JP2003195675A - Image forming apparatus and fixing device evaluation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing device evaluation method to previously decide whether releasing properties can be secured by the combination of a press- contact thermal fixing device and toner, and to provide an image forming apparatus equipped with the fixing device excellent in the releasing property. <P>SOLUTION: This fixing device evaluation method employs the fixing device which consists of a heating roller and a pressure roller in press-contact with the heating roller, and an image supporting body carrying an unfixed toner image is held and transported by such a press-contact part, and the toner image is heated and fixed in press-contact with the image supporting body. The toner of an amount of 2.0 mg/cm<SP>2</SP>is stuck to the image supporting body whose rigidity is 20 to 30 cm<SP>3</SP>/100, and the surface pressure of the press-contact part is set to 2.8×10<SP>5</SP>Pa. Then whether tensile load is ≤10 g is measured by a 90° peeling test after holding and transport. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus used as a copying machine, a printer or the like, and a method of evaluating a fixing device included in the apparatus.

[0002]

2. Description of the Related Art In recent years, an image forming method of an electrophotographic system has been adopted in almost all cases in an image forming apparatus requiring high speed and high image quality.

The reason therefor is that high-quality images can be obtained at high speed, stable image formation can be performed for a long period of time, and color images can be formed. However, there is a strong demand for further improvement in the performance of the electrophotographic system, and technical improvements are being actively made even now.

Of the above-mentioned requirements, the greatest number is the further improvement of the image quality, and the improvement of the stability capable of forming an excellent image for a longer period of time. Particularly, in order to improve the image quality, it is effective to use a toner having a small particle size and a uniform shape, but for that purpose, it is not the pulverization method which has been widely adopted as a method for producing a toner, After the monomer is dispersed into droplets, there is an increasing tendency to produce by a polymerization method in which the particles are polymerized to form toner particles. However, when the toner particle size and shape or the toner manufacturing method is changed in this way, the appropriate conditions of each step during image formation vary. Especially when the materials used in manufacturing and the conditions thereof are changed, the influence is great. For example, even if the resin composition forming the toner does not change, in the polymerization toner, since it is necessary to prepare particles having a uniform small particle size in advance, the kind and amount of the surfactant used during the polymerization reaction are different from those of the pulverization method. This is different from the case, and since there is a limit to removing it after the polymerization reaction, the amount remaining in the toner also differs.

On the other hand, when forming an image by the electrophotographic method, in most cases, a method of transferring an unfixed toner image formed on a photosensitive member to an image support and fixing the toner image by heat contact is adopted. Has been. This method is inexpensive because the photoconductor can be used repeatedly, can be fixed at high speed, and is highly reliable, but toner tends to adhere to the heating roller during fixing.
A lot of improvement studies have been conducted to improve it.

When the toner adheres to the heat fixing roller (toner offset), the toner is gradually fixed and solidified on the heating roller, and at a certain point of time, it is scraped off to stain the image support or press it. This is one of the major factors that impair the reliability (stability) of the entire image forming apparatus when it is used for a long period of time, because it results in the transfer to the pressure roller and further soiling of the back surface of the image support.

As described above, in the development of the image forming apparatus of the electrophotographic system, the characteristics of the toner used are changed and the problem of toner offset still exists. Moreover, in order to simplify the mechanism, there is a tendency that the heating roller is not provided with a conventional mechanism for applying a release agent.
This tendency is naturally disadvantageous in terms of prevention of toner offset, but since the characteristics of the toner have changed due to the reasons described above, it is easy to select a combination of toner and fixing device that does not cause toner offset. is not. In particular, in order to study the reliability during long-term use, it is often found that the problem is not confirmed until after making a prototype of the image forming apparatus and actually conducting a reliability test.

[0008]

The present invention has been made in consideration of solving the above-mentioned problems of the present situation. In developing the current image forming apparatus, it is required to shorten the period, and at the same time, to reduce the development cost. In such a situation, it is advantageous to be able to predict whether offset will occur at a time when the combination of the fixing device and the toner is as fast as possible.

The object of the present invention is to determine in advance whether or not the releasability can be secured by the combination of the contact type oilless pressure contact heat fixing device to be adopted and the toner. An object of the present invention is to provide a fixing device evaluation method capable of determining a good combination of roller release layers, and an image forming apparatus equipped with a fixing device having good release properties.

[0010]

Means for Solving the Problems As a result of intensive studies by the inventors, it was found that the object of the present invention can be achieved by adopting any of the following constitutions.

[1] A heating roller composed of a cylindrical cored bar having a heating source inside, an elastic layer provided around the cylindrical cored bar, and a release layer covering the elastic core, and the pressure roller is pressed against the heating roller. An image support having an unfixed toner image carried by the pressure roller is sandwiched and conveyed at the pressure contact portion, and the toner image is fixed to the image support by heating under pressure. 30 cm ^3/100 the toner on the image support 2.0 mg / cm ² attached to the, the surface pressure of the contact portion and 2.8 × 10 ⁵ Pa, at 90 ° peeling test after holding transport, tensile A method for evaluating a fixing device, which comprises measuring whether or not a load is 10 g or less.

[2] A heating roller composed of a cylindrical cored bar having a heating source inside, an elastic layer provided around the cylindrical cored bar, and a release layer covering the elastic layer, and the roller is pressed against the heating roller. An image forming apparatus comprising a pressure roller, and a fixing device for nip-conveying an image support carrying an unfixed toner image at its pressure contact portion, and fixing the toner image by heating it in pressure contact with the image support. At a rigidity of 20 to 30 cm ³ /
Toner of 2.0 mg / cm ^{2 was} adhered onto 100 image supports, and the surface pressure of the pressure contact portion was set to 2.8 × 10 ⁵ Pa,
Tensile load of 10 at 90 ° peeling test after nipping and conveyance
An image forming apparatus characterized by using a combination of a heating roller release layer of g or less and toner.

[3] The image forming apparatus according to [2], wherein the toner is a polymerization toner.

[4] The image forming apparatus according to [2], wherein the toner contains a release agent.

[5] The image forming apparatus as described in [2], wherein the release layer contains a fluororesin.

The "90 ° peel test" is carried out by the method shown in FIG. That is, 2.0 mg / toner of toner T is applied to a pressure contact heat fixing device having a heating roller 21 and a pressure roller 22.
cm ^{2 The} image support P adhered thereto is nipped and conveyed (the surface pressure of the pressure contact part is 2.8 × 10 ² kPa / cm ² ), and the line connecting the tip of the image support to the center point of the heating roller, The angle formed by the line connecting the center point of the heating roller and the center line of the pressure roller is 45
When the temperature reaches 0 °, it is peeled off in the direction of 90 ° (normal direction) from the tangent line drawn on the surface of the heating roller at the tip of the image support, and the load applied at that time is measured. In the present invention, a digital balance 50 was used for load measurement.

JIS P8 is used to measure the rigidity used at this time.
According to the method specified in 143. Also, 20 to 30c
The m ^3/100 image support, usually a less thin paper 55kg paper.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Materials and elements relating to the constituent features of the present invention, applied techniques, image forming apparatuses and the like will be described.

1. Toner Production Method The toner production method of the present invention is not particularly limited, and various methods such as a pulverization method in which a resin, a colorant, and other additives are kneaded, pulverized, and classified can be used. However, those obtained by a so-called polymerization method in which at least a polymerizable monomer is polymerized in an aqueous medium are more preferable because the effects of the present invention are more remarkable.

<Suspension Polymerization Method> As an example of the method for producing the toner of the present invention, various constituent materials such as a coloring agent, a release agent if necessary, and a polymerization initiator are added to the polymerizable monomer. Then, various constituent materials are dissolved or dispersed in the polymerizable monomer by using a homogenizer, a sand mill, a sand grinder, an ultrasonic disperser or the like. The polymerizable monomer in which these various constituent materials are dissolved or dispersed is dispersed in an oil droplet having a desired size as a toner in a water-based medium containing a dispersion stabilizer by using a homomixer or a homogenizer. Then, the reaction mixture is transferred to a reaction device (stirring device) having a stirring mechanism and heated to cause the polymerization reaction to proceed. After completion of the reaction, the dispersion stabilizer is removed, filtered, washed, and dried to prepare the toner of the present invention. In addition, in the present invention, the “aqueous medium” refers to one containing at least 50% by mass of water.

<Emulsion Polymerization Method> As a method for producing the toner of the present invention, a method of salting out / fusing resin particles in an aqueous medium for preparation is particularly preferably used. This method is not particularly limited, but for example, JP-A-5-265252 and JP-A-6-329947.
The methods disclosed in Japanese Patent Application Laid-Open No. 9-15904 and Japanese Patent Application Laid-Open No. 9-15904 can be mentioned. That is, a method of salting out / fusing a plurality of resin particles and constituent particles such as a colorant or the like, or fine particles composed of a resin and a colorant, in particular, dispersing these in water using an emulsifier. After that, a salting-out agent having a critical coagulation concentration or more is added for salting out, and at the same time, the particles are gradually grown while forming fused particles by heating and fusing at a temperature not lower than the glass transition temperature of the formed polymer itself. When the target particle size is reached, particle size growth is stopped, and the particle surface is smoothed while heating and stirring to control the shape,
The toner of the present invention can be formed by heating and drying the particles in a fluid state in a fluid state. Here, a solvent such as alcohol, which is infinitely soluble in water, may be added simultaneously with the salting-out agent.

A typical method for producing a toner of the present invention comprises salting out / fusing composite resin particles obtained by a multi-step polymerization method and colorant particles. The multi-step polymerization method will be described below.

<Production Method of Composite Resin Particles Obtained by Multi-Stage Polymerization Method> The production method of the toner of the present invention comprises the following steps.

1: multi-stage polymerization step 2: salting out / fusing composite resin particles and colorant particles to obtain toner particles Salting out / fusing step 3: filtering the toner particles from a dispersion system of toner particles Then
A filtration / washing step for removing a surfactant and the like from the toner particles, a drying step for drying the washed toner particles, and a step for adding an external additive to the dried toner particles.

Hereinafter, each step will be described in detail. (Multi-step polymerization step) The multi-step polymerization step is a polymerization method carried out in order to widen the molecular weight distribution of the resin particles in order to obtain a toner in which offset generation is prevented. That is, the polymerization reaction is performed in multiple stages in order to form a phase having different molecular weight distributions in one resin particle, and the obtained resin particle has a molecular weight gradient from the center of the particle toward the surface layer. It is intended to be formed. For example, a method of forming a low molecular weight surface layer by first adding a polymerizable monomer and a chain transfer agent after obtaining a high molecular weight resin particle dispersion liquid is adopted.

In the present invention, it is preferable to adopt a multi-step polymerization method of three or more steps from the viewpoint of stability of production and crushing strength of the obtained toner. The two-step polymerization method and the three-step polymerization method, which are typical examples of the multi-step polymerization method, will be described below. In the toner obtained by such a multi-step polymerization reaction, a resin having a lower molecular weight is preferable as the surface layer resin from the viewpoint of crushing strength.

(Two-Step Polymerization Method) The two-step polymerization method comprises a central portion (nucleus) formed of a high molecular weight resin containing a crystalline organic compound and an outer layer (shell) formed of a low molecular weight resin. Is a method for producing composite resin particles.

This method will be described in detail. First, a crystalline organic compound is dissolved in a monomer to prepare a monomer solution, and the monomer solution is added to an aqueous medium (for example, a surfactant aqueous solution). After dispersing oil droplets therein, this system is subjected to a polymerization treatment (first-stage polymerization) to prepare a dispersion liquid of high molecular weight resin particles containing a crystalline organic compound.

Next, a polymerization initiator and a monomer for obtaining a low molecular weight resin are added to the dispersion liquid of the resin particles, and the monomer is subjected to a polymerization treatment in the presence of the resin particles (second-stage polymerization). Is a method of forming a coating layer made of a low molecular weight resin (polymer of monomer) on the surface of the resin particles.

(Three-step polymerization method) The three-step polymerization method comprises a central portion (nucleus) formed of a high molecular weight resin, an intermediate layer containing a crystalline organic compound, and an outer layer (shell) formed of a low molecular weight resin. Is a method for producing composite resin particles composed of

To explain this method in detail, first, a dispersion of resin particles obtained by a polymerization treatment (first-stage polymerization) according to a conventional method is added to an aqueous medium (for example, an aqueous solution of a surfactant). Along with the addition, a monomer solution obtained by dissolving the crystalline organic compound described below in a monomer is dispersed in the aqueous medium as an oil droplet, and then this system is subjected to a polymerization treatment (second-stage polymerization).
By doing so, a coating layer (intermediate layer) made of a resin (monomer polymer) containing a crystalline organic compound is formed on the surface of the resin particles (core particles), and the composite resin particles (high molecular weight resin) are formed. -Medium molecular weight resin) dispersion is prepared.

Next, a polymerization initiator and a monomer for obtaining a low molecular weight resin are added to the obtained dispersion liquid of the composite resin particles, and the monomer is subjected to a polymerization treatment in the presence of the composite resin particles (first). By three-step polymerization), a coating layer made of a low molecular weight resin (polymer of monomer) is formed on the surface of the composite resin particles. In the above method, by incorporating an intermediate layer, the crystalline organic compound can be finely and uniformly dispersed, which is preferable.

One of the features of the method for producing a toner according to the present invention is to polymerize a polymerizable monomer in an aqueous medium. That is, when forming a resin particle (nucleus particle) or a coating layer (intermediate layer) containing a crystalline organic compound, the crystalline organic compound is dissolved in a monomer, and the resulting monomer solution is added to an aqueous medium. It is a method of obtaining resin particles (latex particles) by dispersing oil droplets in step (3), adding a polymerization initiator to this system and performing a polymerization treatment.

The aqueous medium referred to in the present invention is water 50 to 10
A medium composed of 0 mass% and a water-soluble organic solvent of 0 to 50 mass%. As the water-soluble organic solvent, for example, methanol, ethanol, isopropanol, butanol,
Acetone, methyl ethyl ketone, tetrahydrofuran and the like can be exemplified, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable.

As a suitable polymerization method for forming resin particles or a coating layer containing a crystalline organic compound, a crystalline organic compound is prepared by dissolving a crystalline organic compound in an aqueous medium in which a surfactant having a concentration below the critical micelle concentration is dissolved. A monomer solution prepared by dissolving a compound in a monomer is dispersed into oil droplets using mechanical energy to prepare a dispersion liquid, and a water-soluble polymerization initiator is added to the obtained dispersion liquid to form oil droplets. A method in which radical polymerization is carried out (hereinafter, referred to as “miniemulsion method” in the present invention) can be mentioned, and the effects of the present invention can be exhibited more preferably. In the above method, an oil-soluble polymerization initiator may be used instead of the water-soluble polymerization initiator or together with the water-soluble polymerization initiator.

According to the mini-emulsion method of mechanically forming oil droplets, unlike the usual emulsion polymerization method, the crystalline organic compound dissolved in the oil phase is less desorbed, and the resin particles or the coating formed. A sufficient amount of crystalline organic compound can be introduced into the layer.

Here, the disperser for dispersing the oil droplets by mechanical energy is not particularly limited, and for example, a stirrer "CLEARMIX" (M -Technique Co., Ltd.), ultrasonic disperser, mechanical homogenizer,
Menton Gorin, a pressure type homogenizer, etc. can be mentioned. Further, as the dispersed particle size, 10 to
1000 nm, preferably 50-1000 nm,
More preferably, it is 30 to 300 nm.

As another polymerization method for forming resin particles or a coating layer containing a crystalline organic compound, known methods such as emulsion polymerization method, suspension polymerization method and seed polymerization method may be adopted. it can. Further, these polymerization methods can also be adopted to obtain resin particles (core particles) or a coating layer constituting the composite resin particles, which does not contain a crystalline organic compound.

The particle size of the composite resin particles obtained in this polymerization step is 10 to 10 in terms of the weight average particle size measured by using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).
It is preferably in the range of 1000 nm.

Further, the glass transition temperature (T
g) is preferably in the range of 50 to 65 ° C, more preferably 52 to 64 ° C.

The softening point of the composite resin particles is 95 to 140.
It is preferably in the range of ° C. <Salting-out / fusion-bonding step> In this salting-out / fusion-bonding step, the composite resin particles obtained in the polymerization step and the colorant particles are salted-out / fusion-bonded (simultaneously causing salting-out and fusion-bonding). This is a process of obtaining amorphous (non-spherical) toner particles.

The term "salting out / fusion" used in the present invention means that salting out (aggregation of particles) and fusion (disappearance of interface between particles) occur simultaneously, or salting out and fusion occur simultaneously. Refers to an act. In order to perform salting out and fusion at the same time, particles (composite resin particles, colorant particles) are formed under the temperature condition of the glass transition temperature (Tg) of the resin constituting the composite resin particles or higher.
Need to be aggregated.

In this salting-out / fusing step, internal additive particles (fine particles having a number average primary particle diameter of about 10 to 1000 nm), such as a charge control agent, are salted out / fused together with the composite resin particles and the colorant particles. You may let me. Also, the colorant particles are
The surface may be modified, and as the surface modifier, a conventionally known one can be used.

Specific examples of the salting-out agent are shown below. Two
Examples of the valent inorganic salt include magnesium chloride, calcium chloride, zinc chloride, copper sulfate, magnesium sulfate and manganese sulfate, and examples of the trivalent inorganic salt include aluminum chloride, aluminum hydroxide, aluminum sulfate and iron chloride. Is mentioned. Examples of the tetravalent inorganic salt include titanyl sulfate and tin tetrachloride.

Although these are appropriately selected depending on the purpose, a divalent or trivalent inorganic salt is preferable because aggregation proceeds at an appropriate speed without abrupt progress and the toner particle size is easily controlled. It is particularly preferable to use a divalent inorganic salt.

In the present invention, the concentration of the salting out agent may be higher than the critical coagulation concentration, but is preferably 1.
The amount is 2 times or more, more preferably 1.5 times or more.

When the salting out progresses and the resin particles reach the target size, a salting out stopper may be added. A salting-out stopper coexists with an inorganic salt used as a salting-out agent (two kinds of metal ions or non-metal cations exist in the resin particle dispersion liquid).
In this case, a substance having a function of lowering the cohesive force of the resin particles due to salting out compared to the case where they are used alone. Specifically, it is a salt having a different valence of cations with respect to the salting-out agent, or a salt having the same valence but a different ionic radius of the cation. It is preferable to use a salt having a small

Growth can be stopped quickly by using a salting-out stopping agent, and as a result, a toner having few coarse particles, that is, a sharp particle size distribution can be obtained.

Examples of monovalent inorganic salts that can be used as the salting-out stopping agent include sodium chloride, potassium chloride, lithium chloride and the like. In addition to inorganic metal salts, ammonium salts such as ammonium chloride can be used.
As the divalent and trivalent inorganic salts, those similar to the salting-out agent can be used.

<Aging Step> The aging step is a step subsequent to the salting-out / fusion step, and the temperature is kept near the melting point of the crystalline organic compound, preferably at the melting point ± 20 ° C., even after the resin particles are fused. In this step, the crystalline organic compound is phase-separated by continuing stirring at a constant intensity. In this step, it is possible to control the shape factor of the crystalline organic compound and the coefficient of variation thereof.

The colorant particles are subjected to salting-out / fusion treatment in a state of being dispersed in an aqueous medium. The aqueous medium in which the colorant particles are dispersed is preferably an aqueous solution in which the surfactant is dissolved at a concentration equal to or higher than the critical micelle concentration (CMC).

The disperser used for the dispersion treatment of the colorant particles is not particularly limited, but preferably a stirring device "CLEARMIX (CLEAR) equipped with a rotor rotating at high speed.
MIX) "(manufactured by M-Technique Co., Ltd.), ultrasonic disperser,
Examples thereof include a pressure homogenizer such as a mechanical homogenizer, Manton-Gaulin, a pressure homogenizer, and a medium type homogenizer such as a Getzman mill and a diamond fine mill.

In order to salt out / fuse the composite resin particles and the colorant particles, the salting agent (aggregating agent) having a critical coagulation concentration or more is added to the dispersion liquid in which the composite resin particles and the colorant particles are dispersed. ) Is added and the dispersion is heated to the glass transition temperature (Tg) or higher of the composite resin particles.

A suitable temperature range for salting out / fusing is (Tg + 10 ° C.) to (Tg + 50 ° C.),
Particularly preferably, it is (Tg + 15 ° C.) to (Tg + 40 ° C.). In addition, an organic solvent infinitely soluble in water may be added in order to effectively carry out the fusion.

<Filtration / Washing Step> In this filtration / washing step, a filtering treatment for filtering the toner particles from the dispersion system of the toner particles obtained in the above step and the filtered toner particles (cake-shaped A cleaning process is performed to remove deposits such as surfactants and salting-out agents from the aggregate. Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using a Nutsche or the like, or a filtration method using a filter press or the like.

<Drying Step> This step is a step of drying the washed toner particles.

Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, a vacuum dryer and the like. A stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, a rotary dryer It is preferable to use a dryer or a stirring dryer.

The water content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

The dried toner particles are
When the aggregates are aggregated by the weak attraction between particles, the aggregates may be crushed. Here, as the disintegration processing device,
A mechanical crushing device such as a jet mill, a Henschel mixer, a coffee mill or a food processor can be used.

<Step of adding an external additive> In the case of producing a toner, a step of adding an external additive is usually followed by the above step, and inorganic fine particles such as silica and titanium oxide, and / or
Alternatively, the production of the toner is completed by adding organic fine particles such as a methacrylic acid ester resin.

The toner of the present invention forms composite resin particles in the absence of a colorant, adds the dispersion liquid of the colorant particles to the dispersion liquid of the composite resin particles, and mixes the composite resin particles and the colorant particles. It is preferably prepared by salting out / fusing.

Thus, by carrying out the preparation of the composite resin particles in a system in which no colorant is present, the polymerization reaction for obtaining the composite resin particles is not hindered. Therefore, according to the toner of the present invention, the excellent offset resistance is not impaired, and the contamination of the fixing device and the image stain due to the accumulation of the toner do not occur.

Further, as a result of the polymerization reaction being surely performed to obtain the composite resin particles, no monomer or oligomer remains in the obtained toner particles, and the image forming method using the toner can be used. No offensive odor is generated in the heat fixing step.

Next, each constituent factor used in the toner manufacturing process will be described in detail. <Polymerizable Monomer> As the polymerizable monomer for producing the resin (binder) used in the present invention, a hydrophobic monomer is used as an essential constituent component, and a crosslinkable monomer is added if necessary. Used. Further, it is desirable to contain at least one kind of monomer having an acidic polar group or basic polar group in the structure as described below.

(1) Hydrophobic Monomer The hydrophobic monomer constituting the monomer component is not particularly limited, and conventionally known monomers can be used. Further, one kind or a combination of two or more kinds can be used so as to satisfy the required characteristics.

Specifically, a monovinyl aromatic monomer,
(Meth) acrylic acid ester-based monomer, vinyl ester-based monomer, vinyl ether-based monomer, monoolefin-based monomer, diolefin-based monomer, halogenated olefin-based monomer, etc. may be used. it can.

Examples of vinyl aromatic monomers include:
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Examples thereof include styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

As the (meth) acrylic acid ester type monomer, acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
-Ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, γ-aminopropyl acrylate, methacrylic acid Stearyl, dimethylaminoethyl methacrylate,
Diethylaminoethyl methacrylate and the like can be mentioned.

Examples of the vinyl ester-based monomer include vinyl acetate, vinyl propionate, vinyl benzoate, etc., and examples of the vinyl ether-based monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether. Etc.

As the mono-olefin type monomer, ethylene, propylene, isobutylene, 1-butene, 1-
Examples thereof include pentene and 4-methyl-1-pentene, and examples of the diolefin-based monomer include butadiene, isoprene and chloroprene.

(2) Crosslinkable Monomer A crosslinkable monomer may be added to improve the properties of the resin particles. Examples of the crosslinkable monomer include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and diallyl phthalate.

(3) Monomer having acidic polar group As the monomer having an acidic polar group, (a) a polymerizable monomer having a carboxyl group (—COOH), and
(B) a sulfonic group include a polymerizable monomer having a (-SO ₃ H).

Examples of the polymerizable monomer having a carboxyl group (a) include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, maleic acid monoester. Examples thereof include octyl ester, and metal salts thereof such as Na and Zn.

Examples of the polymerizable monomer having a sulfone group (b) include sulfonated styrene and its Na salt,
Examples thereof include allyl sulfosuccinic acid, octyl allyl sulfosuccinate, and their Na salts.

In the present invention, the polymerizable monomer (a) having a carboxyl group is preferably used, and methacrylic acid and acrylic acid are particularly preferably used.

(4) Monomer Having Basic Polar Group As the monomer having a basic polar group, (i) an amine group or a quaternary ammonium group having 1 to 1 carbon atoms
2, preferably 2 to 8, particularly preferably 2 (meth) acrylic acid ester of an aliphatic alcohol, (ii) (meth)
Acrylic amide or optionally 1 to 1 carbon atoms on N
(Meth) acrylic acid amide mono- or di-substituted with 18 alkyl groups, (iii) vinyl compound substituted with a heterocyclic group having N as a ring member, and (iv) N, N-diallyl-alkylamine or The quaternary ammonium salt can be illustrated. Among them, (i) an (meth) acrylic acid ester of an aliphatic alcohol having an amine group or a quaternary ammonium group is preferable as the monomer having a basic polar group.

Examples of the (meth) acrylic acid ester of an aliphatic alcohol having an amine group or a quaternary ammonium group (i) include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, Quaternary ammonium salt of 4 compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-
3-methacryloxypropyl trimethyl ammonium salt etc. can be mentioned.

Examples of the (meth) acrylic acid amide of (ii) or the (meth) acrylic acid amide optionally substituted with mono- or dialkyl on N include acrylamide, N-butyl acrylamide, N, N-dibutyl acrylamide, piperidyl acrylamide, Methacrylamide, N-butylmethacrylamide, N, N-dimethylacrylamide,
N-octadecyl acrylamide etc. can be mentioned.

Examples of the vinyl compound substituted with a heterocyclic group having N as a ring member in (iii) include vinyl pyridine,
Examples thereof include vinylpyrrolidone, vinyl-N-methylpyridinium chloride and vinyl-N-ethylpyridinium chloride.

Examples of (iv) N, N-diallyl-alkylamine include N, N-diallylmethylammonium chloride and N, N-diallylethylammonium chloride.

<Surfactant> It is preferable to disperse oil droplets in an aqueous medium using a surfactant in order to carry out miniemulsion polymerization using the above-mentioned polymerizable monomer. The surfactant that can be used in this case is not particularly limited, but the following ionic surfactants can be mentioned as examples of suitable compounds.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate,
Aryl alkyl polyether sodium sulfonate,
3,3-disulfone diphenylurea-4,4-diazo-
Sodium bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol -6-
Sodium sulfonate, etc.), sulfate ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.),
Examples thereof include fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.).

In the present invention, the surfactants represented by the following general formulas (1) and (2) are particularly preferably used.

General formula (1) R ¹ (OR ² ) _n OSO ₃ M General formula (2) R ¹ (OR ² ) _n SO ₃ M In the general formulas (1) and (2), R ¹ has 6 carbon atoms. ~ 22
Is preferably an alkyl group or an arylalkyl group having 8 to 20 carbon atoms, and more preferably an alkyl group or an arylalkyl group having 9 to 16 carbon atoms.

Examples of the alkyl group having 6 to 22 carbon atoms represented by R ¹ include n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n-undecyl group and n-hexadecyl group. Group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc., and the arylalkyl group represented by R ¹ includes benzyl group, diphenylmethyl group, cinnamyl group, styryl group, trityl group, phenethyl group and the like. .

In the general formulas (1) and (2), R ² represents an alkylene group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms. ² carbon atoms represented by R 2
Examples of the alkylene group of to 6 include ethylene group, trimethylene group, tetramethylene group, propylene group and ethylethylene group.

In the general formulas (1) and (2), n is 1 to
Although it is an integer of 11, it is preferably 2 to 10, more preferably 2 to 5, and particularly preferably 2 to 3.

In the general formulas (1) and (2), examples of the monovalent metal element represented by M include sodium, potassium and lithium. Among them, sodium is preferably used.

Specific examples of the surfactants represented by the general formulas (1) and (2) are shown below, but the present invention is not limited thereto.

Compound (101): C ₁₀ H ₂₁ (OCH ₂ C
H _{2) 2} OSO ₃ Na Compound _{(102): C 10 H 21} (OCH 2 CH 2) 3 OSO 3
Na compound _{(103): C 10 H 21} (OCH 2 CH 2) 2 SO 3 N
a Compound (104): C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₃ SO ₃ N
a Compound (105): C ₈ H ₁₇ (OCH ₂ CH (CH ₃ )) ₂
OSO ₃ Na compound (106): C ₁₈ H ₃₇ (OCH ₂ CH ₂ ) ₂ OSO ₃
Na <Molecular weight distribution of resin particles and toner> The toner of the present invention is
The peak or shoulder of the molecular weight distribution is 100,000-
1,000,000, and preferably 1,000 to 50,000, and moreover, the peak or shoulder of the molecular weight distribution is 100,000 to 1,000,000, 25.0.
It is preferable that it exists in the range of 0 to 150,000 and 1,000 to 50,000.

The resin particles have a molecular weight of 100,000 to
A resin containing at least a high molecular weight component having a peak or shoulder in the region of 1,000,000 and a low molecular weight component having a peak or shoulder in the region of 1,000 to less than 50,000 is preferable, and more preferably Is
It is preferable to use an intermediate molecular weight resin having a peak or shoulder in the portion of 15,000 to 100,000.

The method for measuring the molecular weight of the above-mentioned toner or resin is carried out according to GP using THF (tetrahydrofuran) as a solvent.
Measurement by C (gel permeation chromatography) is preferable. That is, 1.0 ml of THF is added to 0.5 to 5 mg of the measurement sample, more specifically 1 mg, and stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve the sample. Next, pore size 0.45
After treatment with a 0.50 μm membrane filter,
Inject into GPC. The GPC measurement conditions are as follows: the column is stabilized at 40 ° C., THF is allowed to flow at a flow rate of 1.0 ml / min, and a sample having a concentration of 1 mg / ml is injected in an amount of about 100 μl. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Shodex GPC KF-801, 80 manufactured by Showa Denko KK
2, 803, 804, 805, 806, 807 combination and TSKgel G1000H, G200 manufactured by Tosoh Corporation
0H, G3000H, G4000H, G5000H, G
6000H, G7000H, TSK guard co
Examples include a combination of lumn. As a detector, a refractive index detector (IR detector) or U
A V 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 prepared using monodisperse polystyrene standard particles. About 10 points may be used as polystyrene for preparing the calibration curve.

<Colorant> The toner of the present invention is obtained by salting out / fusing the above-mentioned composite resin particles and colorant particles. Examples of the colorant (colorant particles to be salted out / fused with the composite resin particles) constituting the toner of the present invention include various inorganic pigments, organic pigments and dyes.
As the inorganic pigment, conventionally known ones can be used. Specific inorganic pigments are exemplified below.

As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite can be used.

These inorganic pigments can be used alone or in combination of two or more as desired. Further, the amount of the pigment added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.

When used as a magnetic toner, the above magnetite can be added. In this case, from the viewpoint of imparting a predetermined magnetic characteristic, 20 to 6 is contained in the toner.
It is preferable to add 0% by mass.

Conventional organic pigments and dyes can be used as well, and specific organic pigments and dyes are exemplified below.

As the pigment for magenta or red,
For example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I.
Pigment Red 6, C.I. I. Pigment Red 7,
C. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I.
I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I.
Pigment Red 149, C.I. I. Pigment Red 1
66, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222
Etc.

Examples of pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I.
I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I.
Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 9
4, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 1
85, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 156 and the like.

As the pigment for green or cyan,
For example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

Examples of dyes include C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19,
44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I.
I. Solvent Blue 25, 36, 60, 70,
No. 93, No. 95 and the like can be used, and a mixture thereof can also be used.

These organic pigments and dyes can be used alone or in combination of two or more as desired.
The amount of pigment added is 2 to 20% by mass based on the polymer.
And preferably 3 to 15% by mass.

<Crystalline Organic Compound> In the toner used in the present invention, the resin particles containing the crystalline organic compound are fused in an aqueous medium, and the crystalline organic compound is appropriately aggregated by an aging step to form a sea island. It is preferable that the toner has a structure. The crystalline organic compound means a crystalline polyester having a fixing-improving function, and the crystalline organic compound having a releasing function is defined as a releasing agent. The releasing function is exhibited when the solution viscosity at 200 ° C. is 200 cps or less, and the crystalline organic compound having such physical properties is also referred to as a releasing agent.

Thus, the resin particles containing the crystalline organic compound in the resin particles are salted out with the colorant particles in an aqueous medium.
By fusing, a toner in which the crystalline organic compound is finely dispersed can be obtained.

In the toner of the present invention, a low molecular weight polypropylene (number average molecular weight = 1
500 to 9000) and low molecular weight polyethylene are preferable, and ester compounds represented by the following formulas are particularly preferable.

In the formula R _1- (OCO-R ₂ ) _n , n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4. R ₁ , R
₂ represents a hydrocarbon group which may have a substituent. R ₁
Has 1 to 40 carbon atoms, preferably 1 to 20 carbon atoms, and more preferably 2 to 5 carbon atoms. R ₂ has 1 to 40 carbon atoms, preferably 16 to 30 carbon atoms, and more preferably 18 to 26 carbon atoms.

Representative compound examples are shown below.

[0108]

[Chemical 1]

[0109]

[Chemical 2]

In the present invention, crystalline polyester can also be used as the crystalline organic compound. As the crystalline polyester, a polyester obtained by reacting an aliphatic diol with an aliphatic dicarboxylic acid (including an acid anhydride and an acid chloride) is preferable.

As the diol used for obtaining the crystalline polyester, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,
4-butanediol, 1,4-butenediol, neopentyl glycol, 1,5-pentane glycol, 1,
Examples include 6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A, and the like. it can.

Examples of the dicarboxylic acid used to obtain the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, maleic acid and fumaric acid. , Citraconic acid, itaconic acid, glutacoic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, their acid anhydrides or Mention may be made of acid chlorides.

Particularly preferred crystalline polyesters are polyesters obtained by reacting 1,4-cyclohexanedimethanol and adipic acid, polyesters obtained by reacting 1,6-hexanediol and sebacic acid, and ethylene glycol. And polyesters obtained by reacting succinic acid, polyesters obtained by reacting ethylene glycol and sebacic acid, and polyesters obtained by reacting 1,4-butanediol and succinic acid. Among them, the polyester obtained by reacting 1,4-cyclohexanedimethanol and adipic acid is most preferable.

The amount of the above compound added is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass, based on the whole toner.

2. Developer The toner of the present invention may be used as a one-component developer or a two-component developer. When it is used as a one-component developer, it is a non-magnetic one-component developer or 0.1-0.5% in the toner.
A magnetic one-component developer containing magnetic particles of about μm can be used, and any of them can be used.

However, it is most preferable to use it as a two-component developer by mixing it with a carrier. In this case, conventionally known materials such as metals such as iron, ferrite and magnetite and alloys of these metals with metals such as aluminum and lead can be used as the magnetic particles of the carrier. Ferrite particles are particularly preferable. The volume average particle diameter of the magnetic particles is 15 to 100 μm, and more preferably 25 to 80 μm.

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution measuring apparatus "HELOS" equipped with a wet disperser (SYMPATIC (SYMP).
(Made by ATEC)).

The carrier is preferably one in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but, 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 forming the resin-dispersed carrier is not particularly limited, and known ones can be used. For example, styrene-acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. be able to.

3. Image Forming Apparatus Next, an image forming apparatus using the toner of the present invention will be described.

FIG. 2 is a sectional view showing an example of the image forming apparatus of the present invention. Reference numeral 4 denotes a photosensitive drum which is a member to be charged, which is formed by forming an organic photoconductor (OPC) which is a photosensitive layer on an outer peripheral surface of a drum base made of aluminum, and rotates at a predetermined speed in an arrow direction. .

In FIG. 2, exposure light is emitted from the semiconductor laser light source 1 based on information read by a document reading device (not shown). This is distributed by the polygon mirror 2 in the direction perpendicular to the paper surface of FIG. 2, and is irradiated on the surface of the photoconductor through the fθ lens 3 that corrects image distortion to form an electrostatic latent image. The photoconductor drum 4 is uniformly charged in advance by the charger 5, and starts rotating clockwise in accordance with the timing of image exposure.

The electrostatic latent image on the surface of the photosensitive drum is the developing device 6
The developed image formed by is transferred by the action of the transfer device 7 to the transfer paper 8 which has been conveyed at a timing. Further, the photosensitive drum 4 and the transfer paper 8 are separated by a separator (separation pole) 9, and the developed image is transferred and carried on the transfer paper 8 and guided to a fixing device 10 to be fixed.

The untransferred toner and the like remaining on the surface of the photoconductor are
It is cleaned by a cleaning device 11 of a cleaning blade type, the residual charge is removed by pre-charge exposure (PCL) 12, and it is uniformly charged again by the charging device 5 for the next image formation.

Next, the transfer paper is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and a PET base for OHP and the like are of course included.

The cleaning blade 13 has a thickness of 1
A rubber-like elastic body of about 30 mm is used, and urethane rubber is most often used as the material. Since this is used in pressure contact with the photoconductor, it is easy to transfer heat. In the present invention, it is desirable to provide a releasing mechanism and keep it away from the photoconductor when the image forming operation is not performed.

The present invention can be preferably used for an image forming apparatus by an electrophotographic method, particularly an apparatus for forming an electrostatic latent image on a photosensitive member by a modulated beam modulated by digital image data from a computer or the like.

In recent years, in the field of electrophotography and the like in which an electrostatic latent image is formed on a photoconductor and the latent image is developed to obtain a visible image, image quality improvement, conversion, editing, etc. are easy and a high quality image is obtained. Research and development of an image forming method using a digital method capable of forming an image are actively performed.

As a scanning optical system that is optically modulated by a digital image signal from a computer or a copy manuscript adopted in this image forming method and apparatus, an acousto-optic modulator is interposed in a laser optical system, and the acousto-optic modulator is used for optical There is a device for modulating and a device for directly modulating the laser intensity by using a semiconductor laser. These scanning optical systems perform spot exposure on a uniformly charged photoconductor to form a dot-shaped image.

The beam emitted from the above-mentioned scanning optical system has a circular or elliptical luminance distribution which has a skirt that spreads to the left and right and approximates a normal distribution. One or both of the scanning direction and the sub-scanning direction is an extremely narrow round or elliptical shape of 20 to 100 μm.

4. Fixing Device The present invention includes a step of passing an image support on which a toner image is formed between a heating roller and a pressure roller which form the fixing device to fix the image support.

FIG. 3 is a schematic sectional view showing an example of a fixing device used in an image forming apparatus using a toner for pressure contact heating. The fixing device 10 shown in FIG.
It is provided with a pressure roller 22 that comes into contact with this. In addition,
In FIG. 3, T is a toner image formed on the transfer paper (image forming support) P.

In the heating roller 21, a coating layer 32 made of an elastic material is formed on the surface of a cored bar 31, a release layer 35 as a surface coating layer is formed thereon, and a heating source 25 made of a linear heater is provided. Is included.

The core metal 31 is made of metal and has an inner diameter of 10 to 70 mm. The metal constituting the cored bar 31 is not particularly limited, but examples thereof include metals such as iron, aluminum and copper, and alloys thereof.

The core 31 has a wall thickness of 0.1 to 15 mm, and is determined in consideration of the balance between the demand for energy saving (thinning) and the strength (depending on the constituent materials). For example,
In order for the core metal made of aluminum to maintain the same strength as the core metal made of iron of 0.57 mm, it is necessary to make the wall thickness 0.8 mm.

The fluororesin constituting the release layer 34 covering the surface and its processing method include PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), P
FC (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer coat type) and the like can be exemplified.

The coating layer 35 made of fluororesin has a thickness of 1
The thickness is 0 to 500 μm, and preferably 20 to 400 μm.

The coating layer 35 made of fluororesin has a thickness of 1
If it is less than 0 μm, the function as a coating layer may not be sufficiently exhibited, and in that case, the durability as a fixing device cannot be secured. On the other hand, 500
The surface of the coating layer having a thickness of more than μm is likely to be scratched by paper powder, and toner or the like may be attached to the scratched portion, resulting in image stains.

As the elastic body constituting the coating layer 32, it is preferable to use silicone rubber such as LTV, RTV, HTV or the like having good heat resistance and silicone sponge rubber.

Asker C, which is an elastic material constituting the coating layer 32
The hardness is less than 80 °, preferably less than 60 °.

The thickness of the elastic coating layer 32 is 0.1 to 30 mm, preferably 0.1 to 20 mm.
It is said that

Asker C, which is an elastic material constituting the coating layer 32
When the hardness exceeds 80 ° and the thickness of the coating layer 32 is less than 0.1 mm, the fixing nip (pressure contact portion) cannot be increased, and the effect as the pressure heat fixing method is sufficient. It may not be possible to exert it.

As the heating source 25, a halogen heater can be preferably used. The pressure roller 22 may have a coating layer made of an elastic material formed on the surface of the cored bar 33, but in this case, the elastic material constituting the coating layer is not particularly limited, and urethane is used. Examples include various soft rubbers such as rubber and silicone rubber, and sponge rubber.

The material forming the core 33 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 21 and the pressure roller 22 is usually 40 to 350 N,
Preferably 50-300 N, more preferably 50-2
It is set to 50N. The contact load is defined in consideration of the strength of the heating roller 21 (the thickness of the cored bar 81), and is, for example, 0.
For a heating roller having a cored bar made of iron of 3 mm, it is preferably 250 N or less.

From the viewpoint of offset resistance and fixing property, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is 0.6 × 10 ⁵ Pa to 1.5 ×.
It is preferably 10 ⁵ Pa.

As an example of fixing conditions by the fixing device shown in FIG. 3, the fixing temperature (surface temperature of the heating roller 21) is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 mm.
/ Sec.

[0147]

[Embodiments] Next, the constitutional example of the present invention will be concretely shown and the effect thereof will be described, but of course, the constitution of the present invention is not limited thereto.

1. Production of Resin Particles [Resin Particles 1HML] (1) Preparation of Core Particles (First Stage Polymerization) An anionic surfactant (101) was placed in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device. ) C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na 7.08 g was dissolved in ion-exchanged water 3010 g to prepare a surfactant solution (water-based medium), which was fed under a nitrogen stream 230r.
While stirring at a stirring speed of pm, set the temperature in the flask to 8
The temperature was raised to 0 ° C.

To this surfactant solution, 9.2 g of a polymerization initiator (potassium persulfate: KPS) was added 200 g of ion-exchanged water.
Was added to the solution of the initiator, and the temperature was adjusted to 75 ° C. Then, 70.1 g of styrene and 1 of n-butyl acrylate were added.
A monomer mixture liquid consisting of 9.9 g and methacrylic acid 10.9 g was added dropwise over 1 hour, and this system was heated and stirred at 75 ° C. for 2 hours to perform polymerization (first-stage polymerization), Resin particles (dispersion liquid of resin particles composed of high molecular weight resin) were prepared. This is designated as "resin particle (1H)".

(2) Formation of Intermediate Layer (Second Stage Polymerization) In a flask equipped with a stirrer, styrene 1
To a monomer mixture liquid consisting of 05.6 g, 30.0 g of n-butyl acrylate, 15.4 g of methacrylic acid, and 5.6 g of n-octyl-3-mercaptopropionic acid ester,
As the crystalline organic compound, the above-exemplified compound 19)
(Hereinafter, referred to as “Exemplified compound (19)”) was added, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

On the other hand, a surfactant solution prepared by dissolving 1.6 g of an anionic surfactant (the above compound (101)) in 2700 ml of ion-exchanged water was heated to 98 ° C., and this surfactant solution was charged with core particles. The resin particles (1
After adding 28 g of H) in terms of solid content, a mechanical dispersing machine “CLEARMIX (CLEARMI) having a circulation path
X) ”(manufactured by M-Technique Co., Ltd.), the monomer solution of the exemplified compound (19) was mixed and dispersed for 8 hours to prepare a dispersion liquid (emulsion liquid) containing emulsified particles (oil droplets).

Next, to this dispersion (emulsion), an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water were added, and this system was added to 98 Polymerization (second-stage polymerization) is performed by heating and stirring at ℃ for 12 hours, and resin particles (dispersion liquid of composite resin particles having a structure in which the surface of resin particles made of high molecular weight resin is covered with intermediate molecular weight resin) Got
This is referred to as "resin particles (1HM)".

(3) Formation of Outer Layer (Third Stage Polymerization) In the resin particles (1HM) obtained as described above, 7.4 g of a polymerization initiator (KPS) was dissolved in 200 ml of deionized water. Add the solution, and under the temperature condition of 80 ° C,
A monomer mixture liquid consisting of 300 g of styrene, 95 g of n-butyl acrylate, 35.4 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester was added dropwise over 1 hour. After completion of the dropwise addition, polymerization (third stage polymerization) is performed by heating and stirring for 2 hours, and then cooled to 28 ° C. to form resin particles (a central portion made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, A composite resin particle having an outer layer made of a low molecular weight resin and containing the exemplary compound (19) in the intermediate layer was obtained. The resin particles are referred to as "resin particles (1HML)".

The composite resin particles constituting this resin particle (1HML) are 138,000, 878,000 and 1.
Has a peak molecular weight of 4,500, and
The weight average particle diameter of the composite resin particles was 124 nm.

2. Preparation of toner Anionic surfactant (sodium dodecyl sulfate) 5
Dissolve 9.0 g in 1600 ml of ion-exchanged water with stirring, and while stirring this solution, 420.0 g of carbon black
Was gradually added, and then dispersion treatment was performed using "CLEARMIX" (manufactured by M-Technique Co., Ltd.) to prepare a dispersion liquid of colorant particles.

Resin particles 1HML 420.7 g (as solid content), ion-exchanged water 900 g, and colorant dispersion liquid 166.
and g were placed in a reaction container (four-necked flask) equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device and stirred. After adjusting the temperature in the vessel to 30 ° C., a 5 mol / liter sodium hydroxide aqueous solution was added to this solution to p.
The H was adjusted to 9.

Next, a salting-out agent was added to ion exchange water of 1000 m.
The aqueous solution dissolved in 1 was added with stirring at 30 ° C. over 10 minutes. The temperature was started after standing for 3 minutes, and the temperature of this system was raised to 90 ° C. over 30 minutes to start the growth of particles.

The particle size of the grown particles was measured with a Coulter Multisizer (manufactured by Coulter, Inc.), and when the volume average particle size reached 4 μm, the salting-out terminator was changed to ion-exchanged water 10.
An aqueous solution dissolved in 00 ml was added to stop grain growth. Further, as the aging treatment, the particles were continuously fused by heating and stirring at a liquid temperature of 98 ° C. for 2 hours.

Then, the mixture was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. Shortly thereafter,
The formed associated particles are filtered, washed by repeatedly suspending and dispersing with ion-exchanged water at 45 ° C., then dried with warm air at 40 ° C., and then mixed with 1% by mass of hydrophobic silica. Toner was obtained. The volume average particle diameter of this toner was 4.5 μm.

3. Heating roller The following was made.

Roller A Diameter 30 mm Release Layer Thickness 0.5 μm PFC (Coat) Roller B Diameter 30 mm Release Layer Thickness 3.0 μm PFC (Coat) Roller C Diameter 30 mm Release Layer Thickness 0.3 μm PFA (Tube) Roller D Diameter 30 mm Release layer thickness 0.8 μm PFA (tube) Roller E Diameter 30 mm Release layer thickness 1.7 μm PFC (coat) 4. A silicone-coated carrier having a volume average particle size of 60 μm was used as a developer for real-life evaluation, and was mixed with the toner so that the toner mass concentration was 6%.

The copy image was printed on an A4 transfer paper at the same size using a character original having an A4 size blackened area ratio of 5%.

5. Evaluation Items and Evaluation Criteria The above-mentioned heating rollers having different surface characteristics were loaded in the winding tester of the fixing device having the constitution as shown in FIG. 1, and the peeling load was measured with the above-prepared polymerization toner.

Further, in order to investigate the degree of actual winding, a commercially available digital copying machine S is used as the image forming apparatus.
It was used by modifying itios Konica 7075 (manufactured by Konica) (basically the same configuration as in FIG. 2). In addition,
The "degree of wrapping" was defined as "○" for 10,000 or less actual photographs, "△" for 3 to 10 photographs, and "x" for worse.

6. Evaluation results The evaluation results of "peeling load" and "degree of wrapping" are plotted on the graph of FIG.

As is apparent from FIG. 4, the winding characteristics are very good when the peeling load is 10 g or less.

[0167]

As described above, according to the present invention, it is possible to judge in advance whether or not the releasability can be ensured by the combination of the pressure contact heat fixing device and the toner, and the toner composition and the heating roller releasing layer can be well conditioned. It is possible to provide a fixing device evaluation method capable of determining a combination and an image forming apparatus provided with a fixing device having good toner releasability.

[Brief description of drawings]

FIG. 1 is a schematic view of a wrapping test machine for a fixing device according to the present invention.

FIG. 2 is a cross-sectional configuration diagram showing an example of an image forming apparatus applied to the present invention.

FIG. 3 is a schematic sectional view of a fixing device applied to the present invention.

FIG. 4 is a graph showing evaluation results of “peeling load” and “degree of wrapping”.

[Explanation of symbols]

1 Semiconductor laser light source 2 polygon mirror 3 fθ lens 4 photoconductor drum 5 charger 6 developer 7 Transfer device 9 separator 10 Fixing device 11 Cleaning device 12 Exposure before charging 13 Cleaning blade 21 heating roller 22 Pressure roller 25 heating source 31, 33 core metal 32 coating layer 35 coating layer P image support (transfer paper) T toner image

Claims (5)

[Claims] 1. A heating roller comprising a cylindrical cored bar having a heating source inside, an elastic layer provided around the cored bar, and a release layer covering the elastic core layer, and a pressing roller pressed against the heating roller. A pressure roller is used to nip and convey an image support bearing an unfixed toner image at its pressure contact portion, and the toner image is pressure contact heated to the image support to fix the toner image. ^3/100 image support on the toner 2.0 mg / cm ² attached to, 2 the surface pressure of the contact portion.
An evaluation method of a fixing device, wherein the fixing load is 8 × 10 ⁵ Pa, and whether or not the tensile load is 10 g or less is measured in a 90 ° peeling test after nipping and conveying. 2. A heating roller comprising a cylindrical cored bar having a heating source inside, an elastic layer provided around the cored bar, and a release layer covering the elastic layer, and a pressing roller pressed against the heating roller. An image forming apparatus including a fixing device which is composed of a pressure roller, holds and conveys an image support bearing an unfixed toner image at its pressure contact portion, and fixes the toner image by heating it in pressure contact with the image support. , stiffness 20~30cm ^3/100
Toner of 2.0 mg / cm ^{2 was} adhered to the image support, the surface pressure of the pressure contact portion was set to 2.8 × 10 ⁵ Pa, and a tensile load of 10 g or less was obtained in a 90 ° peeling test after nipping and conveyance. An image forming apparatus using a combination of a heating roller release layer and a toner. 3. The image forming apparatus according to claim 2, wherein the toner is a polymerization toner. 4. The image forming apparatus according to claim 2, wherein the toner contains a release agent. 5. The image forming apparatus according to claim 2, wherein the release layer contains a fluororesin.