KR101532606B1 - Electrophotographic toner, process for preparing the same, and image forming method and image forming apparatus using the toner - Google Patents

Abstract

An electrophotographic toner, a method for producing the same, and an image forming method and an image forming apparatus employing the toner are provided. The toner is excellent in low-temperature fixing property, fixing property, heat storage property and anti-offset property, and can be made high in gloss upon image formation, and the harmfulness to the human body and the environment is reduced. can do.

Description

TECHNICAL FIELD [0001] The present invention relates to an electrophotographic toner, a method for producing the same, and an image forming method and an image forming apparatus employing the toner,

The present invention relates to an electrophotographic toner, a process for producing the same, and an image forming method and an image forming apparatus employing the toner, and is excellent in low temperature fixability, fixing property, heat storage property and anti- Provided is an electrophotographic toner capable of high gloss and reduced harmfulness to human body and environment, and provides a method for producing toner capable of effective agglomeration. An image forming method and an image forming apparatus employing the toner are also provided.

In the electrophotographic method or the electrostatic recording method, a developer for visualizing an electrostatic latent image or an electrostatic latent image includes a two-component developer composed of toner and carrier particles, and a one-component developer substantially consisting of only toner and not using carrier particles. A one-component developer includes a magnetic one-component developer containing a magnetic component and a non-magnetic one-component developer containing no magnetic component. In the non-magnetic one-component developer, a fluidizing agent such as colloidal silica is often added independently in order to improve the fluidity of the toner. As the toner, colored particles in which pigments such as carbon black or other additives are dispersed in latex are generally used.

The toner is produced by a pulverization method and a polymerization method. In the pulverization method, a synthetic resin, a pigment and, if necessary, other additives are melt-mixed and pulverized, and then classified to obtain particles having a desired particle size to obtain a toner. In the polymerization method, a polymerizable monomer composition is prepared by uniformly dissolving or dispersing various additives such as a pigment, a polymerization initiator, a cross-linking agent and an antistatic agent, if necessary, into a polymerizable monomer. Subsequently, an aqueous dispersion medium containing a dispersion stabilizer, To form fine droplet particles of the polymerizable monomer composition, followed by elevating the temperature and suspending to obtain a polymerized toner which is colored polymer particles having a desired particle size.

In an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, an image is formed on a uniformly charged photoreceptor to form an electrostatic latent image. Toner is attached to the electrostatic latent image to form a toner image. And then the unfixed toner image is fixed on the transfer material by various methods such as heating, pressurization, solvent vapor, and the like. In a fixing step, in most cases, a toner is transferred between a fixing roll and a pressing roll through a transfer material having a toner image transferred thereon, and the toner is heat-pressed and fused onto the transfer material.

An image formed by an image forming apparatus such as an electrophotographic copying machine is required to be improved in precision and fineness. Conventionally, as the toner used in the image forming apparatus, the toner obtained by the pulverization method was the main stream. The pulverization method tends to form colored particles having a wide particle diameter distribution. Therefore, in order to obtain satisfactory developing properties, it is necessary to classify the pulverized product to a narrower particle diameter distribution to some extent. However, in the conventional kneading / pulverizing process for producing toner particles suitable for the electrophotographic process or the electrostatic recording process, it is difficult to precisely control the particle size and particle size distribution, and the yield of toner production due to classification in the production of small particle size toners is reduced. Further, there is a problem that the change / adjustment of the toner design for the charging property and the fixing property is restricted. Therefore, polymerized toners, which have recently been easily controlled in particle size and do not have to undergo complicated manufacturing processes such as classification, have been attracting attention.

When a toner is produced by such a polymerization method, a polymerized toner having a desired particle size and particle size distribution can be obtained without pulverization or classification. However, even when such a polymerization method is used, uniform control of the particle size and shape is still insufficient, and agglomeration of the latex and the coloring agent is not efficient, and there is a problem that the aluminum-based material used as the coagulating agent is harmful to the environment and human body.

In addition, such a toner has a characteristic that the fixing area is narrowed as the printing speed is increased. Therefore, it is inconvenient to use a toner having different fixing characteristics depending on the printing speed.

Therefore, it is possible to efficiently coagulate and harmless to the human body, maintain a wide fixation area at high speed while maintaining high gloss during image formation, realize low temperature fixability with small particle size and narrow particle size distribution, and have excellent heat retention property and anti- Excellent toner is required.

The first object to be achieved by the present invention is to provide an electrophotographic toner which is excellent in low temperature fixability, fixation property, heat storage property and anti-offset property, can be made high in gloss upon image formation, and has reduced harmfulness to human body and environment .

A second object to be achieved by the present invention is to provide a method for producing the electrophotographic toner.

A third object to be achieved by the present invention is to provide an image forming method employing the electrophotographic toner.

A fourth object to be achieved by the present invention is to provide an image forming apparatus employing the electrophotographic toner.

According to an aspect of the present invention,

An electrophotographic toner comprising a latex, a colorant, and a wax,

Wherein the toner contains 3 to 1,000 ppm of Si and Fe, the molar ratio of Si to Fe (Si / Fe) is in the range of 0.1 to 5,

Wherein the fixing property of the toner satisfies the following equations (1) and (2):

&Quot; (1) "

&Quot; (2) "

In the formula,

MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec,

MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec,

HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec,

HOT _B represents the hot offset temperature at a low speed of 290 mm / sec,

Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec.

According to one embodiment of the present invention, the toner, TMA 0.7 ± 0.03 mg / cm 2 of the fixing of the fixed image (Belt-type fixing device, Nip width: 10mm, line pressure: 4 kgf) in the low-speed printing of 160mm / sec And the maximum gloss difference due to high-speed printing of 290 mm / sec has a value of 1 or less.

According to one embodiment of the present invention, the value of the storage modulus G 'according to the temperature change in the dynamic viscoelasticity measurement of the toner is about 2E + 05 to about 3E + 07 Pa · s And about 5E + 02 to about 2E + 03 Pa · s, and the change slope of the storage elastic modulus G 'according to a frequency change measured at a temperature of 140 ° C has a value of about -0.4 or less.

According to one embodiment of the present invention, the toner has a starting temperature of the highest endothermic peak in the differential scanning calorimeter measurement of 68 to 75 占 폚, and a peak temperature range of 75 to 95 占 폚.

According to one embodiment of the present invention, the average particle size of the toner is preferably 3 to 8 mu m.

According to an embodiment of the present invention, the average value of the circularity of the toner is preferably 0.940 to 0.970.

According to one embodiment of the present invention, the difference in average circularity between the average particle size of 2 mu m and 5 mu m of the toner is preferably 0.020 or less.

According to an embodiment of the present invention, the PSDv and PSDp values of the toner are preferably 1.25 or less.

In order to achieve the second object,

Mixing a primary latex particle containing a wax with a pigment dispersion, and adding a metal salt containing Si and Fe to prepare a primary agglomerated toner;

Coating a secondary latex prepared by polymerizing at least one polymerizable monomer on the primary aggregation toner to aggregate the obtained microparticles to prepare a secondary aggregation toner; And a method for producing the electrophotographic toner.

According to one embodiment of the present invention, the manufacturing method may further include coating a tertiary latex prepared by polymerizing at least one polymerizable monomer onto the secondary aggregation toner.

According to one embodiment of the present invention, the primary latex particles are preferably polyester-based particles, a polymer obtained by polymerizing at least one polymer, or a mixture thereof.

According to one embodiment of the present invention, the primary latex particles comprising the wax are preferably a mixture or composite of wax and primary latex particles.

According to a third aspect of the present invention,

There is provided an image forming method comprising a step of attaching toner to a surface of a photoconductor on which an electrostatic latent image is formed to form a visible image, and transferring the visible image to a transfer material, wherein the toner is an electrophotographic toner containing latex, The toner contains 3 to 1,000 ppm of Si and Fe, and the molar ratio (Si / Fe) of Si to Fe is in the range of 0.1 to 5, and satisfies the above-mentioned conditions (1) and (2).

According to a fourth aspect of the present invention,

Organophotoreceptors; Image forming means for forming an electrostatic latent image on the surface of the organophotoreceptor; Means for containing the toner; Toner supplying means for supplying the toner to the surface of the organophotoreceptor to develop the electrostatic latent image onto the surface of the organophotoreceptor; And toner transferring means for transferring the toner image from the surface of the organophotoreceptor to a transfer material, wherein the toner is an electrophotographic toner comprising latex, a colorant and wax, wherein the toner comprises 3 to 1,000 ppm Si and Fe, and the molar ratio (Si / Fe) of Si and Fe has a range of 0.1 to 5, and satisfies the above-mentioned conditions (1) and (2).

The present invention relates to a metal salt flocculant for use in the production of a toner, which can efficiently aggregate at a lower temperature and at a lower temperature using a metal salt containing Si and Fe, so that an organic color component such as a rhodamine series Can also be agglomerated, and it is possible to exclude influences on the environment and the human body due to the residual aluminum of the conventional flocculant. In addition, since the capsular toner structure can be controlled through the control of the coagulation process, it is possible to suppress the surface exposure of the colorant and the wax contained in the toner to improve the uniform charging property, fluidity and heat storage property, A stable fixing region is maintained even at a high fixing speed, so that the toner can be used at a low speed and a high speed at the same time.

Hereinafter, the present invention will be described in detail.

The electrophotographic toner according to an embodiment of the present invention includes Si and Fe containing 3 to 1,000 ppm of a latex, a coloring agent, and a wax in a molar ratio (Si / Fe) of 0.1 to 5, The following conditions are satisfied: " (1) "

&Quot; (1) "

&Quot; (2) "

In the formula,

MFT _A indicates the minimum fusing temperature at a low speed of 160 mm / sec. MFT _B indicates the lowest fixing temperature at a high speed of 290 mm / sec. HOT _A indicates a hot offset temperature (Hot offset temperature). HOT _B represents the hot offset temperature at a low speed of 290 mm / sec. Gloss _A represents the gloss at the time of low-speed printing of a measurement angle of 60 °, a fixing temperature of 160 ° C and 160 mm / . The fusing jig conditions for the lowest fusing temperature and hot offset temperature were a belt-type fuser, a Nip of 10 mm, a Nip pressure of 4 kgf, and a paper of 90 g / m ² (Exclusive, Xerox) Respectively.

Equations (1) and (2) relational expressions of the ratio of the lowest fixing temperature and the hot offset temperature at the time of low-speed printing and at the time of high-speed printing. When the equations (1) and Which means that the fixing region having a low fixing speed does not greatly decrease even at a high fixing speed. Therefore, the stable fixing region is maintained even at a high fixing speed, which provides an advantage of being able to provide a common toner capable of coping with low speed and high speed.

The improvement of the fixing properties of the present invention is achieved, for example, by controlling the coagulation process. The anti-offset property of the toner is important in terms of securing a stable fixing region of the toner, which is closely related to the rheology characteristic of the toner, and the physical properties such as molecular weight and crosslinking degree of the latex, The wax is involved, but in a high-speed fixing process, the fixing region tends to be narrowed. In the present invention, the coagulation process is controlled by the use of the coagulant to improve the rheological properties of the toner, thereby suppressing the tendency of the fixing area to become narrow in a high-speed fixing process. That is, in one embodiment of the present invention, the metal salt containing Si and Fe is used as the metal salt flocculant used in toner manufacture to efficiently aggregate toner components such as latex, wax and coloring agent at a lower temperature at a lower content And it is possible to improve the rheological property of the toner in accordance with such coagulation process control. Therefore, a wide fixing region can be ensured even in high-speed printing, and at the same time, high glossiness can be realized in image formation. In addition, since the control of the toner structure of the capsule type is enabled by the control of the coagulation process, it is possible to suppress the surface exposure of the coloring agent and the pigment, thereby contributing to uniformization of charging, improvement of fluidity and heat retention.

The toner according to an exemplary embodiment of the present invention has a high gloss of 160 mm at a fixation image fixing speed of TMA 0.7 ± 0.03 mg / cm ² (Belt-type fixing device, Nip width: 10 mm, line pressure: 4 kgf) (measured at a measurement angle of 60 degrees and measured with a micro-TRI-gloss) according to the low-speed printing at a speed of 290 mm / sec and the high-speed printing at a speed of 290 mm / sec. do.

In the dynamic viscoelasticity measurement of the toner according to an embodiment of the present invention, the value of the storage modulus G 'according to the temperature change is, for example, about 2E + 05 to about 3E + 07 Pa · s and about 5E + 02 to about 2E + 03 Pa · s, and the change slope of the storage elastic modulus G 'according to a frequency change measured at a temperature of 140 ° C may have a value of, for example, about -0.4 or less.

The electrophotographic toner contains Si and Fe each having a concentration of 3 to 1,000 ppm by using a metal salt containing Si and Fe as an aggregating agent in the toner manufacturing process. If the concentration of Si and Fe is less than 3 ppm, the desired effect of the present invention is difficult to obtain. If the concentration of Si and Fe is more than 1,000 ppm, there is a problem such as lowering of chargeability of the toner.

The toner according to an embodiment of the present invention may have a peak temperature range of from 68 to 75 ° C and a peak temperature range of from 75 to 120 ° C when the differential scanning calorimeter is measured according to the coagulation control as described above, And has one or two endothermic peaks.

In using the metal salt of Si and Fe as a coagulant in the toner according to an embodiment of the present invention, the molar ratio (Si / Fe) of Si and Fe components is preferably 0.1 to 5, more preferably 0.15 to 3 . If the molar ratio is less than 0.1, there is a problem that the cohesive force is lowered. If the molar ratio is more than 5, the chargeability of the toner may be lowered.

By using the above-mentioned Si and Fe-containing metal salt as the coagulant in the toner production process, it is possible to perform the pulverization hardening and control the particle shape. Accordingly, the electrophotographic toner according to the present invention has an average particle size of 3 to 8 占 퐉 and an average value of circularity of 0.940 to 0.970. Particularly when the average circularity difference between the particle size distribution of 2 mu m and 5 mu m is 0.020 or less, the uniformity of the particles is improved. In particular, the value of PSD (p, v) is 1.25 or less, preferably 1.23 to 1.2.

In particular, the electrophotographic toner according to one embodiment of the present invention has a storage modulus G 'value at 80 ° C of 1E + 05 to 1E + 07, and a storage modulus value at 140 ° C (Storage stability, heat resistance, anti-blocking property) of the toner at a storage modulus value of 1E + 05 or less at 80 DEG C, and has a value of 5E + 02 to 3E + 03. (MFT) may occur. If the storage modulus G 'value at 140 ° C is below 5E + 02, there is a problem with anti-hot offset property. If the storage modulus G' is below 3E + 03, there is a problem that high-gloss toner can not be obtained.

The above-described electrophotographic toner provides a method for producing toner which can achieve efficient coagulation by using the above-described Si and Fe-containing metal salt as coagulant.

The method for producing an electrophotographic toner according to the present invention comprises the steps of mixing a primary latex particle containing wax with a pigment dispersion and adding a metal salt containing Si and Fe to prepare a primary agglomerated toner; And coating a secondary latex prepared by polymerizing at least one polymerizable monomer onto the primary aggregation toner to agglomerate the resulting microparticles to prepare a secondary aggregation toner.

The addition of Fe and the Si-containing metal salt increases the size of the primary agglomerated toner due to increased ionic strength and collision between particles. Examples of Fe and Si-containing metal salts include polysilica iron, and specific examples thereof include PSI-025, PSI-050, PSI-075, PSI-100, PSI-200 and PSI- Etc.) can be used. For example, the physical properties and compositions of PSI-025, PSI-050, PSI-075, PSI-100, PSI-200 and PSI-300 are shown in Table 1 below.

Kinds PSI-025 PSI-050 PSI-075 PSI-100 PSI-200 PSI-300 Silica / Fe molar ratio (Si / Fe) 0.25 0.5 0.75 One 2 3 chief ingredient
density Fe (wt%) 5.0 3.5 2.5 2.0 1.0 0.7 SiO ₂ (wt%) 1.4 1.9 2.0 2.2 pH (1 w / v%) 2-3 Specific gravity (20 ° C) 1.14 1.13 1.09 1.08 1.06 1.04 Viscosity (mPa.S) 2.0 or higher Average molecular weight (Dalton) 500,000 Exterior Apparently a yellowish brown transparent liquid

In the above production process, the primary latex particles can be obtained by using a polyester alone or by polymerizing one or more polymerizable monomers, or a mixture thereof (hybrid type). When the polymer is used, the polymer may be polymerized together with the wax in the polymerization process to form a composite, or may be separately mixed with wax. The polymerization process produces a wax-containing latex having a size of 1 탆 or less, preferably 100 to 300 nm, as an emulsion polymerization dispersion.

The polymerizable monomers used herein include styrene-based monomers of styrene, vinyltoluene, and? -Methylstyrene; Acrylic acid, methacrylic acid; Acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, , (Meth) acrylic acid derivatives of dimethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide and methacrylamide; Ethylenically unsaturated monoolefins of ethylene, propylene, and butylene; Vinyl chloride, vinylidene chloride, vinyl halides of vinyl fluoride; Vinyl esters of vinyl acetate and vinyl propionate; Vinyl methyl ether, vinyl ethyl ether of vinyl ethyl ether; Vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; Vinylpyridine, 2-vinylpyridine, 4-vinylpyridine, and N-vinylpyrrolidone nitrogen-containing vinyl compounds.

The wax used in the primary latex or toner manufacturing process is fixed at a low fixation temperature on the final image receptor and serves to provide a toner exhibiting excellent final image durability and abrasion resistance characteristics. Examples of the wax include, but are not limited to, polyethylene wax, polypropylene wax, silicone wax, paraffin wax, ester wax, carnauba wax, and metallocene wax. Preferably, the wax has a melting point of from about 50 to about 150 < 0 > C. The wax component is physically in close contact with the toner particles, but is preferably not covalently bonded to the toner particles.

The amount of the wax may be 0 to 20 parts by weight based on 100 parts by weight of the toner. If the amount of the wax is more than 20 parts by weight, economical efficiency is lowered. The wax may be contained in the latex process or separately in the coagulation process.

In the primary latex production process, a polymerization initiator and a chain transfer agent may be used for efficient polymerization.

Examples of the polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate; 2-azobis (2-amidinopropane) dihydrochloride, 2, 3-azobis (2-aminopropanecarboxylic acid) Azobis-2-methyl-N-1,1-bis (hydroxymethyl) -2-hydroxyethylpropioamide, 2,2'-azobis (2,4-dimethylvaleronitrile), 2 , Azo compounds such as 2'-azobisisobutyronitrile and 1,1'-azobis (1-cyclohexanecarbonitrile); But are not limited to, methyl ethylperoxide, di-t-butyl peroxide, acetyl peroxide, dicumyl peroxide, lauroyl peroxide, benzoyl peroxide, Peroxides such as dicyclohexyl peroxide, oxy dicarbonate and di-t-butyl peroxyisophthalate. Further, an oxidation-reduction initiator in which these polymerization initiators and a reducing agent are combined can be mentioned.

The chain transfer agent refers to a substance that changes the type of the chain transfer agent in a chain reaction. And that the new chain has a markedly reduced activity over that of the previous one. Through the chain transfer agent, the polymerization degree of the monomer can be reduced and a new chain can be initiated. The molecular weight distribution can be controlled through the chain transfer agent.

Examples of such chain transfer agents include, but are not limited to, sulfur containing compounds such as dodecanethiol, thioglycolic acid, thioacetic acid and mercaptoethanol; Phosphorous acid compounds such as phosphorous acid and sodium phosphite; Hypophosphorous acid compounds such as hypophosphorous acid and sodium hypophosphite; And alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-butyl alcohol.

The primary latex particles may further include a charge control agent. The charge control agent used in the present invention may be any of a negative charge control agent and a positive charge control agent. The negative charge control agent may be chromium-containing azo Organometallic complexes or chelate compounds such as azo dyes or monoazo metal complexes; Metal-containing salicylic acid compounds such as chromium, iron and zinc; And an organometallic complex of an aromatic hydroxycarboxylic acid and an aromatic dicarboxylic acid can be used, and there is no particular limitation as long as it is a known one. Examples of the positive charge control agent include nigrosine and a product thereof modified with a fatty acid metal salt or the like, a quaternary ammonium salt such as tributylbenzylammonium 1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, And the like can be used singly or in combination of two or more. Such a charge control agent stably supports the toner on the developing roller by the electrostatic force, so that stable and fast charging speed becomes possible by using the above charge control agent.

The primary latex thus obtained is mixed with the pigment dispersion. The pigment dispersion is obtained by uniformly dispersing a composition containing a pigment such as black, cyan, magenta, yellow and an emulsifier using an ultrasonic disperser or a micro fludizer .

Among the pigments used in the pigment dispersion, carbon black or aniline black is used for black color, and at least one color selected from yellow, magenta and cyan pigments is used.

The yellow pigment may be a condensed nitrogen compound, an isoindolinone compound, an atlakin compound, an azo metal complex, or an allyl imide compound. Specifically, C.I. Pigment yellow 12, 13, 14, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168,

The magenta pigment may be a condensed nitrogen compound, an anthraquin, a quinacridone compound, a base dye rate compound, a naphthol compound, a benzoimidazole compound, a thioindigo compound, or a perylene compound. Specifically, C.I. Pigment red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, or 254 may be used.

The cyan pigment may be a copper phthalocyanine compound or its derivative, an anthraquinone compound, or a base dye rate compound. Specifically, C.I. Pigment blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, or 66 may be used.

These pigments may be used singly or as a mixture of two or more of them, and they are selected in consideration of color, saturation, lightness, weatherability, dispersibility in the toner, and the like.

The content of the pigment as described above is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the primary latex. The amount of the pigment may be an amount enough to color the toner. If the amount is less than 0.1 part by weight based on 100 parts by weight of the primary latex, the coloring effect is not sufficient. If the amount is more than 20 parts by weight, A sufficient frictional electrification amount can not be obtained, which is not preferable.

As the emulsifier used in the pigment dispersion, emulsifiers known in the art can be used, and anionic emulsifiers, nonionic emulsifiers or mixtures thereof can be used. Examples of the anionic reactive emulsifier include HS-10 (manufactured by Dai-ichi Kogyo) and Dawfax 2-A1 (manufactured by Dow Chemical). Nonionic reactive emulsifiers include RN-10 ), And the like.

After mixing the wax-containing primary latex particles and the pigment dispersion obtained as described above, the aggregated toner is prepared by adding the Si and Fe-containing flocculant. More specifically, after the wax-containing primary latex particles and the pigment dispersion are mixed, the Si and Fe-containing flocculant is added under the condition of pH 1 to 4 to form a primary aggregation toner of 2.5 탆 or less which acts as a core After the secondary latex is added thereto and the pH in the system is adjusted to 6 to 8, when the particle size is kept constant for a certain time, the temperature is raised in the range of 90 to 96 캜 and the pH is lowered to 6 to 5.8 The secondary aggregated toner can be prepared by combining.

The secondary latex can be obtained by polymerizing one or more polymerizable monomers as described above, and such polymerization produces an emulsion polymerization dispersion with a latex having a size of 1 탆 or less, preferably 100 to 300 nm. The secondary latex may contain wax as in the case of the primary latex, and the wax may be included in the secondary latex during polymerization.

On the other hand, it is possible to coat a tertiary latex obtained by polymerizing the above-mentioned one or more polymerizable monomers on the secondary aggregation toner.

By forming the shell layer with the secondary latex or the tertiary latex as described above, it becomes possible to improve the durability of the toner and to solve the toner storage problem in terms of shipping and handling.

The secondary aggregated toner or the tertiary aggregated toner obtained as described above is filtered to separate and dry the toner particles. The dried toner is subjected to external addition using silica or the like, and the charge amount and the like are adjusted to obtain a final dry toner.

It is preferable that the primary latex particles located in the core of the toner obtained through the above method are controlled in molecular weight and Tg and rheological characteristics so as to be advantageous for low temperature fixation.

The volume average particle diameter of the toner particles prepared is 3 to 8 占 퐉, preferably 5 to 8 占 퐉. If the average particle diameter is less than 3 m, there is a problem of cleaning of the photoreceptor and lowering of the yield of mass production. If the average particle diameter is more than 8 占 퐉, electrification is uneven and the fixability of the toner is deteriorated. And it is not preferable.

According to another embodiment of the present invention, there is provided an image forming method comprising the steps of attaching toner to a surface of a photoconductor on which an electrostatic latent image is formed to form a visible image and transferring the visible image to a transfer material, An electrophotographic toner containing 3 to 1,000 ppm of Si and Fe, wherein the molar ratio of Si and Fe is 0.2 to 0.8, and satisfies the following conditions (1) and (2) Wherein the toner is a photographic toner.

&Quot; (1) "

&Quot; (2) "

In the formula,

MFT _A indicates the minimum fusing temperature at a low speed of 160 mm / sec. MFT _B indicates the lowest fixing temperature at a high speed of 290 mm / sec. HOT _A indicates a hot offset temperature (Hot offset temperature). HOT _B represents the hot offset temperature at a low speed of 290 mm / sec. Gloss _A represents the gloss at the time of low-speed printing of a measurement angle of 60 °, a fixing temperature of 160 ° C and 160 mm / .

Representative electrophotographic imaging processes include a series of steps that form an image on a receptor, including charging, exposure, development, transfer, fusing, cleaning, and erasing steps.

In the charging step, the photoreceptor is covered with a charge of a desired polarity, which is either negative or positive, typically by a corona or a charging roller. In the exposure step, the optical system, typically a laser scanner or diode array, selectively discharges the charged surface of the photoreceptor in an imagewise manner corresponding to the target image formed on the final image receptor to form a latent image. Electromagnetic radiation, which may be referred to as "light ", may include, for example, infrared radiation, visible light, and ultraviolet radiation.

In the developing step, toner particles of suitable polarity generally contact a latent image on the photoreceptor, and typically use a developer electrically-biased developer having the same potential polarity as the toner polarity. The toner particles migrate to the photoreceptor and are selectively attached to the latent image by electrostatic force, forming a toned image on the photoreceptor.

In the transfer step, the toned image is transferred from the photoreceptor to the desired final image receptor, sometimes the intermediate transfer element is used to affect the transfer of the toned image from the photoreceptor to the final image receptor with subsequent transfer of the toned image .

In the fixing step, the toned image on the final image receptor is heated to soften or melt the toner particles, thereby causing the toned image to settle on the final receptor. Another method of fixing involves fixing the toner to the final receptor under high pressure with or without heat.

In the cleaning step, the residual toner remaining on the photoreceptor is removed.

Finally, in the erase step, the photoreceptor charge is exposed to light of a specific wavelength band and is reduced to a substantially uniformly low value, whereby the residual of the original latent image is removed and the photoreceptor is prepared for the next image forming cycle.

According to another embodiment of the present invention, there is provided an image forming apparatus comprising: a photosensitive member; Developing means for transferring the toner to the photoreceptor surface; An electrophotographic toner having toner supply means for supplying toner to the developing means and toner storage means for storing toner to be supplied to the toner supply means, wherein the toner comprises latex, colorant and wax, Si and Fe, wherein the molar ratio (Si / Fe) of Si and Fe is in the range of 0.1 to 5, and satisfies the following conditions (1) and (2):

&Quot; (1) "

&Quot; (2) "

In the formula,

MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec,

MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec,

HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec,

HOT _B represents the hot offset temperature at a low speed of 290 mm / sec,

Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec.

According to another embodiment of the present invention, there is provided an image forming apparatus comprising: an organophotoreceptor; Image forming means for forming an electrostatic latent image on the surface of the organophotoreceptor; Means for containing the toner; Toner supplying means for supplying the toner to the surface of the organophotoreceptor to develop the electrostatic latent image onto the surface of the organophotoreceptor; And toner transferring means for transferring the toner image from the surface of the organophotoreceptor to a transfer material, wherein the toner is an electrophotographic toner comprising latex, a colorant and wax, wherein the toner comprises 3 to 1,000 ppm Si and Fe, wherein the molar ratio of Si and Fe is 0.2 to 0.8 and satisfies the following conditions (1) and (2)

&Quot; (1) "

&Quot; (2) "

In the formula,

MFT _A indicates the minimum fusing temperature at a low speed of 160 mm / sec. MFT _B indicates the lowest fixing temperature at a high speed of 290 mm / sec. HOT _A indicates a hot offset temperature (Hot offset temperature). HOT _B represents the hot offset temperature at a low speed of 290 mm / sec. Gloss _A represents the gloss at the time of low-speed printing of a measurement angle of 60 °, a fixing temperature of 160 ° C and 160 mm / .

Fig. 1 shows an embodiment of an image forming apparatus of a non-contact development type in which a toner manufactured according to the production method of the present invention is accommodated.

The nonmagnetic one-component developer of the developing apparatus 4 is fed onto the developing roller 5 by the supplying roller 6 constituted by an elastic member such as a polyurethane foam, a sponge or the like. The developer 8 supplied onto the developing roller 5 reaches the contact portion between the developer regulating blade 7 and the developing roller 5 as the developing roller 5 rotates. The developer regulating blade 7 is made of an elastic member such as metal or rubber. The layer of the developer 8 is regulated as a constant layer between the contact portions of the developer regulating blade 7 and the developing roller 5 when the developer is passed therethrough to form a thin layer and sufficiently charge the developer. The thinned developer 8 is conveyed by the developing roller 5 to a developing region where the developer 8 is developed on the electrostatic latent image of the photoconductor 1 as a latent image bearing member. At this time, the prismatic latent image is formed by scanning the photoconductor 1 with light (3).

The developing roller 5 is positioned facing the photosensitive member 1 with a certain gap therebetween, not in contact with each other. The developing roller 5 rotates counterclockwise and the photoconductor 1 rotates clockwise.

The developer 8 transferred to the developing area of the photoconductor 1 is transferred to the developing roller 5 by the DC superimposed AC voltage applied to the developing roller 5 and the latent image potential of the photoconductor 1 charged by the charging means 2 The electrostatic latent image formed on the photoconductor 1 is developed by the electric force generated by the potential difference to form a toner image.

The developer 8 developed on the photoconductor 1 reaches the position of the transfer means 9 in accordance with the rotational direction of the photoconductor 1. The developer developed on the photoreceptor 1 is transferred to the printing paper while the printing paper 13 passes by the transfer means 9 to which a high voltage of the opposite polarity to the developer 8 is applied in the form of corona discharge or roller, And an image is formed.

The image transferred onto the printing paper is fused to the printing paper while passing through a high-temperature and high-pressure fixing device (not shown), and the image is fixed. On the other hand, the unremoved residual developer 8 'on the developing roller 5 is recovered by the supply roller 6 in contact with the developing roller 5, 8 'are recovered by the cleaning blade 10. The above process is repeated.

The invention will be described in more detail with reference to the following examples, but the invention is not limited thereto.

Example 1: Synthesis of latex

To the 3L beaker was added a monomer mixture solution (970 g of styrene, 192 g of n-butyl acrylate, 36 g of b-carboxyethyl acrylate (Sipomer, Rhodia)), 4.2 g of cross-linking agent A-decane diol diacrylate, ) Dodecanethiol was added, 500 g of an aqueous solution of sodium dodecyl sulfate (Aldrich) (2 wt% based on water) was added and stirred to prepare a monomer emulsion. 300 g of a 5% aqueous solution of initiator (KPS) and 650 g of an aqueous solution of sodium dodecyl sulfate (0.13% by weight in water) as an emulsifier were added to a 3 L double jacket reactor heated to 75 캜 and the monomer emulsion prepared above was added dropwise over 2 hours, . The reaction was carried out at the reaction temperature for 8 hours. The particle size of the prepared latex was measured by a light scattering method (Horiba 910) and was 150-200 nm.

Example 2: Preparation of pigment dispersion

A total of 10 g of an anionic reactive emulsifier (HS-10; DAI-ICH KOGYO) and a nonionic reactive emulsifier (RN-10; DAI-ICH KOGYO) ), And 400 g of glass beads having a diameter of 0.8 to 1 mm were put into the milling bath and milled at room temperature to prepare a dispersion. The dispersing machine was an ultrasonic dispersing machine.

color Pigment type HS-10: RN-10 (weight ratio) Experimental conditions black Mogul-L 100: 0 K-A 80: 20 K-B 0: 100 K-C yellow PY-74 100: 0 Y-A 50: 50 Y-B 0: 100 Y-C magenta PR-122 100: 0 M-A 50: 50 M-B 0: 100 M-C draft PB 15: 4 100: 0 C-A 80: 20 C-B 70: 30 C-C

Example 3: Coagulation and Toner Production

A 1 L reactor was charged with 15 g of nitric acid (0.3 mol) to 500 g of deionized water, 150 g of the primary latex for core, 35 g of the cyan pigment dispersion (HS-10 100%) and 27 g of the wax dispersion P- And 15 g of PSI-025 (manufactured by Kankyo Kogyo Co., Ltd.) was added thereto. The mixture was stirred at 11,000 rpm for 6 minutes using a homogenizer to obtain agglomerates of 1.5 to 2.5 μm. The mixed solution was put into a 1 L double jacket reactor, and the temperature was raised from room temperature to 0.5 deg. C per minute to 50 deg. C (Tg-5 degree of latex). When the size reached about 5.8 mu m, 50 g of a secondary latex obtained by polymerizing the styrene-based polymerizable monomer was added. When the D50 (Volume) reached 6.0 mu m, 1 mol of NaOH was added to adjust the pH to 7. When the particle size D50 (Volume) value was kept constant for 10 minutes, the temperature was raised to 96 deg. C (0.5 deg. C / min). After reaching 96 캜, 0.3 mol of nitric acid was added to adjust the pH to 6.6, and after 3-5 hours of mixing, a potato-shaped secondary agglomerated toner of 5-6 탆 was obtained. Subsequently, the coagulation reaction solution was cooled to Tg or lower, and the toner particles were separated through filtration and dried.

0.5 parts by weight of NX-90 (Nippon Aerosil), 1.0 part by weight of RX-200 (Nippon Aerosil) and 0.5 part by weight of SW-100 (Titan Kogyo) were added to the dried toner particles, The mixture was stirred at rpm for 4 minutes to externally add. As a result, a toner having a D50 (volume) of 5.9 micro was obtained.

Example 4

The procedure of Example 3 was repeated except that cyan pigment was used instead of black pigment.

Example 5

The procedure of Example 3 was repeated except that a magenta pigment was used instead of the black pigment.

Example 6

The procedure of Example 3 was repeated except that a yellow pigment was used instead of the black pigment.

Comparative Example 1

Model 5440 Toner (Cyan) manufactured by Konica Minolta Co., Ltd. was used.

Comparative Example 2

And a model C4300 toner (Black) manufactured by Fuji Xerox Co., Ltd. was used.

Comparative Example 3

And a model C4300 toner (Magenta) manufactured by Fuji Xerox Co., Ltd. was used.

≪ Evaluation of fixing area of toner &

- Equipment: Belt-type Fuser

- Unfixed images for test: 100% pattern

Test temperature: 100 to 250 占 폚 (10 占 폚 interval)

Speed: 160 mm / sec (for 26 ppm), 290 mm / sec (for 45 ppm)

- dwell time: 0.08 sec

After the test under the above conditions, the fixability of the fixed image was evaluated as follows.

After the optical density (OD) of the fixed image was measured, 3M 810 tape was attached to the image area, and the tape was removed by reciprocating 5 times using a 500 g weight. The OD after tape removal was measured.

Fixability (%) = (OD_after tape removal / OD_ tape removal) x 100

The fixing temperature region where the fixing property was 90% or more was regarded as the fixing region of the toner.

MFT: Minimum Fusing Temperature [Minimum temperature above 90% fixation without cold-offset]

HOT: Hot Offset Temperature [Minimum temperature at which hot-offset occurs]

≪ Evaluation of Gloss of Toner >

Using a gloss meter at each fixing temperature (using the fuser described above).

Measuring angle: 60 ^o

Measurement pattern: 100% pattern

Evaluation of high temperature preservability of toner

After 100 g of the toner was extruded, it was put into a developing machine and kept in a packaged state in a constant temperature and humidity oven as follows.

23 캜, 55% RH (relative humidity) 2 hr

=> 40 ° C, 90% RH 48hr

=> 50 ° C, 80% RH 48hr

=> 40 ° C, 90% RH 48hr

=> 23 ° C, 55% RH 6 hr

After the above conditions were stored, whether or not the toner in the developing device was caking was visually observed, and 100% image was output to evaluate image defects.

- Evaluation standard

○: Good image, No-Caking

?: Bad image, No-Caking

X: Caking occurred

division MFT _A (캜) MFT _B (캜) HOT _A (℃) HOT _B (℃) Gloss _A Gloss _B Latitude _A Latitude _B High Temperature Storage Example 3 130 150 250 250 7.3 6.1 120 100 ○ Example 4 140 150 250 250 8.2 7.4 110 100 ○ Example 5 140 150 250 250 7.5 6.1 110 100 ○ Example 6 120 140 250 250 10.7 7.0 130 110 ○ Comparative Example 1 140 175 250 240 3.2 1.9 110 65 △ Comparative Example 2 130 170 240 220 4.4 3.1 110 50 X Comparative Example 3 130 180 200 200 5.5 3.7 70 20 X

MFT _A : Lowest fixing temperature when printing at 160mm / sec (26ppm)

MFT _B : Minimum fixing temperature when printing at 290mm / sec (45ppm)

HOT _A : Hot offset temperature when printing at 160mm / sec (26ppm)

HOT _B : Hot offset temperature when printing at 290mm / sec (45ppm)

Gloss _A : glossiness (measurement angle 60 °, fixation temperature 160 ° C) when printing at 160 mm / sec (26 ppm)

Gloss _B : Gloss (60 ° measurement angle, fixing temperature 160 ° C) when printing at 290mm / sec (45ppm)

Latitude _A: HOT _A -MFT _A

Latitude _B : HOT _B -MFT _B

As shown in Table 3, the toners according to Examples 3 to 6 were excellent in high-temperature storability, had excellent gloss, had a gloss difference of less than 1 according to low-speed printing and high-speed printing, And 2 are satisfied.

On the other hand, the rheology of the toner is measured by a temperature sweep method in which the frequency is fixed and the temperature is raised, and a frequency sweep method in which the temperature is fixed and the frequency is changed and measured The measurement conditions are as follows.

Temperature sweep: equipment TA ARES, heating rate 2 캜 / min, 40 ~ 180 캜, frequency 6.28 rad / s,

Frequency sweep: equipment TA ARES, measuring temperature 140 ° C, frequency 0.1-100 rad / s

Each toner of Examples 3 to 6 had a storage modulus G 'value of the temperature sweep of 2E + 05 to 3E + 05 Pa.s and 5E + 02 to 2E + 03 Pa.s Respectively.

The slope of the linear region in the frequency sweep curve at 140 ° C was -0.2 to -0.4.

Fig. 1 shows an embodiment of an image forming apparatus containing a toner produced according to the present invention.

≪ Brief Description of Drawings &

1: Photoreceptor 2: Charging means

3: light 4: developing device

5: developing roller 6: supply roller

7: developer regulating blade 8: developer

8 ': Residual toner 9: Transferring means

10: Cleaning blade 12: Power source

13: Printing medium

Claims (16)

An electrophotographic toner comprising a latex, a colorant, and a wax, Wherein the toner further comprises a metal salt containing Si and Fe, Wherein the toner contains 3 to 1,000 ppm of Si and Fe, the molar ratio of Si to Fe (Si / Fe) is in the range of 0.1 to 5, Wherein the fixing property of the toner satisfies the following equations (1) and (2): &Quot; (1) "

&Quot; (2) "

In the formula, MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec, MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec, HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec, HOT _B represents the hot offset temperature at a low speed of 290 mm / sec, Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec. The method according to claim 1, The toner has a maximum of 160 mm / sec low-speed printing and 290 mm / sec high-speed printing in the fixing of a fixed image having TMA of 0.7 ± 0.03 mg / cm ² (Belt-type fixing machine, Nip width: 10 mm, line pressure: 4 kgf) Wherein the gloss difference has a value of 1 or less. The method according to claim 1, In the dynamic viscoelasticity measurement of the toner, the values of the storage modulus G 'according to the temperature change are 2E + 05 to 3E + 07 Pa.s and 5E + 02 to 2E + 03 Pa.s Wherein the electrophotographic toner is an electrophotographic toner. The method according to claim 1, Wherein the toner has a change slope of storage elastic modulus G 'according to a frequency change measured at a temperature of 140 ° C of -0.4 or less. The method according to claim 1, Wherein the toner has a starting temperature of a highest endothermic peak in a differential scanning calorimetry measurement of 68 to 75 占 폚 and a peak temperature range of 75 to 95 占 폚. The method according to claim 1, Wherein the average particle size of the toner is 3 to 8 占 퐉. The method according to claim 1, Wherein an average value of the circularity of the toner is 0.940 to 0.970. The method according to claim 1, Wherein the difference in average value of the circularity of the toner particles having an average particle size of 2 mu m and 5 mu m is 0.020 or less. The method according to claim 1, Wherein the PSDv and PSDp values of the toner are 1.25 or less. Mixing a primary latex particle containing a wax with a pigment dispersion, and adding a metal salt containing Si and Fe to prepare a primary agglomerated toner; A step of coating a secondary latex prepared by polymerizing at least one polymerizable monomer onto the primary aggregation toner to agglomerate the obtained microparticles to prepare a secondary aggregation toner, Wherein the fixing property of the toner satisfies the following equations (1) and (2): " (1) " &Quot; (1) "

&Quot; (2) "

In the formula, MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec, MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec, HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec, HOT _B represents the hot offset temperature at a low speed of 290 mm / sec, Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec. 11. The method of claim 10, Further comprising the step of coating a tertiary latex prepared by polymerizing at least one polymerizable monomer onto the secondary aggregation toner. 11. The method of claim 10, Wherein the primary latex particles are a polyester-based particle, a polymer obtained by polymerizing at least one polymer, or a mixture thereof. 11. The method of claim 10, Wherein the primary latex particles containing the wax are a mixture or a composite of wax and primary latex particles. There is provided an image forming method comprising a step of attaching toner to a surface of a photoconductor on which an electrostatic latent image is formed to form a visible image, and transferring the visible image to a transfer material, wherein the toner is an electrophotographic toner containing latex, An image forming method which comprises 3 to 1,000 ppm of Si and Fe and has a molar ratio (Si / Fe) of Si and Fe in the range of 0.1 to 5 and satisfies the following conditions (1) and : &Quot; (1) "

&Quot; (2) "

In the formula, MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec, MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec, HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec, HOT _B represents the hot offset temperature at a low speed of 290 mm / sec, Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec. A photoreceptor; Image forming means for forming an electrostatic latent image on the surface of the photoreceptor; Means for containing the toner; Toner supplying means for supplying the toner to the surface of the photoreceptor to develop the electrostatic latent image on the surface of the photoreceptor onto the toner; And toner transferring means for transferring the toner image from the surface of the photoreceptor surface to a transfer material, wherein the toner is an electrophotographic toner comprising latex, a colorant and wax, wherein the toner comprises 3 to 1,000 ppm An image forming apparatus comprising Si and Fe, wherein the molar ratio (Si / Fe) of Si and Fe has a range of 0.1 to 5, and satisfies the following conditions (1) and (2) &Quot; (1) "

&Quot; (2) "

In the formula, MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec, MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec, HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec, HOT _B represents the hot offset temperature at a low speed of 290 mm / sec, Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec. A photoreceptor; Developing means for transferring the toner to the photoreceptor surface; Toner supply means for supplying the toner to the developing means, and toner storage means for storing the toner supplied to the toner supply means, Wherein the toner comprises 3 to 1,000 ppm of Si and Fe, wherein the molar ratio (Si / Fe) of Si and Fe is in the range of 0.1 to 5, A developing apparatus satisfying the conditions of the equations (1) and (2) &Quot; (1) "

&Quot; (2) "

In the formula, MFT _A shows the lowest fixing temperature at low speed printing of 160 mm / sec, MFT _B shows the lowest fixing temperature during high-speed printing of 290 mm / sec, HOT _A represents the hot offset temperature at low speed printing of 160 mm / sec, HOT _B represents the hot offset temperature at a low speed of 290 mm / sec, Gloss _A shows gloss at low-speed printing with a measurement angle of 60 °, fixing temperature of 160 ° C, and 160 mm / sec.

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