KR101571335B1 - Electrophotographic toner and process for preparing the same - Google Patents

Abstract

There is provided an electrophotographic toner and a method for producing the same, wherein the toner is an electrophotographic toner comprising a latex, a colorant and a releasing agent, and has a complex viscosity d? / and dT) is the absolute value of about 0.03 to about 0.06, the complex viscosity (η) at 140 ℃ is about 1.0 × 10 ² Pa · s to about 6.0 × 10 ² Pa · s in a toner for electrophotography.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner,

The present invention relates to an electrophotographic toner and an electrophotographic toner having a narrow particle size distribution and capable of fixing at a low temperature and having optimized rheological properties to obtain a high gloss optimum image and a print quality, Of the present invention.

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, generally colored particles obtained by dispersing pigments such as carbon black or other additives in latex are used.

The toner is produced by a pulverization method and a polymerization method. In the pulverization method, a synthetic resin, a pigment, and other additives as required 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, in order to ensure excellent printing performance and image quality at the time of printing even when polymerized toners are still used, functional properties such as fixability and durability of the toner must be ensured. For this purpose, development of a toner having optimized rheological properties is required.

According to an embodiment of the present invention,

An electrophotographic toner comprising a latex, a colorant, and a releasing agent,

(D? / DT) of from about 0.03 to about 0.06 and a complex viscosity (?) At 140 占 폚 of from about 1.0 x 10 < ² > Lt; ² > Pa · s to about 6.0 × 10 ² Pa · s.

At a temperature at which the loss tangent (tan?) (= G "/ G ', that is, the ratio of the loss elastic modulus G" and the storage elastic modulus G') of the toner is minimal, the complex viscosity of the toner is about 1.0 × 10 ⁴ Pa · s To about 4.0 x 10 < ⁴ > Pa s, and the specific activation energy of the toner may be about 170 KJ / mol or more.

And the temperature at which the loss tangent (tan delta) of the toner is minimal is about 80 to about 90 deg.

It is preferable that the temperature at which the secondary differential value (d ² η / (dT) ² ) of the complex viscosity according to the temperature change of the toner is minimum is about 50 to about 70 ° C., and the complex viscosity is about 3.0 × 10 ⁷ Pa · s.

The toner may comprise from about 50 to about 10,000 ppm Fe.

Wherein the mold release agent is a mixture of a paraffin wax and an ester wax; Or an ester group-containing paraffin wax.

The toner may have an average particle size of from about 3 to about 9 microns.

The average value of the circularity of the toner may be about 0.940 to about 0.980.

The GSDv and GSDp values of the toner may be about 1.25 or less, respectively.

The ester group content of the releasing agent is preferably about 2 to about 10% by weight based on the total release agent content.

According to another embodiment of the present invention,

Mixing the primary latex particles, the pigment dispersion and the release agent dispersion to prepare a mixed solution;

Adding a flocculant to the mixed liquid to prepare a primary aggregated toner; And

A process for producing an electrophotographic toner comprising a step of coating a secondary latex prepared by polymerizing at least one polymerizable monomer onto the primary aggregated toner to prepare a secondary aggregated toner,

Wherein the absolute value of the complex viscosity (d? / DT) of the complex viscosity according to the temperature change of the electrophotographic toner is about 0.03 to about 0.06 in a temperature range of 100 占 폚 to 160 占 폚, And a complex viscosity (?) Of from about 1.0 x 10 ² Pa · s to about 6.0 × 10 ² Pa · s.

Wherein the primary latex particles are polyester alone; A polymer obtained by polymerizing at least one polymerizable monomer; Or a mixture thereof.

The method may further include the step of coating a tertiary latex prepared by polymerizing at least one polymerizable monomer onto the secondary aggregation toner.

The polymerizable monomer may be a styrene-based monomer; Acrylic acid, methacrylic acid; (Meth) acrylic acid derivatives; Ethylenically unsaturated monoolefins; Vinyl halide; Vinyl esters; Vinyl ether; Vinyl ketone; And a nitrogen-containing vinyl compound.

Wherein the release agent dispersion is a mixture of a paraffin wax and an ester wax; Or an ester group-containing paraffin wax.

The coagulant may be a metal salt containing Si and Fe.

According to another embodiment 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 an absolute value of a complex viscosity (d? / DT) of a complex viscosity with respect to a change in temperature is about 0.03 to about 0.06 and a viscosity at 140 占 폚 is within a range of 100 占 폚 to 160 占 폚 Has a complex viscosity (?) Of from about 1.0 x 10 ² Pa · s to about 6.0 × 10 ² Pa · s.

According to another embodiment of the present invention, there is provided an image forming apparatus comprising: a toner; And a housing for storing the toner, wherein the toner is an electrophotographic toner comprising a latex, a colorant and a releasing agent, wherein the toner has a differential viscosity of a complex viscosity according to a change in temperature in a temperature range of 100 to 160 캜 and the absolute value is about 0.03 to about 0.06 in (dη / dT), the complex viscosity (η) at 140 ℃ is about 1.0 × 10 ² Pa · s to about 6.0 × 10 ² Pa · s.

According to another embodiment of the present invention,

Wherein the toner is an electrophotographic toner comprising a latex, a coloring agent and a releasing agent, wherein the toner has a temperature of 100 占 폚 to 200 占 폚, in a temperature range of 160 ℃, and the absolute value of the complex viscosity differential value (dη / dT) of following the temperature change is about 0.03 to about 0.06, and a complex viscosity (η) at 140 ℃ about 1.0 × 10 ² Pa · s To about 6.0 × 10 ² Pa · s.

According to one embodiment of the present invention, it is possible to provide a toner having an optimum viscosity in the temperature range of the fixing environment, exhibiting excellent fixability and having optimized rheological properties for realizing excellent image characteristics with high gloss, It is possible to provide an electrophotographic toner which is less harmful to the human body and the environment due to a small amount of residues by allowing efficient aggregation at a lower temperature and at a lower temperature,

Hereinafter, the present invention will be described in detail.

An electrophotographic toner according to an embodiment of the present invention is an electrophotographic toner comprising a latex, a colorant, and a releasing agent. The electrophotographic toner has a complex viscosity (d? / DT ) is of the absolute value is about 0.03 to about 0.06, and a complex viscosity (η) at 140 ℃ about 1.0 × 10 ² Pa · s to about 6.0 × 10 ² Pa · s.

The toner is exposed to a wide range of temperature and pressure conditions in a developing device, a fixing device, and the like, so that the viscosity of the physical property of the toner is evaluated as a representative characteristic in order to realize the desired durability and fixability of the toner. At this time, as a viscosity, there is a general viscosity measurement method in which a viscous composition is completely uniformly mixed to measure a viscosity, but in the case of a viscoelastic substance such as a toner, wax and pigment are distributed in the interior thereof, It becomes important to measure the viscous property of the toner.

Therefore, in the case of toner, it is evaluated as a complex viscosity defined by the following formula.

The complex viscosity (?) = (G ' ² + G " ² ) ^1/2 / w

G ": storage elastic modulus (Pa), G ": loss elastic modulus (Pa) w: angular velocity (rad / s)

The complex viscosity measured according to an embodiment of the present invention can be obtained by a temperature dispersion measurement method using a sinusoidal vibration method from room temperature to 180 DEG C in a range of angular velocity (vibration frequency) of 6.28 rad / s, manufactured by Rheometric Scientific Can be measured using the ARES measuring instrument. At this time, the angular velocity value of 6.28 rad / s is set based on the fixing speed of a conventional fixing device.

The complex viscosity is measured at a temperature ranging from 100 to 160 캜. The complex viscosity is measured based on the fixing temperature of the fixing heating roller of 160 to 200 캜, the self temperature in the fixing environment of the toner due to incomplete heat transfer, For reasons based on the history, the temperature is set to be lower by 20 to 40 ° C than the fixing temperature.

The complex viscosity depends on the measurement temperature and the angular velocity condition. The larger the temperature and angular velocity to be measured, the smaller the complex viscosity, and the smaller the temperature and angular velocity to be measured, the larger the complex viscosity.

Wherein when the complex viscosity of 1.0 × 10 ² Pa · s is less than the cohesive force between the toner so lowered may be an offset phenomenon appears in the high-temperature region, 6.0 × 10 if greater than ^2, the cohesive force between the toner is too large, and a result image It may not be easy to obtain the surface gloss of the final fixed image due to an offset or an unstable fixed image and an appropriate fixing strength because the adhesion force between the medium and the toner becomes smaller than the adhesion force between the toner and the roller.

Further, in the viscosity behavior of the toner, the absolute value of the complex viscosity (d? / DT) in accordance with the temperature change within the temperature and angular velocity range as well as the viscosity range in the temperature range of 100 占 폚 to 160 占 폚, It can affect the quality.

That is, the differential value (d? / DT) of the viscosity in the above temperature range represents the tangential slope in the curve showing the change of the complex viscosity according to the temperature, and the optimum physical properties The area can be known.

The absolute value of the complex viscosity (d? / DT) of the complex viscosity according to the temperature change of the toner according to the present invention is about 0.03 or more, preferably about 0.03 to about 0.06.

If the specific gravity is less than 0.03, it is difficult to obtain a glossiness or a fixing effect. If the specific gravity is more than 0.06, a problem such as a hot offset or a lap jam may be inconsistent.

The behavior and flowability of the toner can be predicted at a temperature at which the loss tangent (tan?) Of the toner (= G "/ G ', that is, the ratio of the loss elastic modulus G" and the storage elastic modulus G') is minimal.

The toner tangent of loss tangent is the minimum value of the loss tangent at the position where the derivative of the loss tangent is zero and the second derivative is greater than zero as a function of temperature and loss tangent.

For example, referring to FIG. 3 showing a storage / loss elastic modulus and a loss tangent graph according to an embodiment of the present invention, the loss tangent value is in the range of about 40 ° C. to about 70 ° C., , And then decreased thereafter, and it is confirmed that it increases again after passing about 90 ° C. At this time, the loss tangent has a minimum value at a temperature at which the value of the loss tangent decreases and then increases again, that is, at a temperature of about 90 ° C where the differential value of the loss tangent due to the temperature change is zero.

The temperature at which the loss tangent tan (delta) of the toner is minimal is about 80 to about 90 DEG C, and if the temperature is less than 80, the toner has a poor durability. If the temperature is more than 90 DEG C,

In a loss tangent (tan δ) of the toner is the minimum value temperature, the complex viscosity of the toner include, for example, about 1.0 × 10 ⁴ Pa · s to about 4.0 × 10 ⁴ Pa · s, from about ⁴ to about 3.5 2.0x10 x10 < ⁴ > Pa. If the complex viscosity is less than 1.0 x 10 < ⁴ > Pa s, the durability of the toner is deteriorated. If the complex viscosity is more than 4.0 x 10 &^lt; ¹ > Pa s, the rigidity of the toner becomes excessively large.

At a temperature at which the loss tangent (tan delta) of the toner is minimal, the activation energy of the toner is, for example, about 170 KJ / mol or more, about 170 to about 200 KJ / mol.

That is, the activation energy of the toner is a numerical value showing the sensitivity of the viscosity change with the change of the temperature, which can be expressed by the temperature dependence of the viscosity and can be expressed by Arrhenius Equation or WLF formula (Williams, Landel, Ferry Equation ). ≪ / RTI > The choice of application depends on the T _g of the sample and the measurement temperature. The viscosity and specific activation energy can be determined using the Arrhenius equation of the following formula:

[Equation 1]

η (T) = η (T 0) Exp [U / R (1 / T-1 / T 0)]

Where T is viscosity, T is temperature, T ₀ is reference temperature, U is activation energy, and R is a gas constant.

If the activation energy of the toner is less than 170 KJ / mol, it is difficult to obtain a glossiness or fixation effect. If the activation energy of the toner is more than 200 KJ / mol, a problem such as a hot offset or a lump jam image may become inconsistent .

Further, the complex viscosity of the toner at a temperature at which the secondary differential value (d ² η / (dT) ² ) of the complex viscosity according to the temperature change of the toner is minimum is, for example, about 3.0 × 10 ⁷ Pa · s or more, 3.0 x 10 < ⁷ > to about 5.0 x 10 < ⁷ >

The second differential value d ² ? / (DT) ² represents the rate of change of the slope of the tangent line in the curve of the complex viscosity of the toner with the temperature change. The point at which the secondary differential value is minimum is usually the inflection point of the curve The temperature at which the change in the complex viscosity of the toner starts. Therefore, at the minimum temperature of the secondary differential value, the strength of the toner in the low temperature region, that is, the durability can be indirectly predicted through the temperature range and the viscosity value at which the viscosity change occurs in the toner.

The second derivative of the complex viscosity value ^{(d 2 η / (dT)} 2) the minimum temperature as a function of temperature of the toner is, for example, a least about 50 ℃, about 50 to about 70 ℃. The host value the second derivative of the complex viscosity as a function of temperature of the toner ^{(d 2 η / (dT)} 2) is at the minimum temperature of the complex viscosity of the toner is 3.0 × 10 ⁷ when Pa · less than s, the toner durability off leak streaks and the like may occur and storage stability may be deteriorated.

According to another embodiment of the present invention, there is provided a process for producing a pigment dispersion, comprising the steps of: mixing a primary latex particle, a pigment dispersion and a release agent dispersion to prepare a mixture; Adding a flocculant to the mixed liquid to prepare a primary aggregated toner; And a step of coating a secondary latex prepared by polymerizing at least one polymerizable monomer onto the primary agglomerated toner to prepare a secondary agglomerated toner, (D? / DT) of the complex viscosity according to the temperature change of the electrophotographic toner is in the range of about 0.03 to about 0.06, the complex viscosity (?) Of the electrophotographic toner at 140 占 폚 that provides about 1.0 × 10 ² Pa · s to about 6.0 × 10 ² Pa · s a method of manufacturing toner for electrophotography.

Examples used as the coagulant, NaCl, MgCl _2, MgCl ₂ and _{8H 2 0, [Al 2 (} OH) n Cl 6-n] m (Al 2 (SO 4) 3 and 18H ₂ O, PAC (polyaluminum Chloride, etc.), PAS (polyaluminum sulfate), PASS (polyaluminum sulfate silicate), ferrous sulfate, ferric sulfate, ferric chloride, calcium hydroxide, calcium carbonate, It is not.

The amount of the flocculant is, for example, about 3 to about 16 parts by weight, and about 5 to about 12 parts by weight, based on 100 parts by weight of the primary latex particles. If the amount of the coagulant is less than 3 parts by weight, the coagulation efficiency is lowered. If the amount is more than 16 parts by weight, the chargeability of the toner may deteriorate.

According to one embodiment of the present invention, the electrophotographic toner uses Si and Fe-containing metal salt as a coagulant in the toner manufacturing process, and the resulting toner contains about 50 to about 10,000 ppm of Fe. If the Fe content is less than 50, it is difficult to obtain the desired effect of the present invention. If the Fe content is more than 10,000 ppm, the chargeability of the toner may deteriorate.

The Si and Fe-containing metal salts may include polysilica iron. In particular, by adding Si and Fe-containing metal salts in the toner manufacturing process according to an embodiment of the present invention, the ionic strength and the inter- The size of the primary agglomerated toner may increase due to collision or the like. Examples thereof include Poly Silica Iron, and specific examples thereof include PSI-025, PSI-050, PSI-075, PSI-100, PSI-200 and PSI-300 (manufactured by Suido Kiko Kaisha, Ltd.)) and the like can be used. For example, the physical properties and compositions of PSI-025, PSI-050 and PSI-075 are shown in Table 1 below.

Kinds PSI-025 PSI-050 PSI-075 PSI-100 PSI-200 PSI-300 Silica / Fe mole ratio
(Si / Fe) 0.25 0.5 0.75 One 2 3 chief ingredient
density Fe (wt%) 5.0 3.5 5.0 2.0 1.0 0.7 SiO ₂ (wt%) 1.4 1.9 1.4 2.2 pH (1 w / v%) 2-3 Specific gravity (20 ℃) 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

By using the Si and Fe-containing metal salt according to one embodiment of the present invention as a flocculant in the toner manufacturing process, it is possible to perform the pulp hardening and control the particle shape.

Accordingly, the volume average particle diameter of the electrophotographic toner according to an embodiment of the present invention is about 3 to about 9 mu m, and the average value of the circularity is about 0.940 to about 0.980.

Generally, the smaller the toner particles are, the more advantageous to obtain high-resolution and high image quality, but at the same time, it is disadvantageous from the viewpoint of the transfer speed and the cleaning power, so it is important to have proper particle diameters.

The volume average particle diameter of the toner can be measured by a light scattering method.

When the volume average particle diameter of the toner is less than 3 mu m, there arises a problem of cleaning of the photoreceptor and deterioration of the yield of the mass production, and it is harmful to the human body due to scattering and difficult to obtain an image of high resolution and quality when it exceeds 9 mu m, The fixability of the toner is lowered, and it may be difficult for the doctor blade (Dr-Blade) to regulate the toner layer. When the average value of the circularity of the toner is less than 0.940, the developed image on the transfer material has a large height, the toner consumption amount becomes large, the gap between the toner becomes too large and the sufficient coverage rate on the developed image And therefore, a larger amount of toner is required to obtain the necessary image density, resulting in an increase in the toner consumption amount. When the average value of the circularity of the toner is more than 0.980, the toner is excessively supplied onto the developing sleeve, and the sleeve may be unevenly coated on the toner together with the toner to cause contamination.

The circularity of the toner can be calculated according to the following equation using Image J Software 1.33u (National Institutes of Health, USA) for image data quantitative analysis after selecting 50 toner images from SEM photographs.

<Formula>

Circularity = 4π × (area / circumference ² )

The circularity value is a value between 0 and 1, and the closer the circularity value is to 1, the closer to a sphere.

The volume average particle size distribution index GSDv or the number average particle size distribution index GSDp described below can be used as an index of the toner particle distribution, which is calculated and measured as follows.

First, the particle size distribution of the toner measured using a Coulter Multisizer II (manufactured by Beckman-Coulter, Inc.) was measured on a small diameter side (channel) with respect to the volume and number of individual toner particles And a particle diameter of cumulative 50% is defined as a volume average particle diameter D50v and a number average particle diameter D50p. The cumulative distribution is defined as the volume average particle diameter D16v and the number average particle diameter D16p. Similarly, the particle diameter at which the cumulative value is 84% is defined as a volume average particle diameter D84v and a number average particle diameter D84p. The volume average particle size distribution index GSDv is defined as D84v / D16v and the number average particle size index GSDp is defined as D84p / D16p. The average particle size index (GSDp) can be calculated.

At this time, the values of GSDv and GSDp are, for example, about 1.25 or less, about 1.20 to about 1.25. When the values of GSDv and GSDp exceed 1.25, the particle size may become uneven.

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, it may be polymerized with a releasing agent such as wax in a polymerization process or may be mixed with a releasing agent separately.

The polymerization process produces a primary latex having a size of, for example, about 1 탆 or less and about 100 to about 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.

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 polymerizable monomer can be reduced and a new chain can be initiated. The molecular weight distribution can be controlled through the chain transfer agent.

The amount of chain transfer agent is, for example, from about 0.5 to about 5.0 parts by weight, and from about 1.0 to about 4.0 parts by weight, based on 100 parts by weight of the at least one polymerizable monomer. If the content of the chain transfer agent is less than 0.5 parts by weight, the molecular weight may be too high, and if it is more than 5.0 parts by weight, the molecular weight may be too low.

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 and the release agent dispersion to prepare a mixed solution. The pigment dispersion is obtained by homogeneously dispersing a composition containing a pigment such as black, cyan, magenta, or yellow and an emulsifier using an ultrasonic disperser or a microfludizer.

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 may be, for example, 0.1 to 20 parts by weight based on 100 parts by weight of the at least one polymerizable monomer. The amount of the pigment may be sufficient for coloring the toner, but if the amount is less than 0.1 part by weight based on 100 parts by weight of the polymerizable monomer, the coloring effect may not be sufficient. If the amount is more than 20 parts by weight, A sufficient frictional electrification amount may not be obtained.

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 Rhodia). Examples of the nonionic reactive emulsifier include RN-10 (manufactured by Dai- And the like.

The release agent dispersion used in the toner manufacturing process includes a release agent, water, an emulsifier, and the like

At this time, since the release agent is fixed at a low fixation temperature on the final image receptor and provides a toner exhibiting excellent final image durability and abrasion resistance characteristics, the kind and content of the release agent plays an important role in determining the characteristics of the toner .

Examples of the form of the mold release agent which can be used include, but are not limited to, polyethylene wax, polypropylene wax, silicone wax, paraffin wax, ester wax, carnauba wax and metallocene wax . The melting point of the release agent is, for example, from about 50 to about 150 캜. The release agent component is physically in close contact with the toner particles, but does not bind covalently with the toner particles. To provide a toner that is fixed at a low fixation temperature on the final image receptor and exhibits excellent final image durability and abrasion resistance properties.

The content of the releasing agent may be, for example, about 1 to about 20 parts by weight and about 5 to about 10 parts by weight based on 100 parts by weight of the at least one polymerizable monomer. When the content of the releasing agent is less than 1 part by weight, And the fixing temperature range can be narrowed, and when it exceeds 20 parts by weight, storage stability and economical efficiency may be deteriorated.

As the release agent, a wax containing an ester group is preferable. Examples thereof include (1) a mixture of an ester-based wax and a non-ester-based wax; Or (2) an ester group-containing wax containing an ester group in a non-ester-series wax.

Since the ester group has high affinity with the latex component of the toner, the wax can be uniformly present in the toner particles, so that the function of the wax can be effectively exerted. The ester-based wax component can be esterified with the latex Excessive waxing action can be suppressed in the case of constituting with only wax, and as a result, good developability of the toner can be maintained for a long period of time.

Examples of the ester waxes include esters of a fatty acid having 15 to 30 carbon atoms and an alcohol having 1 to 5 equivalents such as behenyl behenate, stearyl stearate, stearic acid ester of pentaerythritol, montanic acid glyceride, and the like . The alcohols constituting the ester may have 10 to 30 carbon atoms in the case of a monohydric alcohol, and 3 to 10 carbon atoms in the case of a polyhydric alcohol. Examples of the non-ester-based waxes include polyethylene-based waxes and parisian waxes.

Examples of the ester group-containing wax include a mixture of a paraffin wax and an ester wax; Or an ester group-containing paraffin wax. Specific examples thereof include P-280, P-318 and P-319 of Chukyo Yushi Co., Ltd.,

The ester group content of the releasing agent is about 2 to about 10% by weight based on the total weight of the releasing agent. If the content of the ester group is less than 2% by weight, compatibility with the latex may be deteriorated. If the content of the ester group is more than 10% by weight, plasticity of the toner may become excessively excessive,

The emulsifier used in the release agent dispersion may be an emulsifier known in the art, such as an anionic reactive emulsifier, a nonionic reactive emulsifier, or a mixture thereof, in addition to the emulsifier used in the pigment dispersion. Examples of the anionic reactive emulsifier include HS-10 (manufactured by Dai-ichi Kogyo) and Dawfax 2-A1 (manufactured by Rhodia). Examples of the nonionic reactive emulsifier include RN-10 (manufactured by Dai- And the like.

Through the above method, it is preferable that the primary latex particles have a controlled molecular weight and T _g and rheological characteristics so as to be favorable for low temperature fixation.

After mixing the primary latex particles and the pigment dispersion liquid and the release agent dispersion liquid obtained as described above, an aggregating agent is added to the mixed liquid to prepare an aggregated toner. More specifically, after mixing the primary latex particles, the pigment dispersion and the release agent dispersion, the 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 and the pH in the system is adjusted to 6 to 8, if the particle size remains constant over a period of time, the temperature is raised to 90 to 96 ° C and the pH is lowered to 6 to 5.8, The aggregated toner can be produced.

As the coagulant, at least one selected from Si and Fe-containing metal salts was used. The Si and Fe-containing metal salts include polysilica iron.

The secondary latex may be obtained by polymerizing one or more polymeric monomers as described above, and such polymerization may be used to produce a latex having a size of, for example, about 1 탆 or less and about 100 to about 300 nm as emulsion polymerization do. Such secondary latexes may also include waxes, which 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. At this time, a polymerization inhibitor may be further added to prevent the formation of new latex particles, and the reaction may be carried out under starved-feeding conditions so that the monomer mixture can be coated on the toner.

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 an external additive, and the charge amount and the like are adjusted to obtain a final dry toner.

As the external additive, silica, TiO ₂ or the like is used, and its content is For example, from about 1.5 to about 4 parts by weight, and from about 2 to about 3 parts by weight, based on 100 parts by weight of the extragranular toner. When the content of the external additive is less than 1.5 parts by weight, caking which is a phenomenon that the toner adheres to each other due to the cohesive force between the toner may be generated and the charge amount may become unstable. If the external additive is more than 4 parts by weight, .

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, Wherein an absolute value of a complex viscosity (d? / DT) of a complex viscosity with respect to a change in temperature is about 0.03 to about 0.06 and a viscosity at 140 占 폚 is within a range of 100 占 폚 to 160 占 폚 Wherein the toner has a complex viscosity (?) Of from about 1.0 x 10 ² Pa · s to about 6.0 × 10 ² Pa · s electrophotographic toner.

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 a toner comprising: a toner; And a housing for storing the toner, wherein the toner is an electrophotographic toner comprising a latex, a colorant and a releasing agent, wherein the toner has a differential viscosity of a complex viscosity according to a change in temperature in a temperature range of 100 to 160 캜 and the absolute value is about 0.03 to about 0.06 in (dη / dT), the complex viscosity (η) at 140 ℃ is about 1.0 × 10 ² Pa · s to about 6.0 × 10 ² Pa · s.

FIG. 1 illustrates a cartridge according to an embodiment of the present invention.

The cartridge 100 includes a toner tank 101, a supply portion 103, a toner conveying member 105, and a toner agitating member 110.

The toner tank 101 stores a predetermined amount of toner, and is formed into a substantially hollow cylindrical shape.

The supply unit 103 is installed in the inner lower portion of the toner tank 101 and discharges the toner stored in the toner tank 101 to the outside. In other words, the supply unit 103 protrudes in a columnar shape having a semicircular cross section inward from the bottom surface of the toner tank 101. A toner discharge port (not shown) is formed on the outer circumferential surface of the supply part 103 to discharge the toner.

The toner conveying member 105 is provided on the inner lower side of the toner tank 101 and on one side of the supplying unit 103. When the toner conveying member 105 is rotated, the toner in the toner tank 101 is conveyed to the supplying portion 103. The toner conveying member 105 is formed into a coil spring shape and has one end extended to the inside of the supplying portion 103. [ That is, in the toner supply direction A, as shown in Fig. The toner conveyed by the toner conveying member 105 is discharged to the outside through the toner outlet.

The toner stirring member 110 is provided so as to be rotatable inside the toner tank 101 so that the toner stored in the toner tank 101 is moved downward. That is, when the toner stirring member 110 rotates at the center of the toner tank 101, the toner stored in the toner tank 101 is agitated and the toner is not hardened. Then, the toner is moved downward by its own weight. The toner stirring member 110 includes a rotating shaft 112 and a toner stirring film 120. The rotary shaft 112 is installed to be rotatable at the center of the toner tank 101 and a driving gear (not shown) is provided coaxially at one end protruding to one side of the toner tank 101. Therefore, when the driving gear rotates, the rotating shaft 112 rotates integrally. In addition, it is preferable that the blade plate 114 is formed on the rotary shaft 112 to facilitate the installation of the toner stirring film 120. At this time, it is preferable that the blade 114 is formed to be approximately symmetrical about the rotation axis 112. The toner stirring film 120 has a width corresponding to the inner length of the toner tank 101 and has an elasticity capable of being deformed along the protrusion on the inner side of the toner tank 101,

The toner agitating film 120 is preferably cut from the end of the toner agitating film 120 toward the rotating shaft 112 to form the first agitating part 121 and the second agitating part 122.

According to another embodiment of the present invention, there is provided an image forming apparatus comprising transfer means for transferring a print medium and forming an image using toner, wherein the toner contains latex, colorant and release agent (D? / DT) of from about 0.03 to about 0.06 and a complex viscosity (?) At 140 占 폚 in a temperature range of 100 占 폚 to 160 占 폚, wherein the absolute value of the complex viscosity ) Is about 1.0 x 10 &lt; ² &gt; Pa to about 6.0 x 10 &lt; ² &gt; Pa.

Fig. 2 shows an embodiment of the image forming apparatus containing the toner manufactured according to the production method of the present invention, and the operation principle will be described below.

The nonmagnetic one-component developer of the developing device 204 is supplied onto the developing roller 205 by a supplying roller 206 constituted by an elastic member such as a polyurethane foam, a sponge or the like. The developer 208 supplied onto the developing roller 205 reaches the contact portion between the developer regulating blade 207 and the developing roller 205 as the developing roller 205 rotates. The developer regulating blade 207 is made of an elastic member such as metal or rubber. The layer of the developer 208 is regulated as a constant layer between the contact portions of the developer regulating blade 207 and the developing roller 205 when the developer is passed therethrough to form a thin layer and sufficiently charge the developer. The thinned developer 208 is conveyed by the developing roller 205 to a developing region where the developer 208 is developed on the electrostatic latent image of the photoconductor 201 as a latent image bearing member. At this time, the prismatic latent image is formed by scanning the photoconductor 201 with light 203.

The developing roller 205 is positioned facing the photoreceptor 201 without facing the photoreceptor 201 at a constant interval. The developing roller 205 rotates counterclockwise and the photoconductor 201 rotates clockwise.

The developer 208 transferred to the developing region of the photoreceptor 201 is transferred to the developing roller 205 by the DC superimposed AC voltage applied to the developing roller 205 and the potential difference between the AC voltage superimposed on the latent image of the photoreceptor 201 charged by the charging means 202 The electrostatic latent image formed on the photoconductor 201 is developed by the electric force generated by the potential difference to form a toner image.

The developer 208 developed on the photoreceptor 201 reaches the position of the transfer means 209 in accordance with the rotational direction of the photoreceptor 201. [ The developer developed on the photoreceptor 201 is transferred to the printing paper while the printing paper 213 passes by the transferring means 209 to which corona discharge or roller type reverse polarity high voltage to the developer 208 is applied, 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 undeveloped residual developer 208 'on the developing roller 205 is recovered by the supplying roller 206 in contact with the developing roller 205, 208 'are recovered by the cleaning blade 210. 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.

The shape of the toner thus prepared was confirmed with an SEM photograph, 50 images were selected from a SEM photograph of the toner, and the image was analyzed using Image J Software 1.33u (National Institutes of Health, USA) The circularity of the toner was calculated.

<Formula>

Circularity = 4π × (area / circumference ² )

The circularity value is a value between 0 and 1, and the closer the circularity value is to 1, the closer to a sphere.

Example 1

&Lt; Synthesis of primary latex >

3-liter beaker was charged with a monomer mixture (970 g of styrene, 129 g of n-butyl acrylate, 36 g of? -Carboxyl ethyl acrylate (Sipomer, Rhodia)) and a crosslinking agent? -Decanediol diacrylate ) And 18.8 g of dodecanethiol (Aldrich) as a chain transfer agent were added and 500 g of an aqueous solution of sodium dodecyl sulfate (Aldrich) (2% relative to water) was added and stirred to prepare a monomer emulsion Respectively. 18 g of initiator and 1160 g of emulsifier sodium dodecyl sulfate aqueous solution (Aldrich, 0.13% relative to water) were added to a 3 L double jacket reactor heated to 75 DEG C. and the monomer emulsion prepared above was added dropwise over 2 hours while gradually adding with stirring. The reaction was carried out at reaction temperature for 8 hours. The size of the prepared latex particles was measured by a light scattering method (Horiba 910) and was 150-200 nm.

&Lt; Production 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 (Sonic and materials, VCX750).

<Agglomeration and Toner Production>

A 1 L reactor was charged with 500 g of deionized water, 150 g of the above primary latex for core, 100 g of a cyan pigment dispersion (HS-10 100%), (0.3 mol) of nitric acid (0.3 mol) as a flocculant and 136.4 g (coagulant solid content 15 g) of 11% solution of PSI-025 as a flocculant was placed in a mixed solution containing 35 g of a wax dispersion P- The mixture was stirred at 11,000 rpm for 6 minutes using a homogenizer to obtain a primary aggregate having a volume average particle diameter of 1.5 to 2.5 占 퐉. The mixed solution was put into a 1 L double jacket reactor and the temperature was raised from room temperature to 0.02 ° C per minute to 50 ° C (T _{g of the} latex was -5 ° C). When the ratio of the volume average particle diameter of the primary aggregate of about 5.5 탆 or less reaches 2% or less of the total volume, 50 g of a secondary latex obtained by polymerizing the polystyrene type polymerizable monomer is added, and a volume average particle diameter of 6.0 탆 , The pH was adjusted to 7 by adding NaOH (1 mol). When the value of the volume average particle diameter for 10 minutes was kept constant, the temperature was raised to 96 DEG C (0.5 DEG C / min). After reaching 96 캜, nitric acid (0.3 mol) was added to adjust the pH to 6.6, and after 3-6 hours of mixing, a potato-shaped secondary agglomerated toner having a volume average particle diameter of 5-6 탆 was obtained. Then filtered through a process of cooling, the agglomerated reaction solution below the T _g of the toner particles were separated 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 parts by weight of SW-100 (Titan Kogyo) were added to 100 parts by weight of the dried toner particles, Tech) at 3,000 rpm for 5 minutes. Thus, a toner having a volume average particle diameter of 5.8 mu m was obtained. The GSDp and GSDv values of the toner were 1.23 and 1.22, respectively. The circularity of the toner was 0.950.

Example 2

Toner was prepared in the same manner as in Example 1 except that 11.35 g of 1-dodecanethiol as a chain transfer agent (CTA) was added. Thus, a toner having a volume average particle diameter of 5.6 탆 was obtained. The GSDp and GSDv values of the toner were 1.23 and 1.21, respectively. The circularity of the toner was 0.950.

Example 3

Toner was prepared in the same manner as in Example 1 except that 22.7 g of 1-dodecanethiol as a chain transfer agent (CTA) was added. Thus, a toner having a volume average particle diameter of 5.9 mu m was obtained. The GSDp and GSDv values of the toner were 1.23 and 1.21, respectively. The circularity of the toner was 0.940.

Example 4

A toner was prepared in the same manner as in Example 1 except that 34.05 g of 1-dodecanethiol as a chain transfer agent (CTA) was added. Thus, a toner having a volume average particle diameter of 6.0 mu m was obtained. The GSDp and GSDv values of the toner were 1.22 and 1.20, respectively. The circularity of the toner was 0.950.

Example 5

Toner was prepared in the same manner as in Example 1, except that 63.6 g of an 11% solution of a flocculant PSI-025 (solid flocculant 7 g) was used. Thus, a toner having a volume average particle diameter of 5.9 mu m was obtained. The GSDp and GSDv values of the toner were 1.24 and 1.21, respectively. The circularity of the toner was 0.960.

Example 6

Toner was prepared in the same manner as in Example 1, except that 90.9 g of an 11% solution of a flocculant PSI-025 (solid flocculant 10 g) was used. Thus, a toner having a volume average particle diameter of 5.8 mu m was obtained. The GSDp and GSDv values of the toner were 1.22 and 1.20, respectively. The circularity of the toner was 0.950.

Example 7

Toner was prepared in the same manner as in Example 1 except that 163.6 g of an 11% solution of a flocculant PSI-025 (solid flocculant of 18 g) was used. Thus, a toner having a volume average particle diameter of 6.0 mu m was obtained. The GSDp and GSDv values of the toner were 1.23 and 1.20, respectively. The circularity of the toner was 0.950.

Comparative Example 1

Toner was prepared in the same manner as in Example 1 except that 56.76 g of 1-dodecanethiol as a chain transfer agent (CTA) was added. Thus, a toner having a volume average particle diameter of 6.0 mu m was obtained.

The GSDp and GSDv values of the toner were 1.25 and 1.20, respectively. The circularity of the toner was 0.940.

Comparative Example 2

Toner was prepared in the same manner as in Example 1 except that 5.676 g of 1-dodecanethiol as a chain transfer agent (CTA) was added. Thus, a toner having a volume average particle diameter of 5.8 mu m was obtained.

The GSDp and GSDv values of the toner were 1.23 and 1.20, respectively. The circularity of the toner was 0. 960.

Comparative Example 3

Toner was prepared in the same manner as in Example 1 except that 9.1 g of an 11% solution of a flocculant PSI-025 (solid flocculant 1 g) was used. Thus, a toner having a volume average particle diameter of 6.2 mu m was obtained.

The GSDp and GSDv values of the toner were 1.26 and 1.20, respectively. The circularity of the toner was 0. 980.

Comparative Example 4

Toner was prepared in the same manner as in Example 1 except that 272.7 g of an 11% solution of a flocculant PSI-025 (solid flocculant 30 g) was used. Thus, a toner having a volume average particle diameter of 6.5 mu m was obtained.

The GSDp and GSDv values of the toner were 1.27 and 1.22, respectively. The circularity of the toner was 0.976.

Evaluation method of toner

<Complex viscosity measurement>

The complex viscosity was measured using a Rheometric Scientific ARES measuring device.

The sample was placed between two circular plates with a diameter of 8 mm and measured in a linear region at a rate of 2 to 3 ° C / min from 40 ° C to 180 ° C. The measurement time was taken at intervals of 30 seconds, and the measurement accuracy was secured by setting the temperature error range to within 1 ° C after starting the measurement.

3 shows the storage / loss elastic modulus and the loss tangent graph of the toner of Example 1 according to the temperature.

4 is a graph showing a complex viscosity according to the temperature of the toner of Example 1 and a graph of a secondary differential of the complex viscosity.

&Lt; Evaluation of fixing property &

 Equipment: Belt-type fixing machine (manufacturer: Samsung Electronics, product name: color laser 660 model fixing machine)

- Unfixed images for test: 100% pattern

- Test temperature: 100 ~ 200 ℃ (10 ℃ interval)

- Fixing speed: 160mm / sec

- Settling time: 0.08 sec

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

After the OD of the fixed image is measured, 3M 810 tape is attached to the image portion, and the tape is removed after five reciprocations using a 500 g weight. The OD after tape removal is measured.

Fixability (%) = (OD_tape peeling / OD_tape peeling) x100

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

MFT: Minimum Fusing Temperature [Minimum temperature at which fixability is 90% or more without cold offset]

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

&Lt; Evaluation of Gloss >

The glossiness is measured at 160 ° C using a gloss meter (manufacturer: BYK Gardner, product name: micro-TRI-gloss), which is a gloss meter.

Measuring angle: 60 ^o

Measurement pattern: 100% pattern

<Evaluation of high temperature packaging stability>

After 100 g of the toner is extruded, it is put into a developing device (manufacturer: Samsung Electronics, product name: color laser 660 model developing device) and stored in a packaged state in a constant temperature and humidity oven as follows.

23 캜, 55% RH (Relative Humidity) 2 hours

=> 40 ° C, 90% RH 48 hours

=> 50 ° C, 80% RH 48 hours

=> 40 ° C, 90% RH 48 hours

=> 23 ° C, 55% RH 6 hours

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

- Evaluation standard

○: Good image, no caking (No-Caking)

△: Bad image, no caking

X: Caking occurs

<Streak Test>

The durability was determined by using a color laser printer (manufacturer: Samsung Electronics, product name: color laser 660 model fixing machine) to determine whether a streak occurred after printing 500 sheets at 0 ppm under the operating conditions of 20PMM. Indicates that the contamination has occurred but the image is not affected, and the case where the contamination has an influence on the image is marked with &quot; X &quot;. The results are shown in Table 2 below.

<Fe content evaluation>

The Fe content in the toner was measured by using a 25 mm press mold to prepare a specimen having a diameter of 25 mm and a thickness of 3 mm or less and using XRF equipment (Shimatsu, EDAX-720).

Rheological characteristics Settlement characteristic durability XRF Complex viscosity
Differential value
(d? / dT) ? (Pa · s)
@ d ² ? / (dT) ²
at least ? (Pa · s)
@ tanδ
Minimal Specialization
Activation
energy
(KJ / mol) Complex
Viscosity
(?)
(Pa · s) @ 140 ° C MFT
(° C) tape
Test
(%) ore
Select
[60 ^o ] High temperature packing stability Streak Fe
content
(ppm) Example 1 -0.042 3.4 × 10 ⁷
@ 55 ℃ 2.9 × 10 ⁴
@ 89 ℃ 184 350 120 94 11.4 ○ ○ 3900 Example 2 -0.035 3.7 × 10 ⁷
@ 59 ℃ 3.8 × 10 ⁴
@ 89 ℃ 171 590 130 95 10.7 ○ ○ 3800 Example 3 -0.038 3.1 × 10 ⁷
@ 51 ℃ 2.7 × 10 ⁴
@ 86 ℃ 188 495 120 98 10.9 ○ ○ 4100 Example 4 -0.034 3.5 × 10 ⁷
@ 57 ℃ 2.9 × 10 ⁴
@ 88 ℃ 179 550 130 93 10.5 ○ ○ 3800 Example 5 -0.033 3.5 × 10 ⁷
@ 56 ℃ 2.8 × 10 ⁴
@ 88 ℃ 180 500 120 94 10.0 ○ ○ 1500 Example 6 -0.035 3.2 × 10 ⁷
@ 53 ℃ 2.9 × 10 ⁴
@ 90 ℃ 186 420 120 94 10.2 ○ ○ 2100 Example 7 -0.051 3.7 × 10 ⁷
@ 55 ℃ 3.5 × 10 ⁴
@ 89 ℃ 195 320 130 95 11.2 ○ ○ 8200 Comparative Example 1 -0.027 2.8 x 10 ⁷
@ 48 ℃ 2.1 x 10 ⁴
@ 82 ℃ 173 290 110 98 10.1 × △ 4100 Comparative Example 2 -0.025 4.5 × 10 ⁷
@ 61 ° C 5.1 x 10 ⁴
@ 88 ℃ 169 1442 140 85 3.5 ○ ○ 3800 Comparative Example 3 -0.018 4.8 × 10 ⁷
@ 71 ° C 5.0 × 10 ⁴
@ 91 ℃ 140 1300 120 82 5.8 × △ 45 Comparative Example 4 -0.065 3.5 × 10 ⁷
@ 50 ℃ 3.4 × 10 ⁴
@ 91 ℃ 230 246 120 95 11.5 △ ○ 12500

In Table 2, 'η (Pa · s ) @d 2 η / (dT) 2 Min "is the second derivative of the complex viscosity as a function of temperature of the toner value ^{(d 2 η / (dT)} 2) is at least the temperature (= G "/ G ', that is, the ratio of the loss elastic modulus G" to the dynamic elastic modulus G') of the toner is expressed by the following equation: Shows the complex viscosity of the toner at a temperature which is a minimum value.

Referring to Table 2, the toner prepared according to Examples 1 to 7 exhibited an absolute value of the differential value (d? / DT) of the complex viscosity of about 0.03 to about 0.06, It has been found that by having an appropriate viscosity in the temperature range of the environment, it exhibits excellent fixability and high gloss image characteristics and at the same time has improved durability.

1 illustrates a cartridge according to an embodiment of the present invention.

FIG. 2 shows an embodiment of an image forming apparatus containing a toner manufactured according to an embodiment of the present invention.

3 shows the storage / loss elastic modulus and the loss tangent graph of the toner of Example 1 according to the temperature.

4 is a graph showing a complex viscosity according to the temperature of the toner of Example 1 and a graph of a secondary differential of the complex viscosity.

&Lt; Brief Description of Drawings &

100: Cartridge 101: Toner tank

103: Supply unit 105: Toner transfer member

110: Toner stirring member 112:

114: wing plate 120, 130: toner stirring film

121, 131: first agitating part 122, 132:

A: Toner feeding direction

201: Photoreceptor 202: Charging means

203: light 204: developing device

205: Developing roller 206: Feed roller

207: developer regulating blade 208: developer

208 ': Residual toner 209: Transferring means

210: cleaning blade 212: power source

213: Printing medium

Claims (21)

An electrophotographic toner comprising a latex, a colorant, and a releasing agent, In a temperature range of 100 ℃ to 160 ℃, and the absolute value of the complex viscosity differential value (dη / dT) of following the temperature change is 0.03 to 0.06, and a complex viscosity (η) at ^{140 ℃ 1.0 × 10 2 Pa ·} s To 6.0 x 10 &lt; ² &gt; Pa. S. The method according to claim 1, At a temperature at which the loss tangent (tan?) Of the toner (= G "/ G ', that is, the ratio of the loss elastic modulus G" and the dynamic elastic modulus G') is a minimum value, the toner has a complex viscosity of 1.0 × 10 ⁴ Pa · s 4.0 x 10 &lt; ⁴ &gt; Pa s, and the activation energy of the toner is 170 KJ / mol or more. 3. The method of claim 2, Wherein a temperature at which the loss tangent (tan delta) of the toner is a minimal value is 80 to 90 占 폚. The method according to claim 1, Wherein a complex viscosity of the toner is not less than 3.0 x 10 ⁷ at a temperature at which a secondary differential value (d ² ? / (DT) ² ) of a complex viscosity according to a temperature change of the toner is minimum. 5. The method of claim 4, Wherein the temperature at which the secondary differential value (d ² ? / (DT) ² ) of the complex viscosity according to the temperature change of the toner is minimum is 50 to 70 占 폚. The method according to claim 1, Wherein the toner contains 50 to 10,000 ppm of Fe. The method according to claim 1, Wherein the mold release agent is a mixture of a paraffin wax and an ester wax; Or an ester group-containing paraffin wax. 8. The method of claim 7, Wherein the ester group content of the releasing agent is 2 to 10% by weight based on the weight of the total releasing agent. The method according to claim 1, Wherein the toner has an average particle size of 3 to 9 占 퐉. The method according to claim 1, Wherein an average value of the circularity of the toner is 0.940 to 0.980. The method according to claim 1, Wherein the toner has a GSDv and a GSDp of 1.25 or less. Mixing the primary latex particles, the pigment dispersion and the release agent dispersion to prepare a mixed solution; Adding a flocculant to the mixed liquid to prepare a primary aggregated toner; And A process for producing an electrophotographic toner comprising a step of coating a secondary latex prepared by polymerizing at least one polymerizable monomer onto the primary aggregated toner to prepare a secondary aggregated toner, Wherein an absolute value of a complex viscosity (d? / DT) of the complex viscosity according to a change in temperature of the electrophotographic toner is 0.03 to 0.06 in a temperature range of 100 占 폚 to 160 占 폚 and a complex viscosity (?) of from 1.0 × 10 ² Pa · s to 6.0 × 10 ² Pa · s. 13. The method of claim 12, Wherein the primary latex particles are polyester alone; A polymer obtained by polymerizing at least one polymerizable monomer; Or a mixture thereof. &Lt; / RTI &gt; 13. The method of claim 12, Further comprising the step of coating a tertiary latex prepared by polymerizing at least one polymerizable monomer onto the secondary aggregation toner. 15. The method according to any one of claims 12 to 14, Wherein the polymerizable monomer is a styrene-based monomer; Acrylic acid, methacrylic acid; (Meth) acrylic acid derivatives; Ethylenically unsaturated monoolefins; Vinyl halide; Vinyl esters; Vinyl ether; Vinyl ketone; And a nitrogen-containing vinyl compound. 13. The method of claim 12, Wherein the release agent dispersion is a mixture of a paraffin wax and an ester wax; Or an ester group-containing paraffin wax. 13. The method of claim 12, Wherein the coagulant is a metal salt containing Si and Fe. 13. The method of claim 12, wherein the coagulant comprises polysilica iron. 11. An image forming method comprising the steps of attaching a 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 a toner according to any one of claims 1 to 11 Wherein the electrophotographic toner is an electrophotographic toner. toner; And a housing for storing the toner, Wherein the toner is the electrophotographic toner according to any one of claims 1 to 11. And conveying means for conveying the print medium, Wherein the electrophotographic toner according to any one of claims 1 to 11 is used to form an image.

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