JP2002341597A - Electrostatic charge image developing toner and electrophotographic image forming apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having excellent low temperature fixing property and heat-resistant storage property with which good images can be stably obtained without causing toner spent to the carrier and to provide a two-component developer by using the toner. SOLUTION: The two-component developer is composed of the toner and the carrier, and the toner contains an electrification controlling agent and wax. The electrification controlling agent consists of a zirconium-based compound (A) obtained from aromatic oxycarboxylic acids, derivatives of these or their salts and compounds containing zirconium or oxyzirconium. The weight proportion of the zirconium-based compound (A) to the wax (B) satisfies 3.0<=(A/B)×100<=60.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner used for developing an electrostatic latent image such as an electrophotographic method, an electrostatic recording method, and an electrostatic printing method, and a two-component developing method using the same. More specifically, the present invention relates to an electrophotographic image forming apparatus, a toner for developing an electrostatic image for the purpose of achieving sufficient low-temperature fixability and heat preservability, securing a fixing temperature range, and stabilizing charging over time. And an electrophotographic image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and Japanese Patent Publication No. 49-23910 are used.
Various methods are described in Japanese Patent Publication No. JP-A-43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means.
Next, the latent image is developed using toner, and if necessary, a toner powder image is transferred to paper or the like, and then fixed by heating, pressing, or solvent vapor to obtain a copy image.

[0003] The method of heat-fixing a toner image on transfer paper is roughly classified into a contact fixing method and a non-contact fixing method. The former includes heating roller fixing and belt fixing, and the latter includes flash fixing and oven (atmosphere) fixing. However, heating roller fixing is widely and generally used because of its high energy efficiency. Further, in recent years, energy saving has been increasingly advanced, and there is a case where a heat source is cut off during standby without fixing. In such an apparatus, the heat roller is heated immediately after the heat source is turned on, and it is necessary to reach a desired temperature in an extremely short time. For this reason, attempts have been made to reduce the thickness of the fixing roller on the side in contact with the toner image support surface in order to increase the thermal energy efficiency of the fixing device used in such an apparatus. This makes it possible to reach a desired temperature in a very short time.

[0004] However, by reducing the thickness of the fixing roller, the mechanical strength of the roller itself is weakened, and a large load cannot be applied between the rollers. As a result, the toner used in such a fixing device is a conventional toner. It has become necessary to have a characteristic that can be fixed at a lower temperature than the toner. It is generally attempted to improve the low-temperature fixability of a toner used for such low-temperature fixing by using a resin or wax having a low softening point. However, it is known that such a low-temperature fixing toner hardens due to heat of a machine used or heat during storage, that is, causes so-called blocking.

To solve this problem, several methods using two types of polyester resins having different properties have been proposed. For example, a method of mixing a non-linear polyester resin and a linear polyester resin (Japanese Unexamined Patent Publication No.
No. 90344), Tg 50 ° C. or higher, softening point 200 ° C.
The following cross-linked polyester resin and softening point 150 ° C or less, M
a method of mixing a linear polyester resin having a w of 3,000 to 50,000 (JP-A-64-15755);
w5,000 or more, non-linear high-molecular polyester resin having a dispersion ratio of 20 or more and Mw of 1,000 to 5,000, dispersion ratio of 4
The following method for containing a non-linear polyester resin (Japanese Patent Application Laid-Open No. 2-82267), containing an organometallic compound comprising a linear polyester resin having an acid value of 5 to 60 and a non-linear polyester resin having an acid value of less than 5 Method (Japanese Unexamined Patent Application Publication No.
9264) and a method of mixing different polyester resins having an acid value ratio of 1.5 or more with a saturated polyester resin (JP-A-3-41470).

[0006] More recently, many copying machines have a printer function, so that the output of only one copy or print is increased, and the stirring time of the developer during development is longer than the number of copies or prints. Is coming. In particular, one copy is used for one manuscript (commonly known as 1 to
1 copy, low duty mode), the development rotation time per copy in continuous copying is 2 to 8
Twice the rotation time is required. In the case of such a mode, thermal stress generated between the developer and the developer regulating member at the time of stirring of the developer is increased, and in addition to blocking, the toner is spent on the carrier and shortens the life of the developer. And so on.

Further, in recent years, the necessity for low-temperature fixing has been increasing more and more. Further, in a use environment in which the above-mentioned fixing device of low surface pressure is used and the stirring time of the developer is long, the conventional technology requires a sufficiently low temperature. It is difficult to achieve both fixing performance and fixing temperature range while preserving heat.

[0008]

SUMMARY OF THE INVENTION The present invention provides a method for fixing with low surface pressure, which ensures a low-temperature fixing property and a high heat resistance even in a use environment in which the stirring time of the developer is long and the thermal stress on the developer is large. An object of the present invention is to provide a toner for developing an electrostatic image capable of stably obtaining a high and good image, a two-component developer using the toner, and an electrophotographic image forming apparatus.

[0009]

According to the present invention, the surface pressure (roller load / contact area) at the time of fixing using a two-component developer composed of a toner and a carrier is 1.5 × 10 ⁵ Pa or less. An oil-less fixing type electrophotographic image forming apparatus with a system speed of 150 to 760 mm / sec.
The developer stirring time for one copy per original is 4 seconds or more, and the developer stirring time for one copy per original is 2 to 8 times the developer stirring time for one continuous copy. A toner used in an electrophotographic image forming apparatus, wherein the toner contains a charge control agent and a wax, and the charge control agent is composed of an aromatic oxycarboxylic acid or a derivative or salt thereof, and zirconium or oxyzirconium. Wherein the weight ratio of the zirconium compound (A) to the wax (B) satisfies the following formula: A developing toner is provided. 3.0 ≦ (A / B) × 100 ≦ 60.0 According to the present invention, the zirconium-based compound is represented by the following general formula (1)

Embedded image[Wherein, R¹Is a quaternary carbon, methine, methylene,
It may contain N, S, O, P heteroatoms and Y is saturated
A cyclic structure connected by a bond or an unsaturated bond, ^Two,
R^ThreeAre each independently an alkyl group, alkenyl group,
Coxy group, aryl group which may have a substituent or aryl
A ruoxy group or an aralkyl group or an aralkyloxy group,
A halogen group, a hydroxyl group, an amino group which may have a substituent,
Carboxyl group, alkoxycarbonyl group, nitro group,
Represents a nitroso group, a sulfonyl group, or a cyano group;^FourIs water
Represents an alkyl or alkyl group, 1 is 0 or an integer of 3 to 12,
m is an integer of 1 to 20, n is an integer of 0 to 20, o is 0 to 4
, P is an integer of 0 to 4, q is an integer of 0 to 3, r is 1
Integer of -20, s represents an integer of 0-20. ]
Zirconium-based compound containing zirconium
The toner for developing an electrostatic image described above is provided.
You. According to the present invention, the toner may be chloroform.
The above-mentioned, comprising 2 to 45% by weight of an insoluble content.
An electrostatic image developing toner according to any one of the above, is provided.
You. Further, according to the present invention, the average volume particle size of the toner
Is 5 to 10 μm and the toner content is 5 μm or less.
Is 60 to 80% by number.
An electrostatic image developing toner according to any of the above items is provided. Also
According to the invention, the wax is carnauba bak
1 selected from water, rice wax and ester wax
The above-mentioned, characterized in that it is a kind or two or more kinds of waxes
An electrostatic image developing toner according to any one of the above, is provided.
You. Further, according to the present invention, the binder resin is a polyester resin.
Characterized in that it contains 30% by weight or more of
An electrostatic image developing toner according to any one of the above, is provided.
You. Further, according to the present invention, any of the above-mentioned to
And a carrier whose surface is coated with silicone resin.
A two-component developer is provided. further
According to the invention, there is provided a two-component toner and a carrier.
Surface pressure during fixing using developer (roller load / contact surface
Product) is 1.5 × 10^FiveOil-less fixing system below Pa
An electrophotographic image forming apparatus having a system speed of 150
At a speed of up to 760 mm / sec,
The developer agitation time per sheet is 4 seconds or more,
The developer stirring time for one copy per copy is 1 for continuous copying.
2 to 8 times the developer stirring time per sheet, and
The toner described in any of the above as a toner
An electrophotographic image forming apparatus is provided.

The inventors of the present invention have conducted intensive studies and have conducted an oil-less fixing using a two-component developer composed of a toner and a carrier, in which the surface pressure (roller load / contact area) at the time of fixing is 1.5 × 10 ⁵ Pa or less. -Type electrophotographic image forming apparatus, wherein the system speed is 150 to 760 mm / sec, the developer stirring time for one copy per original is 4 seconds or more, and the developer for one copy per original is When an image is formed using an image forming apparatus in which the stirring time is 2 to 8 times the developer stirring time per sheet in continuous copying, a toner containing a charge control agent and a wax is used as the toner,
As the charge control agent contained in the toner, a zirconium compound (A) obtained from an aromatic oxycarboxylic acid or a derivative thereof or a salt thereof and a compound containing zirconium or oxyzirconium is used. When the relationship between the weight ratio of the wax and the wax (B) satisfies the following expression, the inventors have found that the above problem can be solved, and have completed the present invention. 3.0 ≦ (A / B) × 100 ≦ 60.0

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. As described above, the electrostatic image developing toner of the present invention contains at least a binder resin, a colorant, a charge control agent, and a wax, and the charge control agent is the specific zirconium-based compound (A); The relationship between the weight ratio of the zirconia-based compound (A) and the wax (B) satisfies the following expression. 3.0 ≦ (A / B) × 100 ≦ 60.0

In the toner of the present invention, the dispersibility of the wax can be improved by defining the ratio of the zirconium compound (A) and the wax (B). Although the details of this mechanism have not been clarified, the highly reactive sites of the zirconium compound (A) and the wax (B) are bonded, and the wax is dispersed with the fine dispersion of the zirconium compound, and the wax is dispersed. It is considered that the dispersion diameter can be reduced. As a result, toner spent on the carrier surface does not occur even with thermal stress from the use environment where the stirring time of the developer is long,
It is possible to secure a wide fixing temperature range that can achieve both good low-temperature fixing property and hot offset resistance without adversely affecting the life of the developer.

The amount of the zirconium compound is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the toner resin component. Here, when the value of (A / B) × 100 is smaller than 3.0 in the weight ratio of the zirconium-based compound (A) and the wax (B), the wax (B) can be sufficiently dispersed. Since there is no zirconium-based compound (A), the dispersion diameter becomes large, and toner spent on the carrier surface is likely to occur. On the other hand, when the value of (A / B) × 100 is larger than 60.0, the wax (B) and the zirconium-based compound (A)
Since the number of bonds with OH is too large, the heat storage stability is improved, but the hot offset resistance deteriorates.

In the toner of the present invention, the zirconium compound is preferably represented by the following general formula (1):

Embedded image[Wherein, R¹Is a quaternary carbon, methine, methylene,
It may contain N, S, O, P heteroatoms and Y is saturated
A cyclic structure connected by a bond or an unsaturated bond, ^Two,
R^ThreeAre each independently an alkyl group, alkenyl group,
Coxy group, aryl group which may have a substituent or aryl
A ruoxy group or an aralkyl group or an aralkyloxy group,
A halogen group, a hydroxyl group, an amino group which may have a substituent,
Carboxyl group, alkoxycarbonyl group, nitro group,
Represents a nitroso group, a sulfonyl group, or a cyano group;^FourIs water
Represents an alkyl or alkyl group, 1 is 0 or an integer of 3 to 12,
m is an integer of 1 to 20, n is an integer of 0 to 20, o is 0 to 4
, P is an integer of 0 to 4, q is an integer of 0 to 3, r is 1
Integer of -20, s represents an integer of 0-20. ]
Zirconium-based compounds containing zirconium
Thus, the above-mentioned disadvantage can be further improved.

General production of the zirconium compound of the present invention
The method is based on aromatic oxycarboxylic acid or its derivative or its derivative.
These salts are converted to zirconium using water or / and an organic solvent.
Compound containing metal or oxyzirconium (metallic agent)
The product is collected by filtration and washed.
Can be obtained. Zirconium compound of the present invention
Aromatic oxycarboxylic acids that can be used in the production of
And 3,5-di-t-butylsalicylic acid,
Di-i-propylsalicylic acid, 5-methoxysalicyl
Acid, 3,5-dichlorosalicylic acid, 3-t-butyl-5
-Methylsalicylic acid, 2-hydroxy-3-naphthoe
Acid, 2-hydroxy-6-t-butyl-3-naphthoic acid
And the like. Also derivatives of aromatic oxycarboxylic acids
Examples thereof include those in which a hydroxyl group is substituted with an alkoxy group.
And the alkoxy group is a methoxy group, an ethoxy group.
Groups. In addition, aromatic oxycarboxylic acid or its
Derivative salts include alkali metal salts and the like.
As a metal-imparting agent, in the case of a tetravalent cation, ZrC
l_Four, ZrF_Four, ZrBr _Four, ZrI_FourHalogenated Jill
Conium compounds, Zr (OR)_Four(R is an alkyl group,
Alkenyl group etc.) or Zr (SO_Four)_TwoSuch as inorganic di
Ruconium compounds and the like, and divalent oxo compounds
ZrOCl for cationic substances_Two, ZrO (NO_Three)_Two,
ZrO (ClO_Four)_Two, H_TwoZrO (SO_Four)_Two, ZrO
(SO_Four) ・ Na_TwoSO_Four, ZrO (HPO_Four)_TwoEtc. inorganic
Zirconium acid compound, ZrO (CO_Three), (NH_Four)_Two
ZrO (CO_Three)_Two, (NH_Four)_TwoZrO (C_TwoH_ThreeO_Two)_Two,
ZrO (C_TwoH_ThreeO_Two)_Two, ZrO (C₁₈H₃₅O_Two)_TwoEtc.
Zirconium acid acid compounds and the like.

In the case where the toner of the present invention contains 2 to 45% by weight of a chloroform-insoluble component,
It is possible to obtain a toner having a high tolerance for hot offset resistance without impairing the low-temperature fixability in a use environment where there is a lot of thermal stress. Here, when the chloroform-insoluble content is less than 2% by weight, a problem occurs in hot offset resistance. When the chloroform-insoluble content is more than 45% by weight, heat resistance and hot offset resistance are further improved. This causes a problem that the low-temperature fixability deteriorates.

Further, when the toner of the present invention has an average volume particle diameter of 5 to 10 μm and a content of toner having a particle size of 5 μm or less of 60 to 80% by number, the toner is good even in a use environment in which thermal stress is high. It has excellent fixability and can maintain good images. When the content of the toner of 5 μm or less is less than 60% by number, the image quality stability such as reproducibility of fine lines may be deteriorated, and the content of the toner of 5 μm or less exceeds 80% by number. In some cases, homogenization of the toner may be impaired, charging stability may be degraded, and image density may be reduced.

In the present invention, as the wax to be dispersed in the toner, any known wax used as a release agent in the toner can be used, but carnauba wax, rice wax, ester wax, or montan wax is used. It is effective. These waxes are superior in low-temperature fixability to other waxes. Carnauba wax is a natural wax obtained from the leaves of carnauba palm. In particular, low-acid-type waxes from which free fatty acids have been eliminated can be uniformly dispersed in a binder resin, and furthermore, since they have less volatile components, they are photosensitive. It is particularly preferable because filming on a body and spent on a charge-imparting member are small, and a microcrystal is preferable, the acid value is 5 or less, and the particle diameter when dispersed in a binder resin of a toner is 1 μm or less. Are preferred. Rice wax is a natural wax obtained by refining crude wax produced in a dewaxing or wintering step when refining rice bran oil extracted from rice bran.
Oxidized rice wax obtained by air-oxidizing this rice bran wax is preferable, and one having an acid value of 10 to 30 is preferable. The synthetic ester wax is synthesized from a monofunctional linear fatty acid and a monofunctional linear alcohol by an ester reaction.
The montan wax is generally refined from mineral oil, is preferably a microcrystalline one, and preferably has an acid value of 5 to 14. These wax components are used alone or in combination. The addition amount of the wax component is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the toner resin component.

The toner of the present invention preferably contains a polyester resin as a resin component as a binder resin in an amount of 30% by weight or more. Polyester resins are generally preferable binder resins because they can be fixed at a low temperature while maintaining heat-resistant storage stability as compared with other resins.

The polyester resin used in the present invention is:
It is obtained by polycondensation between a polyhydric alcohol and a polycarboxylic acid. Examples of the polyhydric alcohol used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; etherified bisphenols such as 1,4-bis (hydroxymethyl) cyclohexane and bisphenol A; and other dihydric alcohols. And polyhydric alcohol monomers having three or more alcohols. Examples of the polycarboxylic acid include divalent organic acid monomers such as maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, and malonic acid; and 1,2,4-benzenetricarboxylic acid. , 1,2,5-benzenetricarboxylic acid,
1,2,4-cyclohexanetricarboxylic acid, 1,2,2
Trivalent or higher polyvalent carboxylic acids such as 4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methylenecarboxypropane, and 1,2,7,8-octanetetracarboxylic acid Acid monomers can be mentioned. Here, the glass transition temperature Tg of the polyester resin is preferably 55 ° C. or more from the viewpoint of heat storage properties.
More preferably, the temperature is 60 ° C. or higher.

In the present invention, a resin other than the polyester resin may be used as a resin component in the toner, as long as the performance of the toner is not impaired. In this case, examples of usable resins include the following, but are not limited thereto. Polystyrene, chloropolystyrene, poly α-methylstyrene, styrene /
Chlorostyrene copolymer, styrene / propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / maleic acid copolymer, styrene / acrylic acid ester copolymer Polymers (styrene / methyl acrylate copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.),
Styrene / methacrylic acid ester copolymer (styrene /
Methyl methacrylate copolymer, styrene / ethyl methacrylate copolymer, styrene / butyl methacrylate copolymer, styrene / phenyl methacrylate copolymer), styrene / α-methyl methyl acrylate copolymer, styrene / Styrene resins such as acrylonitrile / acrylic acid ester copolymers (homopolymers or copolymers containing styrene or styrene substituents), vinyl chloride resins, styrene / vinyl acetate copolymers, rosin-modified maleic acid resins, phenolic resins Petroleum resins and hydrogenated petroleum resins such as epoxy resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene / ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin.
These resins are not limited to being used alone, and may be used in combination of two or more. In addition, the production method is not particularly limited, and any of bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be used.

As the colorant used in the toner of the present invention,
For example, dyes such as carbon black, lamp black, iron black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6C lake, chaco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, and triallylmethane dyes Any conventionally known dyes and pigments such as pigments can be used alone or in combination, and can be used as a black toner or a full-color toner. The amount of these colorants to be used is generally 1 to 30% by weight, preferably 3 to 20% by weight, based on the toner resin component.

The toner of the present invention may contain a charge controlling agent, another releasing agent, a fluidity improving agent, and the like, if necessary. As the charge control agent, any conventionally known charge control agents such as a nigrosine dye, a metal complex type dye, and a quaternary ammonium salt can be used by mixing with the zirconium-based compound. The amount of use of these charge control agents is 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the toner resin component.

As the other release agents, any conventionally known release agents such as solid silicone varnish, higher fatty acid higher alcohol, montan ester wax, low molecular weight polypropylene wax and the like can be mixed and used. The amount of the release agent used is 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the toner resin component. In the weight relationship between the zirconium compound (A) and the wax (B), the weight of the wax (B) is the total weight of the wax used.

As the fluidity improver, any conventionally known fluidity improver such as silicon oxide, titanium oxide, silicon carbide, aluminum oxide and barium titanate can be used alone or in combination. These fluidity improvers are used in an amount of 0.1 to 5 parts by weight, based on 100 parts by weight of the toner.
Preferably it is 0.5 to 2 parts by weight.

As the carrier used when the toner of the present invention is used as a two-component developer, all known carriers can be used. For example, powders having magnetism such as iron powder, ferrite powder and nickel powder can be used. Examples thereof include glass beads and the like, and those obtained by treating the surfaces thereof with a resin or the like.

In the present invention, the resin powder that can be coated on the carrier includes a styrene-acrylic copolymer,
Silicone resin, maleic acid resin, fluorine resin, polyester resin, epoxy resin and the like are available. In the case of a styrene-acrylic copolymer, those having a styrene content of 30 to 90% by weight are preferred. In this case, if the styrene content is less than 30% by weight, the developing characteristics are low, and if the styrene content exceeds 90% by weight, the coating film becomes hard and easily peels off, shortening the life of the carrier. In particular, it is preferable to use a carrier whose surface is coated with a silicone resin. Conventionally, carriers coated with various resins have been proposed in order to prevent toner spent on the carrier surface. However, silicone resin-coated carriers are extremely effective for spent wax. In addition, the resin coating of the carrier in the present invention may contain an adhesion-imparting agent, a curing agent, a lubricant, a conductive material, a charge control agent, and the like, in addition to the above resin.

FIG. 1 shows an example of a fixing device in an electrophotographic image forming apparatus used in the present invention. Reference numeral 1 denotes a fixing roller, and 2 denotes a pressure roller. The fixing roller 1 is provided on a surface of a metal cylinder 3 made of a high thermal conductor such as aluminum, iron, stainless steel or brass, by RT.
V, silicone rubber, an anti-offset layer 4 such as tetrafluoroethylene-perfluoroalkylvinylether (PFA), polytetrafluoroethylene (PTFE). A heating lamp 5 is disposed inside the fixing roller 1. On the other hand, the same material as the fixing roller 1 is often used for the metal cylinder 6 of the pressure roller 2, and its surface is covered with an offset prevention layer 7 such as PFA or PTFA. Although not necessary, a heating lamp 8 is disposed inside the pressure roller 2. Further, although not shown, the fixing roller 1 and the pressure roller 2 are pressed and rotated by springs at both ends, and rotate. The fixing support 1 (transfer paper such as paper) of the toner image T is passed between the fixing roller 1 and the pressure roller 2 to perform fixing.

In the fixing device of the present invention, by setting the thickness of the metal cylinder of the fixing roller 1 to 1.0 mm or less,
The temperature rising characteristics of the fixing roller can be improved, and the temperature can be raised to a desired temperature in a very short time. The preferred thickness of the metal cylinder varies depending on the strength and thermal conductivity of the material used, but is preferably 0.2 to 0.7 mm. Further, the load (surface pressure) applied between the fixing roller and the pressure roller is preferably 1.5 × 10 ⁵ Pa or less. The surface pressure is a value obtained by dividing the load applied to both ends of the roller by the roller contact area, and the roller contact area is a sheet such as OHP paper between rollers heated to a fixable temperature and whose surface properties change greatly by heating. , Stopped on the way, held for several tens of seconds, then discharged, and the area of the portion where the surface properties changed. A higher roller surface pressure is advantageous for fixing a toner image. However, in a fixing device in which the thickness of the metal cylinder of the fixing roller is 1.0 mm or less, a large load is not applied because the roller distortion is caused. The load is preferably 1.5 × 10 ⁵ Pa or less, more preferably 0.5 to 1.0 × 10 ⁵ Pa.

[0030]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples. In the examples, parts are parts by weight.

The measuring methods of each physical property value and each performance evaluation in the examples are shown below. (Measurement method of physical property value)-Chloroform-insoluble content For the measurement of chloroform-insoluble content, about 1.0 g of a toner is weighed, and about 50 g of chloroform is added thereto, and a sufficiently dissolved solution is first separated by centrifugation and separated by JIS. Standards (P3
801) Filter at room temperature using five types of quantitative filter paper. The dried paper residue is weighed and expressed as a ratio (% by weight) between the used resin and the filter paper residue. When measuring an unnecessary portion of chloroform in the binder resin when the toner is used, the toner is required to be about 1.0%.
g is weighed and performed in the same manner as for the binder resin. However, since solid matter such as pigment is present in the filter paper residue, it is separately determined by thermal analysis. Average Volume Particle Size The average volume particle size is measured using a Coulter Counter TAII (aperture diameter: 100 μm) manufactured by Coulter Electronics, USA.

(Evaluation of heat resistance storage stability)
After placing the sample in a 0 ml glass bottle and tapping the glass bottle approximately 50 times to solidify the sample, the sample is left in a constant temperature bath at 50 ° C. for 24 hours, and then the penetration is determined using a penetration tester as follows. Was. (Good) ：: penetration, ：: 25 mm or more, □: 20 mm or more, less than 25 mm, Δ: 15 mm or more, less than 20 mm,
×: less than 15 mm (bad)

(Evaluation of Fixing Ability) Using a device in which the fixing section of a copying machine MF-200 manufactured by Ricoh Co., Ltd. using a Teflon (registered trademark) roller as a fixing roller was modified, Ricoh type 6200 paper was added thereto. It was set and a copy test was performed. A copy image having an image density of 1.2 with a Macbeth densitometer was obtained, and the copy image with a fixed fixing temperature was changed to 1 by a clock meter equipped with an eraser.
Rubbing was performed 0 times, the image density before and after the rubbing was measured, and the fixing rate was determined by the following equation. Fixing rate (%) = ｛(image density after 10 times of sand eraser) /
(Previous image density) Δ × 100 The temperature at which the fixing rate is 70% or more is defined as the lower limit fixing temperature which is a measure of the low-temperature fixing property. The minimum fixing temperature of the conventional low-temperature fixing toner is about 140 to 150 ° C. The evaluation condition of the low-temperature fixing was that the linear speed of the paper feed was 120 to 150 mm /
sec, surface pressure 1.2 kgf / cm ² , nip width 3 mm,
Evaluation condition of hot offset is linear velocity of paper feed 50m
m / sec, surface pressure 2.0 kgf / cm ² , nip width 4.
It was set to 5 mm.

The cold offset occurrence temperature and the hot offset occurrence temperature were obtained as follows. (Low-temperature fixability) good ◎: less than 130 ° C., ○: 130 ° C. to less than 140 ° C., □: 140 ° C. to less than 150 ° C., Δ: 150 ° C. to 16 ° C.
Less than 0 ° C, ×: 160 ° C or more, bad (hot offset property) Good ◎: 200 ° C or more, ○: 190 ° C to less than 200 ° C, □: 180 ° C to less than 190 ° C, Δ: 170 ° C to 18 ° C
Less than 0 ° C., ×: Less than 170 ° C. Bad.

(Evaluation of Image Stability and Spenting Ratio) The image stability and the spent ratio were evaluated using a copying machine image3550 manufactured by Ricoh. Image Stability 100,000 copies (print rate 6%) were made continuously, and the image density, fine line reproducibility, background contamination, etc. after 100,000 copies were examined, and these were comprehensively judged. ：: particularly excellent, ：: excellent, Δ: slightly poor, ×: extremely poor. -Spent ratio: The toner was removed from the developer after the 300,000-sheet copy test by a blow-off method, the remaining carrier weight W1 was placed in toluene to dissolve, wash, and dry the fused material. From the weight W2 of the melt at that time, The spent ratio was determined and evaluated. Spent ratio (wt%) = [(W1-W2) / W1] ×
100 (good) ：: 0 to less than 0.02 wt%, ：: 0.02 wt% to less than 0.05 wt%, Δ: 0.05 wt% to less than 0.08 wt%, ×: 0.08 wt% or more (poor)

The zirconium compounds used in the examples are shown below. -Zirconium based compound 1 3,5-di -t- zirconium obtained by reaction with butyl salicylic acid and zirconium compound ZrCl ₄ compound zirconium compounds 1 (the ratio in the reaction product 4: 1) to. -Zirconium-based compounds 2, 3 The ligands, metal-imparting agents and ratios of zirconium-based compounds 2, 3 obtained in the same manner are shown in Table 1 below.

[Table 1]

Example 1 20 parts of polyester resin A (chloroform-insoluble content: 3% by weight) 80 parts of styrene / acrylic resin 5 parts of low molecular weight polypropylene (Viscol 660P: manufactured by Sanyo Chemical) 10 parts of carbon black (# 44: Mitsubishi Chemical Corporation) 1 part of zirconium-based compound 1 After sufficiently mixing and mixing the mixture having the above composition in a Henschel mixer, the mixture was rolled at a temperature of 130 to 140 ° C with a roll mill to a temperature of about 3 parts.
After heating and melting for 0 minutes and cooling to room temperature, the obtained kneaded material was pulverized and classified by a jet mill, a mechanical pulverizer, or an air classifier to obtain a toner base. 0.5 wt% of hydrophobic silica was added to and mixed with the obtained toner base to obtain a final toner.
At this time, the toner has an average volume particle size of 6.5 μm and 5 μm
The content below was 85% by number. Further, the chloroform-insoluble content of the toner was 0% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Comparative Example 1 A toner similar to that of Example 1 was obtained except that the amounts of the wax and zirconium compound 1 of Example 1 were changed as follows. Low molecular weight polypropylene 15 parts (Viscol 660P: manufactured by Sanyo Chemical Co., Ltd.) Zirconium-based compound 1 0.3 parts At this time, the average volumetric particle diameter of the toner is 6.5 μm and 5 μm
The content below was 85% by number. Further, the chloroform-insoluble content of the toner was 0% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Comparative Example 2 The amounts of the wax and zirconia compound 1 of Example 1 were
A toner similar to that of Example 1 was obtained except that the following was changed. Low molecular weight polypropylene 4 parts (Viscol 660P: manufactured by Sanyo Kasei Co., Ltd.) Zirconium-based compound 1 3 parts The toner average volume particle size at this time is 6.5 μm and 5 μm
The content below was 85% by number. Further, the chloroform-insoluble content of the toner was 0% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Comparative Example 3 A toner similar to that of Example 1 was obtained except that the zirconium compound 1 of Example 1 was changed to the following. Chromium-containing azo dye (S-34: manufactured by Orient) 2 parts The average volume particle size of the toner at this time is 6.5 μm and 5 μm
The content below was 85% by number. Further, the chloroform-insoluble content of the toner was 0% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Example 2 Polyester resin B 20 parts (chloroform-insoluble content 25% by weight) Styrene / acrylic resin 80 parts Low molecular weight polypropylene 5 parts (Viscol 660P: manufactured by Sanyo Chemical Co., Ltd.) Carbon black 10 parts (# 44: Mitsubishi Chemical Corporation) Manufacture) Zirconium Compound 1 1 part A mixture having the above composition was prepared in the same manner as in Example 1 to obtain a toner. At this time, the average volume particle diameter of the toner is 6.5 μm.
m, the content of 5 μm or less was 85% by number. The chloroform-insoluble content of the toner was 21% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Example 3 Kneading was carried out with the same raw material formulation as in Example 2, and then the pulverizing step and the classifying step were adjusted to obtain a toner base. 0.5 wt% of hydrophobic silica was added to and mixed with the obtained toner base to obtain a final toner. At this time, the average volume particle diameter of the toner was 6.5 μm, and the content of 5 μm or less was 65% by number. The chloroform-insoluble content of the toner was 22% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Example 4 20 parts of polyester resin B (chloroform-insoluble content: 25% by weight) 80 parts of styrene / acrylic resin 5 parts of free fatty acid-type carnauba wax 5 parts of carbon black (# 44: manufactured by Mitsubishi Kasei Corporation) Zirconium-based compound 2 1 part A mixture having the above composition was prepared in the same manner as in Example 1 to obtain a toner. At this time, the average volumetric particle diameter of the toner is 6.5 μm.
m, the content of 5 μm or less was 68 number%. The chloroform-insoluble content of the toner was 21% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Example 5 100 parts of polyester resin B (chloroform insoluble content: 25% by weight) 5 parts of free fatty acid type carnauba wax 10 parts of carbon black (# 44: manufactured by Mitsubishi Kasei Co., Ltd.) 1 part of zirconium compound 3 The mixture was prepared in the same manner as in Example 1 to obtain a toner. At this time, the average volumetric particle diameter of the toner is 6.5 μm.
m, the content of 5 μm or less was 63% by number. The chloroform-insoluble content of the toner was 21% by weight. A ferrite carrier without resin coating was used as a carrier, and the ferrite carrier was mixed with the toner at a concentration of 4.0% by weight and used as a developer.

Example 6 The same toner as in Example 5 was used, and the carrier used was magnetite particles having an average particle diameter of 50 μm coated with a silicone resin (film thickness 0.5 μm). % By weight and used as a developer.

The results of evaluation of the developers obtained in the above Examples and Comparative Examples are shown in Table 2 below.

[Table 2]

[0047]

According to the present invention, even in a use environment where the stirring time for development is long due to the low surface pressure and the thermal stress on the developer is large, the heat resistance is high while the low-temperature fixability is ensured, and good An electrostatic image developing toner capable of stably obtaining an image, a two-component developer using the toner, and an electrophotographic image forming apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of a part of a fixing device of an electrophotographic image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fixing roller 2 ... Pressure roller 3 ... Metal cylinder 4 ... Offset prevention layer 5 ... Heat lamp 6 ... Metal cylinder 7 ... Offset prevention layer 8 ... Heating Lamp T: Toner image S: Adhesive support

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Fumihiro Sasaki, 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Hiroto Higuchi 1-3-6, Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Zhu Bing 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Yasushi Furuichi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. F term (reference) 2H005 AA06 BA06 CA12 CA14 CA17 DA02 EA05 EA07 FA01 FB02

Claims (8)

[Claims] 1. An oilless fixing type electrophotographic image forming apparatus using a two-component developer composed of a toner and a carrier and having a surface pressure (roller load / contact area) at the time of fixing of 1.5 × 10 ⁵ Pa or less. And the system speed is 150 ~ 760mm
At a speed of / sec, the developer agitation time of one copy per original is 4 seconds or more, and the developer agitation time of one copy per original is less than the developer agitation time per continuous copy. A toner used in an electrophotographic image forming apparatus having a magnification of 2 to 8 times, wherein the toner contains a charge control agent and a wax, and the charge control agent is an aromatic oxycarboxylic acid, a derivative thereof, or a salt thereof. And a zirconium-based compound (A) obtained from a compound containing zirconium or oxyzirconium, and the relationship between the weight ratio of the zirconium-based compound (A) and the wax (B) satisfies the following formula: Characteristic toner for developing electrostatic images. 3.0 ≦ (A / B) × 100 ≦ 60.0 2. The method according to claim 1, wherein the zirconium compound is
Formula (1)[Wherein, R¹Is a quaternary carbon, methine, methylene,
It may contain N, S, O, P heteroatoms and Y is saturated
A cyclic structure connected by a bond or an unsaturated bond, ^Two,
R^ThreeAre each independently an alkyl group, alkenyl group,
Coxy group, aryl group which may have a substituent or aryl
A ruoxy group or an aralkyl group or an aralkyloxy group,
A halogen group, a hydroxyl group, an amino group which may have a substituent,
Carboxyl group, alkoxycarbonyl group, nitro group,
Represents a nitroso group, a sulfonyl group, or a cyano group;^FourIs water
Represents an alkyl or alkyl group, 1 is 0 or an integer of 3 to 12,
m is an integer of 1 to 20, n is an integer of 0 to 20, o is 0 to 4
, P is an integer of 0 to 4, q is an integer of 0 to 3, r is 1
Integer of -20, s represents an integer of 0-20. ]
Zirconium-based compound containing zirconium
The toner for developing an electrostatic image according to claim 1, wherein: 3. The toner according to claim 1, wherein the chloroform-insoluble content is 2%.
3 to 45% by weight.
3. The toner for developing an electrostatic image according to item 1. 4. The toner according to claim 1, wherein the toner has an average volume particle size of 5 to 10.
μm and a toner content of 5 μm or less is 60 to 80.
The toner for developing an electrostatic image according to any one of claims 1 to 3, wherein the number is%. 5. The method according to claim 1, wherein the wax is carnauba wax.
2. A wax selected from the group consisting of rice wax and ester wax.
5. The toner for developing an electrostatic image according to any one of items 1 to 4. 6. The method according to claim 1, wherein the binder resin is a polyester resin.
The electrostatic image developing toner according to claim 1, wherein the toner is contained in an amount of 0% by weight or more. 7. A two-component developer comprising the toner according to claim 1, and a carrier having a surface coated with a silicone resin. 8. An oilless fixing type electrophotographic image forming apparatus using a two-component developer composed of a toner and a carrier and having a surface pressure (roller load / contact area) at the time of fixing of 1.5 × 10 ⁵ Pa or less. And the system speed is between 150 and 76
At a speed of 0 mm / sec, one copy per document
The developer agitation time of a sheet is 4 seconds or more, the developer agitation time of one copy per original is 2 to 8 times the developer agitation time per continuous copy, and the toner is used as a toner. Item 7. An electrophotographic image forming apparatus using the toner according to any one of Items 1 to 6.