JP2012252248A - Toner for electrostatic charge image development, method of manufacturing toner for electrostatic charge image development, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner that secures the low-temperature fixability from the viewpoint of fold fixability and suppresses the occurrence of image shift, a method of manufacturing the toner, and an image forming method.SOLUTION: A toner for electrostatic charge image development is formed by the process in which an aqueous dispersion liquid of conjugate polyester resin particles containing diene resin and polyester resin and an aqueous dispersion liquid of colorant are mixed and aggregated.

Description

  The present invention relates to an electrostatic image developing toner, a method for producing an electrostatic image developing toner, and an image forming method.

  Global warming is regarded as a global problem, and reduction of energy consumption is an important issue from the viewpoint of protecting the global environment. In the copier industry, there is an increasing demand for more energy-saving technologies. Among them, the energy consumption is the largest, energy-saving in the fixing process, and low-temperature fixing technology is required as one of the solutions. Yes. In addition, in the production print market where high-speed printing equivalent to printing is required, higher-speed output and low-temperature fixing are required.

  As a low-temperature fixing technique, it is known that it is effective to lower the glass transition temperature of the toner resin. However, if the glass transition temperature of the toner resin is lowered, offset occurs in a high temperature region or storage stability (heat resistant storage stability) is lowered. Therefore, fixing at a low temperature is possible only by lowering the glass transition temperature. However, it is difficult to sufficiently function as a toner in other characteristics such as heat-resistant storage property and high-temperature offset.

  In general, a polyester resin has sharp melt properties while maintaining a high glass transition temperature, and therefore has a preferable property as a toner resin compared to a styrene-acrylic resin. However, since the toner using the polyester resin has low elasticity, it has a defect that mechanical strength, that is, internal cohesive force is weak, and therefore has a problem that it is inferior in high-temperature offset resistance and heat-resistant storage stability.

  Polyester resin technology that improves elasticity at high temperatures, that is, in a molten state, by using a polyester resin having a crosslinked structure in order to improve the problem of poor high temperature offset resistance and heat storage stability when using a polyester resin. It is disclosed (for example, see Patent Document 1). However, in a method for producing a toner containing a polyester resin having such a crosslinked structure, it is difficult to produce a toner having a small particle diameter, and thus it is difficult to form a high-quality image with such a toner. It was.

  On the other hand, in order to obtain a toner having desired charging characteristics and gloss characteristics, a copolymer of styrene and butadiene, a copolymer of styrene and methacrylate, a copolymer of acrylate and methacrylate, a copolymer of methacrylate and acrylic acid, a copolymer of acrylate and acrylonitrile, methylstyrene And butadiene copolymers, methacrylate and butadiene copolymers, acrylate and butadiene copolymers, styrene and isoprene copolymers, methylstyrene and isoprene copolymers, methacrylate and isoprene copolymers, acrylate and isoprene copolymers, and combinations thereof In other words, a toner containing a gel containing a toner is disclosed (see Patent Document 2).

  However, the toner is supposed to be obtained through a process in which the gel particles containing the crosslinked polymer and the polyester emulsion are aggregated and agglomerated, but the aggregation rate of the solution containing the gel particles containing the crosslinked polymer and the polyester emulsion Therefore, the gel particles and the polyester emulsion grow as particles, and there is a problem that high elasticity cannot be imparted to the original polyester particles. In order to avoid this problem, the glass transition temperature Tg should be close or the solution amount of the gel particles should be relatively reduced. In this case, the resin design for obtaining the desired elasticity is restricted. There was a problem.

  In general, the heat fixing process is performed by passing a transfer sheet on which toner is transferred between a heating roller (upper roller) and a pressure roller (lower roller). A portion where the heating roller and the pressure roller are in contact with each other through the transfer paper is called a nip. In the heat roller fixing, the heating temperature and pressure and the nip passage time, that is, the nip length and the linear velocity affect the fixing property.

  As the fixing device, for example, there is a belt nip type in which a fixing belt is pressed against a heating member or a pressure member.

  As a fixing device using a belt nip method, for example, as disclosed in Patent Document 3, a heating member rotatably supported, an endless belt whose outer peripheral surface is pressed against the heating member, and this endless shape And a pressure applying member that presses the heating member through an endless belt along the outer peripheral surface of the heating member. In such a belt nip type fixing device, a sufficient nip passing time, that is, a sufficient contact time between the unfixed toner image and the heating member is ensured, so that an image having high glossiness can be formed. .

  However, such a fixing device by the belt nip method is arranged such that a pressure applying member whose upper surface is formed of an elastic layer such as rubber is in contact with an inner peripheral surface of an endless belt. The sliding resistance between the belt and the pressure applying member becomes large, and the rotational operation becomes unstable. In particular, in the case of forming a solid image with a large amount of toner adhesion, if an image shift occurs, the micro wrinkles are shifted and visually recognized as uneven gloss.

  Therefore, in order to solve such a problem, the upper surface of the pressure applying member is covered with a sheet-like member (hereinafter referred to as “sliding sheet”) in which a glass fiber sheet is coated with fluororesin (PFA). , A method for suppressing wear on the inner peripheral surface of an endless belt, and a method for reducing friction by reducing the contact area by covering the surface of the pressure applying member with a sliding sheet having an uneven surface. (See Patent Document 4), however, depending on such a method, the configuration of the fixing device becomes complicated, and there is a problem that the replacement cycle is shortened as the belt and the sliding sheet deteriorate.

JP 2009-223281 A JP 2010-55093 A JP 2004-109878 A JP 2002-148970 A

  The present invention has been made to solve the above-mentioned problems, and its purpose is to secure low-temperature fixability from the viewpoint of crease fixability, and to suppress occurrence of image misalignment even in a fixing machine having a long nip length. The present invention provides a toner, a toner manufacturing method, and an image forming method.

The above-described problems of the present invention are solved by the following configuration.
1.
An electrostatic image developing toner containing at least a polyester resin, a diene resin, and a colorant, wherein the electrostatic image developing toner is at least
(1) A polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain a polyester resin solution liquid containing diene resin particles. Forming an aqueous dispersion of a composite polyester resin solution in which drops are dispersed in an aqueous medium;
(2) removing an organic solvent from the aqueous dispersion of the composite polyester resin solution to form an aqueous dispersion of composite polyester resin particles containing diene resin particles;
(3) mixing the aqueous dispersion of the composite polyester resin particles and the aqueous dispersion of the colorant particles, and aggregating the composite polyester resin particles and the colorant particles;
A toner for developing an electrostatic charge image, which is produced through
2.
2. The electrostatic image developing toner according to 1 above, wherein the diene resin contains 15% by mass to 95% by mass of a toluene insoluble component.
3.
3. The electrostatic charge image developing toner according to 1 or 2 above, wherein the diene resin is a styrene-butadiene copolymer.
4).
4. The electrostatic image developing toner according to any one of 1 to 3 above, wherein the diene resin contains 30% by mass or more and 70% by mass or less of a toluene insoluble content.
5.
A method for producing an electrostatic image developing toner comprising at least a polyester resin, a diene resin, and a colorant, wherein the electrostatic image developing toner comprises at least
(1) A polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain a polyester resin solution liquid containing diene resin particles. Forming an aqueous dispersion of a composite polyester resin solution in which drops are dispersed in an aqueous medium;
(2) removing an organic solvent from the aqueous dispersion of the composite polyester resin solution to form an aqueous dispersion of composite polyester resin particles containing diene resin particles;
(3) mixing the aqueous dispersion of the composite polyester resin particles and the aqueous dispersion of the colorant particles, and aggregating the composite polyester resin particles and the colorant particles;
A method for producing a toner for developing an electrostatic charge image, wherein
6).
6. The method for producing a toner for developing an electrostatic charge image according to 5 above, wherein the diene resin contains 15% by mass to 95% by mass of a toluene insoluble content.
7).
7. The method for producing a toner for developing an electrostatic charge image according to 5 or 6 above, wherein the diene resin is a styrene-butadiene copolymer.
8).
8. The method for producing a toner for developing an electrostatic charge image according to any one of 5 to 7, wherein the diene resin contains 30% by mass or more and 70% by mass or less of a toluene insoluble content. .
9.
A transfer step of transferring a toner image formed on the image carrier to a transfer material;
In the image forming method having a fixing step of fixing the toner image transferred onto the transfer material,
The fixing step includes an endless belt in which at least one of a heating member and a pressure member is stretched around a plurality of rollers, and the heating member and the pressure member are pressed against each other to form a fixing nip. 5. An image forming method using the toner for developing an electrostatic charge image according to any one of 1 to 4, which is performed using a fixing device.

  According to the present invention, by adopting the above-described configuration, the mechanical strength is high and the crease fixability is good while having good low-temperature fixability, and image misalignment also occurs in a fixing machine having a long nip length. No good image can be obtained.

FIG. 3 is an explanatory cross-sectional view illustrating an example of a configuration of a fixing device used in the image forming method of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail, but the present invention is not limited thereto.

  The present invention relates to an electrostatic charge image developing toner containing at least a binder resin composed of a polyester resin and a diene resin and a colorant, a production method thereof, and an image forming method using the electrostatic charge image development toner. is there.

  Conventionally, in a toner containing a polyester resin as a binder resin, there is a linear velocity difference between the upper roller and the lower roller of the fixing device, so that the molten toner is sheared, resulting in image misalignment. There was a problem that it was easy to get up. As a result of intensive studies, the present inventors have found that the cause of image misalignment is that the elastic component of the toner resin is small, so that it cannot withstand shearing, and the image shifts when passing between rollers. It was. Thus, the inventors have found that the object of the present invention can be achieved by producing a toner containing high-elastic diene resin particles in a polyester resin in a specific step, thereby completing the present invention.

  When the diene resin particle dispersion containing the diene resin and the polyester resin particle dispersion are mixed and aggregated, the aggregation rates of the diene resin particles containing the diene resin and the polyester resin particles are different. It is impossible to form toner particles that are agglomerated and uniformly mixed with each other. Therefore, even if a diene resin is used, high elasticity cannot be imparted to the original polyester resin particles. The present inventors mixed an aqueous dispersion of a polyester resin solution in which a polyester resin is dissolved in an organic solvent and an aqueous dispersion of diene resin particles to prepare a dispersion of a polyester resin solution containing diene resin particles. It has been found that toner particles having a uniform composition can be produced by removing the solvent and then mixing and aggregating with an aqueous dispersion of colorant particles to complete the present invention.

≪Diene resin particles≫
The diene resin particles are composed of a specific polymer containing a structural unit derived from a diene monomer (hereinafter also referred to as “diene resin”).

  The diene resin of the present invention is a polymer containing a structural unit derived from a diene monomer, and includes a copolymer or a homopolymer obtained from a conjugated diene monomer.

  Examples of the conjugated diene monomer include butadiene, isoprene, 2-chloro-1,3-butadiene, 2-methyl-1,3-butadiene and the like. Among these, butadiene is particularly preferable from the viewpoint of securing the fixing strength.

  Other copolymer components used include vinyl monomers such as styrene monomers, acrylate monomers, methacrylate esters, vinyl ester monomers, and monoolefin monomers. And copolymers thereof are preferably used as the diene resin of the present invention. The conjugated diene monomer in the diene resin of the present invention is preferably 20% by mass to 90% by mass, and particularly preferably 21% by mass to 65% by mass. Within this range, sufficient elasticity can be secured when used as a binder resin for toner.

  A particularly preferable copolymerization component is a styrene monomer, specifically styrene. Other examples of the styrene monomer include o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-phenyl styrene, p-ethyl styrene, 2,4-dimethyl styrene. Styrene or styrene derivatives such as p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, and pn-dodecyl styrene. It is done. These can be used alone or in combination of two or more.

  Acrylic acid ester monomers and methacrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, methacrylic acid. Examples include ethyl acetate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like. .

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate. Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Specific examples of the diene resin used as the diene resin of the present invention include styrene butadiene rubber (SBR), nitrile rubber (NR), butadiene rubber (BR), and isoprene rubber (IR). Among these, styrene butadiene rubber (SBR) is preferably used, and in this case, the copolymerization ratio of styrene and butadiene is preferably 30:70 to 50:50 by mass ratio.

(Acid monomer)
The diene resin preferably contains a structural unit derived from an acid monomer from the viewpoint of enhancing the dispersion stability of the toner particle structure. Specifically, a carboxylic acid monomer having a carboxy group is preferable from the viewpoint of production stability.

  Specific examples of the carboxylic acid monomer include unsaturated monovalent carboxylic acids such as (meth) acrylic acid; maleic acid, fumaric acid, itaconic acid, citraconic acid, glutaconic acid, tetrahydrophthalic acid, and aconite. Examples thereof include unsaturated polyvalent carboxylic acids such as acid, maleic anhydride, itaconic anhydride, glutaconic anhydride, citraconic anhydride, aconitic anhydride, norbornene dicarboxylic acid anhydride, and tetrahydrophthalic acid anhydride. These can be used alone or in combination of two or more.

  Here, as a method for introducing a structural unit derived from a carboxylic acid monomer into the diene resin of the present invention, a method of copolymerizing a diene monomer and a carboxylic acid monomer is preferable, For example, an acrylic acid alkyl ester such as butyl acrylate may be copolymerized with a diene monomer and then hydrolyzed with hydrochloric acid or the like.

  In addition, it is preferable that the copolymerization ratio of a carboxylic acid-type monomer is 1 mass%-5 mass%, for example. When the copolymerization ratio of the carboxylic acid monomer is within the above range, aggregation between particles due to the diene resin as a rubber component can be suppressed.

(Toluene insoluble content of diene resin)
The polyester resin that can be used in combination with the diene resin is preferably partially compatible at the interface. It is considered that the toluene-soluble component of the diene resin is compatible, and it is particularly preferable that the toluene-insoluble component forms an interface by forming an interface without being compatible with the polyester resin. The diene resin preferably has a toluene-insoluble content of 15% by mass to 95% by mass, more preferably 30% by mass to 70% by mass.

  When the content ratio of the toluene-insoluble component of the diene resin is within the above range, the toner has high-temperature offset resistance and crease-fixability without hindering low-temperature fixability. That is, if it is less than 15% by mass, the elasticity in the high temperature region is insufficient, and high temperature offset may occur under severe conditions, and if it exceeds 95% by mass, the elasticity is too high and the low temperature fixability may be impaired. Also, if it exceeds 95% by mass, the diene resin tends to aggregate during the aggregation process, resulting in a decrease in yield, non-uniform toner composition, or a toner having a desired composition. There is a risk of not being able to.

  The content ratio of the toluene-insoluble component of the diene resin can be controlled by a crosslinking agent that acts on a diene monomer such as butadiene. Specifically, an organic peroxide, sulfur or the like is used. Alternatively, the content of toluene insolubles can be controlled using a divinyl compound such as divinylbenzene. On the other hand, the mass average molecular weight (Mw) of the toluene soluble component is preferably 20,000 to 1,500,000, particularly preferably 40,000 to 800,000.

(Method for measuring toluene insolubles in diene resins)
As the toluene-insoluble content of the diene resin, 0.03 g of the diene resin was immersed in 100 ml of toluene at 20 ° C. for 20 hours, and then filtered through a 120-mesh wire mesh. Can be calculated.

(Diene resin glass transition temperature)
The glass transition temperature (Tg) of the diene resin is −85 ° C. to + 35 ° C., more preferably −40 ° C. to + 30 ° C. When the glass transition temperature of the diene resin is within this range, the toner has excellent crease fixability. In particular, when the glass transition temperature of the diene resin is within a range of −40 ° C. to + 30 ° C., the toner transfer property is excellent, and further, the graininess in a halftone image tends to be good.

  When the glass transition temperature of the diene resin is less than −85 ° C., the toner does not have sufficient blocking resistance and does not have sufficient heat storage stability. On the other hand, when the glass transition temperature of the diene resin exceeds + 35 ° C., the toner does not have sufficient low-temperature fixability.

(Measurement method of glass transition temperature of diene resin)
The diene resin particles were freeze-dried, and 4.5 mg of the dried sample was precisely weighed to two digits after the decimal point, sealed in an aluminum pan, and the differential scanning calorimeter “DSC8500” (Perkin Elmer) Set in a sample holder. The reference uses an empty aluminum pan, and performs heat-cool-heat temperature control at a measurement temperature of −120 ° C. to 100 ° C., a temperature increase rate of 10 ° C./min, and a temperature decrease rate of 10 ° C./min. 2nd. Analysis was performed based on the data in Heat. The glass transition temperature is defined as the value of the intersection of the baseline extension before the rise of the first endothermic peak and the tangent indicating the maximum slope between the rise of the first endothermic peak and the peak apex.

(Domain diameter)
The size of the domain phase in the matrix phase is 50 nm to 300 nm in ferret diameter, and more preferably 75 nm to 250 nm.

  When the size of the domain phase is within the above range, a sufficient contact area with the matrix resin can be obtained, the elasticity of the rubber component diene resin is effectively exhibited, and the toner has excellent high temperature offset resistance. And it has crease fixability.

  When the size of the domain phase is less than 50 nm in terms of the ferret diameter, the elasticity due to the diene resin that is a rubber component is not effectively exhibited, and the toner does not have excellent crease fixability. On the other hand, when the size of the domain phase exceeds 300 nm in terms of the ferret diameter, the toner does not have sufficient blocking resistance.

  The toner particles containing the binder resin having a domain / matrix structure can be confirmed by observing the cross section of the toner particles dyed with osmium using a transmission electron microscope. At this time, when a section of toner particles is cut out using a microtome, the thickness of the section is set to 100 nm.

  In the present invention, the size of the domain phase is specifically determined by preparing a thin piece of toner particles, photographing a cross section of the thin piece at a magnification of 10,000 using a transmission electron microscope, and obtaining 100 domain phases. The horizontal ferret diameter is measured and the arithmetic average value is calculated. Further, the coefficient of variation in the particle size distribution of the ferret diameter of the domain phase is preferably 20% or less. Because the coefficient of variation is 20% or less, even when a small amount of diene resin is added, the toner has a low temperature fixability while having a heat resistant storage property, and an excellent crease fixability. It becomes.

  The variation coefficient is an index indicating the relative variation of the ferret diameter of the domain phase, and is calculated by the following formula (CV).

Formula (CV): coefficient of variation (%) = (S2 / K2) × 100
[In the formula (CV), S2 represents the standard deviation of the horizontal ferret diameter of 100 domain phases, and K2 represents the arithmetic mean value of the horizontal ferret diameters of 100 domain phases. ]
(Diene resin content)
In the toner of the present invention, the content of the diene resin with respect to the binder resin is preferably 0.3% by mass to 7.0% by mass of the total of the polyester resin and the diene resin, and more preferably 2.5%. It is mass%-4.0 mass%.

  When the content of the diene resin is within the above-mentioned range, the toner has sufficient blocking resistance while having low-temperature fixability. On the other hand, when the content of the diene resin is excessive, the toner may not have sufficient blocking resistance. Further, when the content of the diene resin is too small, the toner does not have sufficient low-temperature fixability, and sufficient crease fixability cannot be obtained, and furthermore, a high-temperature offset phenomenon occurs. There is a fear.

(Monomer constituting polyester resin)
The polyester resin used in the present invention is produced by a polycondensation reaction using a polyester-forming composition comprising a polyvalent carboxylic acid (derivative) and a polyhydric alcohol (derivative) as raw materials.

  The polyhydric alcohol that forms the polyester resin is a dihydric or higher alcohol such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1, 4-butylene diol, neopentyl glycol, 1,5-pentane glycol, 1,6-hexane glycol, 1,7-heptane glycol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol , Pinacol, cyclopentane-1,2-diol, cyclohexane-1,4-diol, cyclohexane-1,2-diol, cyclohexane-1,4-dimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, Diols such as tetramethylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A; trivalent or more polyvalents such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, trisphenol PA, phenol novolac, cresol novolac Examples thereof include alkylene oxide adducts of the above divalent or higher polyhydric aliphatic alcohols. These can be used alone or in combination of two or more.

  Further, as the polyvalent carboxylic acid forming the polyester-based resin, divalent or higher carboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid Maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, n-octenyl succinic acid, etc. Dicarboxylic acids; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid; trimellitic acid, pyromellitic acid, their anhydrides, or trivalent or higher carboxylic acids such as acid chlorides Can be mentioned. These can be used alone or in combination of two or more.

(catalyst)
As the catalyst for polymerization of the polyester resin of the present invention, generally known catalysts can be used. Specifically, titanium compounds such as dibutyltin oxide, titanium tetraisopropoxide, titanium tetra tert-butoxide, and octylic acid Examples thereof include tin (II) compounds having no Sn—C bond such as tin, and these are used singly or in combination.

  As the polyester resin, a linear polyester is preferable in view of low-temperature fixability and production stability. The molecular weight of the polyester resin is preferably 10,000 to 28,000 as a mass average molecular weight (Mw).

(Glass transition temperature of polyester resin)
The glass transition temperature of the polyester resin is preferably 43 ° C to 65 ° C. When the glass transition temperature of the polyester resin is excessively low, the toner does not have sufficient blocking resistance, and the toner may easily aggregate while being stored. On the other hand, the glass transition of the matrix resin may occur. If the temperature is excessively high, the toner may not have sufficient low-temperature fixability.

  The glass transition temperature of the polyester resin can be measured in the same manner as in the above-described method for measuring the glass transition temperature of the diene resin, except that the measurement sample is changed to a matrix resin.

<Configuration of toner>
Next, the configuration of the toner of the present invention will be described in detail.

(Binder resin)
As described above, a polyester resin is used as the binder resin constituting the toner of the present invention. Particularly preferably used is a linear polyester containing no crosslinking component or a polyester resin containing less than 10% by mass of a trivalent or higher polyvalent carboxylic acid monomer such as trimellitic acid as a crosslinking component.

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

  As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 111, 122, C.I. I. Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93, 95, etc. can be used, and mixtures thereof can also be used. Examples of the pigment include C.I. I. Pigment Red 5, 48: 1, 53: 1, 57: 1, 122, 139, 144, 149, 166, 177, 178, 222, C.I. I. Pigment Orange 31 and 43, C.I. I. Pigment Yellow 14, 17, 74, 93, 94, 138, 155, 180, 185, C.I. I. Pigment green 7, C.I. I. Pigment Blue 15: 3, 60, etc. can be used, and a mixture thereof can also be used. The number average primary particle size varies depending on the type, but is preferably about 10 nm to 200 nm.

(Dispersion of colorant)
A dispersion of colorant particles can be prepared by dispersing a colorant in an aqueous medium. The dispersion treatment of the colorant is preferably performed in a state where the surfactant concentration in the aqueous medium is equal to or higher than the critical micelle concentration because the colorant is uniformly dispersed. A known disperser can be used as the disperser used for the dispersion treatment of the colorant. The disperser used for dispersing the colorant is not particularly limited. For example, a commercially available stirring device “CLEARMIX” (manufactured by M Technique Co., Ltd.) equipped with a rotor that rotates at high speed is representative. Device. In addition to the agitation device described above, examples include an ultrasonic disperser, a mechanical homogenizer, a manton gourin, and a pressure homogenizer. Moreover, as a surfactant which can be used, a publicly known thing can be used. Specifically, a dispersion stabilizer selected from cationic surfactants, anionic surfactants, nonionic surfactants and the like used for emulsion polymerization described later can be used. Two or more of these surfactants may be used in combination.

(Release agent)
In the toner of the present invention, various known waxes can be used as a release agent.

  Examples of the wax include polyolefin waxes such as polyethylene wax and polypropylene wax, branched hydrocarbon waxes such as microcrystalline wax, long chain hydrocarbon waxes such as paraffin wax and sazol wax, and dialkyls such as distearyl ketone. Ketone wax, carnauba wax, montan wax, behenate behenate, trimethylolpropane tribehenate, pentaerythritol tetrabehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate, 1,18-octadecanedioldi Ester waxes such as stearate, tristearyl trimellitic acid, distearyl maleate, ethylenediamine behenylamide, tristearyl trimellitic acid Such as amide-based waxes such as bromide and the like.

  It is preferable that content of a mold release agent is 0.1-30 mass parts with respect to 100 mass parts of binder resin, More preferably, it is 1-20 mass parts.

(Charge control agent)
The toner of the present invention can contain a charge control agent as required. As the charge control agent, various known ones that can be dispersed in an aqueous medium can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof. The charge control agent particles preferably have a number average primary particle size of about 10 nm to 500 nm in a dispersed state.

(External additive)
In the present invention, an external additive can be added for the purpose of improving the fluidity and charging characteristics of the toner. Examples of external additives that can be used from the viewpoint of controlling the fluidity and charging performance of the toner include various inorganic fine particles such as silicon dioxide, titanium dioxide, strontium titanate, cerium oxide, and zinc oxide. From the viewpoints of heat-resistant storage stability and environmental stability, it is preferably hydrophobized with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like. Other organic fine particles, organic-inorganic composite fine particles, and the like can also be used. Examples of the organic fine particles that can be used as the external additive include spherical fine particles having a number average primary particle diameter of about 10 to 2000 nm. Examples of the constituent material of the organic fine particles include polystyrene, polymethyl methacrylate, styrene-methyl methacrylate copolymer, and the like. The addition amount of the external additive is preferably in the range of 0.05% by mass to 5.0% by mass with respect to the toner particles including the external additive fixed by the above-described method. More preferably, it is 0.1 mass part-3 mass parts. Various external additives may be used in combination.

(Lubricant)
In addition, a lubricant can be used in order to improve the cleaning property of the toner remaining on the photoreceptor such as the transfer residual toner. As a specific example of the lubricant, a metal salt of a higher fatty acid can be cited as a representative example. Specific examples of metal salts of higher fatty acids include stearic acid metal salts such as zinc stearate, aluminum stearate, copper stearate, magnesium stearate, calcium stearate; zinc oleate, manganese oleate, iron oleate, oleic acid Oleic acid metal salts such as copper and magnesium oleate; palmitic acid metal salts such as zinc palmitate, copper palmitate, magnesium palmitate and calcium palmitate; linoleic acid metal salts such as zinc linoleate and calcium linoleate; ricinoleic acid There are ricinoleic acid metal salts such as zinc and calcium ricinoleate.

  Examples of the method for adding and mixing the external additive and the lubricant include a dry method in which the external additive is added in powder form to the dried toner particles. Examples of the mixing device include mechanical mixing such as a Henschel mixer and a coffee mill. Apparatus.

(Developer)
The toner of the present invention can be used as a two-component developer composed of a carrier and a toner, or as a non-magnetic one-component developer composed only of a toner. Carriers that are magnetic particles used when used as a two-component developer are conventionally known materials such as metals such as iron, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead. It is possible to use. Among these, ferrite particles are preferable. Further, as the carrier, a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, a resin dispersion type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used. The carrier has a volume average particle size of preferably 15 μm to 100 μm, more preferably 25 μm to 80 μm.

(Toner particle size)
The toner particles constituting the toner of the present invention have a volume-based median diameter of 4.3 μm to 7.0 μm, and more preferably 4.3 μm to 6.8 μm. When the volume-based median diameter of the toner particles is within the above range, a high-quality image can be formed. When the volume-based median diameter of the toner particles is less than 4.3 μm, the formed image becomes sticky and the low-temperature fixability of the toner may be impaired. On the other hand, when the volume-based median diameter of the toner particles exceeds 7.0 μm, the resolution and halftone homogeneity of the formed image may be insufficient.

(Toner particle size measurement method)
The volume-based median diameter of the toner particles is measured using a measuring device in which a computer system equipped with data processing software “Software V3.51” is connected to “Coulter Multisizer 3” (manufactured by Beckman Coulter). It shall be calculated. Specifically, 0.02 g of toner is added to 20 ml of a surfactant solution (for example, a surfactant solution obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). Then, ultrasonic dispersion is performed for 1 minute to prepare a toner dispersion, and this toner dispersion is placed in a beaker containing “ISOTON II” (manufactured by Beckman Coulter) in a sample stand. Pipet until the indicated concentration is 8%. Here, a reproducible measurement value can be obtained by setting the concentration range. In the measuring apparatus, the measurement particle count is set to 25000, the aperture diameter is set to 50 μm, and the frequency value is calculated by dividing the range of 1 μm to 30 μm, which is the measurement range, into 256. % Particle diameter is the volume-based median diameter (D ₅₀ ).

(Toner average circularity)
The toner particles constituting the toner of the present invention preferably have an average circularity of 0.930 to 1.000, more preferably 0.950 to 0.995, from the viewpoint of improving transfer efficiency. The circularity of the toner particles can be measured using “FPIA-2100” (manufactured by Sysmex). Specifically, the toner is blended with an aqueous solution containing a surfactant and subjected to ultrasonic dispersion treatment for 1 minute to disperse, and then measurement conditions HPF (high magnification imaging) are performed using “FPIA-2100” (manufactured by Sysmex). ) Mode, images are taken at an appropriate density of 3,000 to 10,000 HPF detections, the circularity is calculated for each toner particle according to the following formula (T), and the circularity of each toner particle is added. Then, the average circularity is calculated by dividing by the total number of toner particles.

Formula (T): Average circularity = (perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)
(Toner softening point)
The softening point temperature of the toner of the present invention is preferably 80 ° C. to 110 ° C., more preferably 90 ° C. to 105 ° C. When the softening point temperature of the toner is excessively low, a high temperature offset phenomenon may occur easily in the fixing process. May not have.

Regarding the softening point temperature of the toner, specifically, in an environment of 20 ° C. and 50% RH, 1.1 g of the toner is placed in a petri dish and left flat for 12 hours or more, and then the molding machine “SSP-10A” is used. (Shimadzu Corporation) pressurizes with a force of 3820 kg / cm ² for 30 seconds to create a cylindrical molded sample with a diameter of 1 cm. Then, the molded sample is flown in an environment of 24 ° C. and 50% RH. With a tester “CFT-500D” (manufactured by Shimadzu Corporation), a cylindrical die hole (1 mm diameter × 1 mm) under the conditions of a load of 196 N (20 kgf), a starting temperature of 60 ° C., a preheating time of 300 seconds, and a heating rate of 6 ° C./min. ) than, extruded from the time of preheating ends with piston diameter 1 cm, offset temperature T _Offse measured by setting the offset value 5mm at a melt temperature measurement method of temperature ramps _t can be measured as the softening point temperature of the toner.

(Glass transition temperature of toner)
The glass transition temperature of the toner of the present invention is preferably 20 ° C. to 65 ° C., more preferably 30 ° C. to 50 ° C., from the viewpoint of achieving both heat-resistant storage and blocking resistance and low-temperature fixability. . When the glass transition temperature of the toner is excessively low, the toner does not have sufficient blocking resistance, and the toner may easily aggregate during storage. On the other hand, when the glass transition temperature is excessively high In this case, the toner is difficult to melt and may not have low-temperature fixability.

  The glass transition temperature (Tg) of the toner can be measured using a differential scanning calorimeter “DSC8500” (manufactured by Perkin Elmer). Specifically, 4.5 mg of toner is precisely weighed to two digits after the decimal point, sealed in an aluminum pan, and set in a DSC-7 sample holder. The reference uses an empty aluminum pan, performs heat-cool-heat temperature control at a measurement temperature of 0 ° C. to 200 ° C., a heating rate of 10 ° C./min, and a cooling rate of 10 ° C./min. . Analysis is performed based on the data in Heat. The glass transition temperature is defined as the value of the intersection of the baseline extension before the rise of the first endothermic peak and the tangent indicating the maximum slope between the rise of the first endothermic peak and the peak apex.

≪Toner production method≫
Hereinafter, the method for producing the toner of the present invention will be described.

The toner of the present invention is
(1) A polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain a polyester resin solution liquid containing diene resin particles. Step of forming aqueous dispersion of composite polyester resin solution in which droplets are dispersed in aqueous medium (2) Composite polyester containing diene resin particles by removing organic solvent from aqueous dispersion of composite polyester resin solution A step of forming an aqueous dispersion of resin particles (3) A step of mixing the aqueous dispersion of composite polyester resin particles and an aqueous dispersion of colorant particles, and aggregating the composite polyester resin particles and the colorant particles. Manufactured.

  In the present invention, a phase inversion emulsification method can be employed in the step (1). Here, the phase inversion emulsification will be described. For emulsification, three types of natural emulsification, phase inversion emulsification and forced emulsification are identified, and an emulsion obtained by emulsification is an emulsion. The case where the dispersoid is oil and the dispersion medium is water is called O / W type, and the case where the dispersoid is water and the dispersion medium is oil is called W / O type. Either an oil-in-water (O / W type) emulsion in which oil droplets are dispersed in water or a water-in-oil (W / O type) emulsion is employed. In the present invention, once a water-in-oil (W / O type) emulsion is once formed and the aqueous medium is increased, the phenomenon of oil-in-water (W / O type) emulsion transfer and its operation are called phase inversion emulsification. Generally, it is preferable to use the phase inversion emulsification method because a finer emulsion can be obtained.

  In this invention, it is preferable to set it as the following phase inversion emulsification processes in the process of said (1). That is, a polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain an oil phase of the polyester resin solution containing the diene resin particles. A W / O emulsion in which droplets of an aqueous medium are dispersed is prepared. Next, by adding water to the W / O emulsion and stirring, the droplets of the polyester resin solution containing the diene resin particles as the O / W emulsion are dispersed in an aqueous medium. An aqueous dispersion is formed. By adopting this method, it is possible to obtain a dispersion of fine composite polyester resin particles in which a diene resin is dispersed in a polyester resin, and using this, a more uniform toner is produced by an emulsion aggregation method. Toner particles having a composition can be produced.

(Method for producing diene resin particles)
The diene resin particles can be produced by an emulsion polymerization method or a miniemulsion polymerization method.

  In the emulsion polymerization method, a polymerizable monomer to form a diene resin is dispersed in an aqueous medium to form emulsion particles (oil droplets), and then a polymerization initiator is added to form a polymerizable monomer. It is formed by polymerizing. The diene resin particles can also be produced by a method in which a specific polymer constituting the diene resin is prepared in advance and then dispersed and emulsified in an aqueous surfactant solution.

(Polymerization initiator)
In the present invention, a water-soluble polymerization initiator is preferably used as the polymerization initiator used in the step of preparing the dispersion of diene resin particles. Specifically, for example, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, peroxide Lauroyl, ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, pertriphenylacetic acid-tert-hydroperoxide, performic acid-tert- Butyl, peracetic acid-tert-butyl, perbenzoic acid-tert-butyl, perphenylacetic acid-tert-butyl, permethoxyacetic acid-tert-butyl, per-N- (3-toluyl) palmitic acid-tert-butyl Oxides; 2, 2 -Azobis (2-aminodipropane) hydrochloride, 2,2'-azobis- (2-aminodipropane) nitrate, 1,1'-azobis (sodium 1-methylbutyronitrile-3-sulfonate), 4 , 4'-azobis-4-cyanovaleric acid, poly (tetraethylene glycol-2,2'-azobisisobutyrate) and other azo compounds.

(Chain transfer agent)
In the present invention, a chain transfer agent may be added in the aqueous dispersion preparation step of diene resin particles. The molecular weight of the polymer can be controlled by adding a chain transfer agent. Known chain transfer agents can be used, and examples thereof include alkyl mercaptans and mercapto fatty acid esters. The addition amount of the chain transfer agent varies depending on the desired molecular weight and molecular weight distribution, but specifically, it is preferably added in the range of 0.1 to 5% by mass with respect to the polymerizable monomer.

(Surfactant)
A dispersion stabilizer is usually added to the aqueous medium in order to prevent aggregation of dispersed droplets. As the dispersion stabilizer, a known surfactant can be used, and a dispersion stabilizer selected from a cationic surfactant, an anionic surfactant, a nonionic surfactant and the like can be used. Two or more of these surfactants may be used in combination. The dispersion stabilizer can also be used in a dispersion liquid such as a colorant and an offset preventing agent. Specific examples of the cationic surfactant include dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide and the like.

  Specific examples of nonionic surfactants include dodecyl polyoxyethylene ether, hexadecyl polyoxyethylene ether, norylphenyl polyoxyethylene ether, lauryl polyoxyethylene ether, sorbitan monooleate polyoxyethylene ether, styrylphenyl poly Examples thereof include oxyethylene ether and monodecanoyl sucrose. Specific examples of the anionic surfactant include aliphatic soaps such as sodium stearate and sodium laurate, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, polyoxyethylene (2) sodium lauryl ether sulfate and the like. it can.

(Dispersed particle size of diene resin particles)
The particle size of the diene resin particles obtained in the diene resin particle dispersion preparation step is preferably in the range of 75 nm to 250 nm in terms of volume-based median diameter. For volume-based median diameter of diene resin particles, several drops of a sample are dropped on a graduated cylinder, pure water is added and dispersed using an ultrasonic cleaner “US-1” (manufactured by asone) for measurement. A sample is prepared, and this measurement sample can be measured using “Microtrac UPA-150” (manufactured by Nikkiso Co., Ltd.).

  When the volume-based median diameter of the diene resin particles is too small, the domain phase due to the diene resin particles cannot be made sufficiently large, and as a result, due to the diene resin that is a rubber component There is a risk of producing a toner that does not exhibit its elasticity effectively. On the other hand, when the volume-based median diameter of the diene resin particles is excessive, the domain phase due to the diene resin particles becomes excessively large, and as a result, a toner that does not have sufficient blocking resistance can be obtained. May be manufactured. In addition, it is thought that one domain phase is formed by one to plural diene resin particles.

(Toner base particles)
The toner base particles of the present invention are obtained by dispersing a diene resin composed of diene resin particles in a matrix resin composed of a polyester resin.

As described above, the toner base particles are obtained by mixing (1) a polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle aqueous dispersion, and adding “polyester containing diene resin particles” in an aqueous medium. Forming a “polyester resin solution aqueous dispersion” in which the resin solution droplets are dispersed;
(2) removing the “aqueous dispersion of the composite polyester resin solution” to form “an aqueous dispersion of the composite polyester resin particles containing the diene resin particles”;
(3) It is produced through a step of mixing and aggregating the above-mentioned “aqueous dispersion of composite polyester resin particles containing diene resin particles” and the aqueous dispersion of colorant particles.

  As described above, the step (1) preferably employs a phase inversion emulsification method.

  A method for producing a dispersion in which a polyester resin is dispersed in an aqueous medium is obtained by dissolving the polyester resin in an organic solvent such as ethyl acetate, and then dispersing the polyester resin in water to which a surfactant is added, and then distilling the organic solvent. be able to.

  The organic solvent used in the present invention can dissolve the polyester resin and partially dissolves in water, but does not completely dissolve and phase-separates, and has a solubility in water of 30 at 20 ° C. % Or less is preferable. Here, examples of the organic solvent for dissolving the polyester resin include ethyl acetate, toluene, ethylbenzene, xylene, chloroform, propyl acetate, MEK and the like, and ethyl acetate is particularly preferable. These are organic solvents that partially dissolve in water but do not completely dissolve, but phase separate when mixed with water.

  In this step, a solution obtained by dissolving a polyester resin in an organic solvent is added to an aqueous medium, and then a dispersion treatment is performed by the action of mechanical energy by a known method to form oil droplets of the polyester resin. The dispersion device for dispersing oil droplets by mechanical energy is not particularly limited. For example, a commercially available stirring device “CLEARMIX” (manufactured by M Technique Co., Ltd.) equipped with a rotor that rotates at high speed, etc. Is a typical device. In addition to the agitation device described above, examples include an ultrasonic disperser, a mechanical homogenizer, a manton gourin, and a pressure homogenizer. With these apparatuses, dispersed particles of oil droplets of about 100 nm are formed in an aqueous medium.

  Next, an aqueous dispersion of a diene resin is mixed, and the diene resin particles are taken into dispersed oil droplets obtained by dissolving a polyester resin in an organic solvent to prepare an oil droplet dispersion of composite resin particles. Thereafter, the organic solvent is distilled off to obtain a polyester resin particle dispersion containing diene resin particles.

  The “aqueous medium” as used in the present invention is a liquid composed of water and an organic solvent soluble in water, and contains at least 50% by mass of water. Here, examples of the organic solvent that can be dissolved in water that is a component other than water constituting the aqueous medium include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohol-based organic solvents such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the resin, are preferable.

(Aggregation association)
Next, the step of aggregating and assembling the resin particles in the emulsion aggregation method will be described.

  In the agglomeration step, an aqueous dispersion of resin particles is mixed with a dispersion of colorant particles, wax particles, charge control agent particles, and other toner constituent particles to prepare an agglomeration dispersion liquid in an aqueous medium. To form a dispersion of colored particles. The flocculant used in the present invention is not particularly limited, but those selected from metal salts are preferably used. For example, salts of monovalent metals such as alkali metal salts such as sodium, potassium and lithium, salts of divalent metals such as calcium, magnesium, manganese and copper, salts of trivalent metals such as iron and aluminum Specific examples of the salt include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, and manganese sulfate. A divalent metal salt is preferred. When a divalent metal salt is used, agglomeration can be promoted with a smaller amount. These may be used alone or in combination of two or more.

  In the flocculation step, it is preferable that the standing time (time until heating is started) to be left after adding the flocculant is as short as possible. That is, after adding the flocculant, it is preferable to start heating the flocculating dispersion liquid as quickly as possible so as to be equal to or higher than the glass transition point of the resin composition. The reason for this is not clear, but the agglomeration state of the particles fluctuates with the passage of the standing time, and there is a possibility that the particle size distribution of the obtained toner particles becomes unstable or the surface property fluctuates. Because there is. The standing time is usually within 30 minutes, preferably within 10 minutes.

  Moreover, in the fusion | melting process, it is preferable to raise temperature rapidly by heating, and it is preferable that a temperature increase rate shall be 1 degree-C / min or more. The upper limit of the heating rate is not particularly limited, but is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to rapid progress of fusion. Furthermore, it is important to continue the fusion by holding the temperature of the aggregation dispersion liquid for a certain period of time after the aggregation dispersion liquid reaches a temperature equal to or higher than the glass transition temperature. Thereby, the growth and fusion of the colored particles can be effectively advanced, and the durability of the toner particles finally obtained can be improved.

  By producing the toner of the present invention by the above method, it is possible to obtain toner base particles in which domains composed of a diene resin are uniformly dispersed in a matrix resin composed of a polyester resin. Since it can exhibit high elasticity, it has good low-temperature fixability while suppressing high-temperature offset, excellent heat-resistant storage stability, high mechanical strength and good crease fixability, Even in a fixing machine having a long nip length, it is possible to obtain a good image with no image displacement.

≪Description of fixing device≫
[Fixing device]
In the image forming method of the present invention, in the fixing step, at least one of the heating member and the pressure member is an endless belt stretched around a plurality of rollers, and the heating member and the pressure member are pressed against each other. This is performed using a belt nip type fixing device in which a fixing nip is formed.

  Hereinafter, embodiments of the fixing device suitably used in the image forming method of the present invention will be described in detail.

  FIG. 1 is an explanatory sectional view showing an example of the configuration of a fixing device used in the image forming method of the present invention.

  The fixing device 10 is of a belt nip type, and includes a heating member (hereinafter referred to as “heating roller”) 11 formed of a rotating roller and an endless belt (hereinafter referred to as “endless”) stretched between three rollers. Belt) ”) and the pressure applying member 12B. The fixing nip portion N is formed by the pressure contact portion between the heating roller 11 and the pressure applying member 12B of the pressure member 12. It is set as the structure. The longer the length of the nip portion (nip length) is, the more advantageous for fixing, and the longer the time for passing through the nip is, the higher the nip pressure is, the more the fixing property is improved.

  The nip length of the fixing nip portion N is preferably 20 mm to 50 mm. When the nip length of the fixing nip portion N is within the above range, image misalignment is suppressed while ensuring high gloss in the formed image. In the fixing device 10, the nip length of the fixing nip portion N is specifically 35 mm.

  The heating roller 11 has a built-in heating source 13 made of a halogen heater, and is formed on a metal cylindrical metal core 11a in which the heating source 13 is disposed, and on the outer peripheral surface of the cylindrical metal core 11a. The heat-resistant elastic body layer 11b is formed. The cylindrical cored bar 11a constituting the heating roller 11 is made of a metal having a high thermal conductivity such as iron, aluminum, or an alloy. The heat-resistant elastic layer 11b constituting the heating roller 11 includes, for example, an elastic layer made of HTV silicone rubber having high heat resistance, and covers the elastic layer, such as PFA (perfluoroalkyl vinyl ether) or PTFE (polytetrafluoroethylene). And a release layer made of a fluororesin.

The surface temperature T ₁ of the heating roller 11 is preferably 130 ° C. to 170 ° C. when the fixing linear velocity is 340 mm / sec. On the surface of the heating roller 11, a heating member temperature detection unit 101a is disposed so as to face the heating roller 11, and based on a temperature measurement value of the heating member temperature detection unit 101a, a control unit (not shown) in the image forming apparatus. by controlling the heat source 13, the surface temperature T ₁ of the heating roller 11 is set. When the surface temperature T ₁ of the heating roller 11 is too small, there is a possibility that high gloss to an image to be formed is not ensured, whereas, in the case the surface temperature T ₁ of the heating roller 11 is too large, the image There is a possibility that the occurrence of deviation is not sufficiently suppressed. Specifically, the surface temperature T ₁ of the heating roller 11 in the fixing device 10 is 150 ° C.

  The pressure member 12 is heated through three endless belts 12A and 12b and a pressure roller 12c. The endless belt 12A is heated on the inner peripheral surface of the endless belt 12A via the endless belt 12A. And a pressure applying member 12 </ b> B that pressurizes the roller 11. The endless belt 12A constituting the pressure member 12 includes a belt stretching roller 12a provided on the upstream side of the fixing nip portion N in the conveyance direction of the transfer material P, a belt stretching roller 12b that supports the endless belt 12A, It is an endless one that is suspended on the outer periphery of each roller with a pressure roller 12c provided on the downstream side of the fixing nip portion N and is rotatably supported. The belt stretching rollers 12a and 12b and the pressure roller 12c Is driven to rotate.

  The endless belt 12A includes a base formed of a heat-resistant elastic resin such as polyimide, an elastic layer made of, for example, silicone rubber that covers the outer surface of the base, and a fluorine resin such as PFA or PTFE that covers the elastic layer. It is comprised by the release layer which consists of.

  The pressure applying member 12B that constitutes the pressing member 12 includes a pressing roller 12c and a pressing member 12e. The pressure applying member 12B is disposed in contact with the inner peripheral surface of the endless belt 12A, and the pressure applying member 12B is connected to the heating roller 11 from the inner peripheral surface side of the endless belt 12A via the endless belt 12A. By applying pressure, a fixing nip portion N is formed between the heating roller 11 and the endless belt 12A.

  The pressure roller 12c constituting the pressure applying member 12B is provided in a downstream area of the fixing nip portion N in the transfer direction of the transfer material P. The pressure roller 12c has a hardness higher than that of the first to third pads 121, 122, and 123 constituting the pressing member 12e, and is a cylindrical cored bar formed of a metal such as aluminum, iron, or alloy, for example. Consists of. The pressure roller 12c has a function of pressing the heating roller 11 from the inner peripheral surface side of the endless belt 12A via the endless belt 12A and supporting the endless belt 12A.

  The pressing member 12e constituting the pressure applying member 12B supports the first pad 121, the second pad 122, the third pad 123, and the holding member 124, and stores a compression spring (not shown) that applies a pressing force, and these. And a sliding contact sheet (not shown) that covers the upper surfaces of the first pad 121 and the third pad 123 and slidably contacts the inner peripheral surface of the endless belt 12A.

  The first pad 121 and the second pad 122 constituting the pressing member 12e form a member layer laminated in a direction perpendicular to the transfer material P conveyance direction, and the fixing nip portion N in the transfer material P conveyance direction. In the upstream region. The first pad 121 that is the layer (upper layer) closest to the fixing nip N has a hardness lower than the second pad 122 that is the layer (lower layer) farthest from the fixing nip N.

  In addition, the hardness of the entire member layer constituting the pressing member 12 e is higher than the hardness of the first pad 121 and not more than the hardness of the second pad 122. For example, the first pad 121 is formed using a heat-resistant sponge and the second pad 122 is formed using a heat-resistant urethane, so that the hardness of the entire member layer is higher than the hardness of the first pad 121. The hardness of the second pad 122 is high or less.

  The third pad 123 that constitutes the pressing member 12e is a central region of the fixing nip N along the transfer material P conveyance direction, that is, a member layer including the first pad 121 and the second pad 122, the pressure roller 12c, and the like. It is provided between. The third pad 123 has a hardness lower than that of the entire member layer including the first pad 121 and the second pad 122. The third pad 123 is made of an elastic material such as silicone rubber having heat resistance, for example.

  The holding member 124 that constitutes the pressing member 12e is made of a metal plate such as stainless steel that holds the first to third pads 121, 122, and 123 and a resin plate that supports the metal plate. It is made of a rigid material that can maintain a strength that does not break even when subjected to force.

  The elastic force of the compression spring is applied to the endless belt 12A as a constant pressure through the holding member 124 and the first to third pads 121, 122, 123.

  Here, the distribution of the applied pressure in the fixing nip N in the conveyance direction of the transfer material P will be described. As described above, the pressure applying member 12B includes the member layer including the first pad 121 and the second pad 122 provided in the upstream region of the fixing nip N along the conveyance direction of the transfer material P, and the central region. The third pad 123 is provided and the pressure roller 12c provided in the downstream region, and has different hardnesses. The hardness H1 of the entire member layer composed of the first pad 121 and the second pad 122, the hardness H2 of the third pad 123, and the hardness H3 of the pressure roller 12c are expressed by the following relational expression 1.

(Relational expression 1): H3>H1> H2
The upstream region of the fixing nip N in the transfer direction of the transfer material P receives a pressure P1 from a member layer constituted by the first pad 121 and the second pad 122. Further, the downstream area of the fixing nip N in the transport direction of the transfer material P receives a pressure P3 from the pressure roller 12c. The central region of the fixing nip N in the conveyance direction of the transfer material P receives a pressure P2 from the third pad 123. Therefore, the distribution of the pressing force in the fixing nip N in the conveyance direction of the transfer material P is expressed by the following relational expression 2.

(Relational expression 2): P3>P1> P2
Pressure member 12, the surface temperature _{T 2} of the endless belts 12A Specifically, when the fixing line speed of 340 mm / sec, preferably from 90 ° C. to 110 ° C.. On the surface of the endless belt 12A, the pressure member temperature detection means 101b are disposed so as to face, by the pressure member temperature detection means 101b, the surface temperature T ₂ of the endless belt 12A is detected. Specifically, the surface temperature T ₁ of the pressure member 12 in the fixing device 10 is 100 ° C.

The difference (T ₁ −T ₂ ) between the surface temperature T ₁ of the heating roller 11 and the surface temperature T ₂ of the pressure member 12 is preferably 40 ° C. to 70 ° C. When the difference (T ₁ −T ₂ ) is within the above range, an image having higher gloss can be formed. When the difference (T ₁ −T ₂ ) is too small, an image having high glossiness may be formed. However, since the resistance to image displacement is reduced, the overall image gloss is uniform. May become unstable.

  In the fixing device 10 as described above, when the heating roller 11 is connected to a drive motor (not shown) and rotated in the direction of the arrow, the endless belt 12A is fixed to the heating roller 11 as a pressure contact portion following the rotation. The pressure applying member 12B that moves in the same direction at the nip N and the toner image on the transfer material P acts on the fixing nip N when the transfer material P onto which the toner image has been transferred passes through the fixing nip N. And the heat supplied from the heating roller 11 are fixed.

  As described above, the embodiment of the fixing device suitably used in the image forming method of the present invention has been described. However, the fixing device used in the image forming method of the present invention is not limited to the above embodiment. And various changes can be made.

  According to the present invention, when a belt nip type fixing device is used, the use of specific toner suppresses the occurrence of image misalignment while ensuring high gloss in the formed image.

  Examples of the present invention will be described in detail below, but the present invention is not limited thereto.

[Preparation Example 1 of Diene Resin Particle Dispersion (LxZ1)]
A pressure vessel is charged with 50 parts by mass of butadiene as a polymerizable monomer, 30 parts by mass of styrene, 18 parts by mass of methyl acrylate, and 2 parts by mass of acrylic acid, and further 200 parts by mass of ion-exchanged water and 1 part by mass of t-dodecyl mercaptan. , 0.2 parts by weight of sodium dodecylbenzenesulfonate and 1 part by weight of potassium persulfate were charged, followed by polymerization in a nitrogen atmosphere at a temperature of 70 ° C. for 2 hours. Thereafter, the reaction was further continued for 3 hours to complete the polymerization. By continuously terminating the polymerization, a dispersion (LxZ1) of diene resin particles in which the diene resin particles (Z1) were dispersed was prepared.

  About the obtained dispersion liquid (LxZ1) of the diene resin particles, the glass transition temperature, the volume-based median diameter, and the toluene insoluble content of the diene resin particles (Z1) were measured by the following methods. The glass transition temperature was −20 ° C., the volume-based median diameter was 150 nm, and the toluene insoluble content was 56 mass%.

(1) Glass transition temperature <Glass transition temperature as raw material of diene resin>
The diene resin particles were freeze-dried, and 4.5 mg of the dried sample was precisely weighed to two digits after the decimal point, sealed in an aluminum pan, and the differential scanning calorimeter “DSC8500” (Perkin Elmer) Set in a sample holder. The reference uses an empty aluminum pan, and performs heat-cool-heat temperature control at a measurement temperature of −120 ° C. to 100 ° C., a temperature increase rate of 10 ° C./min, and a temperature decrease rate of 10 ° C./min. 2nd. Analysis was performed based on the data in Heat. The glass transition temperature was defined as the value of the intersection of the base line extension before the rise of the first endothermic peak and the tangent line indicating the maximum slope between the rise portion of the first endothermic peak and the peak apex.

(2) Volume-based median diameter A few drops of a diene resin particle dispersion (LxZ1) are added to a 50 ml graduated cylinder, 25 ml of pure water is added, and an ultrasonic cleaner “US-1” (manufactured by as one) A sample for measurement is prepared by dispersing the sample for 3 minutes, and 3 ml of this sample for measurement is put into “Microtrack UPA-150” (manufactured by Nikkiso Co., Ltd.), and the value of Sample Loading is in the range of 0.1-100. It confirmed that there was and it measured on condition of the following.
(Measurement condition)
Transparency (transparency): Yes
Refractive Index (refractive index): 1.59
Particle Density (particle specific gravity): 1.05 / cm ³
Spherical Particulate (spherical particles): Yes
(Solvent conditions)
Refractive Index (refractive index): 1.33
Viscosity (Viscosity): High (temp) 0.797 × 10 ⁻³ Pa · s
Low (temp) 1.002 × 10 ⁻³ Pa · s
(3) Toluene-insoluble matter After adjusting the pH of the diene resin particle dispersion (LxZ1) to 7.5, this diene resin particle dispersion (LxZ1) was added to isopropyl alcohol with stirring to coagulate. After the coagulum is washed and dried, a predetermined amount (0.03 g) of sample is immersed in a predetermined amount (100 ml) of toluene at 20 ° C. for 20 hours, and then filtered through a 120 mesh wire net. The mass% with respect to the sample of residual solid content was computed.

[Preparation Example 2 of Diene Resin Particle Dispersions (LxZ2) to (LxZ10)]
In the preparation example (LxZ1) of the diene resin particle dispersion, the diene resin particles (Z2) were respectively changed in the same manner except that the types and / or addition amounts of the components to be added were changed according to the formulation in Table 1 below. Dispersions (LxZ2) to (LxZ10) of diene resin particles in which ~ (Z10) was dispersed were prepared. Regarding the obtained dispersions (LxZ2) to (LxZ10) of the diene resin particles, the glass transition temperature, the volume-based median diameter, and the toluene insoluble matter of the diene resin particles (Z2) to (Z10) are described above. Measured by the method. The results are shown in Table 1.

[Synthesis Example of Polyester Resin [A]]
In a reaction vessel equipped with a stirrer, nitrogen inlet tube, temperature sensor, rectifying column,
Polycarboxylic acid ・ Fumaric acid: 4.2 parts by mass ・ Terephthalic acid: 78 parts by mass Polyhydric alcohol ・ 2,2-bis (4-hydroxyphenyl) propanepropylene oxide 2 mol adduct: 152 parts by mass ・ 2,2 -Bis (4-hydroxyphenyl) propaneethylene oxide 2-mole adduct: Charge 48 parts by mass, raise the temperature of the reaction system to 190 ° C. over 1 hour, and confirm that the inside of the reaction system is uniformly stirred After that, Ti (OBu) ₄ was added as a catalyst in an amount of 0.006% by mass with respect to the total amount of polyvalent carboxylic acid, and the temperature of the reaction system was kept at the same temperature while distilling off the produced water. The polyester resin [A] was obtained by raising the temperature to 240 ° C. over 6 hours and then continuing the dehydration condensation reaction for 6 hours while maintaining the temperature at 240 ° C. The obtained polyester resin [A] had a number average molecular weight (Mn) of 3,100, a glass transition temperature (Tg) of 63 ° C., and a softening point of 90 ° C. The molecular weight, glass transition temperature (Tg) and softening point of the polyester resin [A] were measured as described above.

[Preparation Example of Aqueous Dispersion (A1) of Composite Polyester Resin Particles Containing Diene Resin Particles]
To a reaction vessel equipped with an anchor blade that gives stirring power, 2567 parts by mass of methyl ethyl ketone and 100 parts by mass of isopropyl alcohol are added, and then the above-mentioned polyester resin [A] 2567 parts by mass is roughly pulverized with a hammer mill. The mixture was stirred and completely dissolved to obtain an oil phase.

  To this oil layer, a dispersion (latex) of diene resin particles LxZ1 was added. As addition amount, it adjusted so that diene resin solid content might be 77 mass parts with respect to 2567 mass parts of solid content of polyester resin [A]. Next, an appropriate amount of a dilute aqueous ammonia solution is added dropwise to the stirred oil phase, and the oil phase is added dropwise to 6000 parts by mass of ion-exchanged water for phase inversion emulsification, and then the solvent is removed while reducing the pressure with an evaporator. Thus, a dispersion of polyester resin particles is obtained, and further, ion exchange water is added to the dispersion to adjust the solid content to 40% by mass, thereby obtaining “a composite polyester resin containing diene resin particles”. An aqueous dispersion of particles (A1) ”was obtained. The volume-based median diameter of the resin particles of the obtained “aqueous dispersion (A1) of composite polyester resin particles containing diene resin particles” was 182 nm.

[Preparation Examples of Aqueous Dispersions (A2) to (A16) of Composite Polyester Resin Particles Containing Diene Resin Particles]
In accordance with the configuration shown in Table 2, using the diene resin particle dispersions (LxZ2) to (LxZ10), respectively, a preparation example of an “aqueous dispersion liquid (A1) of composite polyester resin particles containing diene resin particles” and Similarly, “aqueous dispersions (A2) to (A16) of composite polyester resin particles containing diene resin particles” were prepared.

[Preparation Example of Aqueous Dispersion (A17) of Polyester Resin Particles not Containing Diene Resin Particles]
In the preparation example of “Aqueous dispersion of composite polyester resin particles containing diene resin particles (A1)”, except that no dispersion of diene resin particles is added, “polyester not containing diene resin particles” is used. An aqueous dispersion of resin particles (A17) ”was prepared.

[Example of Preparation of Aqueous Dispersion [M] of Magenta Colorant Particles]
Anionic surfactant “Neogen RK” (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by mass is mixed and dissolved in 195 parts by mass of deionized water. I. Pigment Red 122 (manufactured by Clariant Japan) 50 parts by mass and dispersed with a homogenizer “Ultra Tarrax” (manufactured by IKA) for 10 minutes, magenta colorant particles having a volume-based median diameter of 185 nm are dispersed. Further, an aqueous dispersion [M] of magenta colorant particles having a solid content (magenta colorant particles) of 20% by mass was obtained.

[Preparation Example of Release Agent Particle Dispersion [W]]
5 parts by mass of anionic surfactant “Neogen RK” (Daiichi Kogyo Seiyaku Co., Ltd.) and 50 parts by mass of paraffin wax “FNP92” (melting point: 91 ° C., Nippon Seiwa Co., Ltd.) are added to 195 parts by mass of deionized water. After heating to 60 ° C. and sufficiently dispersing with “Ultra Turrax T50” (manufactured by IKA), the release agent particles having a center particle diameter of 170 nm are obtained by dispersing with a pressure discharge type gorin homogenizer. A dispersed release agent particle dispersion [W] having a solid content (release agent particles) of 20% by mass was obtained.

[Production Example of Toner [1]]
Aqueous dispersion (A1) of composite polyester resin particles containing diene resin particles:
2644 parts by mass (in terms of solid content)
Aqueous dispersion of magenta colorant particles [M]: 200 parts by mass (in terms of solid content)
Release agent particle dispersion [W]: 380 parts by mass (in terms of solid content)
Was stirred in a reaction vessel equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. After adjusting the temperature in the container to 30 ° C., a 1.0 mass% nitric acid aqueous solution was added to this solution to adjust the pH to 3.0.

Next, 1.5 parts by mass of polyaluminum chloride was added while being dispersed with a homogenizer “Ultra Turrax T50” (manufactured by IKA), the temperature was raised to 47 ° C. with stirring, and “Multisizer 3” (Beckman Coulter) The volume-based median diameter (D ₅₀ ) of the aggregated particles becomes 6.5 μm while measuring the particle diameter with a 5% by weight aqueous sodium hydroxide solution to adjust the pH to 9.0. The mixture was further heated and stirred at 90 ° C. for 3 hours, then cooled to 30 ° C. at 6 ° C./min, adjusted to pH 2.0 by adding hydrochloric acid, and then the stirring was stopped. As a result, toner base particles [1] were produced. The produced toner base particles [1] were subjected to solid-liquid separation, and washing with 15000 parts by mass of ion-exchanged water was repeated four times, followed by drying with hot air at 40 ° C. to obtain toner base particles [1]. The toner base particle [1] had a volume-based median diameter of 5.2 μm and an average circularity of 0.964.

  To the obtained toner base particles [1], 1% by mass of hydrophobic silica (number average primary particle size = 12 nm, hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle size = 20 nm, hydrophobicity = 63) 1% by mass was added, mixed by “Henschel mixer” (manufactured by Mitsui Miike Chemical Co., Ltd.), and then subjected to an external additive treatment for removing coarse particles using a sieve having an opening of 45 μm. This is designated as toner [1].

[Production Examples of Toners [2] to [18]]
In the production example of toner [1], toner [2] was prepared in the same manner as in Table 2, except that “polyester resin particle dispersions (A2) to (A16) containing diene resin particles” were used. To [18].

[Production Example of Toner [19] (Comparative)]
In the preparation example of the aqueous dispersion (A1) of the composite polyester resin particles containing the diene resin particles, the polyester not containing the diene resin particles is the same except that the dispersion of the diene resin particles is not added. An aqueous dispersion (A17) of resin particles was prepared. A toner [19] containing no diene resin was prepared in the same manner as the toner [1] except that this “aqueous dispersion (A17) of polyester resin particles not containing diene resin particles” was used.

[Production example of toner [20] (for comparison): simultaneous mixing]
Aqueous dispersion (A17) of polyester resin particles not containing diene resin particles:
2567 parts by mass (solid content conversion)
Diene resin particle dispersion (LxZ1): 77 parts by mass (solid content conversion)
Aqueous dispersion of magenta colorant particles [M]: 200 parts by mass (in terms of solid content)
Release agent particle dispersion [W]: 380 parts by mass (in terms of solid content)
Was stirred in a reaction vessel equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. After adjusting the temperature in the container to 30 ° C., a 1.0 mass% nitric acid aqueous solution was added to this solution to adjust the pH to 3.0.

Next, 1.5 parts by mass of polyaluminum chloride was added while being dispersed with a homogenizer “Ultra Turrax T50” (manufactured by IKA), the temperature was raised to 47 ° C. with stirring, and “Multisizer 3” (Beckman Coulter) The volume-based median diameter (D ₅₀ ) of the aggregated particles becomes 6.5 μm while measuring the particle diameter with a 5% by weight aqueous sodium hydroxide solution to adjust the pH to 9.0. The mixture was further heated and stirred at 90 ° C. for 3 hours, then cooled to 30 ° C. at 6 ° C./min, adjusted to pH 2.0 by adding hydrochloric acid, and then the stirring was stopped. Thus, toner base particles [20] were produced. In the toner base particles [20], the volume-based median diameter of the toner particles was 5.3 μm, and the average circularity was 0.952. Next, the toner base particles [20] were treated with an external additive in the same manner as the toner [1] to prepare a toner [20].

[Evaluation]
Each of the obtained toners [1] to [20] and a ferrite carrier having a volume-based median diameter of 60 μm coated with a cyclohexyl methacrylate resin are mixed using a V-type mixer so that the toner concentration becomes 6% by mass. By mixing, developers [1] to [20] were produced. Using the developers [1] to [20], the following evaluation was performed.

[Evaluation 1: Image shift]
A4 coated paper “POD gloss coat (84.9 g / m ² )” (manufactured by Oji Paper Co., Ltd.) was used as an A4 size transfer material using the fixing device shown in FIG. A solid image set to ² mg / cm ² was formed. As the image forming apparatus, a commercially available multifunction machine “bizhub PRO C6501” (manufactured by Konica Minolta Business Technologies) was remodeled and the fixing apparatus shown in FIG. 1 was provided. The fixing conditions are: linear velocity: 340 mm / second, nip length: 35 mm, fixing pressure: 0.5 Pa, heating member surface temperature T ₁ : 150 ° C., pressure member surface temperature T ₂ : 100 ° C. (T ₁ -T ₂ = 50 ° C.). The formed image was visually evaluated according to the following evaluation criteria. If the evaluation is C or higher, it is considered acceptable. The results are shown in Table 3.

(Evaluation criteria)
A: The transfer material is conveyed without causing image misalignment, and there is no image defect such as uneven glossiness B: The transfer material is conveyed without causing image misalignment, but there is slight gloss unevenness C: Transfer material However, the image is slightly misaligned or gloss unevenness is large. D: Image misalignment occurs, resulting in poor conveyance, and gloss unevenness is large.

[Evaluation 2: Fold fixing property]
A commercial copier “bizhub 421” (manufactured by Konica Minolta Business Technologies Co., Ltd.) was modified to an output speed of 84 sheets per minute (double the output speed of commercial products), and the surface temperature of the heating roller of the fixing device Is set to 170 ° C., and a solid black image with an image density of 0.8 is formed at room temperature and normal humidity (temperature 20 ° C., relative humidity 55%) and completely cooled (this state is the state before folding) ) Next, after folding the black solid image and rubbing the folded part with fingers three times, the black solid image is opened and wiped three times with “JK Wiper” (manufactured by Crecia Co., Ltd.) State). Then, the crease fixing rate was calculated according to the following formula (3) from the image density before and after the folding of the solid black image. A crease fixing rate of 70% or more was determined to be acceptable.

Formula (3):
Fold fixing rate (%) = {(image density after folding) / (image density before folding)} × 100

  As is apparent from the above results, the toners [1] to [18] of the present invention are extremely excellent in crease fixing properties and image misalignment characteristics as compared with the comparative toners [19] and [20]. is there.

A Heating roller B Pressure roller C Transfer paper moving direction D Nip length 10 Fixing device 11 Heating member 12A Endless belt member 12B Pressure applying member N Fixing nip 13 Heating source 11a Cylindrical core 11b Heat resistant elastic layer 12a 12b Belt tension roller 12c Pressure roller P Transfer material 12e Press member 121 First pad 122 Second pad 123 Third pad 124 Holding member 101a Heating member temperature detection means 101b Pressure member temperature detection means

Claims (9)

An electrostatic image developing toner containing at least a polyester resin, a diene resin, and a colorant, wherein the electrostatic image developing toner is at least
(1) A polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain a polyester resin solution liquid containing diene resin particles. Forming an aqueous dispersion of a composite polyester resin solution in which drops are dispersed in an aqueous medium;
(2) removing an organic solvent from the aqueous dispersion of the composite polyester resin solution to form an aqueous dispersion of composite polyester resin particles containing diene resin particles;
(3) mixing the aqueous dispersion of the composite polyester resin particles and the aqueous dispersion of the colorant particles, and aggregating the composite polyester resin particles and the colorant particles;
A toner for developing an electrostatic charge image, which is produced through   2. The electrostatic charge image developing toner according to claim 1, wherein the diene resin contains 15% by mass or more and 95% by mass or less of a toluene insoluble content.   The electrostatic image developing toner according to claim 1, wherein the diene resin is a styrene-butadiene copolymer.   The electrostatic image developing toner according to any one of claims 1 to 3, wherein the diene resin contains 30% by mass or more and 70% by mass or less of a toluene-insoluble component. A method for producing an electrostatic image developing toner comprising at least a polyester resin, a diene resin, and a colorant, wherein the electrostatic image developing toner comprises at least
(1) A polyester resin solution in which a polyester resin is dissolved in an organic solvent and a diene resin particle dispersion in which diene resin particles are dispersed in an aqueous medium are mixed to obtain a polyester resin solution liquid containing diene resin particles. Forming an aqueous dispersion of a composite polyester resin solution in which drops are dispersed in an aqueous medium;
(2) removing an organic solvent from the aqueous dispersion of the composite polyester resin solution to form an aqueous dispersion of composite polyester resin particles containing diene resin particles;
(3) mixing the aqueous dispersion of the composite polyester resin particles and the aqueous dispersion of the colorant particles, and aggregating the composite polyester resin particles and the colorant particles;
A method for producing a toner for developing an electrostatic charge image, wherein   6. The method for producing a toner for developing an electrostatic charge image according to claim 5, wherein the diene resin contains 15% by mass or more and 95% by mass or less of a toluene insoluble content.   The method for producing a toner for developing an electrostatic charge image according to claim 5, wherein the diene resin is a styrene-butadiene copolymer.   The electrostatic image developing toner according to any one of claims 5 to 7, wherein the diene-based resin contains 30% by mass or more and 70% by mass or less of a toluene insoluble content. Production method. A transfer step of transferring a toner image formed on the image carrier to a transfer material;
In the image forming method having a fixing step of fixing the toner image transferred onto the transfer material,
The fixing step includes an endless belt in which at least one of a heating member and a pressure member is stretched around a plurality of rollers, and the heating member and the pressure member are pressed against each other to form a fixing nip. An image forming method using the toner for developing an electrostatic charge image according to any one of claims 1 to 4, which is performed using a fixing device.

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