JP2002108009A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method in which toner produced by a polymerization method is used, the emission of a foul odor in heat fixation is suppressed, no odor trouble is caused and a small diameter, superior fixability and a wide color reproduction range are ensured. SOLUTION: In the image forming method including a step for developing an electrostatic latent image formed on a photoreceptor with a toner-containing developer, a step for transferring a toner image formed on the photoreceptor to an image forming support and a step for fixing the transferred toner image, each of the heating roller and pressing roller of a fixing device has a coating layer of an elastic body, the nip width is 3-10 mm and the toner is obtained by polymerizing a polymerizable composition consisting essentially of a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-pentene in an aqueous medium and subjecting the resulting resin particles to salting-out/fusion in an aqueous medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method using a toner for developing an electrostatic latent image used in a copying machine, a printer and the like.

[0002]

2. Description of the Related Art In recent years, it has been desired to reduce the particle size of toner from the viewpoint of high image quality. In recent years, a polymerization toner has been devised as a method for producing a toner having a small particle diameter. In this polymerization method toner, a method of preparing an irregularly shaped toner by associating or salting out / fusing resin particles and colorant particles as needed, or dispersing a radical polymerizable monomer and a colorant, Next, there is a method in which droplets are dispersed in an aqueous medium or the like so as to have a desired toner particle diameter, and suspension polymerization is performed.

It is necessary to control the molecular weight distribution of the resin for toner from the viewpoint of fixability. For example, in order to suppress high-temperature offset, it is necessary to improve the elastic modulus at high temperature, and it is preferable to increase the high molecular weight component. On the other hand, in order to improve the adhesion to an image forming support such as paper (also referred to as a recording material, recording paper, or the like), it is preferable to increase the low molecular weight component. In order to satisfy such contradictory functions with a resin, it is necessary to expand the molecular weight distribution.

[0004] In particular, in a color toner image which forms a desired color by laminating (color superimposing) toner layers of three primary colors,
From the viewpoint of improving color reproducibility, it is necessary to make the surface (interface) of the toner layer of each color as smooth as possible for color matching. In order to smooth the interface of the toner layer, it is advantageous to use a toner having a low melt viscosity at the time of fixing. Further, as a method of fixing a color toner image, a nip width is formed by forming the surfaces of a heating roller and a pressure roller with an elastic material having a low hardness (low elastic modulus) for the purpose of expanding color reproducibility. Is widened, the molten state of the toner at the time of fixing can be maintained, and a smooth toner layer at the interface can be easily formed. Therefore, a heat roller fixing method is used.

[0005] On the other hand, in the pressure contact heat fixing system such as the above-mentioned heat roller fixing system, a large amount of silicone oil has been applied to the roller surface in order to prevent the occurrence of the offset phenomenon. However, in such a method, the silicone oil permeates the transfer paper (image forming support) to impair the brushability of the transfer paper, or the oil adheres to the leading end of the transfer paper that first contacts the roller. Problem. Further, when a PET sheet such as OHP is used as the image forming support, there is a problem that oil is present on the surface of the PET sheet and stickiness is caused.

In order to prevent this, there has been a tendency to use a fixing device that does not supply silicone oil or that supplies a very small amount of silicone oil. However, when fixing a color toner image with a toner having a low melt viscosity by the above-described heat roller fixing method, there is no adverse effect due to the silicone oil and the anti-offset property (in a fixing device in which the silicone oil is not supplied or the supply amount is extremely low). There is no known means for satisfying the releasability.

When a color-fixed image is formed by the above-described heat roller fixing method, a toner that can satisfy both good fixing properties and color reproducibility of a fixed image is formed by a so-called polymerization method or molecular weight distribution. This can be achieved by controlling.

[0008] As an example, the use of an associative toner obtained by salting out / fusing resin particles containing a release agent in a binder resin together with colorant particles in an aqueous medium is used to reduce the offset phenomenon. In addition, a wide fixing property can be secured, and the adhesion between toners can be improved.

The above-mentioned "salting out / fusion" means that salting out (aggregation of particles) and fusion (loss of interface between particles) occur simultaneously, or an act of causing salting out and fusion simultaneously. Say. In order to simultaneously carry out the salting-out and the fusion, it is necessary to agglomerate the particles (resin particles, colorant particles) under a temperature condition equal to or higher than the glass transition temperature (Tg) of the resin constituting the resin particles.

In the above toner, it is necessary to adjust the molecular weight distribution of the resin for the toner in order to improve the fixability and the color reproducibility. When a chain transfer agent is used to control the molecular weight distribution to reduce the molecular weight, mercaptans, particularly dodecyl mercaptan, are used as a suitable chain transfer agent. However, these materials have a peculiar odor, and the chain transfer agent remaining during heat fixing volatilizes,
There is a problem that odor is generated.

In particular, lamination (color superposition) of three primary color toner layers
When a color toner image constituting a desired color is fixed by the above-described heat roller fixing method, the amount of toner adhered to a color image is generally large (particularly, a picture image is more likely to be a picture image than a text image). In the fixing device, in order to enhance the color reproducibility of a color-fixed image, the surfaces of the heating roller and the pressure roller are formed of an elastic body having a low hardness (low elastic modulus), thereby increasing a nip width therebetween. Therefore, there is a problem that the contact between the toner and the heating member is increased and odor is more likely to be generated.

The problem of this odor has not been particularly regarded as a problem in a so-called pulverized toner obtained by melting, kneading and pulverizing a resin and a colorant.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method which suppresses generation of odor during heat fixing by using a so-called polymerization toner and does not cause an odor problem. .

Another object of the present invention is to provide an image forming method capable of forming a color image having excellent fixability and a wide color reproduction range by using a small particle size toner.

[0015]

Means for Solving the Problems As a result of intensive studies, the present inventors have completed the present invention by elucidating the essential difference between the kneading method and the polymerization method. is there. That is, the so-called pulverized toner is converted into a toner by melt-kneading a resin and a colorant, followed by pulverization and classification. In this step, the resin is heated to a temperature higher than the melting temperature, and at the same time, a large share is applied to a kneading device such as a twin screw extruder. For this reason, the chain transfer agent present in the resin is vaporized by the heat at the time of kneading, so that almost no single substance can be present alone in the final toner.

On the other hand, a so-called polymerization toner does not go through this melt-kneading step, and when prepared by a radical polymerization method, the heating is limited to a maximum of about 100 ° C., which is the boiling point of water. As a result, it was presumed that a trace amount of the chain transfer agent remained and vaporized at the temperature at the time of fixing, causing a problem of odor.

As a result, it has been found that it is essential for the polymerization method toner to use a chain transfer agent having a low odor as the chain transfer agent itself.

That is, the object of the present invention is achieved by adopting one of the following constitutions. [1] The electrostatic latent image formed on the photoreceptor is developed with a developer containing toner, the toner image formed on the photoreceptor is transferred to an image forming support, and the transferred toner image is transferred. In the image forming method including a step of fixing by a fixing device, both the heating roller and the pressure roller of the fixing device have an elastic covering layer, and the nip width is 3 to 10 mm, and the toner is Resin particles prepared by polymerizing a polymerizable composition comprising at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-pentene in an aqueous medium are salted out / fused in an aqueous medium. An image forming method characterized by being obtained by performing

[2] The electrostatic latent image formed on the photoreceptor is developed with a developer containing toner, and the toner image formed on the photoreceptor is transferred to an image forming support. In an image forming method including a step of fixing a toner image by a fixing device, each of a heating roller and a pressure roller of the fixing device has an elastic covering layer and a nip width of 3 mm.
-10 mm, and the toner contains at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-
An image forming method, which is obtained by subjecting a polymerizable composition comprising pentene to suspension polymerization in an aqueous medium.

[3] The electrostatic latent image formed on the photoreceptor is developed with a developer containing toner, and the toner image formed on the photoreceptor is transferred to an image forming support. In an image forming method including a step of fixing a toner image by a fixing device, each of a heating roller and a pressure roller of the fixing device has an elastic covering layer and a nip width of 3 mm.
-10 mm, and the toner contains at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-
Image formation characterized by fusing secondary particles obtained by aggregating resin particles and colorant particles prepared by polymerizing a polymerizable composition comprising pentene in an aqueous medium, and by fusing. Method.

[4] The image forming method according to [1], [2] or [3], wherein the supply amount of the silicone oil to the heating roller constituting the fixing device is 2 mg / A4 or less.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION <Polymerization Method> (Suspension Polymerization and Emulsion Polymerization) The toner of the present invention is obtained by emulsifying a monomer in a suspension polymerization method or a liquid containing an emulsion of necessary additives. It can be produced by a method in which polymerization is performed to produce fine polymer particles, and thereafter, an organic solvent, a coagulant, and the like are added to associate.

That is, the toner is prepared by polymerizing a polymerizable composition comprising at least a radical polymerizable monomer and a 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent in an aqueous medium. A method of preparing the resin particles by salting out / fusion in an aqueous medium can be used. Further, resin particles prepared by polymerizing a polymerizable composition comprising at least a radical polymerizable monomer and the above-mentioned 2,4-diphenyl-4-methyl-1-pentene as a chain transfer agent in an aqueous medium, and a colorant A method of fusing secondary particles obtained by aggregating particles with particles can be used. Further, the toner of the present invention contains at least a radical polymerizable monomer and the above-mentioned 2,4-diphenyl- as a chain transfer agent.
A method of preparing a polymerizable composition comprising 4-methyl-1-pentene by suspension polymerization in an aqueous medium can be used.

The term "fusion" means that a plurality of resin particles and colorant particles associate with each other. The term “aqueous medium” used in the present invention means a medium containing at least 50% by mass of water.

In the suspension polymerization, a coloring agent and, if necessary, various constituent materials such as a release agent, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and a homogenizer, a sand mill, a sand mill, and the like are added. Various constituent materials are dissolved or dispersed in the polymerizable monomer using a grinder, an ultrasonic disperser or the like. The polymerizable monomer in which the various constituent materials are dissolved or dispersed is dispersed in an aqueous medium containing a dispersion stabilizer and a chain transfer agent into oil droplets of a desired size as a toner using a homomixer or a homogenizer. Let it. Thereafter, the stirring mechanism is moved to a reaction device, which is a stirring blade described later, and heated to cause the polymerization reaction to proceed. After completion of the reaction, the toner of the present invention is prepared by removing the dispersion stabilizer, filtering, washing and drying.

(Association / Fusion) As a method for producing the toner of the present invention, a method for preparing by associating or fusing resin particles in an aqueous medium can also be mentioned. Although this method is not particularly limited, for example, JP-A-5-265252 and JP-A-6-329947
And JP-A-9-15904. That is, a method of associating a plurality of resin particles and dispersed particles of a constituent material such as a colorant, or a plurality of fine particles composed of a resin and a colorant, particularly, after dispersing these in water using an emulsifier, the critical aggregation concentration At the same time as adding the above flocculant and salting out, the formed polymer itself is heated and fused at a temperature equal to or higher than the glass transition temperature to gradually form a fused particle, thereby gradually growing the particle size. At this point, a large amount of water was added to stop the growth of the particle size, and the surface was smoothened while heating and stirring to control the shape. The toner of the invention can be formed. Here, an organic solvent that is infinitely soluble in water may be added together with the coagulant.

<Chain transfer agent> In the present invention, for the purpose of adjusting the molecular weight, 2,4-diphenyl-4-
Methyl-1-pentene is used as a chain transfer agent.

The amount of the polymerizable monomer used is 0.01%.
To 5% by mass, more preferably 0.03 to 3% by mass.

<Polymerizable monomer> (Vinyl polymerizable monomer) Styrene, o-methylstyrene, m-methylstyrene, p-methyl Styrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-tert-butylstyrene, pn-hexylstyrene, Styrene or styrene such as pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, methacryl Isopropyl acrylate, isobutyl methacrylate, t-methacrylate
-Butyl, n-octyl methacrylate, methacrylic acid 2
-Ethyl hexyl, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, methacrylate derivatives such as dimethylaminoethyl methacrylate, methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, T-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-acrylate
Acrylic ester derivatives such as ethylhexyl, stearyl acrylate, lauryl acrylate, and phenyl acrylate; olefins such as ethylene, propylene and isobutylene; and halogens such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, and vinylidene fluoride Vinyl esters, vinyl esters such as vinyl propionate, vinyl acetate and vinyl benzoate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl compounds such as vinyl naphthalene and vinyl pyridine; and acrylic compounds such as acrylonitrile, methacrylonitrile and acrylamide. There is Le acid or methacrylic acid derivatives. These vinyl monomers can be used alone or in combination.

(Monomer Having Ionic Dissociating Group) It is preferable to use a polymerizable monomer constituting the resin in combination with one having an ionic dissociating group. For example,
Carboxyl group, sulfonic acid group, those having a substituent such as a phosphate group as a constituent group of the monomer, specifically, acrylic acid, methacrylic acid, maleic acid, itaconic acid, cinnamic acid, fumaric acid, Monoalkyl maleate, monoalkyl itaconic, styrenesulfonic acid, allylsulfosuccinic acid, 2-acrylamido-2-methylpropanesulfonic acid, acid phosphooxyethyl methacrylate, 3-chloro-2-acid phosphooxypropyl methacrylate And the like.

(Polyfunctional vinyl monomer) Further, divinylbenzene, ethylene glycol dimethacrylate,
A cross-linked structure using polyfunctional vinyls such as ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, and neopentyl glycol diacrylate. It can also be a resin.

<Radical polymerization initiator> These polymerizable monomers can be polymerized using a radical polymerization initiator.

In this case, an oil-soluble polymerization initiator can be used in the suspension polymerization method. Examples of the oil-soluble polymerization initiator include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile,
1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-
Azo or diazo polymerization initiators such as dimethylvaleronitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t
-Butyl peroxide, dicumyl peroxide,
2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis- (4,4-t-butylperoxycyclohexyl) propane, tris- (t
Peroxide-based polymerization initiators such as (-butylperoxy) triazine and polymer initiators having a peroxide in a side chain can be exemplified.

When the emulsion polymerization method is used, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisaminodipropane acetate, azobiscyanovaleric acid and salts thereof, and hydrogen peroxide.

<Dispersion Stabilizers> Examples of dispersion stabilizers include tricalcium phosphate, magnesium phosphate, zinc phosphate, aluminum phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, and metasilicate. Calcium acid, calcium sulfate,
Examples thereof include barium sulfate, bentonite, silica, and alumina. Further, a surfactant generally used as a surfactant such as polyvinyl alcohol, gelatin, methyl cellulose, sodium dodecylbenzenesulfonate, ethylene oxide adduct, and higher alcohol sodium sulfate can be used as a dispersion stabilizer.

<Flocculant> The flocculant used is not particularly limited, but those selected from metal salts are preferably used. Specifically, as a monovalent metal, for example, a salt of an alkali metal such as sodium, potassium, and lithium, and as a divalent metal, for example, a salt of an alkaline earth metal such as calcium and magnesium, or a divalent metal such as manganese or copper And salts of trivalent metals such as iron and aluminum. Specific examples of the salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. Can be mentioned. These may be used in combination.

It is preferable that these coagulants are added at a concentration higher than the critical coagulation concentration. The critical aggregation concentration is an index relating to the stability of the aqueous dispersion, and indicates the concentration at which aggregation occurs when a coagulant is added. This critical aggregation concentration is
It varies greatly depending on the emulsified component and the dispersant itself. For example, Seizo Okamura et al.
7, 601 (1960), edited by The Society of Polymer Science, Japan, and the like, and a detailed critical aggregation concentration can be determined.
As another method, a desired salt is added to the target particle dispersion at a different concentration, the 、 (zeta) potential of the dispersion is measured, and the salt concentration at which this value changes is defined as the critical aggregation concentration. You can also ask.

The addition amount of the coagulant of the present invention may be not less than the critical coagulation concentration, but is preferably 1.2 to the critical coagulation concentration.
It is better to add it at least twice, more preferably at least 1.5 times.

<Solvent which dissolves infinitely> The solvent which dissolves infinitely means a solvent which dissolves infinitely in water. The solvent which does not dissolve the formed resin in the present invention is selected. Specific examples include alcohols such as methanol, ethanol, propanol, isopropanol, t-butanol, methoxyethanol and butoxyethanol, nitriles such as acetonitrile, and ethers such as dioxane. Particularly, ethanol, propanol and isopropanol are preferred.

The amount of the solvent to be dissolved infinitely is 1 to 100% by volume based on the polymer-containing dispersion to which the flocculant is added.
Is preferred.

<Colorant, fixability improving agent (release agent, charge control agent, etc.), external additive (inorganic fine particles, organic fine particles, etc.)> The toner of the present invention contains at least a resin and a colorant. However, if necessary, a releasing agent or a charge control agent, which is a fixing property improving agent, may be contained. Further, it is preferable to add an external additive composed of inorganic fine particles and organic fine particles to the colored particles mainly composed of the resin and the colorant, and use the resultant as a toner.

(Colorant) As the colorant used in the toner of the present invention, carbon black, a magnetic substance, a dye, a pigment and the like can be arbitrarily used. As the carbon black, channel black, furnace black, acetylene black, and the like can be used. Thermal black, lamp black and the like are used. As the magnetic material, ferromagnetic metals such as iron, nickel, and cobalt, alloys containing these metals, compounds of ferromagnetic metals such as ferrite and magnetite, alloys that do not contain ferromagnetic metals but show ferromagnetism by heat treatment, For example, an alloy of a type called a Heusler alloy such as manganese-copper-aluminum, manganese-copper-tin, chromium dioxide, or the like can be used.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 1
22, C.I. I. Solvent Yellow 19, 44, 7
7, 79, 81, 82, 93, 98, 10
3, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 9
5 and the like, and mixtures thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5,
48: 1, 53: 1, 57: 1, 122, 1
39, 144, 149, 166, 177, 1
78, 222, C.I. I. Pigment Orange 31, 43 and C.I. I. Pigment Yellow 14, 17, and 9
3, 94, 138, 156, 158, 18
0, 185, C.I. I. Pigment Green 7, C.I.
I. Pigment Blue 15: 3, 60 and the like, and mixtures thereof can also be used. Although the number average primary particle diameter varies depending on the type, it is generally 10 to 200 n.
m is preferable.

As a method of adding a coloring agent, a method of adding polymer particles prepared by an emulsion polymerization method at the stage of aggregating by adding an aggregating agent to color the polymer, or a stage of polymerizing a monomer. And a method of adding a colorant, polymerizing, and forming colored particles can be used. When the colorant is added at the stage of preparing the polymer, it is preferable to use the colorant after treating the surface with a coupling agent or the like so as not to inhibit the radical polymerizability.

(Fixability improver (release agent, charge control agent, etc.)) Further, low molecular weight polypropylene (number average molecular weight: 1,500 to 9,000), low molecular weight polyethylene and the like as a fixability improver are added. You may.

Further, in the present invention, it is possible to preferably use a method of adding an electol-based release agent represented by the following structure as a main component and adding the same at the time of monomer polymerization.

[0047] _{R 1 - (OCO-R 2} ) n n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, particularly preferably 4.

R ₁ and R ₂ each represent a hydrocarbon group which may have a substituent. R ₁ has 1 to 40 carbon atoms, preferably 1 to 2 carbon atoms.
0, more preferably 2 to 5. R ₂ has 1 to 1 carbon atoms
40, preferably 16 to 30, more preferably 18 to
26.

Specific examples include the following compounds.

[0050]

Embedded image

[0051]

Embedded image

The amount of addition is 1 to 1 with respect to the whole toner.
It is 30% by mass, preferably 2 to 20% by mass, more preferably 3 to 15% by mass.

The charge control agents are also various known ones.
What can be dispersed in water can also be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Quaternary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

The particles of the charge control agent and the fixability improving agent have a number average primary particle diameter of 10 to 50 in a dispersed state.
Preferably, the thickness is about 0 nm.

<Apparatus configuration such as toner shape control and stirring tank> (Apparatus configuration such as controlling the shape of suspension polymerization toner and stirring tank)
In a suspension polymerization method toner in which a toner component such as a colorant is dispersed or dissolved in a so-called polymerizable monomer is suspended in an aqueous medium and then polymerized to obtain a toner.
The shape of the toner particles may be controlled by controlling the flow of the medium in the reaction vessel in which the polymerization reaction is performed.

That is, when spherical toner is required, no particular control is required. However, in order to make the toner irregular, the flow of the medium in the reaction vessel is made turbulent, and the polymerization proceeds to suspend. When the oil droplets existing in the aqueous medium in a turbid state gradually become polymerized, the oil droplets become soft particles. It can be shaped particles.

(Shape Control of Assembled and Fused Polymerized Toner, Device Configuration such as Stirring Tank) On the other hand, in the case of a polymerized toner in which resin particles are associated or fused in an aqueous medium, the inside of the reaction vessel in the fusion stage is Arbitrarily changes the shape distribution and shape of the entire toner by controlling the flow and temperature distribution of the medium, and by controlling the heating temperature, stirring rotation speed, and time in the shape control step after fusing. Can be.

That is, in the case of the polymerization toner in which the resin particles are associated or fused, the flow in the reactor is made laminar, and the stirring blade and the stirring tank which can make the internal temperature distribution uniform are used. Temperature in the deposition process and the shape control process,
By controlling the number of rotations and time, it is possible to form a toner having the shape factor and uniform shape distribution of the present invention. The reason for this is that when fusion is performed in a place where a laminar flow is formed, strong stress is not applied to the particles that are undergoing aggregation and fusion (association or aggregated particles) and the flow is accelerated in a laminar flow. It is estimated that the shape distribution of the fused particles becomes uniform as a result of the uniform temperature distribution in the stirring tank.
Further, the fused particles gradually become spherical by heating and stirring in the subsequent shape control step, and the shape of the toner particles can be arbitrarily controlled.

<Binder Resin> The binder resin constituting the toner of the present invention has a molecular weight distribution of 100,00 as measured by gel permeation chromatography (GPC).
It is preferable that the resin contains a high molecular weight component having a peak or shoulder in the range of 0 to 1,000,000 and a low molecular weight component having a peak or shoulder in the range of 1,000 to 20,000.

Further, these resins have a number average molecular weight (Mn) of 1,000 to 100, as measured by gel permeation chromatography (GPC).
2,000, 2,000 to 1,0 in weight average molecular weight (Mw)
A thing of 00,000 is preferred. Further, as a molecular weight distribution, Mw / Mn is 1.5 to 100, particularly 1.8 to 70.
Are preferred.

In the method for measuring the molecular weight of a resin by GPC in the present invention, the measurement is performed using tetrahydrofuran (THF) as a solvent. That is, 1 ml of THF is added to 0.5 to 5 mg, more specifically, 1 mg of the measurement sample, and the mixture is stirred at room temperature using a magnetic stirrer or the like to be sufficiently dissolved. Then, pore size 0.45
After treatment with a 0.50 μm membrane filter,
Inject into GPC. GPC measurement conditions were as follows: stabilize the column at 40 ° C., flow THF at a flow rate of 1 ml per minute,
Approximately 100 μl of a sample at a concentration of 1 mg / ml is injected and measured.

The column is preferably used in combination with a commercially available polystyrene gel column. For example, Shodex GPC KF-801, 8 manufactured by Showa Denko KK
02, 803, 804, 805, 806, 807 and TSKgel G1000H, G20 manufactured by Tosoh Corporation.
00H, G3000H, G4000H, G5000H,
G6000H, G7000H, TSK guard c
and a combination of the same. Also,
As the detector, a refractive index detector (IR detector) or a UV detector may be used. In measuring the molecular weight of a sample,
The molecular weight distribution of the sample is calculated using a calibration curve created using monodisperse polystyrene standard particles. It is preferable to use about 10 polystyrenes for preparing a calibration curve.

The resin excellent in the present invention preferably has a glass transition point of 20 to 90 ° C. and a softening point of 8 ° C.
The thing of 0-220 ° C is preferred. The glass transition point is measured by a differential calorimetric analysis method, and the softening point can be measured by a capillary rheometer “Flow Tester CFT-500C” (manufactured by Shimadzu Corporation).

<Shape of Toner> The preferable shape of the toner in the present invention is such that the average value (average circularity) of the shape factor represented by the following equation is 0.930 to 0.990, preferably 0.940 to 0.940. 0.980, more preferably 0.940
0.975.

Shape factor = (circumferential length of circle obtained from equivalent circle diameter) / (perimeter of particle projected image) The distribution of shape factor is preferably sharp, and the standard deviation of circularity is 0.10. The CV value calculated by the following formula is preferably less than 20%, and more preferably 10% or less.
% Is preferred.

CV value = {(standard deviation of circularity) / (average circularity)} × 100 By setting the average circularity to 0.930 to 0.990, the shape of the toner is made somewhat irregular. The heat transfer can be made more efficient, and the fixability can be further improved. That is, an average circularity of 0.9
By setting the ratio to 90 or less, the fixing property can be improved.
Further, by setting the average circularity to 0.930 or more, the degree of irregularity of the particles can be suppressed, and the friability of the particles due to stress during long-term use can be suppressed.

Further, it is preferable that the distribution of the shape factor is sharp, and the standard deviation of the circularity is 0.10 or less, so that a toner having a uniform shape can be obtained. Since it can be reduced, the effect of preventing the fixing device from being contaminated by improving the fixing rate and reducing the offset property is further exhibited. When the CV value is also less than 20%, a sharp shape distribution can be similarly obtained, and the effect of improving the fixing property can be more remarkably exhibited.

The method for measuring the shape factor is not limited.
The average circularity can be calculated by taking a photograph enlarged to 00 times, measuring the circularity of 500 toners using an image analyzer, and calculating the arithmetic average value. In addition, as a simple measurement method, FPIA-1
000 (manufactured by Toa Medical Electronics Co., Ltd.).

In order to control the shape, it is possible to determine an appropriate process end time while monitoring the characteristics of the colored particles whose shape is being controlled in a process such as association.

It should be noted that there is no substantial difference in the above-described characteristics between the measurement of colored particles and the measurement of toner particles to which an external additive or the like is further added.

Monitoring means that a measuring device is incorporated in-line and the process conditions are controlled based on the measurement result. That is, for example, in the case of a polymerization toner formed by incorporating measurement of shape and the like in-line and associating or fusing resin particles in an aqueous medium, the shape and particle size are sequentially sampled in steps such as fusing. Is measured, and the reaction is stopped when the desired shape is obtained.

The monitoring method is not particularly limited, but a flow type particle image analyzer FPIA-
2000 (manufactured by Toa Medical Electronics Co., Ltd.) can be used. This apparatus is suitable because the shape can be monitored by performing image processing in real time while passing the sample liquid. That is, a pump or the like is used from the reaction field to constantly monitor and measure the shape and the like, and stop the reaction when the desired shape and the like are obtained.

<Particle Size of Toner> The volume average particle size of the toner of the present invention is measured by Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter). In the present invention, a Coulter Multisizer was used by connecting an interface (manufactured by Nikkaki Co., Ltd.) for outputting a particle size distribution and a personal computer. The aperture used in the Coulter Multisizer is 100 μm and the aperture is 2 μm.
The particle size distribution and the average particle size were calculated by measuring the volume distribution of the toner described above.

The particle diameter of the toner of the present invention is preferably 3 to 8 μm in terms of volume average particle diameter. When toner particles are formed by a polymerization method, the particle diameter can be controlled by the concentration of the coagulant, the amount of the organic solvent added, the fusing time, and the composition of the polymer itself.

When the volume average particle diameter is 3 to 8 μm, in the fixing step, toner particles having a large adhesive force which fly and adhere to the heating member to cause offset are reduced, and the transfer efficiency is increased. The halftone image quality is improved, and the image quality of fine lines and dots is improved.

[Measurement conditions] (1) Aperture: 100 μm (2) Sample preparation method: Electrolyte [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml, and the mixture is stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to a dispersion treatment with an ultrasonic disperser for 1 minute.

<External Additive of Toner> Further, a so-called external additive can be added to the toner of the present invention for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles, and lubricants can be used.

Conventionally known inorganic fine particles can be used. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic.

Specifically, as silica fine particles, for example, commercially available products R-805 and R-976 manufactured by Nippon Aerosil Co., Ltd.
R-974, R-972, R-812, R-809, HVK-2150, H-200 manufactured by Hoechst, TS-720, TS-530, TS-6 manufactured by Cabot Corporation
10, H-5, MS-5 and the like.

Examples of the titanium fine particles include commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercially available products MT-100S, MT-100B and MT-5 manufactured by Teika.
00BS, MT-600, MT-600SS, JA-
1. Commercial products TA-300SI, TA-
500, TAF-130, TAF-510, TAF-5
10T, commercial products IT-S, IT-OA manufactured by Idemitsu Kosan Co., Ltd.
IT-OB, IT-OC, TTO manufactured by Ishihara Sangyo Co., Ltd.
-55 and the like.

Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd.

Further, these inorganic fine particles are preferably subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent or the like. The degree of the hydrophobizing treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is to evaluate the wettability to methanol. This method is 200ml
0.2 g of the inorganic fine particles to be measured is weighed and added to 50 ml of distilled water placed in a beaker. Methanol is slowly dropped from a burette whose tip is immersed in the liquid until the whole of the inorganic fine particles is wet with stirring slowly. When the amount of methanol required to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following equation.

Degree of hydrophobicity = {a / (a + 50)} × 100 The organic fine particles have a number average primary particle diameter of 10 to 20.
Spherical organic fine particles of about 00 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

Examples of the lubricant include salts of zinc, aluminum, copper, magnesium, calcium and the like of stearic acid, salts of zinc, manganese, iron, copper and magnesium of oleic acid, and zinc, copper, magnesium and calcium of palmitic acid. Metal salts of higher fatty acids such as salts of linoleic acid such as zinc and calcium, and salts of ricinoleic acid such as zinc and calcium.

The addition amount of these external additives is from 0.1 to 5% by mass, and preferably from 0.5 to 4.0% by mass, based on the toner. As a method for adding the external additive, various known mixing devices such as a Turbula mixer, a Hensiel mixer, a Nauta mixer, and a V-type mixer can be used.

Further, various kinds of external additives may be used in combination. <Developer> When the toner of the present invention contains a magnetic material and is used as a one-component magnetic toner, when used as a two-component developer by mixing with a so-called carrier, or when a non-magnetic toner is used alone Any of them can be suitably used, but in the present invention, it is preferable to use as a two-component developer used by mixing with a carrier.

As the carrier constituting the two-component developer, conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead are used as the magnetic particles. be able to.
Particularly, ferrite particles are preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle diameter of the carrier can be typically measured by a laser diffraction type particle size distribution analyzer “HELOS” (manufactured by SYMPATEC) equipped with a wet disperser.

The carrier is preferably a carrier further coated with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, for example, an olefin resin, a styrene resin, a styrene / acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for constituting the resin-dispersed carrier is not particularly limited, and a known resin can be used.
Acrylic resin, polyester resin, fluorine resin, phenol resin, and the like can be used.

<Fixing Apparatus> An image forming apparatus applied to the fixing apparatus and the image forming method of the present invention will be described below. The toner of the present invention is used in an image forming method (an image forming method of the present invention) including a fixing step using a specific fixing device.

FIG. 1 is a sectional view showing an example of a fixing device used in the present invention. The fixing device shown in FIG. 1 includes a heating roller 10 and a pressure roller 20 that comes into contact with the heating roller 10. In FIG. 1, T is a toner image formed on a transfer paper (image forming support).

The heating roller 10 has a coating layer 12 made of an elastic material formed on the surface of a metal core 11 and contains a heating member 13 made of a linear heater.

The core metal 11 is made of metal and has an inner diameter of 10 to 70 mm. The metal constituting the metal core 11 is not particularly limited, but examples thereof include metals such as iron, aluminum and copper or alloys thereof.

The core metal 11 has a thickness of 0.1 to 2 mm.
It is determined in consideration of the balance between the demand for energy saving (thinning) and the strength (depending on the constituent materials). For example, 0.
In order to maintain the same strength as the iron core of 57 mm with the aluminum core, the wall thickness must be 0.8 mm.
mm.

The elastic body constituting the coating layer 12 is L
It is preferable to use silicone rubber and silicone sponge rubber having good heat resistance such as TV, RTV, and HTV.

Elastic Asker C constituting the coating layer 12
The hardness is less than 70 °, preferably less than 60 °.

The thickness of the coating layer 12 is 0.1 to 30 m.
m, and preferably 0.1 to 20 mm.

Elastic Asker C constituting the coating layer 12
If the hardness exceeds 70 ° and the thickness of the coating layer 12 is less than 0.1 mm, the fixing nip cannot be increased, and the effect of soft fixing (the toner layer at the smoothed interface) Color reproducibility).

As the heating member 13, a halogen heater can be suitably used. The pressure roller 20
A coating layer 22 made of an elastic body is formed on the surface of the core metal 21. The elastic body constituting the coating layer 22 is not particularly limited, and examples thereof include various soft rubbers such as urethane rubber and silicone rubber and sponge rubber, and the silicone rubber exemplified as the material constituting the coating layer 12 and the like. It is preferable to use silicone sponge rubber.

Elastic Asker C constituting the coating layer 22
The hardness is less than 70 °, preferably less than 60 °.

The thickness of the coating layer 22 is 0.1 to 30 m.
m, and preferably 0.1 to 20 mm.

Elastic Asker C constituting the coating layer 22
When the hardness exceeds 70 ° and when the thickness of the coating layer 22 is less than 0.1 mm, the nip for fixing cannot be increased, and the effect of soft fixing cannot be exhibited.

The material constituting the metal core 21 is not particularly limited, but examples thereof include metals such as aluminum, iron and copper or alloys thereof.

The contact load (total load) between the heating roller 10 and the pressure roller 20 is usually 40 to 350 N, preferably 50 to 300 N, and more preferably 50 to 300 N.
２５０250N. This contact load is applied to the heating roller 1
It is defined in consideration of the strength of 0 (the thickness of the core 11). For example, in a heating roller having a core of 0.3 mm made of iron, the heating roller is preferably set to 250 N or less.

Further, from the viewpoints of offset resistance and fixing property, the nip width needs to be 3 to 10 mm, preferably 3 to 8 mm. The nip width in the present invention refers to the length of the contact between the heating roller and the pressure roller that are actually in close contact.

The surface pressure of the nip is 0.6 × 10 ⁵ -1.
It is preferably 5 × 10 ⁵ Pa.

An example of the fixing condition by the fixing device shown in FIG. 1 is as follows. Fixing temperature (surface temperature of heating roller 10)
Is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 m.
m / sec.

The fixing device used in the present invention may be provided with a cleaning mechanism as required. In this case, as a method of supplying the silicone oil to the upper roller (heating roller) of the fixing unit, a method of supplying and cleaning with a pad, a roller, a web, or the like impregnated with the silicone oil can be used.

As the silicone oil, those having high heat resistance are used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone and the like are used. Since those having a low viscosity have a large outflow during use, those having a viscosity at 20 ° C. of 1 to 100 Pa · s are preferably used.

However, the effect of the present invention is particularly remarkably exhibited when a color fixing image is formed by using a fixing device that does not supply silicone oil or that supplies a very small amount of silicone oil. Therefore,
Even when the silicone oil is supplied, the supply amount is preferably 2 mg / A4 or less.
It is preferable to be 5 mg / A4 or less.

The supply amount of silicone oil was 2 mg / A4
By the following, the amount of silicone oil adhering to the transfer paper (image forming support) after fixing is reduced,
There is no difficulty in writing an oil-based pen such as a ball-point pen with the silicone oil attached to the transfer paper, and the writing performance is not impaired.

Here, the supply amount of the silicone oil is transferred to the fixing device (between the rollers) heated to a predetermined temperature by the transfer paper (A).
100 sheets of 4 size white paper) are continuously passed, and the mass change (Δw) of the fixing device before and after the paper passing is measured and calculated (Δw / 100).

<Image Forming Method and Image Forming Apparatus> In the present invention, as an example of the image forming method, an image forming apparatus using an electrophotographic method shown in FIG. 2 can be used.

In FIG. 2, reference numeral 31 denotes an image forming body composed of a negatively chargeable OPC photosensitive member having a charge transport layer as an upper layer, and rotates in the direction of the arrow. Reference numeral 32 denotes an image input unit. The image input unit 32 includes an illumination light source 33, a color separation filter 34 composed of, for example, blue, green, red, and ND filters that can be exchanged, a reflection mirror 35, and a lens 36. And a one-dimensional CCD image sensor 37. 38, an image processing unit including an inverter for converting color separation information into complementary color information; 39, a multicolor original;
L is a laser beam output from the laser optical system 40, and 41 is a negative charging charger including a scorotron band electrode. 42 is a corona discharger for transfer, 43 is a separation electrode,
Reference numeral 44 denotes a fixing device (a fixing device having a configuration as shown in FIG. 1), reference numeral 45 denotes a pre-cleaning static eliminator, and reference numeral 46 denotes a cleaning device. A, B, C, and D are developing devices that store yellow, magenta, cyan, and black developers, respectively.

The reflected light input from the image input section 32 is color-separated by a color separation filter 34, color separation information is read by a CCD image sensor 37, and converted into an electric signal. This electric signal is converted into data suitable for recording by the image processing unit 38. In the first rotation of the image forming body 31 based on the image data thus obtained,
Among the image data, a laser beam L according to, for example, recording data of a yellow component is irradiated by a laser optical system 40 onto an image forming body 31 whose surface is uniformly negatively charged by a negative charging charger 41. On the image forming body 31, an electrostatic latent image corresponding to the recording data is formed.

This electrostatic latent image is developed by a developing unit A containing yellow toner. Similarly, magenta, cyan, and black toner images are superimposed to form a color toner image composed of four basic colors. The color toner image thus obtained was collectively transferred onto the image forming support P by the transfer corona discharge electrode 42, and then the image forming support was separated from the image forming body 31 by the separation electrode 43. Thereafter, a fixing process is performed by the fixing device 44 to form a color image.

On the other hand, after the transfer of the color toner image, the image forming body 31 is neutralized by the pre-cleaning static eliminator 45 and then cleaned by the cleaning device 46 to be used for forming the next color image.

[0117]

Next, embodiments of the present invention will be described specifically, but of course the present invention is not limited to these embodiments.

<Latex Preparation Example> (Latex Preparation Example 1) An anionic activator (sodium n-dodecyl sulfate: SDS) 7 was previously placed in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introducing device. 0.08 g of ion-exchanged water 2760 g
Is added. 230rpm under nitrogen stream
The internal temperature was raised to 80 ° C. while stirring at a stirring speed of.
On the other hand, 72.0 g of Exemplified Compound (19) was
In addition to a monomer consisting of 5.1 g, n-butyl acrylate 42.0 g, and methacrylic acid 10.9 g, the mixture was heated to 80 ° C. and dissolved to prepare a monomer solution.

Here, the above-mentioned heated solution was mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle diameter. Next, 0.84 g of a polymerization initiator (potassium persulfate: KPS) was added to 200 parts of ion-exchanged water.
g), and the mixture was heated and stirred at 80 ° C. for 3 hours to produce latex particles.

Subsequently, a polymerization initiator (KPS) 7.
A solution in which 73 g was dissolved in 240 g of ion-exchanged water was added, and 15 minutes later, at 80 ° C., 383.6 g of styrene, 140.0 g of n-butyl acrylate, and 36.4 g of methacrylic acid.
g, 2,4-diphenyl-4-methyl-1-pentene 1
6.2 g of the mixture was added dropwise over 126 minutes. After completion of the dropwise addition, the mixture was heated and stirred for 60 minutes and then cooled to 40 ° C. to obtain latex particles. This latex particle is referred to as “latex 1”.

(Latex Preparation Example 2) Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 120.0 g of (18) was used instead of Exemplified Compound (19). This is designated as "latex 2".

(Latex Preparation Example 3) Latex particles were obtained in the same manner as in Latex Preparation Example 1, except that 22.6 g was used in place of 16.2 g of 2,4-diphenyl-4-methyl-1-pentene. . This is designated as "latex 3".

(Latex Preparation Example 4) In latex preparation example 1, t-dodecylmercaptan was used in place of 2,4-diphenyl-4-methyl-1-pentene for 15.0.
Latex particles were obtained in the same manner except that g was used. This is designated as "latex 4".

<Example of Toner Preparation> (Production Example of Colored Particle 1Bk) 9.2 g of sodium n-dodecyl sulfate is dissolved under stirring in 160 g of ion-exchanged water.
To this solution, 20 g of Mogar L (carbon black manufactured by Cabot Corporation) was gradually added under stirring, and then dispersed using CLEARMIX. The particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, it was 112 nm in weight average diameter. This dispersion is referred to as “colorant dispersion 1Bk”.

1250 g of the above-mentioned "Latex 1", 2,000 g of ion-exchanged water and "1Bk of colorant dispersion" were stirred in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. I do. After adjusting to 30 ° C., a 5 mol / L aqueous sodium hydroxide solution was added to the solution to adjust the pH to 10.0. Then
52.6 g of magnesium chloride hexahydrate was added to deionized water 7
The aqueous solution dissolved in 2 g was added at 30 ° C. for 10 minutes with stirring. Thereafter, after standing for 3 minutes, heating is started and the temperature is raised to 90 ° C. in 6 minutes (heating rate 10 ° C.).
/ Min). In this state, the particle size is measured using a Coulter Counter TA-
When measured by II, when the volume average particle diameter became 6.5 μm, an aqueous solution in which 115 g of sodium chloride was dissolved in 700 g of ion-exchanged water was added to stop the particle growth, and the liquid temperature was further continued at 90 ° C. ± 2. The mixture was heated and stirred at 6 ° C. for 6 hours to cause salting out / fusion. Thereafter, the mixture was cooled to 30 ° C. at 6 ° C./min, hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The generated colored particles were filtered, washed repeatedly with ion-exchanged water, and then dried with warm air at 40 ° C. to obtain colored particles. The colored particles obtained as described above are referred to as “colored particles 1Bk”.

(Production Example of Colored Particle 1Y) Instead of carbon black, C.I. I. Colored particles were obtained in the same manner except that Solvent Yellow 162 was used. This is referred to as “colored particle 1Y”.

(Production Example of Colored Particle 1M) Instead of carbon black, C.I. I. Pigment Red 122 was used, and colored particles were obtained in the same manner. This is referred to as “colored particles 1
M ”.

(Production Example of Colored Particle 1C) Instead of carbon black, C.I. I. Pigment Blue 15: 3 was used, and colored particles were obtained in the same manner. This is referred to as “colored particle 1C”.

("Colored particles 2Bk / 2Y / 2M / 2C"
Production Example of “Colored Particles 4Bk / 4Y / 4M / 4C”) Similarly, except that the other “latex 2” to “latex 4” were used and carbon black and colorant shown in Table 1 were used. "Colored particles 2Bk / 2Y / 2
M / 2C "to" colored particles 4Bk / 4Y / 4M / 4C ".

Table 1 below shows the component combinations of the colored particles.

[0131]

[Table 1]

In the following description, “colored particles 1
The “group” refers to “colored particles 1Bk / 1Y / 1M / 1C” manufactured using “latex 1”. The other colored particles manufactured using “latex 2” to “latex 4” are referred to as “colored particles 2” to “colored particles 4”.

(Example of producing colored particles 5Bk): Example of suspension polymerization method In a four-necked flask equipped with a high-speed stirrer (TK homomixer), 710 parts by mass of ion-exchanged water and 0.1 mol / l of phosphoric acid Add 450 parts by mass of aqueous sodium solution and add
C. and gradually added 68 parts by mass of a 1.0 mol / l aqueous solution of calcium chloride under stirring conditions at a rotation speed of 12,000 rpm to prepare an aqueous dispersion medium comprising a dispersion containing colloidal tricalcium phosphate. did. Then, 165 parts by mass of a styrene monomer and 35 parts of n-butyl acrylate were used.
30 parts by mass of Exemplified Compound (19) was added to 14 parts by mass of carbon black (Mogal L), and 30 parts by mass of the dispersion liquid dispersed by a sand grinder was dissolved at 80 ° C. Then, 2,4-diphenyl-4-methyl-1-pentene 2
The addition of 10 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator and 1 part by weight of a polymerization initiator was carried out in the aqueous dispersion medium at a rotation speed of 12,000 rpm.
m, and the solution containing the monomer was dispersed in water.

Next, a polymerization reaction was carried out for 10 hours under a nitrogen stream at 65 ° C. and 200 rpm under a stirring condition using a two-stage reactor having a stirring blade having a slit in the center.

At the end of the polymerization reaction, hydrochloric acid was added to remove tricalcium phosphate as a dispersion stabilizer, followed by filtration, washing and drying.
Colored particles were prepared. This is referred to as “colored particles 5Bk”. In addition, by monitoring during the polymerization, controlling the liquid temperature, the number of rotations of the stirring, and the heating time, the variation coefficient of the shape and the shape coefficient is controlled, and further, the classification coefficient in the liquid, the variation coefficient of the particle size and the particle size distribution Was arbitrarily adjusted.

(Production example of colored particles 6Bk): Example of suspension polymerization method In the production example of colored particles 5Bk, 2 parts by mass of t-dodecylmercaptan was used instead of 2,4-diphenyl-4-methyl-1-pentene. Other than the above, colored particles were obtained in the same manner. This is referred to as “colored particles 6Bk”.

"Colored particles 1Bk / 1Y / 1M / 1C"
Table 2 shows the average circularity, the standard deviation of the circularity, the circularity CV value, and the volume average particle diameter of “colored particles 4Bk / 4Y / 4M / 4C”, “colored particles 5Bk”, and “colored particles 6Bk”.

[0138]

[Table 2]

* The circularity was measured using FPIA-1000, the sample analysis volume was 0.3 μl, and the number of detected particles was 1,50.
It was measured under the condition of 0 to 5,000 pieces.

The peak molecular weight of the high molecular weight component, the peak molecular weight of the low molecular weight component, the number average molecular weight, and the weight average molecular weight of the “colored particle 1 group” to “colored particle 4 group” and the “colored particles 5Bk” and “colored particles 6Bk” are shown. 3 is shown.

[0141]

[Table 3]

* Note that “colored particle 4 group” in “colored particle 4 group”
“Bk / 4Y / 4M / 4C” and “colored particles 6Bk” are comparative examples.

<Preparation of Toner> Next, the above-mentioned “colored particles 1
Bk / 1Y / 1M / 1C ”to“ colored particles 4Bk / 4Y /
4M / 4C "," colored particles 5Bk "," colored particles 6B "
k ”is a hydrophobic silica (number average primary particle size 12n
m, hydrophobicity 68) of 1% by mass and hydrophobic titanium oxide (number average primary particle diameter 20 nm, hydrophobicity 63) of 1.2.
% By mass and mixed with a Henschel mixer to obtain a toner. These are referred to as “toner 1Bk / 1Y / 1M / 1
C "to" toner 4Bk / 4Y / 4M / 4C "," toner 5Bk ", and" toner 6Bk ".

Note that there is no difference between the colored particles and the toner in physical properties such as shape and particle diameter.

<Preparation of Developer> A ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm was mixed with each of the above toners to prepare a developer having a toner concentration of 6%. These are designated as “developer group 1” to “developer group 4” (“developer 1Bk / 1Y / 1M /
1C "to" Developer 4Bk / 4Y / 4M / 4C ")," Developer 5 ", and" Developer 6 "(" Developer 5Bk "," Developer 6Bk ").

<Evaluation of actual photography> Using the developer prepared here, a digital color copying machine Konica 3015 having almost the same construction as that of FIG. did.

As a fixing method, a pressure fixing type heat fixing device as shown in FIG. 1 was used. The specific configuration is as follows.

[0148] A cylindrical shape (inner diameter 30 mm, wall thickness 1.0 mm, full width 3
A heating roller (upper roller) is formed by coating the surface of a core metal (10 mm) with a sponge-like silicone rubber (Asker C hardness 30 °, thickness 8 mm), and has a cylindrical shape (inner diameter 40 mm, wall thickness 2) made of iron. 0 mm) with a sponge-like silicone rubber (Asker C hardness 30)
(Thickness: 2 mm) to form a pressure roller (lower roller), and the heating roller and the pressure roller are brought into contact with each other with a total load of 150 N to 6.6.
A nip having a width of mm was formed.

By using this fixing device, the linear velocity of printing is set to 1
It was set to 80 mm / sec. Note that polydiphenyl silicone (20 ° C.) is used as a cleaning mechanism of the fixing device.
(The viscosity of which is 10 Pa · s) was used. The fixing temperature was controlled by the surface temperature of the heating roller (set temperature: 175 ° C.). The amount of silicone oil applied was 0.6 mg / A4. This is referred to as “fixing device 1”.

The Asker C hardness of the surface coating layer of the heating roller and the pressure roller, the thickness of the coating layer, and the abutment load (total load) were changed. 0, 3.0, 8.0, 10.0, 11.0
mm fixing devices 2 to 6 were prepared.

<Characteristics Evaluation> In the above-described actual shooting evaluation, a full-color image (pixel ratio: 50%) was formed, and the green secondary color chroma was evaluated. The measuring instrument uses “Macbeth Color Eye” and the light source visual field (ASTM-D65) 2
°, evaluated in SCE mode. The higher the value, the better
It is practically desirable that the number be 60 or more.

The standard glossiness of the initial copied image (first sheet in one cycle) in the formation of a full-color image was measured according to the following method. This value is 17-37
In the range, glossiness (surface smoothness) necessary for ensuring color reproducibility in a color image and suppression of surface reflection components (matte property) required for office documents and the like are provided. More preferably, it is 17 to 27.

The measurement of the standard glossiness is performed in a region where the toner coverage on the image forming support is 90 area%. Here, the toner covering ratio is measured using a high-speed color image analyzer “SPICCA” (manufactured by Nippon Avionics Co., Ltd.). The above measurement area is measured at an incident angle of 75 ° by a method 2 described in JIS-Z8741-1983 using a gloss meter VGS-1D (manufactured by Nippon Denshoku Industries Co., Ltd.).

The evaluation of the fixing property was made by evaluating the A4 halftone image in which Y / M / C / Bk was printed in a single color (the relative reflection density was 1.times. When the image density was "0" on the paper). 0) was printed, and the fixing rate was measured. The fixing rate is a value obtained by rubbing a fixed image with a 1 kg weight of “rolled cloth” and calculating a percentage change in image density before and after the rubbing.

Fixing rate (%) = ｛(image density after rubbing) /
(Image density before rubbing) Δ × 100 The surface temperature of the heating roller was 175 ° C. as a center value.

At a set temperature of 175 ° C., a pixel rate of 5
The operation of printing 1,000 images of a 0% full-color image continuously and pausing overnight was repeated 10 times. At that time, the back surface stain of the first sheet of the image after the pause was observed. The presence or absence of dirt was visually determined and classified into the following ranks. The number of occurrences of rank C after 10 repetitions, and when the rank C was not reached, the tenth stain condition was observed.

Rank A: No dirt at all Rank B: Slight dirt is generated, but there is no problem in practical use Rank C: Dirt can be visually observed and becomes a problem in practical use In addition, the floor is 5 m × 5 m, and the height is 5 m × 5 m. At a set temperature of 175 ° C., a full-color image having a pixel ratio of 50% was continuously printed on 1,000 sheets in a 2 m closed room, and the presence or absence of odor was evaluated by sensory evaluation. For the presence or absence of odor, 20 evaluators were used to evaluate the number of persons who felt odor.

[0158]

[Table 4]

As is apparent from the results shown in Table 4,
It was found that Examples 1 to 4 in the present invention were all practically excellent. It can be seen that Comparative Examples 1 and 2 outside the present invention have a problem in at least one of the characteristics. In particular, the odor characteristics are problematic.

Next, under the above conditions, the “developer groups 1 to 3”
And "Developer 5" all showed good characteristics, but more severe conditions, especially with regard to odor, could actually be considered.
Therefore, using “developer groups 1 to 3” and “developer 5”,
The size of a closed room is 2.5m x 2.5m (almost 4
The size of the tatami mat) and the height were 2 m, and the same performance test as above was performed by five evaluators who could enter the room when the apparatus was operating. The nip width is 2.0, 3.0, 8.0, 10.0, 1
Table 5 below shows the relationship between the 1.0 mm “fixing devices 2 to 6” and the fixing rate test (the method is the same as described above).

[0161]

[Table 5]

From the above results, the nip width was 3 mm or more and 1
It can be seen that it is better to set the range to 0 mm or less.

Next, the supply amount of the silicone oil was set to 0,
The ratio was changed to 1.5, 2.0, and 2.5 mg / A4, but the other conditions were the same as in the “fixing device 4”, and the presence or absence of a problem with the following silicone oil was confirmed.

The problem with the silicone oil was evaluated by printing 400 sheets of a character original with a pixel ratio of 15% for all colors continuously on transfer paper (A4 size), and after a pause of 5 minutes, a blank original was transferred to the transfer paper. Using (A3 size), one-sheet printing is repeated three times, and a total of three sheets are printed. The presence or absence of traces of silicone oil adhering to these three transfer papers is confirmed.

[0165]

[Table 6]

From the above results, it is understood that the supply amount of the silicone oil is preferably set to 2 mg / A4 or less.

[0167]

According to the present invention, it is possible to provide an image forming method which suppresses generation of odor at the time of heat fixing by using a so-called polymerization toner and does not cause odor problem.

Further, it is possible to provide an image forming method capable of forming a color image having a wide color reproduction range with excellent fixability using a small particle size toner.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of a fixing device used in the present invention.

FIG. 2 is a cross-sectional view of a configuration of an image forming apparatus for performing the image forming method of the present invention.

[Explanation of symbols]

 Reference Signs List 10 heating roller 11 core metal 12 coating layer 13 heating member 20 pressure roller 21 core metal 22 coating layer 31 image forming body 32 image input unit 33 illumination light source 34 color separation filter 35 reflection mirror 36 lens 37 CCD image sensor 38 image processing unit 39 Multicolor document 40 Laser optical system 41 Negative charging charger 42 Transfer corona discharger 43 Separating electrode 44 Fixing device 45 Pre-cleaning static eliminator 46 Cleaning device A Yellow developing device B Magenta developing device C Cyan developing device D Black developing device L Laser beam P Image forming support T Toner image formed on transfer paper (image forming support)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) G03G 9/08 384 (72) Inventor Ken Omura 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term ( Reference) 2H005 AA01 AB06 CA02 CA06 FB02 2H033 BA24 BA43 BA46 BA58 BB04 BB14 BB15 BB17 BB29 BB30 BB33 BB34 4J011 AA05 NA12 NB04 4J100 AA02P AA02 AG03P AA04P AB00P AB02P AB03P04 AJ03P AJ08P AJ09P AL03P AL03Q AL04P AL05P AL08P AL36P AL44P AL62P AL66P AM02P AM15P AM21P AQ08P AQ12P AQ25P AQ26P BA02P BA16P BA31P BA56P BA64P BB01P BC43P CA01 CA04 CA05 GC04 GC21

Claims (4)

[Claims] An electrostatic latent image formed on a photoreceptor is developed with a developer containing a toner, and the toner image formed on the photoreceptor is transferred to an image forming support. In an image forming method including a step of fixing an image by a fixing device, both a heating roller and a pressure roller of the fixing device have an elastic covering layer, and a nip width thereof is 3 to 10 m.
m, and the toner is obtained by polymerizing a polymerizable composition comprising at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-pentene in an aqueous medium, in an aqueous medium. An image forming method characterized by being obtained by salting out / fusing in a medium. 2. An electrostatic latent image formed on a photoreceptor is developed with a developer containing a toner, and the toner image formed on the photoreceptor is transferred to an image forming support. In an image forming method including a step of fixing an image by a fixing device, both a heating roller and a pressure roller of the fixing device have an elastic covering layer, and a nip width thereof is 3 to 10 m.
m, and the toner is obtained by subjecting a polymerizable composition comprising at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-pentene to suspension polymerization in an aqueous medium. An image forming method comprising: 3. An electrostatic latent image formed on a photoreceptor is developed with a developer containing a toner, and the toner image formed on the photoreceptor is transferred to an image forming support. In an image forming method including a step of fixing an image by a fixing device, both a heating roller and a pressure roller of the fixing device have an elastic covering layer, and a nip width thereof is 3 to 10 m.
m, wherein the toner is colored with resin particles prepared by polymerizing a polymerizable composition comprising at least a radical polymerizable monomer and 2,4-diphenyl-4-methyl-1-pentene in an aqueous medium. An image forming method comprising fusing secondary particles obtained by aggregating agent particles. 4. The image forming method according to claim 1, wherein a supply amount of the silicone oil to a heating roller constituting the fixing device is 2 mg / A4 or less.