JP2002072551A - Electrostatic charge image developing toner, developer for two-component electrostatic charge image development and method for forming image using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner, a two- component electrostatic charge image developing developer and a method for forming images, by using the developer with fixed images, having high gloss and superior low-temperature fixing property, OHP transparency, offset resistance and preventing property with respect to winding can be formed, while oil is substantially not applied for fixing by heating and pressurizing and moreover without using a release submember or the like. SOLUTION: In the electrostatic charge image developing toner, the two- component electrostatic charge image developer and the method for forming images by using the developer, the mol.wt. distribution of the component of the toner dissolved in tetrahydrofuran measured by gel permeation chromatography shows that the weight ratio is in the range of <=5,000 mol.wt. is <=20 wt.%, proportion in the range from 5,000 to 10,000 mol.wt. is 10 to 20%, proportion in the range from 10,000 to 50,000 mol.wt. is 40 to 60%, and the ratio in the range of 105 to 106 mol.wt. is <=5%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image using electrophotography and electrostatic recording, a developer for developing a two-component electrostatic image, and an image forming method using the same. It is.

[0002]

2. Description of the Related Art Conventionally, when an image can be formed in a copying machine, a laser beam printer, or the like, the Carlson method is generally used. In a conventional image forming method using black-and-white electrophotography, an electrostatic latent image formed on a photoreceptor by optical means is developed in a developing process, and then transferred to a recording medium such as a recording paper in a transfer process. In the fixing step, the toner is generally fixed on a recording medium such as recording paper by heat and pressure to obtain a black and white image.

In recent years, electrophotographic technology has been rapidly developed from black and white to full color. Color image formation by full-color electrophotography generally reproduces all colors using four colors of three primary color toners of yellow, magenta, and cyan plus black. In general full-color electrophotography, an original is first separated into yellow, magenta, cyan, and black colors, and an electrostatic latent image is formed on the photoconductive layer for each color. Next, the toner is held on a recording medium through development and transfer steps. Next, the above-described steps are sequentially performed a plurality of times, and the toner is superimposed on the same recording medium while adjusting the position. Then, a full-color image is obtained by one fixing step. The fact that several kinds of toners having different colors are superposed on each other is a great difference between the black-and-white electrophotographic method and the full-color electrophotographic method. In the color toner used in the full-color electrophotography, it is necessary that the multi-color toner is sufficiently mixed in the fixing process, and by sufficiently mixing, the color reproducibility and the transparency of the OHP image are improved, so that a full-color image with high image quality is obtained. Can be obtained. Compared with black toner for black-and-white printing, color toner is generally desired to be formed of a sharp melt low molecular weight resin in order to enhance this color mixing property.

In a conventional black toner for black-and-white printing, a fixing device such as a heat roller contacts with a fixing device such as a heat roller at the time of fixing, so that a part of the toner image adheres to the surface of the heat roller and transfers. In order to prevent the offset phenomenon, a wax having a high crystallinity and a relatively high melting point, such as polyethylene or polypropylene, is included. Generally, in the case of a high-viscosity toner, such as a black toner for black and white printing, since the intermolecular cohesion at the time of thermal melting of the toner is strong,
Offset can be prevented by exuding a small amount of wax.

On the other hand, when it is necessary to form a color by superposing two or more color toners, such as a full-color toner, or to produce a flat fixed image surface in order to impart transparency to an OHP image, a low image quality is required. It is necessary to increase viscosity and heat fusibility. In this case, it is necessary to add a large amount of wax in order to exert a sufficient effect on the offset resistance.
However, in the case of the toner manufactured by the melt-kneading / pulverization method, the toner has a toner structure in which the wax is exposed on the surface of the toner. The surface of the developing sleeve is easily contaminated, and the image is easily deteriorated.

For this reason, a normal full-color color toner does not contain wax, and for the purpose of preventing this offset, the surface of the heat-fixing roller is formed of silicone rubber or fluororesin having excellent releasability from the toner. Further, a method of supplying a releasing liquid such as silicone oil to the surface is adopted. Although this method is extremely effective in preventing the offset phenomenon of the toner, it has a problem that a device for supplying an anti-offset liquid is required.
This is in the direction opposite to the reduction in size and weight, and the anti-offset liquid may be heated to evaporate to give an unpleasant odor or to cause contamination inside the machine.

[0007] Because of these problems, a low-molecular weight resin of sharp melt is used in a full-color color toner, a small amount of a low-melting-point wax is included, and a releasing liquid is supplied to the surface of the heat-fixing roller. A toner capable of fixing without performing the fixing is being studied.

As one of the studies, various reports have been made for the purpose of controlling the molecular weight distribution of a binder resin.
Generally, a low molecular weight resin has a low viscosity and is a sharp melt, which is advantageous for low-temperature fixing and flat fixed image formation, but is inferior in offset resistance. A high molecular weight resin has high viscosity and is advantageous for offset resistance, but is disadvantageous for low-temperature fixing and flat fixed image formation.

Therefore, there have been some attempts to satisfy both the low-temperature fixability and the anti-offset property by combining a low molecular weight resin and a high molecular weight resin or by defining the molecular weight distribution. For example, as those defining the molecular weight distribution, those defining the value of Mw / Mn as disclosed in JP-A-10-207126, those disclosed in JP-A-10-6206
JP-A-10-228131, JP-A-3-278067
Japanese Patent Application Laid-Open Publication No. H11-157, as well as those in which the ratio between the low molecular weight component and the high molecular weight component is finely defined.

However, Japanese Patent Application Laid-Open No. 10-207126 discloses
In the molecular weight distribution having a wide distribution as disclosed in JP-A-10-228131 and JP-A-10-228131, the ratio of high-molecular-weight components is large, and low-temperature fixing and OHP transparency are not sufficient.
Japanese Patent Application Laid-Open No. Hei 10-63035 discloses a molecular weight of 500
A toner having a peak in a very low molecular weight region of 1000 to 1000 or a toner having a molecular weight distribution of 10000 or less and a ratio of 55% to 80% in JP-A-3-278067 is disclosed. These toners include:
Since the toner contains a large amount of low molecular weight components, it is difficult to adopt a fixing method in which no oil is supplied in the fixing step. Even if a fixing method that does not supply oil by strictly controlling the fixing temperature range could be used, when these toners are used, the paper is heated in a fixing process, especially on paper having a small basis weight or on paper that has absorbed moisture. The phenomenon of winding around the member occurs. Therefore, the fixing has to be performed by slightly widening the fixing temperature range in which the fixing can be performed by preventing the paper from being wrapped around by using the separation assisting member or the like in the fixing step.

FIG. 2 shows an example of a fixing device provided with a peeling assisting member. The fixing device shown in FIG.
And a pressure member 2, and a transport belt 4
Is pressed through. A peeling assisting member 3 is provided on the transport belt 3 near a contact point (nip) between the heating member (heating roll) 1 and the pressing member (pressure roll) 2.
Such a peeling assisting member 3 is, in its attachment,
The positions of the heating member 1, the pressing member 2, and the separation assisting member 3 must be strictly controlled, and the efficiency of the assembling process of the electrophotographic apparatus becomes very poor. Further, when the user uses paper having a small basis weight other than the positional accuracy of the peeling assisting member 3 or the one which is not guaranteed by the electrophotographic apparatus, once the paper is wound around the heating member, the paper becomes the heating material. It becomes jammed in a slight gap with the separation assisting member, and it becomes very difficult to remove the jammed paper.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a low-temperature fixing property, an OHP transparency, an offset resistance, and an anti-winding property without substantially applying oil in heat and pressure fixing and without using a peeling auxiliary member or the like. The present invention relates to a toner for developing an electrostatic image capable of forming a fixed image with excellent glossiness, a two-component developer for developing an electrostatic image, and an image forming method using the same.

[0013]

The above object is achieved by the following means. That is, the present invention relates to: <1> In a toner for developing an electrostatic image containing toner particles containing at least a binder resin, a colorant, and a wax, the molecular weight of a tetrahydrofuran-soluble component of the toner by gel permeation chromatography In the distribution, the weight ratio distributed in the range of molecular weight of 5,000 or less is 20% by weight or less, and the molecular weight is 5,000 to 10,000.
Is 10% to 20%, the weight ratio distributed in the molecular weight range of 10,000 to 50,000 is 40% to 60%, and the weight ratio distributed in the molecular weight range of 10 ⁵ to 10 ⁶ is It is a toner for developing an electrostatic image, wherein the toner content is 5% or less. <2> A two-component developer for developing an electrostatic image, comprising the electrostatic image developing toner described in <1> and a carrier. <3> a latent image forming step of forming an electrostatic latent image on the latent image carrier, a developing step of developing the electrostatic latent image with toner to form a toner image, and applying the toner image to a transfer material An image forming method comprising: a transferring step of forming a transferred image by transferring; and a fixing step of fixing the transferred image using a heating material and a pressing material, wherein the toner is described in <1>. An image forming method, which is an electrostatic image developing toner.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Electrostatic Image Developing Toner) The electrostatic image developing toner of the present invention comprises toner particles containing at least a binder resin, a colorant and a wax. Permeation chromatography (GPC) of tetrahydrofuran (THF) dissolved components in water
Weight ratio distributed in the range of molecular weight 5000 or less in the molecular weight distribution according to
The weight ratio distributed in the range of 0 to 10000 is 10% to 2%.
0%, the weight percentage distributed in the molecular weight range of 10,000 to 50,000 is 40% to 60%, and the molecular weight is 10 ⁵
The weight ratio distributed in the range of -10 to ⁶ is 5% or less.
Hereinafter, this molecular weight distribution may be referred to as “specific molecular weight distribution”. Preferably, the TH of the toner particles is
In the molecular weight distribution of the F-dissolved component by GPC, the weight ratio distributed in the molecular weight range of 5000 or less is 18% or less (more preferably 15% or less), and the molecular weight is 5000 or less.
The weight ratio distributed in the range of 10,000 to 10% is 18%.
% (More preferably 10% to 15%) and a molecular weight of 1
The weight ratio distributed in the range of 0000 to 50,000 is 45.
% To 60% (more preferably 50% to 60%),
The weight ratio distributed in the range of molecular weight 10 ⁵ to 10 ⁶ is preferably 3% or less (more preferably 1% or less).

Since the toner for developing an electrostatic image of the present invention has the above-mentioned specific molecular weight distribution, it can be fixed at a low temperature without substantially applying oil in heat and pressure fixing and without using a peeling assisting member. It has excellent transparency, OHP transparency, offset resistance, and anti-winding properties, and can form a fixed image with high gloss. For this reason, when the weight ratio of the THF-soluble component of the toner in the molecular weight distribution by GPC of less than 5000 is more than 20% by weight, the offset resistance is remarkably inferior. Molecular weight 50
The weight ratio distributed in the range of 00 to 10,000 is 1
If it is less than 0%, the wrapping property around a fixing member (for example, a heating member) decreases, while if it is more than 20%, the low-temperature fixing property is lost. If the weight ratio distributed in the range of molecular weight of 10,000 to 50,000 is less than 40%, the wrapping property around the heating member is reduced, while if it is more than 60%, the low-temperature fixability is lost. If the weight ratio distributed in the range of molecular weight 10 ⁵ to 10 ⁶ is more than 5%, the low-temperature fixability and OHP transparency will be significantly reduced.

FIG. 1 shows an example of a specific molecular weight distribution in the toner for developing an electrostatic image of the present invention. The specific molecular weight distribution shown in FIG. 1 shows the relationship between the molecular weight and its differential molecular weight distribution value (%). As described above, in the present invention, the offset resistance is improved by reducing the amount of the low molecular weight component, and the low temperature fixing property, the OHP transparency, and the flat fixed image forming performance are improved by further reducing the high molecular weight component. Is increasing. In other words, by narrowing the molecular weight distribution and controlling the amounts of the low molecular weight component and the high molecular weight component, it is possible to simultaneously satisfy various characteristics required for a full-color toner. Further, in the present invention, the wrapping property around a fixing member (for example, a heating member) can be reduced by strictly controlling the amounts of the low molecular weight component, the medium molecular weight component, and the high molecular weight component. It is considered that the property of preventing the toner from winding around the fixing member has a large correlation with the molecular weight distribution of the toner. If the amount of the low molecular weight component in the toner is large, the wrapping property is increased. It is presumed that if the amount of the medium and high molecular weight components is too small, the winding property will increase.

In the toner for developing electrostatic images of the present invention,
The specific molecular weight distribution was obtained under the following conditions.
GPC is "HLC-8120 GPC, SC-8020
(Manufactured by Tosoh Corporation) and the column is “TSK
gel, SuperHM-H (6.0 manufactured by Tosoh Corporation)
mmID × 15 cm) ”and used as eluent TH
F (tetrahydrofuran) was used. The experimental conditions include a sample concentration of 0.5%, a flow rate of 0.6 ml / min. An experiment was performed using a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “po” manufactured by Tosoh Corporation.
lystyrene standard sample TSK standard
d ":" A-500 "," F-1 "," F-10 ",
"F-80", "F-380", "A-2500",
"F-4", "F-40", "F-128", "F-7"
"00".

In the toner for developing an electrostatic image of the present invention,
The toner having the above specific molecular weight distribution can be obtained by appropriately selecting the types or amounts of the binder resin, the colorant, the wax, and other internal additives and the external additives constituting the toner particles. . Hereinafter, each material will be described in detail. However, as each of these materials, conventionally known materials can be used, and the materials are not limited to these specific examples.

Examples of the binder resin include styrenes such as styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl acetate; acrylic acid A-methylene aliphatic monocarboxylic esters such as methyl, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate; vinyl Homopolymers or copolymers of vinyl ethers such as methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone;

Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer,
Styrene-maleic anhydride copolymer, polyethylene, polypropylene and the like. In addition, polyester resin, polyurethane resin, epoxy resin, silicone resin,
Polyamide resin, modified rosin, paraffin, and waxes are also included.

Of these, polyester resins are particularly preferred. A polyester resin can be synthesized from a polyol component and a polycarboxylic acid component by polycondensation. As the polyol component, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3 butanediol, diethylene glycol, triethylene glycol, 1,5-butanediol, 1,6-hexanediol , Neopentyl glycol, cyclohexanedimethanol, hydrogenated bisphenol A, bisphenol-A ethylene oxide adduct, bisphenol-A propylene oxide adduct, and the like. As the polyol component, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, dodecenylsuccinic acid, trimellitic acid, pyromellitic acid, cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 2,4-naphthalene tricarboxylic acid 1,2,5 hexane tricarboxylic acid, 1,3
-Dicarboxyl-2-methylenecarboxypropanetetramethylenecarboxylic acid and their anhydrides. Among them, as the polyester resin, a linear polyester resin composed of a polycondensate containing bisphenol A as a polyol component and a polyvalent aromatic carboxylic acid as a polycarboxylic acid component as a main monomer component is particularly preferably used. can do.

The binder resin has a softening point of 90 to 150 °.
Resins having physical properties such as C, a glass transition point of 55 to 75 ° C., an acid value of 5 to 30, and a hydroxyl value of 5 to 40 can be particularly preferably used.

Examples of the coloring agent include carbon black, nigrosine, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose bengal. , C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 1
22, C.I. I. Pigment Red 57: 1, C.I. I.
Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment Blue 15: 1, C.I.
I. Pigment Blue 15: 3 and the like.

As the wax, those having a melting point in a temperature range of 70 to 100 ° C. are preferable. This melting point is 70
If the temperature is lower than 0 ° C, the change temperature of the wax may be too low and the blocking resistance may be poor, or the developability may be deteriorated when the temperature in the copying machine is increased. On the other hand, when the temperature exceeds 100 ° C., the temperature at which the wax changes may be too high, and fixing at a high temperature may be performed, but this is not preferable from the viewpoint of energy saving.

As the wax, 1 to 110 ° C.
Those having a melt viscosity of 200 mPa · s (1 to 200 centipoise) are preferred, and more preferably 1 to 100 m
It shows a melt viscosity of Pa · s (1 to 100 centipoise). When the melt viscosity is less than 1 mPa · s, the viscosity of the wax is too low in the kneading and pulverizing method, so that the dispersibility in the toner particles may be deteriorated. On the other hand, 200m
If it is higher than Pa · s, the dissolution from the toner particles is weak, and the fixability and releasability may be insufficient.

The amount of the wax added to the toner particles is as follows:
It is preferably from 5 wt% to 10 wt%, more preferably from 5 to 8 wt%. If the addition amount is less than 5%, a sufficient fixing latitude (a fixing member temperature range in which fixing can be performed without toner offset) may not be selected. On the other hand, if the content is more than 10 wt%, the amount of wax detached and released from the toner particles increases, and the developer carrier is likely to be contaminated. In addition, the powder fluidity of the toner particles deteriorates, and free wax adheres to the surface of the photoconductor on which the electrostatic latent image is formed, so that the electrostatic latent image cannot be accurately formed. Further, since wax is inferior in transparency as compared with a binder resin, transparency of an image such as OHP is reduced,
This may result in a distorted projected image.

The wax is preferably one having an endothermic onset temperature of 40 ° C. or more, more preferably 50 ° C. or more, as measured by a DSC curve measured by a differential scanning calorimeter. If the heat absorption start temperature is lower than 40 ° C., toner particles may aggregate in a copying machine or a toner bottle. The endothermic onset temperature is determined by the molecular weight distribution of the wax, which has a low molecular weight and the type and amount of the polar group having the structure. In general, when the molecular weight is increased, the endothermic onset temperature rises together with the melting point, but this method detracts from the inherently low melting temperature and low viscosity of the wax. Therefore, it is effective to select only those having a low molecular weight from the molecular weight distribution of the wax, and there are methods such as molecular distillation, solvent fractionation, and gas chromatographic fractionation.

Specific examples of the wax include those obtained from waxes such as paraffin wax and its derivatives, montan wax and its derivatives, microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, and polyolefin wax and its derivatives. It is. Here, the derivative includes an oxide, a polymer with a vinyl monomer, and a graft-modified product. In addition, as the wax, an alcohol, a fatty acid, a vegetable wax, an animal wax, a mineral wax, an ester wax, an acid amide, or the like can be used.

In the toner for developing an electrostatic image of the present invention,
It is preferable to add inorganic fine particles internally to the toner particles. By internally adding the inorganic fine particles to the toner particles, it is possible to finely and uniformly disperse the wax, and fine dispersion of the wax improves the fluidity of the powder, and the inside of the image forming apparatus (e.g. (Container interior) can be reduced. In addition, the properties, particularly the offset resistance, are improved, and the winding property around the heating member can be further improved. It is presumed that this is because the internal addition of inorganic fine particles into the toner particles makes it possible to increase the storage elastic modulus without increasing the loss elastic modulus of the toner particles so much. Since the storage elastic modulus is increased, rubber elasticity is imparted to the toner particles, and the wrapping property around the fixing member (for example, the heating member) can be further reduced. By controlling the amount of inorganic fine particles added,
Since the storage modulus can be increased without increasing the loss modulus, the low-temperature fixability of the toner particles is not impaired.

The addition amount of the inorganic fine particles is 2% to 10%
And more preferably 3% to 8%. If the amount of the inorganic fine particles is less than 2%, the effect of increasing the storage elastic modulus of the toner particles may be substantially lost. On the other hand, if it is more than 10%, the loss elastic modulus of the toner becomes large, and the low-temperature fixability may be lost. In addition, the surface of the fixed image has a structure having irregularities, and the color reproduction range of the color image is reduced. May be smaller.

As the inorganic fine particles, for example, known inorganic compounds such as silica, alumina and titania can be used without any particular limitation. These can be used alone or in combination of two or more. It can also be used. In the present invention, among these, silica fine particles having a refractive index smaller than that of the binder resin are preferable from the viewpoint of OHP transparency. Such silica fine particles may specifically contain aluminum silicate, sodium silicate, potassium silicate, and the like in addition to anhydrous silica, but the refractive index is 1.5 or less. A composition having such a composition is preferable. The silica fine particles may be surface-treated using various methods. Specifically, for example, those surface-treated with a silane coupling agent, a titanium coupling agent, silicone oil, or the like can be preferably used.

In the toner for developing an electrostatic image of the present invention, an aliphatic hydrocarbon-aromatic hydrocarbon copolymer petroleum resin having 9 or more carbon atoms is added to the toner particles for the purpose of improving the dispersibility of the wax. It is also possible. As used herein, the term "aliphatic hydrocarbon-aromatic hydrocarbon copolymerized petroleum resin having 9 or more carbon atoms" refers to a cracked oil fraction by-produced from an ethylene plant that produces ethylene, propylene, etc. by steam cracking of petroleum. Is synthesized using diolefins and monoolefins as raw materials,
Specifically, at least one selected from isoprene, piperylene, 2-methyl-butene-1, and 2-methylbutene-2
At least one kind of aliphatic hydrocarbon monomer, vinyltoluene,
Those obtained by copolymerizing at least one kind of aromatic hydrocarbon monomer selected from α-methylstyrene, indene and isopropenyltoluene are preferred.

Here, when a pure monomer having high monomer purity is used as the aromatic hydrocarbon monomer,
It is more preferable because coloring of the resin and odor during heating can be suppressed low. The purity of the aromatic hydrocarbon monomer is preferably 95% or more, and more preferably 98% or more. The aromatic hydrocarbon monomer comprises a monomer having 9 or more carbon atoms. In the case of a copolymerized petroleum resin obtained from this monomer and an aliphatic hydrocarbon monomer, an aromatic hydrocarbon monomer having less than 9 carbon atoms and an aliphatic hydrocarbon monomer are used. Binder resin compared to copolymerized petroleum resin obtained from aromatic hydrocarbon monomer,
For example, it is preferable because compatibility with the polyester resin becomes higher.

The addition amount of the aromatic hydrocarbon copolymerized petroleum resin is preferably 2% to 10%. If the amount is less than 2%, the effect of improving the dispersibility of the wax may be reduced. On the other hand, if it exceeds 10%, the wax does not disperse in the toner resin (binder resin, etc.),
The aromatic hydrocarbon copolymerized petroleum resin is mainly compatible with itself, and the effect of the wax as a mold release material in the toner may be reduced.

In the toner for developing an electrostatic image of the present invention,
The toner particles may further include one or more charge control agents for adjusting charge as an internal additive. Further, a petroleum resin may be contained in order to satisfy the pulverizability and heat storage property of the toner particles. The petroleum-based resin is synthesized from diolefins and monoolefins contained in a cracked oil fraction produced as a by-product from an ethylene plant that produces ethylene, propylene, etc. by steam cracking of petroleum.

In the toner for developing electrostatic images of the present invention,
Further, an inorganic powder or a resin powder may be externally added to the surface of the toner particles alone or in combination for the purpose of further improving long-term storage properties, fluidity, developability, and transferability (external additive). Examples of the inorganic powder include carbon black, silica, alumina, titania, zinc oxide and the like. PMMA, nylon, melamine, benzoguanamine,
Spherical particles such as fluorine-based; irregular-shaped powders such as vinylidene chloride and fatty acid metal salts. When these inorganic powder and resin powder are externally added to the surface of the toner particles, the amount of each is preferably 0.2 to 4% by weight, more preferably 0.5 to 3% by weight, based on the toner particles. %.

The toner for developing an electrostatic image of the present invention is kneaded
It can be produced by a known method such as a pulverization method, a chemical method such as emulsion polymerization or suspension polymerization. Here, as an example, a manufacturing method by a kneading and pulverizing manufacturing method will be described. In the kneading and pulverizing method, the addition of the internal additive to the inside of the toner particles is performed by a kneading process. The kneading at this time can be performed using various types of heating kneaders. As a heating kneader, a three-roll type, a single screw type, a twin screw type, and a Banbury mixer type are known.
In addition, the method of pulverizing and classifying the toner particles is optional.
Examples of the pulverization of the kneaded material include a micronizer, Ulmax, Jet-o-miser, KTM (Krypton), turbo mill, I-type Jet-Mill, and the like. The classification includes a wind-type elbow jet or the like using the Coander effect. In addition, at the time of classification or as a subsequent step, a hybridization system (manufactured by Nara Machinery), a mechanofusion system (manufactured by Hosokawa Micron), a cryptotron system (manufactured by Kawasaki Heavy Industries)
The shape can be changed by adding the like, and the sphere can be formed by hot air.

(Two-Component Developer) The two-component developer of the present invention contains the electrostatic developing toner of the present invention and a carrier. The carrier is not particularly limited as long as it is a known carrier, and examples thereof include an iron powder-based carrier, a ferrite-based carrier, and a surface-coated ferrite carrier.

(Image Forming Method) In the image forming method of the present invention, a latent image forming step of forming an electrostatic latent image on a latent image carrier, and a toner image is formed by developing the electrostatic latent image with toner. Developing step, a transfer step of transferring the toner image onto a transfer material to form a transfer image, and a fixing step of fixing the transfer image using a heating material and a pressure material. The toner is the electrostatic image developing toner of the present invention. The image forming method of the present invention uses the toner for developing an electrostatic image of the present invention as the toner, and does not substantially apply oil in heat and pressure fixing, and does not use a peeling auxiliary member or the like. It has excellent low-temperature fixing property, OHP transparency, offset resistance, and anti-winding properties, and can form a fixed image with high gloss.

In the fixing step, the surfaces of the heating material and the pressing material are preferably formed of a silicone resin or a fluorine resin.
It is more preferable from the viewpoint of releasability from the toner. Specific examples of such a fluororesin include, for example, a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether, a copolymer of tetrafluoroethylene and ethylene, and a copolymer of tetrafluoroethylene and hexafluoroethylene. Combination is preferred.

In the fixing step, fixing can be performed on the surfaces of the heating material and the pressure material without using a releasable liquid such as silicone oil. Although the release liquid is effective for fixing latitude, it transfers to the transfer material to be fixed, so there is stickiness, and it is not possible to attach tape, and it is not possible to add characters with Magic (registered trademark). There is a problem. This is remarkable for OHP. In addition, since the release liquid cannot make the surface of the fixing surface smooth, it also causes a decrease in OHP transparency. However, the toner for developing an electrostatic image of the present invention exhibits a sufficient fixing latitude, so that the releasing liquid applied to a fixing agent (for example, a fixing roll or the like) is used for fixing which substantially uses. Can be. . However, in the case where high-speed printing is supported, a slight release liquid can be supplied. In this case, the supply amount may be, for example, 1 μl or less per A4 sheet. With the above range, the above-mentioned problems can be substantially avoided.

In the fixing step, the fixing can be performed without using a peeling assisting member. In the image forming method of the present invention, since the toner for developing an electrostatic image of the present invention can be prevented from winding around the fixing member, the fixing can be performed without using the separation assisting member. .

In the image forming method of the present invention, the steps other than the fixing step are not particularly limited, and can be performed by a conventionally known method.

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these embodiments do not limit the present invention. Hereinafter, the present invention will be described more specifically with reference to examples. However, in each of these examples,
It does not limit the invention. Note that all “parts” in the text indicate “parts by weight”.

[Preparation of Binder Resin] Monomers were selected according to Table 1 to prepare seven types of linear polyester binder resins 1 to 7 having various molecular weight distributions. The number average molecular weight (Mn) is also shown.

[0046]

[Table 1]

[Preparation of Toner] <Toner Particle 1> -Composition- Linear Polyester 1 84 parts Magenta pigment (CI Pigment Red 57: 1) 6 parts Microcrystalline wax (melting point 85 ° C.) 5 parts Aromatic Hydrocarbon copolymer petroleum resin 5 parts

The above composition is kneaded with an extruder,
After pulverizing with a surface pulverizer, fine particles and coarse particles were classified by an air classifier to obtain magenta toner particles 1 having an average particle diameter d50 = 6.8 μm.

<Toner particles 2> Linear polyester 2 76 parts Magenta pigment (CI Pigment Red 57: 1) 6 parts Silica fine particles (R972 manufactured by Nippon Aerosil Co., Ltd.) 5 parts Microcrystalline wax (melting point 85 ° C.) 5 Part Aromatic hydrocarbon copolymerized petroleum resin 8 parts

The above composition is kneaded with an extruder,
After pulverizing with a pulverizer of a surface pulverizing method, fine particles and coarse particles were classified by an air classifier to obtain magenta toner particles 2 having an average particle diameter d50 = 7.8 μm.

<Toner Particles 3> The average particle diameter d50 was the same as that of the toner 1 except that the linear polyester 3 was used.
= 6.2 μm magenta toner particles 3 were obtained.

<Toner Particles 4> The average particle diameter d50 was the same as that of the toner 1 except that the linear polyester 4 was used.
= 6.5 μm magenta toner particles 4 were obtained.

<Toner Particles 5> The average particle diameter d50 is the same as that of the toner 1 except that the linear polyester 5 is used.
= 7.9 μm magenta toner particles were obtained.

<Toner Particles 6> The average particle diameter d50 was the same as that of the toner 1 except that the linear polyester 6 was used.
= 7.5 μm was obtained.

<Toner Particles 7> The average particle diameter d50 was the same as that of the toner 1 except that the linear polyester 7 was used.
= 6.8 μm magenta toner particles 7 were obtained.

Using these toner particles 1 to 7, toners 1 to 7 were prepared by adding 1.2 parts of negatively chargeable silica and 0.7 parts of negatively chargeable titania to 100 parts of the toner particles.
Table 2 shows the measurement results of the molecular weight distributions of the toner particles 1 to 7.
Shown in In addition, this molecular weight distribution was performed as shown above.

[0057]

[Table 2]

[Preparation of Developer] M having an average particle diameter of 50 μm
To 100 parts of a carrier obtained by coating n-Mg ferrite with a styrene-methyl methacrylate copolymer, 6 parts of toners 1 to 7 were added and mixed to prepare developers 1 to 7, respectively.

(Examples 1 and 2 and Comparative Examples 1 to 5) An electrophotographic copying machine (A-Color 93) was used
5, manufactured by Fuji Xerox Co., Ltd.), and a copy test was performed without using a peeling assisting member.
At this time, the peripheral speed of the fixing roller was set to 100 mm / sec. For test, A4 transfer paper is 5cm long and 4cm wide.
A solid unfixed toner image was prepared. At this time, toner images were prepared so that the toner amount was 0.5 mg / cm ² and 1.5 mg / cm ^2, and the following evaluation was performed. Table 3 shows the results.

-Fixable temperature range- Using a solid unfixed toner image having a toner amount of 1.5 mg / cm ² , using the A-Color 630 modified so that the fixing roll temperature can be freely set and monitored, and fixed. The supply of the release agent oil to the roll was stopped, and the test was performed in a state where the release agent oil was not substantially present on the surface of the fixing roll (fixing member). That is, the surface temperature of the fixing roll was changed stepwise, and an unfixed toner image was fixed using a transfer sheet holding the toner image at each surface temperature.
At this time, observation was made as to whether toner stains from the fixing roll occurred in the margins of the paper, and the maximum temperature at which no stains occurred was taken as the upper limit temperature of the fixable temperature region. Further, when the paper was wound around the heating roll during the experiment, the offset resistance experiment was stopped at that temperature, and the maximum temperature at which the winding did not occur was set as the upper limit temperature of the fixing temperature range. Further, using a solid unfixed toner image having a toner amount of 0.5 mg / cm ² , the supply of the release agent oil to the fixing roll was stopped, and the release agent oil was substantially not present on the surface of the fixing roll. The temperature was changed stepwise, and the unfixed toner image was fixed using a transfer paper holding the toner image at each surface temperature. At this time, the glossiness of the fixed sample is represented by G
The glossiness of 75 degrees was measured using a loss meter (manufactured by Murakami Color Engineering Laboratory). Among the gloss levels selected at each temperature, the lowest temperature exceeding the gloss level of 40 was set as the lower limit temperature of the fixable temperature range.

-Low-temperature fixability- The low-temperature fixability was evaluated as ○ when the lower limit temperature of the feasible temperature range was less than 135 degrees, Δ when it was 135 degrees or more and less than 145 degrees, and x when 145 degrees or more.

—Offset Property— The anti-offset property is as follows.
0 degrees or more: ○, 170 degrees or more and less than 180 degrees: Δ, 170
The value less than degree was evaluated as x.

Fixing Member Wrapping Property The fixing member wrapping property is determined by the upper limit temperature of the feasible temperature range,
That is, the maximum temperature at which no wrapping occurs is as follows: 180 ° C. or higher: ○; 170 ° C. or higher, but lower than 180 ° C .;
Was evaluated. -OHP permeability-Using a solid unfixed toner image having a toner amount of 0.5 mg / cm ² , releasing the release agent oil to the fixing roll, and substantially eliminating the release agent oil on the surface of the fixing roll,
A test at 160 ° C. was performed. The ratio of the straight traveling light to the transmitted light of the fixed image was determined and defined as OHP transmittance. Specifically, the viewing angle is 3.5 as the straight light component of the transmitted light.
The transmitted light rate (%) was determined by using the value condensed in degrees and the ratio to the value condensed in the viewing angle of 45 degrees. The OHP transparency was evaluated as ○ when the transmittance (%) was 80% or more, Δ when the transmittance was 70% or more and less than 80%, and X when the transmittance was less than 70%.

[0064]

[Table 3]

As is clear from the results in Table 3, Example 1
In No. 2 to No. 2, since the used toner has the above-mentioned specific molecular weight distribution, the low-temperature fixing property and the anti-offset property are obtained without supplying the releasing liquid to the fixing member (heating member) and without attaching the peeling assisting device. Properties, OHP transparency, and anti-winding properties can all be satisfied. Further, in Example 2, since the inorganic fine particles are contained in the toner particles, the fixing temperature range is as wide as 60 ° C. or more, and it can be seen that excellent characteristics are exhibited.

In Comparative Example 1, the toner used had a molecular weight of 50
00 or less, weight ratio distributed in the range of molecular weight 5,000 to 10,000, molecular weight 10,000 to molecular weight 5
Weight ratio, molecular weight 10 ⁵ -1 distributed in the range of 0000
In all of the weight ratio of distribution in the range of 0 ^6, because they do not meet the above specified molecular weight distribution conditions, resistance to winding resistance and OHP transparency it can be seen that very bad.

In Comparative Example 2, the toner used had a molecular weight of 50
Since the ratio of 00 or less does not satisfy the condition of the specific molecular weight distribution, it is understood that the winding resistance is very poor. In Comparative Example 3, the used toner has a molecular weight of 5,000 to 5,000.
3.8% distribution in the molecular weight range of 10,000,
Since the specific molecular weight distribution condition of 10% to 20% is not satisfied, the glossiness is low and the low-temperature fixability is poor. In Comparative Example 4, the toner used had a molecular weight of 1
The ratio distributed in the range of 0000 to 50,000 is 3
2.7% and 40% which is the condition of the specific molecular weight distribution.
It can be seen that the glossiness is low and the low-temperature fixability is poor because it does not satisfy 60%. In Comparative Example 5, the weight ratio at which the used toner was distributed in the molecular weight range of 10 ⁵ to 10 ⁶ was 1
It can be seen that the low-temperature fixability and the OHP transparency are poor because 3.5% and 5% or less, which is the condition of the specific molecular weight distribution, are not satisfied.

[0068]

As described above, according to the present invention, low-temperature fixability, OHP transparency, offset resistance, and the like can be obtained without substantially applying oil in heat and pressure fixing and without using a separation assisting member. Further, it is possible to provide a toner for developing an electrostatic image, which is excellent in anti-winding property and can form a fixed image having a high glossiness, a two-component developer for developing an electrostatic image, and an image forming method using the same.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a specific molecular weight distribution in an electrostatic image developing toner of the present invention.

FIG. 2 is a schematic configuration diagram illustrating an example of a fixing device including a separation assisting member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating member 2 Pressurizing member 3 Peeling auxiliary member 4 Conveyor belt

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruhide Ishida 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture F-Xerox Co., Ltd. F-term (reference) 2H005 AA01 AA06 CA08 CA14 EA06

Claims (3)

[Claims] 1. In a toner for developing an electrostatic image containing toner particles containing at least a binder resin, a colorant, and a wax, the molecular weight of the tetrahydrofuran-soluble component of the toner in the molecular weight distribution determined by gel permeation chromatography. The weight ratio distributed in the range of 5000 or less is 20% by weight or less, and the molecular weight is 5000 to 1%.
The weight percentage distributed in the range of 0000 is 10% to 20%, the weight percentage distributed in the range of molecular weight of 10,000 to 50,000 is 40% to 60%, and the molecular weight is 10 ⁵ to 10 ^6.
The toner for developing an electrostatic charge image, wherein the weight ratio distributed in the range of 5% or less is 5% or less. 2. A two-component developer for developing an electrostatic image, comprising the toner for developing an electrostatic image according to claim 1 and a carrier. 3. A latent image forming step of forming an electrostatic latent image on a latent image carrier, a developing step of developing the electrostatic latent image with toner to form a toner image, and transferring the toner image to a transfer material. 2. An image forming method, comprising: a transfer step of transferring a transfer image to form a transfer image thereon; and a fixing step of fixing the transfer image using a heating material and a pressure material, wherein the toner is defined in claim 1. An image forming method, wherein the toner is a toner for developing an electrostatic image.