JP2012068324A - Toner for electrostatic charge image development, method for manufacturing the same, electrostatic charge image developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner for electrostatic charge image development in which the deterioration of the maintenance property of transfer efficiency (transfer maintenance property) of toner from an image holder to a transfer object is suppressed.SOLUTION: Toner for electrostatic charge image development comprises toner base particles containing at least a binder resin and a coloring agent and the toner base particles have protrusions made of particles of silicone rubber on the surface. The toner for electrostatic charge image development preferably has an average circularity of 0.97 or more and the ratio d/D of the volume average particle diameter D of the toner for electrostatic charge image development and the volume average particle diameter d of the particles of silicone rubber forming the protrusions is preferably 0.05 to 0.12.

Description

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

  In the image formation in the electrophotographic process, when copying, a toner image (developed image) is obtained by attaching toner to the electrostatic latent image formed on the image carrier using a photoconductive substance by a magnetic brush developing method or the like. The toner image on the photoreceptor is transferred to a recording material (transfer material) such as paper or sheet, and then fixed using heat, solvent, pressure, or the like to obtain an image.

  As an electrostatic charge image developing toner used in the electrophotographic process, electrostatic charge image developing toners having protrusions formed on the surface are disclosed (Patent Documents 1 to 3).

JP 2008-158319 A JP 2002-075251 A JP 2005-274964 A

  The problem to be solved by the present invention is to provide a toner for developing an electrostatic image in which a decrease in maintenance efficiency (transfer maintenance) of toner transfer efficiency from an image carrier to a transfer medium is suppressed.

The above problem has been solved by the following means.
<1> an electrostatic charge image developing toner comprising toner base particles containing at least a binder resin and a colorant, wherein the toner base particles have protrusions made of silicone rubber particles on the surface thereof;
<2> The electrostatic image developing toner according to <1>, wherein the average circularity is 0.97 or more,
<3> The ratio d / D between the volume average particle diameter D of the electrostatic image developing toner and the volume average particle diameter d of the silicone rubber particles forming the protrusions is 0.05 to 0.12. 1> or <2> an electrostatic charge image developing toner according to
<4> Aggregation step of aggregating particles contained in a dispersion containing at least a binder resin and a colorant to form an aggregate, a particle adhesion step of adhering silicone rubber particles to the surface of the aggregate, and the aggregation And a step of fusing the particles of the silicone rubber adhering to the aggregate to unite them, wherein the production of the toner for developing an electrostatic image according to any one of the above <1> to <3> Method,
<5> An electrostatic image developer comprising the electrostatic image developing toner according to any one of <1> to <3> and a carrier,
<6> A charging step for charging the image carrier, an electrostatic latent image forming step for exposing the charged image carrier to form an electrostatic latent image, and a developer containing toner for the electrostatic latent image. A developing process for forming a developed image, a transfer process for transferring the developed image onto a substrate to form a transferred image, and a fixing process for fixing the transferred image. <1> to <3> The electrostatic charge image developing toner according to any one of the above, or the developer is the electrostatic charge image developer according to <5>. .

By the means described in <1> above, an electrostatic charge image developing toner is provided in which the toner base particles are prevented from deteriorating in transfer maintainability compared to the case where the toner base particles do not have protrusions made of silicone rubber particles on the surface. Is done.
By means described in the above <2>, a toner for developing an electrostatic charge image in which a decrease in transfer maintainability is further suppressed as compared with a case where the average circularity is less than 0.97 is provided.
As a result of the means described in <3> above, static deterioration in which transfer deterioration is further suppressed and filming is suppressed as compared with a case where d / D is not 0.05 to 0.12. A charge image developing toner is provided.
By the means described in <4> above, a method for producing a toner for developing an electrostatic charge image in which a decrease in transfer maintainability is suppressed as compared with a case where the present configuration is not provided is provided.
By means described in the above <5>, an electrostatic charge image developer in which a decrease in transfer maintainability is suppressed as compared with the case where this configuration is not provided is provided.
By means described in <6> above, an image forming method in which a decrease in transfer maintainability is suppressed as compared with a case where this configuration is not provided is provided.

1 is a schematic cross-sectional view illustrating an example of an image forming apparatus according to an exemplary embodiment.

(Static image developing toner)
The electrostatic image developing toner of the present embodiment (hereinafter also simply referred to as “toner”) has toner base particles containing at least a binder resin and a colorant, and the toner base particles are particles of silicone rubber on the surface. It has the processus | protrusion which consists of.
Hereinafter, a toner constituent material used in the exemplary embodiment, a toner manufacturing method, and the like will be described. In this specification, “A to B” or the like representing a numerical range is synonymous with “A or more and B or less”, and both ends of the numerical range are included in the numerical range.

<Binder resin>
In this embodiment, the toner base particles contain at least a binder resin. The binder resin is not particularly limited, and preferred examples include addition polymerization resins and polycondensation resins. Among these, the addition polymerization resin is preferably an addition polymerization resin of an ethylenically unsaturated compound, and more preferably an acrylic resin. As the polycondensation resin, a polyester resin is preferable, and a polyester resin of a polyol and a polycarboxylic acid is more preferable.
Details are described below.

As the addition polymerization resin, homopolymers and copolymers of various ethylenically unsaturated compounds are preferably used. Examples of addition polymerization resins of ethylenically unsaturated compounds include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene, and isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl acetate, and the like. Α-methylene aliphatic monocarboxylic acid such as ester, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Examples include homopolymers or copolymers of acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone. It is.
Particularly preferred addition polymerization resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-anhydrous maleate. Examples include acid copolymers, polyethylene, and polypropylene.

As the polycondensation resin used in the present embodiment, a polyester resin is preferably exemplified. The polyester resin is synthesized from a polyol component and a polycarboxylic acid component by polycondensation. In the present embodiment, a commercially available product or a synthesized product is used as the polyester resin.
Examples of the polycarboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12- Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid, etc. Aromatic dicarboxylic acids such as dibasic acids, and the like, and anhydrides and lower alkyl esters thereof.
Examples of the trivalent or higher polycarboxylic acid component include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc., and anhydrides thereof. And lower alkyl esters. These are used alone or in combination of two or more.

  It is preferable to contain a dicarboxylic acid component having an ethylenically unsaturated bond in addition to the aforementioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid. A dicarboxylic acid having an ethylenically unsaturated bond is preferably used to prevent hot offset at the time of fixing because it is radically crosslinked through the ethylenically unsaturated bond. Examples of such dicarboxylic acids include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included. Among these, fumaric acid, maleic acid and the like are preferable in terms of cost.

Among the polyol components, divalent alcohols include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4- Alkylene (2-4 carbon atoms) oxide adducts (average addition mole number 1.5-6) of bisphenol A such as hydroxyphenyl) propane, ethylene glycol, propylene glycol, neopentyl glycol, 1,4-butanediol, 1 , 3-butanediol, 1,6-hexanediol and the like.
Examples of the trivalent or higher alcohols include sorbitol, pentaerythritol, glycerol, trimethylolpropane, and the like.

In the amorphous polyester resin (also referred to as “non-crystalline polyester resin”), among the raw material monomers described above, a dihydric or higher secondary alcohol and / or a divalent or higher aromatic carboxylic acid compound is preferable. Examples of the dihydric or higher secondary alcohol include a propylene oxide adduct of bisphenol A, propylene glycol, 1,3-butanediol, and glycerol. In these, the propylene oxide adduct of bisphenol A is preferable.
As the divalent or higher aromatic carboxylic acid compound, terephthalic acid, isophthalic acid, phthalic acid and trimellitic acid are preferable, and terephthalic acid and trimellitic acid are more preferable.

  Moreover, softening point 90-150 degreeC, glass transition point 50-75 degreeC, number average molecular weight 2,000-10,000, weight average molecular weight 8,000-200,000, acid value 5-30 mgKOH / g, hydroxyl value 5 A resin exhibiting ˜40 mg KOH / g is particularly preferably used.

In order to impart low-temperature fixability to the toner, it is preferable to use a crystalline polyester resin as at least a part of the binder resin.
The crystalline polyester resin is preferably composed of a polycondensation resin of an aliphatic dicarboxylic acid and an aliphatic diol, and a linear dicarboxylic acid having a main chain portion of 4 to 20 carbon atoms and a linear aliphatic diol More preferably, it is made of a polycondensation resin. The linear type is excellent in the crystallinity of the polyester resin and has an appropriate crystal melting point, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability. Further, when the carbon number is 4 or more, the ester bond concentration is low, the electric resistance is moderate, and the toner charging property is excellent. Further, when it is 20 or less, it is easy to obtain practical materials. The carbon number is more preferably 14 or less.

  Examples of the aliphatic dicarboxylic acid suitably used for the synthesis of the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9- Nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecane Dicarboxylic acid, 1,18-octadecanedicarboxylic acid, or the like, or lower alkyl esters and acid anhydrides thereof may be mentioned, but not limited thereto. Among these, considering availability, sebacic acid and 1,10-decanedicarboxylic acid are preferable.

Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,20-eicosanediol and the like, but are not limited thereto. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These are used alone or in combination of two or more.

Among the polycarboxylic acid components, the content of the aliphatic dicarboxylic acid is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic dicarboxylic acid is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, so that it is excellent in toner blocking resistance, image storage stability, and low-temperature fixability.
Among the polyol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90 mol% or more. When the content of the aliphatic diol component is 80 mol% or more, the polyester resin is excellent in crystallinity and has an appropriate melting point, and thus is excellent in toner blocking resistance, image storage stability, and low-temperature fixability.
If necessary, a monovalent acid such as acetic acid or benzoic acid or a monovalent alcohol such as cyclohexanol benzyl alcohol may be used for the purpose of adjusting the acid value or the hydroxyl value.

There is no restriction | limiting in particular as a manufacturing method of a polyester resin, The general polyester polymerization method which makes a polycarboxylic acid component and a polyol component react is illustrated, For example, a direct polycondensation, a transesterification method, etc. are mentioned. These production methods are properly used depending on the type of monomer.
The polyester resin is produced by subjecting the polycarboxylic acid component and the polyol component to a condensation reaction according to a conventional method. For example, the polycarboxylic acid component and the polyol component, and if necessary, a catalyst is added, blended in a reaction vessel equipped with a thermometer, a stirrer, and a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas). , By heating at 150 to 250 ° C., continuously removing by-product low molecular weight compounds out of the reaction system, stopping the reaction when a predetermined weight average molecular weight or acid value is reached, cooling, and aiming Produced by obtaining a reactant.

  The content of the binder resin in the toner of the exemplary embodiment is not particularly limited, but is preferably 5 to 95% by weight with respect to the total weight of the electrostatic image developing toner, and is 20 to 90% by weight. More preferably, it is more preferably 40 to 85% by weight. Within the above range, the fixing property, storage property, powder property, charging property and the like are excellent.

<Colorant>
The toner of this embodiment contains a colorant.
Examples of colorants include carbon black, nigrosine, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 238, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 180, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is exemplified as a typical example.
A coloring agent is used individually by 1 type or in combination of 2 or more types.

  In the toner of this embodiment, the colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner. The amount of the colorant added is not particularly limited, but is preferably in the range of 3 to 60% by weight with respect to the total weight of the toner.

<Release agent>
The toner of this embodiment preferably contains a release agent.
There is no restriction | limiting in particular in the mold release agent used for this embodiment, A well-known thing is used and the following waxes are preferable. Examples of the wax include paraffin wax and derivatives thereof, montan wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, and the like. Derivatives include oxides, polymers with vinyl monomers, and graft modified products. In addition, alcohols, fatty acids, plant waxes, animal waxes, mineral waxes, ester waxes, acid amides and the like can be mentioned.

  It is preferable that the wax used as the release agent melts at any temperature of 70 to 140 ° C. and exhibits a melt viscosity of 1 to 200 centipoise at 140 ° C., more preferably 1 to 100 centipoise. preferable. When the melting temperature is 70 ° C. or higher, the change temperature of the wax is sufficiently high, and the blocking resistance and the developability are excellent when the temperature in the copying machine is increased. When the temperature is 140 ° C. or lower, the change temperature of the wax is sufficiently low, it is not necessary to perform fixing at a high temperature, and the energy saving property is excellent. Further, when the melt viscosity is 200 centipoises or less, the elution from the toner is appropriate and the fixing peelability is excellent.

  The content of the releasing agent is preferably 3 to 60% by weight, more preferably 5 to 40% by weight, and further preferably 7 to 20% by weight with respect to the total weight of the toner. preferable. Within the above range, the toner is excellent in the prevention of offset to the heating member and also in the prevention of feed roll contamination.

<Silicon rubber particles>
The toner base particles have protrusions made of silicone rubber particles (hereinafter also simply referred to as “silicone rubber particles”) on the surface. Hereinafter, the silicone rubber particles will be described.

  The polyorganosiloxane constituting the silicone rubber particles includes polyorganosiloxanes such as polydimethylsiloxane, polymethylphenylsiloxane, and polydimethylsiloxane-diphenylsiloxane copolymer, and some of the side chain alkyl groups are substituted with hydrogen atoms. Polyorganohydrogensiloxane or the like is used.

  The polyorganosiloxane preferably has a graft crossover group such as a radically polymerizable ethylenically unsaturated group, and more preferably has a plurality of graft crossover groups per side molecule and / or molecular chain end. It is particularly preferable to have it in the side chain.

  The method for obtaining the polyorganosiloxane is not particularly limited, and examples thereof include solution polymerization, suspension polymerization, and emulsion polymerization. Examples of the method include a method of polymerizing a cyclic, linear or branched organosiloxane, preferably a cyclic organosiloxane, using a catalyst such as an acid, an alkali, a salt or a fluorine compound.

  The weight average molecular weight (Mw) of the organosiloxane used for the polymerization is preferably 20,000 or less, more preferably 10,000 or less, still more preferably 5,000 or less, and particularly preferably 2,500 or less.

  In the above method, a method using a silane having a graft crossing group and / or a cyclic, linear or branched organosiloxane having the same weight average molecular weight (Mw) having a graft crossing group together with the organosiloxane. preferable.

  In the above method, a silane having a graft crossing group and / or a cyclic, linear or branched organosiloxane having the same weight average molecular weight (Mw) having a graft crossing group is used without using the organosiloxane. It may be a method.

  A polyorganosiloxane having a weight average molecular weight (Mw) of preferably 20,000 or more, more preferably 50,000 or more, and further preferably 100,000 or more in a solution, slurry, or emulsion, preferably A silane having a graft crossing group and / or a cyclic, linear or branched organosiloxane having a graft crossing group preferably having a weight average molecular weight (Mw) of 20,000 or less in the presence of the same catalyst as described above. A method of equilibrating is mentioned.

  In solution, slurry, or emulsion, it has a polyorganosiloxane having a weight average molecular weight (Mw) of preferably 20,000 or more and a graft crossover group having a weight average molecular weight (Mw) of preferably 20,000 or more. Examples thereof include a method of equilibrating polyorganosiloxane in the presence of a catalyst as described above.

  Silicone rubber particles are produced from the organosiloxane by emulsion polymerization. Instead of the emulsion polymerization method, the modified or non-modified polyorganosiloxane obtained by the method of modifying the polyorganosiloxane in the emulsion state or the solution polymerization method as described above is mechanically forcedly emulsified using a high-pressure homogenizer or the like. A dispersion containing silicone rubber particles is produced by a method or the like.

  Silicone rubber particles are produced by a known emulsion polymerization method. For example, a cyclic siloxane such as 1,3,5,7-octamethylcyclotetrasiloxane and / or a bifunctional silane having a hydrolyzable group such as methyldimethoxysilane, methyltriethoxysilane, tetrapropyl if necessary Trifunctional or higher functional alkoxysilane such as oxysilane, condensate of trifunctional or higher functional silane such as methyl orthosilicate, and, if necessary, mercaptopropyldimethoxymethylsilane, acryloyloxypropyldimethoxymethylsilane, methacryloyloxypropyldimethoxymethylsilane And a graft crossing agent having an ethylenically unsaturated group such as vinyldimethoxymethylsilane and vinylphenyldimethoxymethylsilane.

The amount of the grafting agent used is preferably 0.03 mol% or more, more preferably 0.06 mol% or more, more preferably 0.15 mol% or more in terms of siloxane units in the polyorganosiloxane, from the viewpoint of obtaining good elasticity. Is more preferable, and 0.5 mol% or more is particularly preferable.
The amount of the grafting agent used is preferably 5 mol% or less, more preferably 3 mol% or less, still more preferably 1 mol% or less in terms of siloxane units in the polyorganosiloxane, from the viewpoint of obtaining good elasticity.

The conditions for polymerization of the silicone rubber particles will be described.
First, the raw material organosiloxane, grafting agent, and the like are emulsified with water and a surfactant together with a homogenizer or the like, and mechanically emulsified and dispersed under high pressure as necessary. Thereafter, acid or base is added to adjust the pH. When adding an acid, the pH is preferably 4 or less, more preferably 3 or less, and even more preferably 2 or less. When adding a base, the pH is preferably 8 or more, more preferably 9.5 or more, and even more preferably 11 or more. By setting the pH within the above range, organosiloxane and the like are hydrolyzed and polycondensed to form silicone rubber particles made of polyorganosiloxane.
The polymerization temperature is preferably 0 ° C. or higher, more preferably 30 ° C. or higher, further preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher. The polymerization temperature is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, and particularly preferably 95 ° C. or lower.
The hydrolysis / condensation reaction is preferably performed in an inert gas atmosphere such as nitrogen or in a vacuum degassed state.

  When polymerizing the cyclic siloxane and / or silane, it is preferable to apply a known seed polymerization method. For example, a method using an organic polymer as a seed particle, a method using a polyorganosiloxane latex as a seed latex, a method using an organic polymer having swelling property with respect to cyclic siloxane as a seed particle, or a latex particle diameter of 20 nm or less, preferably Is a method using a polymer of 15 nm or less, more preferably 10 nm or less as seed particles.

  The dispersion of silicone rubber particles obtained by the above method usually contains a volatile low molecular weight cyclic siloxane. For the purpose of removing this volatile low molecular weight cyclic siloxane, vapor stripping or adsorbent such as diatomaceous earth to adsorb volatile low molecular weight cyclic siloxane, and then filter the silicone rubber particles. The method is applied.

  As another method for obtaining a dispersion of particles of silicone rubber, for example, the content of volatile low molecular weight siloxane is 5% by weight or less, more preferably 1% by weight or less, and the weight average molecular weight (Mw) is preferably 20%. , Not more than 10,000, more preferably not more than 10,000, still more preferably not more than 5,000, particularly preferably not more than 2,500, having a condensable group and / or a hydrolyzable group at the terminal, and if necessary, mercapto Linear or branched modified or unmodified partially substituted with radically polymerizable polymerizable groups such as propyl, methacryloyloxypropyl, acryloyloxypropyl, vinyl, vinylphenyl, and allyl There is a method in which (poly) organosiloxane is preferably emulsified to a desired particle size by mechanical shearing under high pressure and then polymerized. Examples of the condensable group include a hydroxy group, an amino group, and examples of the hydrolyzable group include an alkoxy group, an acyloxy group, a ketoxime group, an alkenoxy group, an amide group, and an aminoxy group.

  The volume average particle diameter of the silicone rubber particles is preferably 0.19 to 0.45 μm, and more preferably 0.25 to 0.35 μm. It is preferable that the value is within the above-mentioned numerical value range because it is possible to prevent burying due to stress in the developing device and to suppress release from the toner. The volume average particle diameter is measured using, for example, MICROTRAC NPA150 manufactured by Nikkiso Co., Ltd.

The weight average molecular weight (Mw) of the polyorganosiloxane contained in the silicone rubber particles is preferably 100,000 or more, and more preferably 160,000 or more. Moreover, 1,000,000 or less is preferable, 600,000 or less is more preferable, and 300,000 or less is still more preferable. It is preferable that the value is within the above-mentioned range because moderate elasticity can be obtained without inhibiting the low-temperature fixability.
As the weight average molecular weight (Mw), a standard polystyrene conversion value by gel permeation chromatography (GPC) analysis is used.

From the viewpoint of holding the elastic particles, the silicone rubber particles are preferably silicone rubber particles having a coating resin layer on the surface thereof.
The method of coating the silicone rubber particles is not particularly limited, but a method of emulsion polymerization of a polymerizable compound in the presence of the silicone rubber particles is preferable. As the polymerizable compound for forming the coating resin layer, an addition polymerizable compound is preferable, and a compound having at least one polymerizable group capable of undergoing a polymerization reaction with the graft crossing group is more preferable. When the graft crossover group is a radically polymerizable ethylenically unsaturated group, the adhesion between the silicone rubber particles and the resin coating layer is improved, so that the polymerizable compound forming the coating resin layer is also radically polymerized. It is preferable that it is a compound which has an ethylenically unsaturated group.

As the polymerizable compound, a polyfunctional monomer is preferably used. The polyfunctional monomer is a compound having two or more polymerizable ethylenically unsaturated groups in one molecule. As the polyfunctional monomer, for example, a (meth) acrylate polyfunctional monomer, an aromatic vinyl polyfunctional monomer, an aromatic polycarboxylic acid ester, a tertiary amine, which will be described later, Examples include isocyanuric acid derivatives, cyanuric acid derivatives, and biphenyl derivatives. In the present embodiment, a (meth) acrylate-based polyfunctional monomer is preferable.
These polyfunctional monomers are used alone or in combination of two or more. Unless otherwise specified, “(meth) acryl” and the like mean “acryl and / or methacryl”.

Examples of the (meth) acrylate-based polyfunctional monomer include allyl (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and the like.
Examples of the aromatic vinyl-based polyfunctional monomer include divinylbenzene, diisopropenylbenzene, divinylnaphthalene, and divinylanthracene.
Examples of aromatic polycarboxylic acid esters include triallylbenzene tricarboxylate and diallyl phthalate.
Examples of the tertiary amine include triallylamine.
Examples of the isocyanuric acid derivatives include diallyl isocyanurate, diallyl-n-propyl isocyanurate, triallyl isocyanurate, trimethallyl isocyanurate, tris ((meth) acryloxyethyl) isocyanurate and the like.
Examples of the cyanuric acid derivative include triallyl cyanurate.
Examples of the biphenyl derivative include tri (meth) acryloylhexahydrotriazine, 2,2′-divinylbiphenyl, 2,4′-divinylbiphenyl, 3,3′-divinylbiphenyl, 4,4′-divinylbiphenyl, 2,4 ′. -Di (2-propenyl) biphenyl, 4,4'-di (2-propenyl) biphenyl, 2,2'-divinyl-4-ethyl-4'-propylbiphenyl, 3,5,4'-trivinylbiphenyl, etc. Is mentioned.
Among these, aromatic vinyl polyfunctional monomers are preferable, and divinylbenzene is more preferable.

  The ratio of such a polyfunctional monomer in the polymerizable compound is preferably 20% by weight or less, more preferably 0.1 to 10% by weight, more preferably 0.5 to 5% from the viewpoint of retention of elastic particles. More preferred is weight percent.

Examples of the monofunctional monomer include aromatic vinyl monomers, alkyl (meth) acrylates, vinyl carboxylic acids, vinyl halides, alkenes, (meth) acrylamides, vinyl group-containing phosphorus compounds, and the like.
From the viewpoint of productivity, alkyl (meth) acrylate is preferable.

Examples of the aromatic vinyl monomer include styrene, α-methylstyrene, monochlorostyrene, dichlorostyrene, vinyl toluene, vinyl naphthalene, vinyl biphenyl, 1,1 &apos; -diphenylethylene, acenaphthylene, and the like.
Alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, and myristyl (meth). Examples include acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, and benzyl (meth) acrylate.
Examples of the vinyl carboxylic acid include (meth) acrylic acid.
Examples of the vinyl halide include vinyl chloride, vinyl bromide, chloroprene and the like.
Examples of alkenes include ethylene, propylene, butylene, isobutylene and the like.
Examples of (meth) acrylamide include (meth) acrylamide, dodecyl (meth) acrylamide, cyclododecyl (meth) acrylamide, adamantyl (meth) acrylamide and the like.
Examples of the vinyl group-containing phosphorus compound include diphenyl vinyl phosphine oxide, phenyl vinyl phenyl phosphinate, vinyl diphenyl phosphonate, and diethyl vinyl phosphonate.
These polymerizable compounds are used alone or in combination of two or more.

  The ratio of the monofunctional monomer in the polymerizable compound is preferably 80% by weight or more, more preferably 90 to 99.9% by weight, from the viewpoint of retention of elastic particles and low-temperature fixability, and 95 to More preferably, 99.5% by weight.

In this embodiment, it is preferable to use a polyfunctional monomer and a monofunctional monomer in combination.
The amount of the polymerizable compound used when the entire silicone rubber particles before forming the coating resin layer is 100 parts by weight is 10 to 200 parts by weight from the viewpoint of retention of the elastic particles and low-temperature fixability. Preferably, 50 to 150 parts by weight is more preferable, and 80 to 120 parts by weight is still more preferable.

  The thickness of the coating resin layer is preferably 25 to 250 nm, more preferably 30 to 140 nm, and still more preferably 35 to 105 nm, from the viewpoint of retention of elastic particles and low temperature fixability.

<Additives>
Various additives such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles are added to the toner of this embodiment as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys, and magnetic materials such as compounds containing these metals.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.
The inorganic powder is added to the toner mainly for the purpose of adjusting the viscoelasticity of the toner. Further, it may be externally added to the toner base particles.
Examples of the inorganic powder include all inorganic particles used as an external additive for toner, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, calcium phosphate, and cerium oxide.

(Toner shape)
The average circularity of the toner for developing an electrostatic charge image of the exemplary embodiment is preferably 0.97 or more, and more preferably 0.98 or more. Within the above numerical range, the transferability, durability and fluidity are excellent.
The average circularity of the toner is measured by, for example, a flow particle image analyzer FPIA series (manufactured by Sysmex Corporation).
The measurement is performed as follows. In 100 to 150 ml of pure water, 0.1 to 0.5 ml of a surfactant such as an alkylbenze sulfonate is added as a dispersant, and about 0.1 to 0.5 g of a measurement sample is further added to suspend the measurement sample. Prepare a suspension. Next, the suspension in which the measurement sample is dispersed is subjected to dispersion treatment for 1 to 3 minutes with an ultrasonic wave disperser, and then the average circularity of the toner is measured by the above apparatus with a dispersion concentration of 3,000 to 10,000 / μl. Is measured.

The ratio d / D between the volume average particle diameter D (diameter) of the electrostatic charge image developing toner and the volume average particle diameter d (diameter) of the silicone rubber particles forming the protrusions is 0.05 to 0.12. Preferably, 0.065 to 0.092 is more preferable.
The volume average particle diameter d of the silicone rubber particles is determined by observing the toner with a scanning electron microscope (SEM) to obtain the number average value of 100 protrusions, and let the number average value of the outer diameter be d.
The volume average particle diameter D of the toner is determined based on, for example, the particle size range (channel) obtained by dividing the particle size distribution of the toner measured using a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). A cumulative distribution is drawn from the small diameter side with respect to the volume, and the particle diameter at which 50% is accumulated is defined as the volume average particle diameter D.

The volume average particle size of the toner base particles of the exemplary embodiment is preferably 2 to 9 μm, and more preferably 3 to 5 μm. Within the above range, the chargeability, developability, and image resolution are excellent.
In the present embodiment, the toner base particles preferably have a volume average particle size distribution index GSDv of 1.27 or less. When the volume distribution index GSDv is 1.27 or less, the image resolution is excellent, and image defects such as toner scattering and fogging can be suppressed.
In this embodiment, the toner particle size and the value of the volume average particle size distribution index GSDv are measured and calculated as follows. First, the toner particle size distribution measured using a measuring machine such as a Coulter Counter TAII (manufactured by Beckman Coulter), Multisizer II (manufactured by Beckman Coulter), etc. A cumulative distribution is drawn from the small diameter side with respect to the volume of the toner particles, and the particle diameter of 16% is defined as the volume average particle diameter D _16v, and the particle diameter of 50% is defined as the volume average particle diameter D _50v. To do. Similarly, the particle size at a cumulative 84% is defined as the volume average particle size D _84v . At this time, the volume average particle size distribution index (GSDv) is calculated using these relational expressions defined as D _84v / D _16v .

In the present embodiment, the number average value of the ratio of the projected area of the protrusions made of silicone rubber particles to the total projected area of the toner base particles by SEM observation is preferably 20 to 80%, and preferably 30 to 70%. Preferably there is.
Further, it is preferable that the protrusions made of silicone rubber particles are embedded in only 1/10 to 2/3 of the diameter of the particles forming the protrusions, and only 1/3 to 1/2 of the diameter of the adhered particles are embedded. More preferably not. The degree of embedding of the adhered particles is determined by taking an electron micrograph of the toner particles.

<Method for producing toner for developing electrostatic image>
The method for producing a toner for developing an electrostatic charge image according to the present embodiment includes an aggregation step of aggregating particles contained in a dispersion containing at least a binder resin and a colorant to form an aggregate, and a silicone rubber on the surface of the aggregate A particle adhering step for adhering the particles, and a fusing step for fusing and coalescing the particles of the silicone rubber adhering to the aggregate.
The aggregating step is preferably a step of aggregating particles contained in a dispersion containing release agent particles in addition to the binder resin and the colorant to form an aggregate.

The particle adhering step is preferably a step of adhering silicone rubber particles together with a binder resin (preferably binder resin particles) to the surface of the aggregate after the aggregation step of forming the aggregate. The silicone rubber particles may be silicone rubber particles having a coating resin layer.
Further, the step of further aggregating or adhering the binder resin particles to the surface of the aggregate and the step of adhering the silicone rubber particles to the surface of the aggregate are partially overlapped even at the same time. May be sequential. In this case, the binder resin dispersion used for the formation of the aggregate and the binder resin dispersion used for the particle adhering step may be different from each other even if the dispersion includes the same kind of binder resin. A dispersion containing a binder resin may also be used.
In the present specification, toner particles excluding external additives are also referred to as toner mother particles. That is, the toner of the present embodiment has a plurality of substantially hemispherical protrusions on the surface of the toner base particles.

As the method for producing the aggregate, preferably, polymerization of particles of a polymerizable compound and / or formation of polymer particles in an aqueous medium such as suspension polymerization, emulsion aggregation, seed polymerization, and swelling polymerization are performed. And a method for producing a toner.
Furthermore, it is preferable to use a wet production method, particularly an emulsion aggregation method, because it is easy to produce a toner having a structure in which the aggregate is coated with a layer containing silicone rubber particles.

  In the emulsion aggregation method, functions required for toner such as an aqueous dispersion such as a colorant, a release agent, a charge control agent, and a release agent are imparted to a resin particle dispersion produced by emulsion polymerization or emulsion. Additive dispersion for mixing in an aqueous medium and coagulate and grow the dispersion using an aggregating agent while mechanically shearing in an aqueous medium using various dispersers such as a homomixer Further, toner mother particles are obtained through a process of fusing resin particles.

The emulsion aggregation method in the present embodiment includes a step of forming an aggregate that is a core particle, and a particle adhesion step in which a number of silicone rubber particles adhere to the surface of the aggregate in a protruding state.
In the previous step of forming the aggregate that is the core particle, the first resin particle dispersion liquid in which the first resin particles made of the first binder resin and having a volume average particle diameter of 1 μm or less are dispersed; An aggregating step is included in which an aggregating agent is added to a mixed dispersion obtained by mixing at least a colorant particle dispersion in which a coloring agent is dispersed and heated to form an aggregate. Note that a fusion step of fusing and aggregating the aggregates may be included.

  In the latter step of attaching the silicone rubber particles to the surface of the aggregate, the mixed dispersion in which the coalesced aggregate is formed as core particles is made of the second binder resin, and the volume average particle size is While adding the second resin particle dispersion liquid in which the second resin particles having a particle size of 1 μm or less and containing the silicone rubber particles are dispersed, the second resin particles are adhered to the surface of the core particles. This is a step of attaching the silicone rubber particles to the surface of the core particles. It is preferable to include a fusing step of fusing and coalescing the whole particles to which the silicone rubber particles are adhered after the particle adhering step.

  In the aggregation step, core particles (core aggregated particles) simply formed by aggregating various particle components in the mixed dispersion liquid may be formed, and the heating temperature is higher than the glass transition temperature of the first binder resin. You may form the core particle (core fusion particle) which made it high and united simultaneously with aggregation. The fusing step may be carried out by heating to a temperature higher than the glass transition temperature of the first or second binder resin, which is higher than the glass transition temperature. When it is formed using fused particles, it may be fused using mechanical stress. Details of these steps will be described later.

  In general, the emulsion aggregation method is a method in which a resin dispersion is prepared by emulsion polymerization or emulsification, while a release agent particle dispersion in which a release agent is dispersed, preferably a colorant particle in which a colorant is dispersed in a solvent. In this method, a dispersion liquid is prepared, and these are mixed to form aggregated particles (aggregation step), and then fused and united by heating (fusion step) to obtain toner particles. In addition, in this embodiment, it has a particle | grain adhesion process which adheres the particle | grains of many more silicone rubbers to the surface of an aggregation particle after an aggregation process and before a fusion process.

-Toner production method-
Next, the toner manufacturing method of this embodiment including the above-described aggregation process, particle adhesion process, and fusion process will be described in detail for each process.

-Aggregation process-
In the aggregation step, first, the flocculant is added to the first binder resin dispersion, the colorant dispersion, preferably the release agent dispersion, and the mixed dispersion obtained by mixing other components, By heating at a temperature slightly lower than the melting point of the first binder resin, aggregated particles (core aggregated particles) obtained by aggregating particles composed of the respective components are formed. The fused particles (core fused particles) may be formed by heating at a temperature equal to or higher than the glass transition temperature of the first binder resin and performing fusion at the same time as aggregation.

Aggregated particles are formed by adding an aggregating agent at room temperature while stirring with a rotary shearing homogenizer. As the aggregating agent used in the aggregating step, a surfactant having a reverse polarity to the surfactant used as a dispersing agent for various dispersions, an inorganic metal salt, and a metal complex having a valence of 2 or more are preferably used.
In particular, the use of a metal complex is particularly preferable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Among these, an aluminum salt and a polymer thereof are particularly preferable. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than divalent, tetravalent than trivalent, and even if the valence is the same, the polymerization type The inorganic metal salt polymer is more suitable.

-Particle adhesion process-
In the particle adhering step, the silicone rubber particles and the second particles are formed on the surface or outside of the core particles (core agglomerated particles or core fusion particles) containing the first binder resin formed through the aggregating step. A coating layer is formed by adhering resin particles made of an adhesive resin (hereinafter, agglomerated particles provided with a coating layer on the core particle surface are also referred to as “particle-adhering agglomerated particles”).
The coating layer is formed by adding a dispersion of second resin particles containing silicone rubber particles to the dispersion in which aggregates (core particles) are formed in the aggregation process. In addition to these particles, other components may be added at the same time if necessary.
The resin solid content weight of the resin particles used for forming the coating layer and the weight of the silicone rubber particles are (weight of resin particles / weight of silicone rubber particles) and are in the range of 3/20 to 3/5. It is preferable.

When the resin particles made of the second binder resin and the silicone rubber particles are uniformly attached to the surface of the core particles, and the obtained particle-attached aggregated particles are heated and fused in the fusion step described later, The resin particles made of the attached second binder resin are melted to form a coating layer. For this reason, it is possible to effectively prevent the components such as the release agent contained in the core particles located inside the coating layer from being exposed to the surface of the toner.
The method for adding and mixing the second resin particle dispersion containing the silicone rubber particles in the particle adhering step is not particularly limited. For example, it may be carried out gradually or divided into multiple times. It may be done step by step. In this way, by adding and mixing the second resin particle dispersion, the generation of fine particles is suppressed, and the particle size distribution of the obtained toner becomes sharp.
In the present embodiment, the number of times that this particle adhesion step is performed may be one time or a plurality of times. In the former case, only one layer mainly composed of the second binder resin is formed on the surface of the core aggregated particles. On the other hand, in the latter case, if not only the second resin particle dispersion but also a plurality of particle dispersions composed of a release agent dispersion and other components are used, a specific component is mainly contained on the surface of the core aggregated particles. A layer as a component is laminated.

  The latter case is advantageous in that a toner having a complicated and precise hierarchical structure can be obtained and a desired function can be imparted to the toner. When the particle adhesion process is performed a plurality of times or in multiple stages, the composition and physical properties of the obtained toner from the surface to the inside can be changed in stages, and the structure of the toner can be easily controlled. In this case, a plurality of layers are laminated stepwise on the surface of the core particle, and a structural change or composition gradient is given from the inside to the outside of the toner particle, thereby changing the physical properties. In this case, the coating layer corresponds to all the layers laminated on the surface of the core particle, and the outermost layer is composed of a layer mainly composed of the second binder resin. In the following description, the description will be made on the assumption that the particle adhesion step is performed only once.

Conditions for attaching the resin particles made of the second binder resin to the core particles are as follows. That is, the heating temperature in the particle adhering step is preferably a temperature in the vicinity of the melting point of the first binder resin contained in the core aggregated particles, and specifically, a temperature range within a melting point ± 10 ° C. Is preferred.
When the heating temperature is equal to or higher than (the melting point of the first binder resin−10 ° C.), the resin particles made of the first binder resin present on the surface of the core particles and the second adhered to the surface of the core aggregated particles. Adhesion with the resin particles made of the binder resin is good, and as a result, the thickness of the coating layer to be formed becomes uniform.
In addition, when the heating temperature is equal to or lower than (the melting point of the first binder resin + 10 ° C.), the resin particles made of the first binder resin existing on the surface of the core particles and the second attached to the surface of the core particles. Adhesion to the resin particles made of the binder resin is suppressed, and the obtained toner base particles are excellent in particle size / particle size distribution.
The heating time in the particle adhering step is not generally defined because it depends on the heating temperature, but it is preferably 5 minutes to 2 hours.

  In the particle adhering step, the dispersion obtained by additionally adding the second resin particle dispersion to the mixed dispersion in which the core particles are formed may be left standing or gently stirred by a mixer or the like. May be. The latter case is advantageous in that uniform adhered resin aggregated particles are easily formed.

-Fusion process-
In the fusing step, the adhered resin aggregated particles obtained in the particle adhering step are fused by heating. The fusion step is preferably performed at a higher temperature or higher of the glass transition temperatures of the first binder resin and the second binder resin. As the fusion time, a short time is sufficient if the heating temperature is high, and a long time is necessary if the heating temperature is low. That is, the fusion time depends on the temperature of heating and cannot be defined generally, but it is preferably 30 minutes to 10 hours.

When the core particles are core fusion particles, resin particles made of the second binder resin may be attached. In this case, the dispersion containing the core fusion particles is once filtered and the water content of the dispersion is controlled to 30 to 50% by weight, and then the second resin particle dispersion is added. Thereby, the particle | grains which consist of 2nd binder resin are made to adhere to the surface of a core fusion particle.
When the water content of the dispersion is 30% by weight or more, the adhesion of the particles made of the second binder resin is good, and the release of the core fusion particles of the particles is suppressed. Further, when the water content is 50% by weight or less, stirring is easy, and particles made of the second binder resin are uniformly attached to the surface of the core fusion particles.

  In addition, the particles adhered aggregated particles obtained by adhering the particles made of the second binder resin and the silicone rubber particles to the surface of the core fused particles are mechanically treated by a Henschel mixer or the like after the washing / drying process described later. By applying stress, the particles made of the second binder resin attached to the surface of the core fusion particles are fused. Thus, the fusion process may be performed by applying mechanical stress instead of heating in the liquid phase.

-Washing / drying process-
The fused particles obtained through the fusion step are preferably subjected to solid-liquid separation such as filtration, washing, and drying. As a result, toner base particles in a state where no external additive is added are obtained.
The solid-liquid separation is not particularly limited, but suction filtration, pressure filtration and the like are preferable from the viewpoint of productivity. The washing is preferably performed with substitution washing with ion-exchanged water from the viewpoint of chargeability. In the drying step, an arbitrary method such as a normal vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like is employed. The moisture content of the toner particles after drying is preferably adjusted to 1.0% by weight or less, and more preferably adjusted to 0.5% by weight or less.

-Preparation of dispersion-
A known emulsification method is used to prepare the binder resin dispersion, but the obtained particle size distribution is sharp and the phase inversion emulsification is easily obtained in the range of volume average particle size of 0.08 to 0.40 μm. The law is effective.
In the phase inversion emulsification method, the resin is dissolved in an organic solvent for dissolving the resin, an amphiphilic organic solvent alone, or a mixed solvent to obtain an oil phase. A small amount of a basic compound is dropped while stirring the oil phase, and water is dropped little by little while stirring, and water droplets are taken into the oil phase. Next, when the dripping amount of water exceeds a certain amount, the oil phase and the water phase are reversed and the oil phase becomes oil droplets. Thereafter, an aqueous dispersion is obtained through a desolvation step of depressurization.
Here, the amphiphilic organic solvent means a solvent having a solubility in water at 20 ° C. of preferably 5 g / L or more, more preferably 10 g / L or more. When the solubility is 5 g / L or more, the effect of accelerating the aqueous treatment rate is excellent, and the resulting aqueous dispersion is also excellent in storage stability.

Examples of such organic solvents include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1 Alcohols such as ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone and isophorone, ethers such as tetrahydrofuran and dioxane, acetic acid Ethyl, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, methyl propionate, propionate Esters such as ethyl acetate, diethyl carbonate, dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol Examples include glycol derivatives such as tilether acetate and dipropylene glycol monobutyl ether, and 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. The
These solvents are used alone or in combination of two or more.

Next, regarding the basic compound, the polyester resin used as the binder resin is preferably neutralized with the basic compound when dispersed in an aqueous medium. In the present embodiment, the neutralization reaction with the carboxy group of the polyester resin is the starting force for aqueous formation, and the electric repulsive force between the generated carboxyl anions prevents aggregation between particles.
Examples of the basic compound include ammonia and organic amine compounds having a boiling point of 250 ° C. or lower.
Examples of preferred organic amine compounds include triethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine , Diethylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, methyliminobispropylamine, 3-methoxypropylamine, monoethanolamine, diethanolamine, Examples include triethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like.

  The basic compound is preferably added in an amount that can be at least partially neutralized according to the carboxy group contained in the polyester resin, that is, 0.2 to 9.0 times the molar equivalent of the carboxy group. It is more preferable to add 6 to 2.0 times molar equivalent. When it is 0.2 times equivalent or more, the effect of adding a basic compound is sufficient, and when it is 9.0 times mole equivalent or less, the hydrophilicity of the oil phase is appropriate and the particle size distribution is narrow. Become a liquid.

The release agent dispersion is formed by dispersing at least a release agent.
The release agent is dispersed by a known method. For the dispersion, for example, a rotary shearing type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high pressure opposed collision type dispersing machine or the like is preferably used. Further, the release agent is dispersed in an aqueous solvent using a polar ionic surfactant and using a dispersing machine as described above. In this embodiment, a mold release agent may be used individually by 1 type, and may use 2 or more types together. The volume average particle size of the release agent particles is preferably 1.0 μm or less, and more preferably 0.1 to 0.5 μm.

The colorant dispersion is formed by dispersing at least a colorant.
The colorant is dispersed by a known method. For the dispersion, for example, a rotary shearing type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high pressure opposed collision type dispersing machine or the like is preferably used. The colorant is dispersed in an aqueous solvent using a polar ionic surfactant and a homogenizer as described above. A coloring agent may be used individually by 1 type, and may use 2 or more types together. The volume average particle size of the colorant is preferably 1 μm or less, more preferably 0.5 μm or less, and particularly preferably 0.01 to 0.5 μm.

There is no restriction | limiting in particular as a combination of the resin of the said resin particle, the said mold release agent, and the said coloring agent, According to the objective, it selects and uses suitably suitably.
In the present embodiment, depending on the purpose, at least one of the binder resin dispersion, the release agent dispersion, and the colorant dispersion may include an internal additive, a charge control agent, an inorganic particle, an organic Other components (particles) such as granules, lubricants and abrasives may be dispersed. In that case, other components (particles) may be dispersed in at least one of the binder resin dispersion, the release agent dispersion, and the colorant dispersion, or the resin particle dispersion and the release agent. You may mix the dispersion liquid which disperse | distributes another component (particle | grains) in the liquid mixture formed by mixing a dispersion liquid and a coloring agent dispersion liquid.

Examples of the dispersion medium in the binder resin dispersion, the release agent dispersion, the colorant dispersion, and the other components include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, alcohol, and the like. These may be used individually by 1 type and may use 2 or more types together. As a suitable combination, distilled water and ion exchange water are preferably used. The addition of a surfactant is not only advantageous in terms of the stability of each dispersed particle, such as resin particles, colorant particles, and release agent particles, in the aqueous medium, and thus the storage stability of the dispersion, but also in the aggregation process. This is also advantageous from the viewpoint of the stability of the aggregated particles.
In addition, rosin, rosin derivatives, coupling agents, polymer dispersions are added as dispersants to further stabilize the dispersion stability of the colorant in the aqueous medium and lower the energy of the colorant in the toner. Agents and the like.

In the present embodiment, it is preferable to add and mix a surfactant in the aqueous medium in order to improve dispersion stability.
The volume average particle size of the particle dispersion thus obtained is measured, for example, with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The particle diameter of each obtained channel was accumulated from the smaller particle diameter, and the volume average particle diameter was determined when the accumulation reached 50%.

-External addition process-
The method for externally adding inorganic particles such as silica and titania to the surface of the toner base particles is not particularly limited, and a known method is used, for example, a method of attaching by a mechanical method or a chemical method. It is done.

(Electrostatic image developer)
The electrostatic image developing toner of this embodiment is used as an electrostatic image developer.
The electrostatic image developer of the exemplary embodiment is not particularly limited except that it contains the electrostatic image developing toner of the exemplary embodiment, and can take an appropriate component composition depending on the purpose. When used alone, the toner for developing an electrostatic image of this embodiment is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, it is prepared as a two-component electrostatic image developer. .
As a one-component developer, a method in which a charged toner is formed by frictional charging with a developing sleeve or a charging member, and development is performed according to an electrostatic latent image is also applied.

  In the present embodiment, the development method is not particularly defined, but the two-component development method is preferable. Further, the carrier is not particularly defined as long as the above conditions are satisfied. Examples of the carrier core material include magnetic metals such as iron, steel, nickel, and cobalt, alloys of these with manganese, chromium, rare earth, and the like, and Magnetic oxides such as ferrite and magnetite are mentioned, and from the viewpoint of core material surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferably mentioned.

  The carrier used in this embodiment is preferably formed by coating the surface of the core material with a resin. There is no restriction | limiting in particular as said resin, According to the objective, it selects suitably. For example, polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone Vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; Silicone resin; Polyester; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, Melamine tree , Benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins, per se known resins and the like. These may be used individually by 1 type and may use 2 or more types together. In the present embodiment, among these resins, it is preferable to use at least a fluorine resin and / or a silicone resin. The use of at least a fluorine-based resin and / or a silicone resin as the resin is advantageous in that the effect of preventing carrier contamination (impaction) due to toner and external additives is high.

  In the resin coating, it is preferable that resin particles and / or conductive particles are dispersed in the resin. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, thermosetting resins are preferable from the viewpoint of relatively easily increasing the hardness, and resin particles made of nitrogen-containing resin containing N atoms are preferable from the viewpoint of imparting negative chargeability to the toner. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together. The volume average particle size of the resin particles is preferably 0.1 to 2 μm, and more preferably 0.2 to 1 μm. When the volume average particle size of the resin particles is 0.1 μm or more, the resin particles are excellent in dispersibility in the coating, whereas when the volume average particle size is 2 μm or less, the resin particles are not easily dropped from the coating.

  Examples of the conductive particles include metal particles such as gold, silver, and copper, carbon black particles, and surfaces of titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate powder, tin oxide, carbon black, metal And particles covered with the like. These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are preferable in terms of good production stability, cost, conductivity and the like. The type of the carbon black is not particularly limited, but carbon black having a DBP oil absorption of 50 to 250 ml / 100 g is preferable because of excellent production stability.

  The coating amount of the resin, the resin particles, and the conductive particles on the surface of the core material is preferably 0.5 to 5.0% by weight, and preferably 0.7 to 3.0% by weight. More preferred.

The method for forming the coating film is not particularly limited. For example, the resin particles and / or the conductive particles and the resin such as a styrene acrylic resin, a fluorine resin, or a silicone resin as a matrix resin are used as a solvent. Examples thereof include a method using a film forming liquid contained therein.
Specifically, the carrier core material is immersed in the film forming liquid, a spray method in which the film forming liquid is sprayed on the surface of the carrier core material, and the carrier core material is floated by flowing air And kneader coater method in which the film forming solution is mixed and the solvent is removed. Among these, the kneader coater method is preferable in the present embodiment.

  The solvent used for the film forming liquid is not particularly limited as long as it can dissolve only the resin as a matrix resin, and is selected from known solvents such as toluene, Aromatic hydrocarbons such as xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and the like. When the resin particles are dispersed in the coating, since the resin particles and the particles as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the carrier is used for a long time. Even when the coating is worn, it is possible to always maintain the same surface formation as when it is not used, and to maintain a good charge imparting ability for the toner over a long period of time. In the case where the conductive particles are dispersed in the coating, the conductive particles and the resin as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even if the coating is worn out over a long period of time, the same surface formation as when not in use can be maintained, and carrier deterioration is prevented for a long period of time. In addition, when the said resin particle and the said electroconductive particle are disperse | distributed to the said film, the above-mentioned effect is exhibited simultaneously.

The electric resistance of the magnetic carrier formed as described above in the state of a magnetic brush under an electric field of 10 ⁴ V / cm is preferably 10 ⁸ to 10 ¹³ Ωcm. When the electric resistance of the magnetic carrier is 10 ⁸ Ωcm or more, adhesion of the carrier to the image portion on the image holding member is suppressed, and a brush mark is difficult to appear. On the other hand, when the electric resistance of the magnetic carrier is 10 ¹³ Ωcm or less, the generation of the edge effect is suppressed and a good image quality is formed.
The volume resistivity is measured as follows.
A measuring jig that is a pair of 20 cm ² circular electrode plates (made of steel) connected to an electrometer (made by KEITHLEY, trade name: KEITHLEY 610C) and a high-voltage power supply (made by FLUKE, trade name: FLUKE 415B). The sample is placed on the lower electrode plate so as to form a flat layer having a thickness of about 1 mm to 3 mm. Next, after the upper electrode plate is placed on the sample, a 4 kg weight is placed on the upper electrode plate in order to eliminate the gap between the samples. In this state, the thickness of the sample layer is measured. Next, the current value is measured by applying a voltage to the bipolar plate, and the volume resistivity is calculated based on the following equation.
Volume resistivity = applied voltage × 20 ÷ (current value−initial current value) ÷ sample thickness In the above formula, the initial current is the current value when the applied voltage is 0, and the current value indicates the measured current value.

  In the two-component electrostatic charge image developer, the mixing ratio of the toner and the carrier of this embodiment is preferably 2 to 10 parts by weight of the toner with respect to 100 parts by weight of the carrier. Moreover, the preparation method of a developing agent is not specifically limited, For example, the method of mixing with a V blender etc. is mentioned.

(Image forming method)
The electrostatic image developer (electrostatic image developing toner) of this embodiment is used in an image forming method of an electrostatic image developing system (electrophotographic system).
The image forming method of the present embodiment includes a charging step for charging an image carrier, an electrostatic latent image forming step for exposing the charged image carrier to form an electrostatic latent image, and the electrostatic latent image, Developing with a developer containing toner to form a developed image, a transferring step for transferring the developed image onto a substrate to form a transferred image, and a fixing step for fixing the transferred image And the toner is an electrostatic charge image developing toner of the present embodiment, or the developer is the electrostatic charge image developer of the present embodiment.

  Each of the above steps is a general step per se, and is described in, for example, JP-A-56-40868 and JP-A-49-91231. Note that the image forming method of the present embodiment is carried out by using a known image forming apparatus such as a copying machine or a facsimile machine.

The charging step is a step of charging the image carrier.
The latent image forming step is a step of forming an electrostatic latent image on the surface of the image carrier.
In the developing step, the electrostatic latent image formed on the surface of the image carrier is developed with the electrostatic image developing toner of the present embodiment or the electrostatic image developer containing the electrostatic image developing toner of the present embodiment. Then, a toner image is formed.
The transfer step is a step of transferring the toner image onto a transfer target.
The fixing step is a step of fixing the toner image by passing the transfer body on which the unfixed toner image is formed between a heating member and a pressure member.

As the heating member used in the fixing step, at least the surface energy of the outermost layer is 30 × 10 ⁻³ N / m or more and 3,000 × 10 ⁻³ N / m or less, and 300 × 10 ⁻³ N / m or more. It is preferably 1,500 × 10 ⁻³ N / m or less.
Thus, the heating member having a high surface energy is preferably formed of a metal material or an inorganic material, and more preferably formed of a metal material.
Examples of the metal material forming the heating member include Fe, Cr, Cu, Ni, Co, Mn, Al, alloys such as stainless steel, and oxides thereof. Among these, Al and stainless steel are preferable, Al Is more preferable.
Examples of the inorganic material forming the heating member include glass and ceramics.
In addition, it is preferable that at least the outermost layer of the heating member is formed of the metal material or the inorganic material. For example, the entire heating member may be formed of the metal material or the inorganic material, the outermost layer of the heating member is formed of the metal material or the inorganic material, and a portion other than the outermost layer is formed of another material. It may be.
Examples of the shape of the heating member include a cylindrical roll shape.

In the fixing step, the heating member is heated to a temperature equal to or higher than the melting point of the release agent, and the release agent contained in the toner is melted by the heating member. The temperature of the heating member in the fixing step is preferably 130 to 170 ° C, and more preferably 140 to 160 ° C. Within the above range, the release agent contained in the toner is surely in a molten state.
As described above, the release agent used in the present embodiment contains an organosilicon compound having a siloxane bond, and a contact angle with a heating member in a molten state is 50 ° or less. For this reason, the release agent eluted from the toner spreads to the heating member evenly with high affinity, and the transfer of the release agent to a recording medium such as a sheet on which an image is formed next is reduced. In this way, contamination by the release agent of the feed roll that transports the recording medium after image formation is suppressed, and malfunction during continuous operation is suppressed.

(Image forming device)
The image forming apparatus includes an image carrier, a charging unit that charges the image carrier, a latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and a static image formed on the surface of the image carrier. Developing means for developing a toner image by developing an electrostatic latent image with an electrostatic charge image developing toner or an electrostatic charge image developer containing an electrostatic charge image developing toner; and the toner image formed on the surface of the image carrier. A transfer unit that transfers to the surface of the transfer target; and a fixing unit that fixes the toner image by passing the transfer target with the unfixed toner image formed between a heating member and a pressure member. It is characterized by that.

In the image carrier and each of the above units, the configurations described in the respective steps of the image forming method are preferably used.
As each of the above-described means, a well-known means is used in the image forming apparatus. Further, the image forming apparatus used in the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus used in the present embodiment may simultaneously perform a plurality of the above-described means.

(Toner cartridge and process cartridge)
The toner cartridge is a toner cartridge that contains at least the electrostatic image developing toner of the present embodiment. The toner cartridge of this embodiment may contain the electrostatic image developing toner of this embodiment as an electrostatic image developer.
Further, the process cartridge includes a developing unit that develops an electrostatic latent image formed on the surface of the image carrier with the electrostatic image developing toner or the electrostatic image developer to form a toner image, and an image carrier. And at least one selected from the group consisting of a charging unit for charging the surface of the image carrier and a cleaning unit for removing the toner remaining on the surface of the image carrier. The toner is preferably a process cartridge containing at least the electrostatic image developing toner or the electrostatic image developer of this embodiment.

The toner cartridge is preferably detachable from the image forming apparatus. In other words, in the image forming apparatus having a configuration in which the toner cartridge is detachable, the toner cartridge containing the toner of the present embodiment is preferably used.
Further, the toner cartridge may be a cartridge that stores toner and a carrier, or a cartridge that stores toner alone and a cartridge that stores a carrier independently.

The process cartridge is preferably detached from the image forming apparatus. The process cartridge may include other members such as a charge removing unit as necessary.
As the toner cartridge and the process cartridge, known configurations may be adopted. For example, Japanese Patent Application Laid-Open Nos. 2008-209489 and 2008-233736 are referred to.

(Example of image forming apparatus)
An example of the image forming apparatus of the present embodiment will be described with reference to FIG. 1, but the present embodiment is not limited at all. FIG. 1 is a schematic cross-sectional view showing an example of the image forming apparatus of the present embodiment.

  In FIG. 1, an automatic document feeder U2 is placed on the upper surface of the platen glass PG at the upper end of an image forming apparatus U1 constituted by a copying machine. The automatic document feeder U2 has a document feed tray TG1 on which a plurality of documents Gi to be copied are stacked. Each of the plurality of documents Gi placed on the document feed tray TG1 is sequentially passed through a copy position on the platen glass PG and discharged to the document discharge tray TG2. The automatic document feeder U2 is rotatable with respect to the image forming apparatus U1 by a hinge shaft (not shown) provided in the rear end portion (−X end portion) extending in the left-right direction, and working the document Gi. When a person puts it on the platen glass PG by hand, it is rotated upward.

  The image forming apparatus U1 has a UI (user interface) through which a user inputs an operation command signal such as a copy start. The document reading apparatus IIT disposed below the transparent platen glass PG on the upper surface of the image forming apparatus U1 includes an exposure system registration sensor (platen registration sensor) Sp disposed at a platen registration position (OPT position) and an exposure optical system A. is doing. The movement and stop of the exposure optical system A are controlled by the detection signal of the exposure system registration sensor Sp, and always stop at the home position. Reflected light from the document Gi passing through the exposure position on the upper surface of the platen glass PG by the automatic document feeder U2 or the document manually placed on the platen glass PG passes through the exposure optical system A and is a solid-state image sensor CCD. Are converted into electrical signals of R (red), G (green), and B (blue).

  The image processing system IPS converts the RGB electrical signals input from the solid-state imaging device CCD into K (black), Y (yellow), M (magenta), and C (cyan) image data and temporarily stores them. Then, the image data is output to the laser drive circuit DL as image data for forming a latent image at a predetermined timing. The laser drive circuit DL outputs a laser drive signal to the latent image forming apparatus ROS according to the input image data. The operations of the image processing system IPS and the laser driving circuit DL are controlled by a controller C constituted by a microcomputer.

  The image carrier PR is rotated in the direction of the arrow Ya. The surface of the image carrier PR is then uniformly charged by a charging machine (charge roll) CR, and then the laser of the latent image forming apparatus ROS at the latent image writing position Q1. Exposure scanning is performed with the beam L to form an electrostatic latent image. When forming a full-color image, electrostatic latent images corresponding to four color images of K (black), Y (yellow), M (magenta), and C (cyan) are sequentially formed. Only the electrostatic latent image corresponding to the (black) image is formed.

  The surface of the image carrier PR on which the electrostatic latent image is formed rotates and moves sequentially through the development area Q2 and the primary transfer area Q3. The rotary developing device G is a four-color developing machine of K (black), Y (yellow), M (magenta), and C (cyan) that sequentially rotates and moves to the developing area Q2 as the rotating shaft Ga rotates. It has GK, GY, GM, and GC. Each of the color developing machines GK, GY, GM, GC has a developing roll GR that conveys the developer to the developing area Q2, and the electrostatic latent image on the image carrier PR that passes through the developing area Q2 is displayed. Develop to toner image. The developing units GK, GY, GM, and GC are supplied with toner of each color from the toner replenishing cartridges mounted on the cartridge mounting portions Hk, Hy, Hm, and Hc (see FIG. 1). It is configured. Such a rotary developing device is described in, for example, Japanese Patent Application Laid-Open Nos. 2000-131942 and 2000-231250.

  Below the image carrier PR are a plurality of belt support rolls (Rd, Rt) including an intermediate transfer belt B, a belt drive roll Rd, a tension roll Rt, a walking roll Rw, an idler roll (free roll) Rf, and a backup roll T2a. , Rw, Rf, T2a), a primary transfer roll T1, and a belt frame (not shown) for supporting them. The intermediate transfer belt B is rotatably supported by the belt support rolls (Rd, Rt, Rw, Rf, T2a), and rotates in the arrow Yb direction when the image forming apparatus is in operation.

  When forming a full-color image, an electrostatic latent image of the first color is formed at the latent image writing position Q1, and a toner image Tn of the first color is formed in the development region Q2. The toner image Tn is electrostatically primarily transferred onto the intermediate transfer belt B by the primary transfer roll T1 when passing through the primary transfer region Q3. Thereafter, similarly, the second, third, and fourth color toner images Tn are sequentially superimposed on the intermediate transfer belt B carrying the first color toner image Tn, and finally transferred to a full color. Are formed on the intermediate transfer belt B. In the case of forming a monochrome monochromatic image, only one developing machine is used, and the monochrome toner image is primarily transferred onto the intermediate transfer belt B. After the primary transfer, the surface of the image carrier PR is cleaned by the image carrier cleaner CL1 after the residual toner is neutralized by the static eliminator JR.

  Below the backup roll T2a, a secondary transfer roll T2b is disposed so as to be movable between a position separated from the backup roll T2a and a position in contact therewith. The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2. A secondary transfer region Q4 is formed by a contact region between the backup roll T2a and the secondary transfer roll T2b. A secondary transfer voltage having a polarity opposite to the charging polarity of the toner used in the developing device G is supplied from the power supply circuit E to the secondary transfer roll T2b, and the power supply circuit E is controlled by the controller C.

  The recording sheet S accommodated in the paper feed tray TR1 or TR2 is taken out by the pick-up roll Rp at a predetermined timing, separated one by one by the separation roll Rs, and registered by the plurality of transport rolls Ra in the paper feed path SH1. It is conveyed to. The recording sheet S conveyed to the registration roll Rr is subjected to the secondary transfer from the pre-transfer sheet guide SG1 in time with the primary transferred multiple toner image or single color toner image moving to the secondary transfer region Q4. Transported to region Q4. In the secondary transfer area Q4, the secondary transfer unit T2 electrostatically secondary-transfers the toner image on the intermediate transfer belt B onto the recording sheet S. The residual toner is removed from the intermediate transfer belt B after the secondary transfer by the belt cleaner CL2. A toner image forming apparatus that forms a toner image by transferring the toner image onto the recording sheet S by the image carrier PR, the charging roll CR, the developing device G, the primary transfer roll T1, the intermediate transfer belt B, the secondary transfer device T2, and the like. PR + CR + G + T1 + B + T2).

  The secondary transfer roll T2b and the belt cleaner CL2 are disposed so as to be freely separated from (contacted with and separated from) the intermediate transfer belt B. When a color image is formed, an unfixed toner image of the final color is formed. Is separated from the intermediate transfer belt B until it is primarily transferred to the intermediate transfer belt B. The secondary transfer roll cleaner CL3 moves away from and in contact with the intermediate transfer belt B together with the secondary transfer roll T2b. The recording sheet S on which the toner image is secondarily transferred is conveyed to the fixing region Q5 by the post-transfer sheet guide SG2 and the sheet conveying belt BH. The fixing region Q5 is a region (nip) where the heating roll Fh and the pressure roll Fp of the fixing device F are in pressure contact, and the recording sheet S passing through the fixing region Q5 is heated and fixed by the fixing device F. The heating roll Fh is formed of, for example, a metal material.

  In FIG. 1, on the downstream side of the fixing region Q5 for fixing the toner image on the recording sheet S, a sheet conveying roll 16 having a driving roll 16a and a driven roll 16b, and a sheet conveying roll having a driving roll Rb1 and a driven roll Rb2. Rb and the sheet discharge path SH2 are sequentially provided. A sheet inversion path SH3 is connected to the sheet discharge path SH2. A switching gate GT1 is provided at a branch point of the sheet discharge path SH2 and the sheet reversal path SH3. The recording sheet S conveyed to the sheet discharge path SH2 is conveyed to the sheet discharge roll Rh by a plurality of conveyance rolls Ra, and is discharged from the sheet discharge port Ka formed at the upper end portion of the image forming apparatus U1 to the discharge tray TR3. The A sheet circulation path SH4 is connected to the sheet reversing path SH3, and a mylar gate GT2 formed of a sheet-like member is provided at the connection portion. The mylar gate GT2 passes the recording sheet S conveyed through the sheet reversing path SH3 from the switching gate GT1 as it is, and the recording sheet S that has been once switched and switched back to the sheet circulation path SH4 side. Let go. The recording sheet S conveyed to the sheet circulation path SH4 is retransmitted to the transfer area Q4 through the sheet feeding path SH1. A sheet conveying path SH is constituted by the elements indicated by the symbols SH1 to SH4. A sheet conveying apparatus US is configured by the sheet conveying path SH and rolls Ra, Rh and the like having a sheet conveying function arranged there.

  Hereinafter, although this embodiment is described in detail with examples, this embodiment is not limited in any way. In the following description, “parts” means “parts by weight” unless otherwise specified.

(Preparation of silicone rubber particle dispersion 1)
100 parts by weight of octamethylcyclotetrasiloxane,
γ-methacryloyloxypropyldimethoxymethylsilane 5 parts by weight,
2 parts by weight of tetraethoxysilane,
0.7 part by weight of sodium alkylbenzene sulfonate was dissolved in 300 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to obtain an emulsion, and then reacted in a reaction kettle at 30 ° C. for 18 hours. .
Thereafter, an aqueous sodium hydrogen carbonate solution was added to adjust the pH in the system to 6.8 to obtain a dispersion of silicone rubber particles. The volume average particle diameter of the silicone rubber particles was 280 nm.
To the silicone rubber particle dispersion, 200 parts by weight of ion-exchanged water and 0.5 parts by weight of sodium dodecylbenzenesulfonate are added and stirred, and methyl methacrylate is added so as to be 20 parts by weight / hour. A mixture of 36 parts by weight and 0.5 parts by weight of divinylbenzene was dropped.
To the silicone rubber particle dispersion, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a dispersion of silicone rubber particles obtained by coating a silicone rubber particle having a volume average particle diameter d of 310 nm measured with a laser diffraction particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.) with a resin. (Silicon rubber particle dispersion 1) was obtained.

(Preparation of silicone rubber particle dispersion 2)
100 parts by weight of octamethylcyclotetrasiloxane,
γ-methacryloyloxypropyldimethoxymethylsilane 5 parts by weight,
2 parts by weight of tetraethoxysilane,
1.2 parts by weight of sodium alkylbenzene sulfonate was dissolved in 300 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to give an emulsion, and then reacted in a reaction kettle at 30 ° C. for 18 hours. .
Thereafter, an aqueous sodium hydrogen carbonate solution was added to adjust the pH in the system to 6.8 to obtain a dispersion of silicone rubber particles. The volume average particle diameter of the silicone rubber particles was 180 nm.
To the silicone rubber particle dispersion, 220 parts by weight of ion-exchanged water and 0.5 parts by weight of sodium dodecylbenzenesulfonate are added and stirred, and methyl methacrylate is added so as to be 20 parts by weight / hour. A mixture of 40 parts by weight and 0.5 parts by weight of divinylbenzene was dropped.
To the silicone rubber particle dispersion, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a dispersion of silicone rubber particles (silicone rubber particle dispersion 2) obtained by coating silicone rubber particles having a volume average particle diameter of 200 nm with a resin was obtained.

(Preparation of silicone rubber particle dispersion 3)
100 parts by weight of octamethylcyclotetrasiloxane,
γ-methacryloyloxypropyldimethoxymethylsilane 5 parts by weight,
2 parts by weight of tetraethoxysilane,
2 parts by weight of sodium alkylbenzene sulfonate was dissolved in 300 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to obtain an emulsion, and then reacted at 30 ° C. for 18 hours in a reaction kettle.
Thereafter, an aqueous sodium hydrogen carbonate solution was added to adjust the pH in the system to 6.8 to obtain a dispersion of silicone rubber particles. The volume average particle diameter of the silicone rubber particles was 145 nm.
To the silicone rubber particle dispersion, 270 parts by weight of ion-exchanged water and 0.5 parts by weight of sodium dodecylbenzenesulfonate are added and stirred, and methyl methacrylate is added thereto so as to be 20 parts by weight / hour. A mixture of 49 parts by weight and 0.5 parts by weight of divinylbenzene was dropped.
To the silicone rubber particle dispersion, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a dispersion of silicone rubber particles (silicone rubber particle dispersion 3) obtained by coating silicone rubber particles having a volume average particle diameter of 165 nm with a resin was obtained.

(Preparation of silicone rubber particle dispersion 4)
100 parts by weight of octamethylcyclotetrasiloxane,
γ-methacryloyloxypropyldimethoxymethylsilane 5 parts by weight,
2 parts by weight of tetraethoxysilane,
0.4 part by weight of sodium alkylbenzene sulfonate was dissolved in 300 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to give an emulsion, and then reacted in a reaction kettle at 30 ° C. for 18 hours. .
Thereafter, an aqueous sodium hydrogen carbonate solution was added to adjust the pH in the system to 6.8 to obtain a dispersion of silicone rubber particles. The volume average particle diameter of the silicone rubber particles was 400 nm.
To the dispersion of the silicone rubber particles, 250 parts by weight of ion exchange water and 0.5 parts by weight of sodium dodecylbenzenesulfonate are added and stirred, and methyl methacrylate is added thereto so as to be 20 parts by weight / hour. A mixture of 45 parts by weight and 0.5 parts by weight of divinylbenzene was added dropwise.
To the silicone rubber particle dispersion, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a dispersion of silicone rubber particles (silicone rubber particle dispersion 4) obtained by coating silicone rubber particles having a volume average particle diameter of 450 nm with a resin was obtained.

(Preparation of silicone rubber particle dispersion 5)
100 parts by weight of octamethylcyclotetrasiloxane,
γ-methacryloyloxypropyldimethoxymethylsilane 5 parts by weight,
2 parts by weight of tetraethoxysilane,
0.3 parts by weight of sodium alkylbenzene sulfonate was dissolved in 300 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to give an emulsion, and then reacted in a reaction kettle at 30 ° C. for 18 hours. .
Thereafter, an aqueous sodium hydrogen carbonate solution was added to adjust the pH in the system to 6.8 to obtain a dispersion of silicone rubber particles. The volume average particle diameter of the silicone rubber particles was 430 nm.
To the silicone rubber particle dispersion, 220 parts by weight of ion-exchanged water and 0.5 parts by weight of sodium dodecylbenzenesulfonate are added and stirred, and methyl methacrylate is added so as to be 20 parts by weight / hour. A mixture of 40 parts by weight and 0.5 parts by weight of divinylbenzene was dropped.
To the silicone rubber particle dispersion, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while stirring and mixing for 20 minutes. Thereafter, the reaction kettle was purged with nitrogen, and then the kettle was heated to 70 ° C. and emulsion polymerization was continued for 5 hours. As a result, a dispersion of silicone rubber particles (silicone rubber particle dispersion 5) obtained by coating silicone rubber particles having a volume average particle diameter of 480 nm with a resin was obtained.

(Preparation of polymethyl methacrylate particle dispersion)
100 parts by weight methyl methacrylate,
0.5 parts by weight of sodium dodecylbenzenesulfonate
Was dissolved in 350 parts by weight of ion-exchanged water, stirred at 10,000 rpm for 15 minutes with a homomixer to prepare an emulsion, and then added to the reaction kettle, and 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved. Was introduced. Thereafter, the temperature was raised to 70 ° C. and a polymerization reaction was carried out for 5 hours to obtain a polymethyl methacrylate particle dispersion having a volume average particle size of 320 nm.

(Synthesis of binder resin)
・ 25 parts by weight of terephthalic acid 10 parts by weight of isophthalic acid 15 parts by weight of dodecenyl succinic acid 25 parts by weight of bisphenol A ethylene oxide adduct 25 parts by weight of bisphenol A propylene oxide adduct 0.1 parts by weight of dibutyltin oxide After putting in a dry two-necked flask and introducing nitrogen gas into the container and keeping it in an inert atmosphere and raising the temperature while stirring, it is subjected to a copolycondensation reaction at 150 to 230 ° C for about 12 hours, and then 210 to 250 ° C Then, the pressure was gradually reduced to synthesize a polyester resin.
The weight average molecular weight of the obtained polyester resin was 50,000.

(Preparation of resin particle dispersion)
・ Binder resin 160 parts ・ Ethyl acetate 233 parts ・ Sodium hydroxide aqueous solution (0.3N) 0.1 part The above ingredients were put into a separable flask and heated at 70 ° C. to produce a three-one motor (manufactured by Shinto Kagaku Co., Ltd.). ) To prepare a resin mixed solution. While further stirring this resin mixture, 373 parts of ion-exchanged water was gradually added, phase-inversion emulsified, and solvent removal was performed to obtain a resin particle dispersion (solid content concentration: 30%).

(Preparation of colorant dispersion)
-Cyan pigment (Daiichi Seika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine) 1,000 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 30 parts-Ion-exchanged water A colorant dispersion obtained by mixing and dissolving 6,000 parts or more and dispersing for 1 hour using a high-pressure impact disperser ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse the colorant. The volume average particle size of the colorant in the colorant dispersion was 0.16 μm, and the solid content concentration was 20% by weight.

(Preparation of release agent dispersion)
-Paraffin wax (Nippon Seiwa Co., Ltd., HNP-9) 50 parts-Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) 0.5 part-Ion exchange water: 230 parts or more The mixture was mixed, heated to 95 ° C., and dispersed using a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin Co., Ltd.) to prepare a release agent dispersion (solid content concentration: 20%) in which the release agent was dispersed. The volume average particle diameter of the release agent was 0.23 μm.

Example 1
-Aggregation process-
Resin particle dispersion 350 parts Colorant dispersion 70 parts Release agent dispersion 70 parts Anionic surfactant (Taika Power / Taika Co., Ltd.) 10 parts The above raw materials are placed in a cylindrical stainless steel container and homogenizer (IKA) , Ultra-Turrax T50), the number of revolutions of the homogenizer was set to 4,000 rpm, and the mixture was dispersed and mixed for 10 minutes while applying a shearing force. Next, 8.0 parts of a 10% aqueous nitric acid solution of polyaluminum chloride (PAC) as a flocculant (the content of nitric acid is 0.05N) is gradually added dropwise to disperse the homogenizer at 5,000 rpm for 15 minutes. And mixed to obtain a raw material dispersion.

  Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 42 ° C. At this time, the pH of the raw material dispersion was adjusted to a range of 3.2 to 3.8 using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The raw material dispersion was kept in the above pH range and allowed to stand for about 2 hours to form aggregated particles.

-Particle adhesion process-
Next, 150 parts of the resin particle dispersion and 80 parts of the silicone rubber particle dispersion 1 were added to the raw material dispersion to adhere the silicone rubber particles to the surface of the aggregated particles.

-Fusion process-
Furthermore, the temperature of the raw material dispersion was raised to 40 ° C., and aggregated particles were prepared using an optical microscope and Multisizer II while confirming the size and form of the particles. Thereafter, in order to fuse the aggregated particles, an aqueous NaOH solution was dropped into the raw material dispersion to adjust the pH to 7.0, and then the raw material dispersion was heated to 80 ° C. Thereafter, the raw material dispersion was allowed to stand for 3 hours to fuse the aggregated particles. After confirming that the aggregated particles were fused with an optical microscope, the colored particle dispersion was cooled at a temperature lowering rate of 1.0 ° C./min.

-Washing process-
Next, the colored particle dispersion was filtered, and the colored particles after solid-liquid separation were dispersed in ion exchanged water at 30 ° C., which is 20 times the solid content of the colored particles, and filtered by stirring for 20 minutes. . The colored particles after filtration were dried with a freeze dryer to obtain toner base particles.

As an external additive, 5 parts of SiO ₂ particles (volume average particle diameter of 50 nm) were added to 100 parts of the toner base particles and mixed for 5 minutes with a Henschel mixer. Furthermore, it was passed through an ultrasonic vibration sieve (45 μm / Dalton) to obtain an electrostatic charge image developing toner. The volume average particle size of the electrostatic image developing toner was 3.8 μm.

<Creation of carrier>
Ferrite particles (volume average particle size: 35 μm) 100 parts by weight Toluene 14 parts by weight Perfluoroacrylate copolymer (critical surface tension 24 dyn / cm) 1.6 parts by weight Carbon black (trade name: VXC-72, (Cabot Corporation, resistance 100Ωcm or less)
0.12 parts by weight / crosslinked melamine resin particles (volume average particle size; 0.3 μm, toluene insoluble) 0.3 parts by weight The above components except for ferrite particles were dispersed with a stirrer for 10 minutes to prepare a coating layer forming solution. Further, this coating layer forming solution and ferrite particles were put into a vacuum degassing type kneader and stirred at a temperature of 60 ° C. for 30 minutes, and then the pressure was reduced and toluene was distilled off to form a resin coating layer to obtain a carrier ( However, carbon black was diluted with toluene in a perfluoroacrylate copolymer as a carrier resin and dispersed with a sand mill.

  8 parts by weight of the electrostatic image developing toner and 92 parts by weight of the carrier obtained above were placed in a V blender and stirred for 20 minutes, followed by sieving with a 105 μm mesh to prepare an electrostatic image developer.

<Filming evaluation method>
Use DocuPrintC3200 (Fuji Xerox Co., Ltd.) remodeling machine (process speed is set to 320 mm / s, and even if the fixing device is removed, it is remodeled to operate as usual until transfer) 5,000 sheets of toner was output in an environment of 20% RH at 10 ° C. with an amount of toner of 0.2 g / m ² , and then 5 in an amount of 0.2 g / m ² toner in an environment of 28 ° C. and 85% RH The number of prints on which 1,000 images were continuously printed and image defects were caused by filming was quantified as a percentage.
◎: Less than 0.5% ○: 0.5% or more and less than 1.0% △: 1.0% or more and less than 5.0% ×: 5.0% or more

<Method for evaluating transfer maintenance>
Fill the developer of DocuPrint C3200 remodeling machine, and print 5,000 sheets of solid image and character mixing chart continuously under the condition of 300mm / sec at 10 ° C and 20% RH, respectively. The residue was evaluated by visual observation by tape transfer.
A: Transfer residue cannot be confirmed.
○: Transfer remains, but is hardly noticeable.
Δ: Slight transfer residue is confirmed, but there is no practical problem.
X: There are many untransferred residues, and there is a serious problem in actual use, which is inappropriate.

<Example 2>
The electrostatic charge image developing toner and the electrostatic charge image development were carried out in the same manner as in Example 1 except that the average circularity of the electrostatic charge image developer toner was changed to 0.97 by changing the fusing time to 2.2 hours. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 3>
The electrostatic charge image developing toner and the electrostatic charge image developer were changed in the same manner as in Example 1 except that the average circularity of the electrostatic charge image developer toner was changed to 0.95 by changing the fusing time to 1 hour. Prepared and evaluated. The evaluation results are shown in Table 1.

<Example 4>
The same procedure as in Example 1 was conducted except that the d / D value of the electrostatic charge image developer toner was changed to 0.05 by changing the silicone rubber particle dispersion to the silicone rubber particle dispersion 2. An electrostatic image developing toner and an electrostatic image developer were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 5>
The same procedure as in Example 1 was performed except that the d / D value of the electrostatic charge image developer toner was changed to 0.04 by changing the silicone rubber particle dispersion to the silicone rubber particle dispersion 3. An electrostatic image developing toner and an electrostatic image developer were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 6>
The same procedure as in Example 1 was performed except that the d / D value of the electrostatic charge image developer toner was changed to 0.12 by changing the silicone rubber particle dispersion to the silicone rubber particle dispersion 4. An electrostatic image developing toner and an electrostatic image developer were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 7>
The same procedure as in Example 1 was conducted except that the d / D value of the electrostatic charge image developer toner was changed to 0.13 by changing the silicone rubber particle dispersion to the silicone rubber particle dispersion 5. An electrostatic image developing toner and an electrostatic image developer were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 8>
The electrostatic charge image developing toner and the electrostatic charge image development were carried out in the same manner as in Example 6 except that the average circularity of the electrostatic charge image developer toner was changed to 0.97 by changing the fusing time to 2.4 hours. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 9>
By changing the fusing time to 1.2 hours, the electrostatic image developer toner and the electrostatic image development are the same as in Example 6, except that the average circularity of the electrostatic image developer toner is 0.96. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 10>
By changing the fusing time to 2.5 hours, the electrostatic image developing toner and the electrostatic image developing were performed in the same manner as in Example 7 except that the average circularity of the electrostatic image developer toner was changed to 0.97. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 11>
The electrostatic charge image developing toner and the electrostatic charge image developer were changed in the same manner as in Example 2 except that the average circularity of the electrostatic charge image developer toner was changed to 0.97 by changing the fusion time to 2 hours. Prepared and evaluated. The evaluation results are shown in Table 1.

<Example 12>
The electrostatic charge image developing toner and the electrostatic charge image development are the same as in Example 2 except that the average circularity of the electrostatic charge image developer toner is changed to 0.96 by changing the fusion time to 0.9 hours. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 13>
By changing the fusing time to 1.8 hours, the toner for developing an electrostatic charge image and the electrostatic image development are the same as in Example 5 except that the average circularity of the electrostatic charge image developer toner is 0.97. Agents were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 14>
The electrostatic charge image development was carried out in the same manner as in Example 1 except that the growth temperature of the aggregated particles was changed to 36 ° C. so that the electrostatic charge image developer toner D was set to 3.0 μm and the average circularity was set to 0.98. Toners and electrostatic charge image developers were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 15>
By changing the growth temperature of the aggregated particles to 32 ° C., the electrostatic charge image developer is developed in the same manner as in Example 1 except that D of the electrostatic charge image developer toner is 2.8 μm and the average circularity is 0.98. Toners and electrostatic charge image developers were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 16>
By changing the growth temperature of the agglomerated particles to 47 ° C., the electrostatic charge image development is performed in the same manner as in Example 1 except that the electrostatic charge image developer toner D is 4.8 μm and the average circularity is 0.98. Toners and electrostatic charge image developers were prepared and evaluated. The evaluation results are shown in Table 1.

<Example 17>
By changing the growth temperature of the agglomerated particles to 50 ° C., the electrostatic charge image developer is developed in the same manner as in Example 1 except that the electrostatic charge image developer toner has a D of 5.2 μm and an average circularity of 0.98. Toners and electrostatic charge image developers were prepared and evaluated. The evaluation results are shown in Table 1. The toner of Example 17 had no problem with transfer maintenance and filming, but the resolution was slightly inferior to the others.

<Comparative Example 1>
An electrostatic image developing toner and an electrostatic image developer were prepared and evaluated in the same manner as in Example 1 except that the silicone rubber particle dispersion 1 was changed to a polymethyl methacrylate (PMMA) particle dispersion. The evaluation results are shown in Table 1.

<Comparative example 2>
A toner for developing an electrostatic charge image and an electrostatic charge image developer were prepared and evaluated in the same manner as in Example 1 except that the silicone rubber particle dispersion 1 was not added. The evaluation results are shown in Table 1.

  U1: Image forming apparatus, PG: Platen glass, U2: Automatic document feeder, Gi: Document, TG1, TG2: Tray, IIT: Document reader, Sp: Exposure system registration sensor, A: Exposure optical system, CCD: Solid-state imaging Element, IPS: Image processing system, DL: Laser drive circuit, ROS: Latent image forming device, C: Controller, PR: Image carrier, CR: Charger, Q1: Latent image writing position, Q2: Development area, Q3 G: rotary shaft, GK, GY, GM, GC: four-color developing device, GR: developing roll, Hk, Hy, Hm, Hc: cartridge mounting portion, B: Intermediate transfer belt, Rd: Belt drive roll, Rt: Tension roll, Rw: Walking roll, Rf: Idler roll, T2a: Backup roll, T1: Secondary transfer roll, JR: Static eliminator, CL1: Image carrier cleaner, T2b: Secondary transfer roll, T2: Secondary transfer device, Q4: Secondary transfer area, E: Power supply circuit, S: Recording sheet, Rp: Pickup Roll, Rs: Separation roll, SH1: Paper feed path, Ra: Transport roll, Rr: Registration roll, SG1: Pre-transfer sheet guide, CL2: Belt cleaner, CL3: Secondary transfer roll cleaner, SG2: Post-transfer sheet guide, BH : Sheet transport belt, Q5: fixing region, F: fixing device, Fh: heating roll, Fp: pressure roll, 16a: drive roll, 16b: driven roll, 16: sheet transport roll, Rb1: drive roll, Rb2: driven Roll, Rb: Sheet transport roll, SH2: Sheet discharge path, SH3: Sheet reversal path, GT1: Switching gate, Ra: Transport roll, Rh: Sh DOO discharge roll, Ka: the sheet discharge port, TR3: discharge tray, SH4: sheet circulating path, GT2: Mairageto, SH: sheet transport path, US: sheet conveying device.

Claims (6)

Having toner base particles containing at least a binder resin and a colorant;
The toner for developing an electrostatic image, wherein the toner base particles have protrusions made of silicone rubber particles on the surface.   The electrostatic image developing toner according to claim 1, wherein the average circularity is 0.97 or more.   The ratio d / D between the volume average particle diameter D of the electrostatic image developing toner and the volume average particle diameter d of the silicone rubber particles forming the protrusions is 0.05 to 0.12. The toner for developing an electrostatic charge image according to 1. An aggregation step of aggregating particles contained in a dispersion containing at least a binder resin and a colorant to form an aggregate;
A particle attaching step of attaching silicone rubber particles to the surface of the aggregate;
The method for producing a toner for developing an electrostatic charge image according to any one of claims 1 to 3, further comprising a fusing step of fusing and coalescing the particles of the silicone rubber adhering to the aggregate. . An electrostatic image developer comprising the electrostatic image developing toner according to claim 1 and a carrier. A charging step for charging the image carrier,
An electrostatic latent image forming step of forming an electrostatic latent image by exposing the charged image carrier;
A development step of developing the electrostatic latent image using a developer containing toner to form a developed image;
A transfer step of transferring the developed image onto a substrate to form a transfer image; and
A fixing step of fixing the transferred image,
An image forming method, wherein the toner is the electrostatic image developing toner according to claim 1 or the developer is the electrostatic image developer according to claim 5. .

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