poor efficiency. On the other hand, if the heat generating layer exceeds 200 μm, the rigidity becomes too high, and the flexibility becomes poor, so that it is not practical to use as a rotating body.

b. Elastic layer 2
The elastic layer 2 is a material having good heat resistance and good thermal conductivity, such as silicone rubber, fluorine rubber, fluorosilicone rubber, and the like.

  The thickness of the elastic layer 2 is preferably 10 to 500 μm in order to prevent uneven glossiness due to the heating surface (release layer 3) not being able to follow the unevenness of the recording material or the unevenness of the toner layer when printing an image. .

  If the hardness of the elastic layer 2 is too high, the unevenness of the recording material or the toner layer cannot be followed and image gloss unevenness occurs. Therefore, the hardness of the elastic layer 2 is preferably 60 ° (J1S-A) or less, more preferably 45 ° (JlS-A) or less.

Regarding the thermal conductivity λ of the elastic layer 2,
2.5 × 10 ^{−3 to} 8.4 × 10 ⁻³ [J / cm · sec · deg. ]
Is good.

The thermal conductivity λ is 2.5 × 10 ⁻³ [J / cm · sec · deg. ], The thermal resistance is large, and the temperature rise in the surface layer (release layer 3) of the fixing belt is delayed. The thermal conductivity λ is 8.4 × 10 ⁻³ [J / cm · sec · deg. ], The hardness becomes too high or the compression set deteriorates.

Therefore, the thermal conductivity λ is 2.5 × 10 ^{−3 to} 8.4 × 10 ⁻³ [J / cm · sec · deg. ] Is good. More preferably, 3.3 × 10 ^{−3 to} 6.3 × 10 ⁻³ [J / cm · sec · deg. ] Is good.

c. Release layer 3
For the release layer 3, a material having good release properties and heat resistance such as fluororesin, silicone resin, fluorosilicone rubber, fluororubber, silicone rubber, PFA, PTFE, and FEP can be selected.

  The thickness of the release layer 3 is preferably 1 to 100 μm. When the thickness of the release layer 3 is smaller than 1 μm, there arises a problem that a part having poor release property is formed due to coating unevenness of the coating film or durability is insufficient. Further, when the release layer exceeds 100 μm, there is a problem that heat conduction is deteriorated. In particular, in the case of a resin release layer, the hardness becomes too high and the effect of the elastic layer 2 is lost.

d. Heat Insulating Layer In the configuration of the fixing belt 10, a heat insulating layer (not shown) may be provided on the belt guide surface side of the heat generating layer 1 (the surface opposite to the elastic layer 2 of the heat generating layer 1).

  As the heat insulating layer, a heat resistant resin such as a fluorine resin, a polyimide resin, a polyamide resin, a polyamideimide resin, a PEEK resin, a PES resin, a PPS resin, a PFA resin, a PTFE resin, or an FEP resin is preferable.

  Moreover, as thickness of a heat insulation layer, 10-1000 micrometers is preferable. When the thickness of the heat insulating layer is smaller than 10 μm, the heat insulating effect cannot be obtained and the durability is insufficient. On the other hand, if it exceeds 1000 μm, the distances from the magnetic cores 17 a, 17 b, and 17 c and the exciting coil 18 to the heat generating layer 1 become large, and the magnetic flux is not sufficiently absorbed by the heat generating layer 1.

  Since the heat insulating layer can insulate the heat generated in the heat generating layer 1 so as not to go to the inside of the fixing belt, the heat supply efficiency to the recording material P side is improved as compared with the case without the heat insulating layer. Therefore, power consumption can be suppressed.

C) Nip The fixing nip portion N made up of a rotary heating member and a pressure member in the heat fixing apparatus of the present invention forms a nip having a width of 5.0 to 15.0 mm in order to ensure good fixability. And are preferred. When the width of the fixing nip N is less than 5.0 mm, it is impossible to give a sufficient amount of heat for fixing the toner to the unfixed toner when forming a full-color image, and the toner cannot be melted and mixed, resulting in an unnatural color image. This is not preferable.

  If the width of the fixing nip N portion exceeds 15.0 mm, a sufficient amount of heat can be applied to fix the toner, but hot offset is likely to occur during fixing. It is not preferable because the curvature change becomes too large at both ends (upstream end and downstream end of the fixing film 10) and the durability of the fixing film 10 is significantly deteriorated.

D) Pressure per unit area The pressure (surface pressure) of the nip portion in the heat fixing apparatus of the present invention is preferably in the range of surface pressure of 9000 to 500,000 N / m ^{2 with} the recording material interposed, and the surface pressure of 30000 to 350,000 N. A range of / m ² is more preferable.

  The pressure applied to the transfer material can be adjusted by the spring pressure of the springs 25a and 25b in FIG. That is, the surface pressure is controlled by arbitrarily changing the spring constant of the springs used for 25a and 25b. It is also possible to control the surface pressure by controlling the distance between the spring stop positions 29a and 29b and the pressure roller 30.

E) Perimeter of fixing film 10 and fixing speed In this example, the peripheral length of fixing film 10 that generates heat by electromagnetic induction and the time required for fixing film 10 to make one rotation are set as follows. The quick start is achieved and the power consumption is reduced while ensuring stable fixing performance.

  Since the heat generating layer 1 of the fixing film 10 is thin, the heat capacity is small, and since the heat conductivity is good because of the metal, heat dissipation is good. For this reason, when the peripheral length L of the fixing film 10 exceeds 200 mm, the temperature drop during the rotation of the fixing film 10 is too large, and quick start cannot be performed. In addition, power consumption increases due to an increase in heating area accompanying an increase in station length. For this reason, the peripheral length L of the fixing film 10 is desirably 200 mm or less.

  On the other hand, when the peripheral length L of the fixing film 10 is less than 70 mm, the change in curvature becomes too large at both ends of the fixing nip portion N (the upstream end and the downstream end of the fixing film 10). Sexually deteriorates. For this reason, the peripheral length L of the fixing film 10 is desirably 70 mm or more.

  If the rotation speed (fixing speed) of the fixing film 10 exceeds 300 mm / sec, the fixing film 10 cannot be stably rotated, and the fixing film 10 is damaged. For this reason, the process speed as the rotation speed V of the fixing film 10 is desirably 300 mm / sec or less.

  FIG. 10 is a schematic configuration of an example of an electromagnetic induction heating type fixing device in which the alternating magnetic flux distribution of the exciting coil is concentrated on the fixing nip to improve efficiency.

  Reference numeral 10 denotes a cylindrical fixing film as an electromagnetic induction heat-generating rotating body having an electromagnetic induction heat-generating layer (conductor layer, magnetic layer, resistor layer).

  Reference numeral 16 denotes a saddle-shaped film guide member having a substantially semicircular arc shape in cross section, and the cylindrical fixing film 10 is loosely fitted outside the film guide member 16.

  Reference numeral 15 denotes a magnetic field generating means disposed inside the film guide member 16, which includes an exciting coil 18 and an E-type magnetic core (core material) 17. Reference numeral 30 denotes an elastic pressure roller. The fixing film 10 is sandwiched between the lower surface of the film guide member 16 so as to form a fixing nip portion N having a predetermined width with a predetermined pressing force, and are pressed against each other. The magnetic core 17 of the magnetic field generating means 15 is disposed so as to correspond to the fixing nip N.

  The pressure roller 30 is rotationally driven by the driving means M in the direction indicated by the arrow. A rotational force acts on the fixing film 10 by the frictional force between the pressure roller 30 and the outer surface of the fixing film 10 by the rotational driving of the pressure roller 30, and the inner surface of the fixing film 10 is fixed at the fixing nip N. The outer periphery of the film guide member 16 is rotated at a peripheral speed substantially corresponding to the rotational peripheral speed of the pressure roller 30 in the direction indicated by the arrow while sliding in close contact with the lower surface of the film guide member 16 (pressure roller). Drive system).

  The film guide member 16 serves to support the exciting coil 18 and the magnetic core 17 as the pressurizing / magnetic field generating means 15 to the fixing nip portion, support the fixing film 10, and transport stability when the film 10 rotates. To do. The film guide member 16 is an insulating member that does not hinder the passage of magnetic flux, and a material that can withstand a high load is used.

  The excitation coil 18 generates an alternating magnetic flux by an alternating current supplied from an excitation circuit (not shown). The alternating magnetic flux is intensively distributed in the fixing nip portion N by the E-type magnetic core 17 corresponding to the position of the fixing nip portion N, and the alternating magnetic flux is an electromagnetic induction heat generating layer of the fixing film 10 in the fixing nip portion N. Generate eddy currents. This eddy current generates Joule heat in the electromagnetic induction heating layer due to the specific resistance of the electromagnetic induction heating layer.

  The electromagnetic induction heat generation of the fixing film 10 is concentrated in the fixing nip portion N where the alternating magnetic flux is concentrated, and the fixing nip portion N is heated with high efficiency.

  The temperature of the fixing nip portion N is controlled so that a predetermined temperature is maintained by controlling the current supply to the exciting coil 18 by a temperature control system including a temperature detection unit (not shown).

  Thus, the pressure roller 30 is driven to rotate, and the cylindrical fixing film 10 rotates around the outer periphery of the film guide member 16, and the fixing film 10 is supplied with power from the excitation circuit to the excitation coil 18 as described above. The recording material P on which the unfixed toner image t1 conveyed from the image forming unit (not shown) is formed is fixed in a state where the fixing nip portion N rises to a predetermined temperature and the temperature is adjusted. The image surface is introduced between the fixing film 10 and the pressure roller 30 in the nip portion N upward, that is, facing the fixing film surface, and the image surface is in close contact with the outer surface of the fixing film 10 and fixed in the fixing nip portion N. The fixing nip portion N is nipped and conveyed together with the film 10. In the process in which the recording material P is nipped and conveyed through the fixing nip N together with the fixing film 10, the fixing film 10 is heated by electromagnetic induction heat generation, and the unfixed toner image t1 on the recording material P is heated and fixed. When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the rotary fixing film 10 and discharged and conveyed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this is not limited to this invention at all. In addition, the number of parts in the following composition is part by mass unless otherwise specified.

<Example 1>
100 parts of polyvinyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., degree of polymerization of about 1400, degree of saponification of about 99%) was added to 10000 parts of ion-exchanged water in the reaction vessel, and kept at 60 ° C. for 60 minutes while purging with N ₂ . An aqueous medium in which the water-soluble polymer was dissolved was prepared using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) while stirring at 170S- ¹ . The pH of the aqueous medium was 5.5 to 6.5.
・ Styrene 80 parts ・ N-butyl acrylate 20 parts ・ Grafted carbon 7 parts ・ Charge control agent (calixarene) 0.7 part ・ Oxycarboxylic acid (1-A) 1.0 part ・ Ester wax (release agent) No. 6) 16 parts, cross-linking agent (divinylbenzene) 0.4 parts In a separate container, the above material is kept at 60 ° C., using a TK homomixer (manufactured by Koki Kogyo Co., Ltd.) at 170 S ⁻¹ Dissolved and dispersed uniformly. To this, 3.5 parts of a polymerization initiator 2,2′-azobis (2-4dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition is charged into the aqueous medium in the reaction vessel, and stirred at 300 S ⁻¹ for 5 minutes with a TK homomixer at 60 ° C. under N ₂ purge. The composition was granulated. Thereafter, the mixture was stirred with a paddle stirring blade at 60 ° C. at 17 S ⁻¹ , and after 3 hours, the mixture was changed to 1.7 S ⁻¹ and further stirred for 3 hours. Thereafter, the temperature was raised to 85 ° C. and reacted for 6 hours. Distillation was performed at 85 ° C. for 6 hours.

  After completion of the polymerization reaction, the reaction vessel was cooled, filtered, washed with water, and dried. 1 was obtained. When the cross section of the black toner particles was observed by TEM, it was recognized that the release agent was well encapsulated with the outer shell resin as shown in FIG.

100 parts of the obtained black toner particles and 1.2 parts of hydrophobic titanium oxide fine powder having a specific surface area of 95 m ² / g by BET method were mixed to obtain negatively triboelectrically black toner. The obtained black toner had a circle-equivalent number average diameter D ₁ of 4.7 μm.

  A developer is prepared by mixing 93 parts of this black toner with 93 parts of an acrylic-coated ferrite carrier, and using a copying machine as shown in FIG. did.

After that, in the electromagnetic induction heating / pressing means, a fixing belt composed of a heat generating layer and a release layer as shown in FIG. 9A is used, the thickness of the heat generating layer is set to 50 μm, and the thickness of the release layer is set to 45 μm. A fixed image was obtained at a pressure per unit area of the rotary heating member and the pressure roller of 65000 N / m ² .

  Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 2>
The ester wax (release agent No. 6) was changed to 34 parts. The procedure was the same as Example 1 except that 2 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 3>
The amount of the polymerization initiator 2,2′-azobis (2-4dimethylvaleronitrile) was changed to 5 parts. The same procedure as in Example 1 was performed except that 3 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 4>
After granulation, the mixture was stirred with a paddle stirring blade at 60 ° C. at 60 S ⁻¹ , and after 3 hours, 12 S ⁻¹ was obtained. Example 4 was repeated except that No. 4 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 5>
The amount of the oxycarboxylic acid (1-A) was 0.18 part, and black toner No. The procedure was the same as Example 1 except that 5 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Reference Example 6>
The oxycarboxylic acid was changed to (2-A) and black toner No. Except that 6 was produced, the procedure was the same as in Example 1. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 7>
The oxycarboxylic acid was changed to (1-F). Except that 7 was produced, the procedure was the same as in Example 1. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 8>
The oxycarboxylic acid was changed to (1-J). The procedure was the same as Example 1 except that 8 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Reference Example 9>
In the same manner as in Example 1, black toner no. 1 was prepared, and 1.6% by mass of the oxycarboxylic acid (1-A) was externally added to the total amount of the toner. 9 is produced. Otherwise, the same procedure as in Example 1 was performed. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 10>
In the same manner as in Example 1, black toner no. 1 was manufactured, and the same procedure as in Example 1 was performed except that the thickness of the heat generating layer in the electromagnetic induction heating / pressurizing unit was changed to 100 μm. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 11>
In the same manner as in Example 1, black toner no. 1 was manufactured, and the same procedure as in Example 1 was performed except that the thickness of the release layer in the electromagnetic induction heating and pressing unit was changed to 80 μm. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Example 12>
In the same manner as in Example 1, black toner no. 1 was manufactured, and the same procedure as in Example 1 was performed except that the pressure per unit area of the rotary heating member and the pressure roller in the electromagnetic induction heating and pressing unit was changed to 370000 N / m ² . Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Comparative Example 1>
Except for setting the thickness of the release layer to 110 μm, the black toner no. 1 was used in the same manner as in Example 1. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Comparative example 2>
Except for changing the pressure per unit area between the rotary heating member and the pressure roller in the electromagnetic induction heating / pressurizing means to 520000 N / m ² , the black toner no. 1 was used in the same manner as in Example 1. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Comparative Example 3>
Except for changing the fixing speed to 365 mm / sec, the black toner no. 1 was used in the same manner as in Example 1. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

<Comparative example 4>
In the same manner as in Example 1, black toner no. No. 1 was prepared, and 21.8 mass% of the oxycarboxylic acid (1-A) was externally added to the total amount of the toner. Example 10 was repeated except that 10 was produced. Table 2 shows the prescription and physical properties of the toner, and Table 3 shows the evaluation results.

  Regarding the evaluation shown in Table 3, the environment was normal temperature and normal humidity (22 ° C., 65% RH), and the mode for fixing was evaluated as a quick start mode by the following method.

・ About evaluation of low temperature offset resistance:
An unfixed image on which the entire surface of black toner was printed was produced using a modified machine of a full-color copying machine (Creative Processor 660, manufactured by Canon) equipped with an intermediate transfer member. At this time, the toner carrying amount was 0.5 to 0.6 dg / m ² , and the transfer material used was A3 size 75 g / m ² recycled transfer paper.

  Next, the unfixed image is fixed under the fixing conditions described in the examples and comparative examples and the fixing conditions where the fixing temperature is 175 ° C.

The obtained image was subjected to a load of 4.9 × 10 ² Pa (5 × 10 ² kg / m ² ) and rubbed with Sylbon paper [Lenz Cleaning Paper “dasper (R)” (Ozu Paper Co. Ltd)] five times. The temperature at which the density reduction rate before and after rubbing is less than 10% is defined as the fixing start point.

The image density was measured using Macbeth RD918 (manufactured by Macbeth).
A: Density reduction rate is less than 5% B; Density reduction rate is 5% or more and less than 10% C; Density reduction rate is 10% or more and less than 15% D; Density reduction rate is 15% or more

・ About evaluation of high temperature offset resistance:
An unfixed image on which the entire surface of black toner was printed was produced using a modified machine of a full-color copying machine (Creative Processor 660, manufactured by Canon) equipped with an intermediate transfer member. At this time, the toner carrying amount was 0.5 to 0.6 dg / m ² , and the transfer material used was A3 size 75 g / m ² recycled transfer paper.

  Next, 500 unfixed images are continuously fixed under the fixing conditions described in the examples and comparative examples and the fixing conditions where the fixing temperature is 190 ° C.

  The difference in average glossiness at five locations between the first fixed image and the fixed 500th image was measured.

The glossiness was measured using PG-3D (manufactured by NIPPON DENYOKU; incident angle 75 degrees).
A: Glossiness difference is less than 4 B; Glossiness difference is 4 or more and less than 7 C; Glossiness difference is 7 or more and less than 10 D; Glossiness difference is 10 or more

1 is a schematic view of an image forming apparatus according to the present invention. 1 is a schematic diagram of a full-color image forming apparatus according to the present invention. It is a schematic cross-sectional side view of the heating device (fixing device) of the present invention. It is a front schematic diagram of the heating apparatus principal part of this invention. It is a vertical front schematic diagram of the heating apparatus principal part of this invention. It is a schematic diagram of the magnetic field generation | occurrence | production means concerning the heating apparatus of this invention. This figure schematically shows how alternating magnetic flux is generated. It is a circuit diagram of the safety circuit concerning the heating apparatus of this invention. It is a layer structure schematic diagram of the fixing belt (fixing film) concerning the heating apparatus of this invention. 2 is a schematic configuration of an example of an electromagnetic induction heating type fixing device. FIG. 4 is a schematic diagram of a cross section of toner particles in which a release agent is encapsulated with an outer shell resin.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat generation layer 2 Elastic layer 3 Release layer 4 Heat insulation layer 10 Fixing belt 15 Magnetic field generation means 16, 16a, 16b Film (belt) guide member 16e Convex rib part 17, 17a, 17b, 17c Magnetic core 18 Excitation coil 18a, 18b Power feeding unit 19 Insulating member (excitation coil holding member)
22 Pressurizing rigid stay 23a, 23b Flange member 25a, 25b Pressure spring 26 Temperature sensor 27 Excitation circuit 29a, 29b Spring receiving member 30 Pressure roller (elastic)
30a Metal core 30b Elastic material layer 40 Good heat conduction member 50 Thermo switch 51 Relay switch 100 Image heating device (fixing device)
N fixing nip P transfer material (recording material)
101 Photosensitive drum 102 Charging device 104 Developing device T1 Primary transfer portion T2 Secondary transfer portion

Claims (14)

In an image forming method in which a toner image on a transfer material is heated and pressed and fixed by a heating and pressing unit to form a fixed image on the transfer material.
The heating and pressing means is a heating and pressing means having a magnetic field generating means, a rotary heating member composed of two layers of a heat generating layer and a release layer that generate heat by electromagnetic induction, and a rotary pressure member.
The rotating heating member has a heating layer having a thickness of 1 to 200 μm, a release layer having a thickness of 1 to 100 μm and a surface pressure of 9000 to 500,000 N / m ² through the transfer material. The toner image is fixed at a fixing speed of 5 to 300 mm / sec while being pressed against the rotating heating member.
The toner forming the toner image is a toner containing at least a binder resin, a colorant, a release agent, and an oxycarboxylic acid, and a 0.1 mol / liter sodium hydroxide aqueous solution from 1 g of the toner The mass X (mg) of the oxycarboxylic acid extracted by, and the mass Y (mg) of the oxycarboxylic acid extracted by methanol,
Y / X = 1.05 to 3.00
X = 0.10 to 3.50
Satisfied with the relationship
The image forming method, wherein the oxycarboxylic acid is a compound represented by the following formula (1).

[In the above formula (1), (A) is selected from the following group, and X ₁ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or aliphatic ammonium. ]

In the toner-based circle equivalent diameter-circularity scattergram measured by the flow type particle image measuring apparatus, the circle equivalent number average diameter D ₁ (μm) of the toner is 2 to 10 μm, and the toner 2. The image forming method according to claim 1, wherein the average circularity is 0.920 to 0.995, and the circularity standard deviation is less than 0.040.   3. The image forming method according to claim 2, wherein the average circularity of the toner is 0.950 to 0.995 and the circularity standard deviation is less than 0.035 in the equivalent circle diameter-circularity scattergram. .   3. The equivalent circle diameter-circularity scattergram, wherein the toner has an average circularity of 0.970 to 0.990 and a circularity standard deviation of 0.015 or more and less than 0.035. Image forming method.   2. The toner equivalent particle diameter-circularity scattergram based on the number of toners measured by a flow type particle image measuring apparatus, wherein toner particles having a circularity of less than 0.950 are 15% by number or less. 5. The image forming method according to any one of 4 above.   6. The image forming method according to claim 1, wherein the toner has a weight average molecular weight of 10,000 to 1,000,000 in a gel permeation chromatography (GPC) of a soluble component of tetrahydrofuran (THF).   6. The image forming method according to claim 1, wherein the toner has a weight average molecular weight of 5,000 to 1,000,000 in a gel permeation chromatography (GPC) of a soluble component of tetrahydrofuran (THF).   The image forming method according to claim 1, wherein the release agent is contained in an amount of 1 to 40 parts by mass per 100 parts by mass of the binder resin.   8. The image forming method according to claim 1, wherein the releasing agent is contained in an amount of 5 to 30 parts by mass per 100 parts by mass of the binder resin.   The image forming method according to claim 1, wherein the release agent is an ester wax having one or more long-chain ester portions having 10 or more carbon atoms.   11. The image forming method according to claim 1, wherein a thickness of the heat generating layer of the rotary heating member is 2 to 150 μm.   12. The image forming method according to claim 1, wherein the thickness of the release layer of the rotary heating member is 10 to 80 [mu] m. The image forming method according to any one of claims 1 to 12, wherein the rotary heating member is pressed with a surface pressure of 30,000 to 350,000 N / m ² through a transfer material. The image forming method according to any one of claims 1 to 13, wherein the toner loading amount on the recording material is 0.05 to 0.80 dg / m ² in the case of mono color.

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