JP2005031222A - Electrostatic charge image developing toner, method for manufacturing the same and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which achieves offset at high temperature while enabling low-temperature fixation and is excellent in glossiness of a fixed image. <P>SOLUTION: The electrostatic charge image developing toner contains at least a non-bisphenol polyester having a glass transition temperature of 0-50°C and a vinyl polymer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０１０３】
【表２】

【０１０４】
表２の画像濃度均一性の評価基準は、画像部５箇所の濃度を分光測定濃度計（Ｘ−Ｒｉｔｅ）により測定し、最高濃度部と最低濃度部の濃度差を画像濃度均一性の評価指標とした。
○：最高濃度部と最低濃度部の濃度差が０．２未満
△：最高濃度部と最低濃度部の濃度差が０．２〜０．３
×：最高濃度部と最低濃度部の濃度差が０．３よりも上
【０１０５】
表２の画像ブロッキング性の評価基準は以下の通りである。
○ ：画像欠損が観察されない
△ ：画像欠損が画像面内の１／２未満
× ：画像欠損が画像面内の１／２以上
【０１０６】
表２のトナーケーキング性の評価基準は以下の通りである。
○ ：トナーの塊が確認されない
△ ：トナーの塊が１／２未満
× ：トナーの塊が１／２以上
【０１０７】
【発明の効果】
本発明は、高温オフセット性及び定着像の光沢性に優れる静電荷像現像用トナー及びその製造方法を提供できる。さらに、光沢性に優れる定着像を形成可能な画像形成方法を提供できる。
【図面の簡単な説明】
【図１】本発明の画像形成方法を適用した電子写真画像形成装置の一例を示す概略構成図である。
【符号の説明】
３０：電子写真感光体（潜像担持体）
３１：帯電ロール
３２：レーザー露光光学系
３３：現像器
３３ａ：現像剤担持体
３４：転写手段
３５：除電装置
３６：クリーニングブレード
３７、３８：定着ロール
４０：用紙[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic image developing toner used for image formation by electrophotography, a method for producing the same, and an image forming method using the electrostatic image developing toner.
[0002]
[Prior art]
A method for visualizing image information through an electrostatic latent image such as electrophotography is currently used in various fields such as a copying machine and a printer with the development of the technology and the expansion of market demand. As a result, demands from users are becoming stricter year by year. In particular, printed images with excellent clarity and fixing properties, copyability with low energy in consideration of the environment, etc. are required more than ever. It is coming. In recent years, environmental protection has been strongly recognized, and the demand for lower energy during copying has been increasing day by day.
[0003]
In order to realize low energy, it is necessary that the fixing temperature of the electrostatic image developing toner (hereinafter abbreviated as “toner”) applied to the hot roll fixing method is low and no offset occurs after fixing. In order to satisfy them, conventionally, a low molecular weight binder resin has been used to lower the melting temperature, to increase the amount of wax contained in the toner, and to lower the melting point.
[0004]
These toners are usually produced by a kneading and pulverizing method in which a thermoplastic resin is melt-kneaded together with a pigment, a charge control agent, a release agent, etc., cooled, finely pulverized, and further classified. For example, inorganic and organic fine particles for improving fluidity and cleaning properties may be added to the toner particle surfaces. In the ordinary kneading and pulverizing method, the toner shape and the surface structure of the toner are indeterminate, and the toner shape and surface structure are intentionally difficult to control because they vary slightly depending on the pulverization properties of the materials used and the conditions of the pulverization process. is there. In particular, in the case of a material having a high pulverization property, the generation of fine powder or a change in toner shape is often caused by mechanical force in the developing machine. Due to these effects, in the two-component developer, the charging deterioration of the developer is accelerated by the adhesion of fine powder to the carrier surface, and in the one-component developer, the toner scattering occurs due to the expansion of the particle size distribution, and the toner shape Deterioration in developability due to change tends to cause image quality degradation.
[0005]
Further, when a toner such as wax is internally added to form a toner, the exposure of the release agent to the surface is often affected by the combination with a thermoplastic resin. In particular, in the case of a combination of a resin imparted with elasticity by a high molecular weight component and slightly pulverized resin and a brittle wax-type release agent such as polyethylene, a large amount of polyethylene is exposed on the toner surface. These are advantageous for releasability during fixing and cleaning of untransferred toner from the surface of the photoreceptor, but because the polyethylene on the surface layer is easily transferred by mechanical force, contamination of the developing roll, photoreceptor and carrier is prevented. It tends to occur, leading to a decrease in reliability. Further, since the toner shape is indefinite, the fluidity is not sufficient even when a fluidity aid is added, and the fine particles on the toner surface move to the concave portions due to the action of mechanical force during use. In particular, the fluidity is lowered or the fluidity aid is buried in the toner, so that the developability, transferability, and cleaning properties are deteriorated. Further, when the toner collected by cleaning is returned to the developing machine and used again, the image quality is likely to further deteriorate. If the flow aid is further increased in order to prevent these problems, black spots are generated on the photoconductor and the aid particles are scattered.
[0006]
In recent years, a method for producing a toner by an emulsion polymerization aggregation method has been proposed as a method for intentionally controlling the toner shape and surface structure (see, for example, Patent Documents 1 and 2). In the emulsion polymerization aggregation method, a small diameter toner can be effectively produced in principle because a starting material is a finely divided raw material that is usually 1 micron or less. Specifically, a resin dispersion is generally prepared by emulsion polymerization or the like, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared, and the resin dispersion and the colorant dispersion are mixed to obtain a toner particle size. This is a manufacturing method in which the corresponding aggregated particles are prepared and then heated to fuse and coalesce the aggregated particles to form a toner. Usually, the surface composition of the toner is the same because the toner surface and the interior have the same composition. It is difficult to control.
[0007]
With regard to this problem, means for realizing more precise particle structure control has been proposed by performing free control from the inner layer to the surface layer even in the toner in the emulsion polymerization aggregation method (for example, Patent Document 3). reference.). These toners can be easily reduced in diameter and precise particle structure control has been realized, so that the image quality of conventional electrophotographic images has been dramatically improved, and at the same time, high reliability can be achieved.
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 63-282275
[Patent Document 2]
JP-A-6-250439
[Patent Document 3]
Japanese Patent No. 3141784
[0009]
[Problems to be solved by the invention]
In the usual melt-kneading method, when a binder resin having a low melting temperature is used, since a binder resin having a low melting temperature is also present on the toner surface and inside, low-temperature fixing is possible. Offset occurs at low temperatures, and both low temperature fixing and high temperature offset cannot be achieved. Further, even if fixing at low temperature is possible, offset at a low temperature occurs, so that the fixing latitude does not spread. Further, if the offset at a high temperature is made possible, there is a drawback that the low-temperature fixing becomes impossible and the gloss (glossiness) of the fixed image is lowered.
[0010]
Accordingly, an object of the present invention is to solve the above-described problems in conventional toners. That is, an object of the present invention is to provide a toner for developing an electrostatic charge image that can be offset at a high temperature and is excellent in glossiness (glossiness) of a fixed image, and a production method thereof. It is another object of the present invention to provide an image forming method using the electrostatic image developing toner.
[0011]
[Means for Solving the Problems]
That is, the present invention
<1> An electrostatic charge image developing toner comprising at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer.
[0012]
<2> The electrostatic charge image according to <1>, which contains a reactive polymer that undergoes a crosslinking reaction when heated at a temperature higher than the maximum temperature during production of the toner for developing an electrostatic charge image. Development toner.
[0013]
<3> The <1> or <2>, wherein the non-bisphenol-based polyester is a reaction product of an aliphatic alcohol, an aromatic dicarboxylic acid, and a trivalent or higher polyvalent monomer. The electrostatic charge image developing toner described.
[0014]
<4> The electrostatic image development according to any one of <1> to <3>, wherein the content of the non-bisphenol-based polyester is 5 to 50% by mass with respect to the total toner mass. Toner.
[0015]
<5> A method for producing an electrostatic charge image developing toner comprising at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer, wherein at least the non-bisphenol polyester fine particle dispersion And a vinyl polymer fine particle dispersion to form an aggregated particle, and a fusion process for heating and aggregating the aggregated particle to produce a toner for developing an electrostatic charge image Is the method.
[0016]
<6> An electrostatic latent image forming step for forming an electrostatic latent image on the electrophotographic photosensitive member, and development for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer to form an image. A transfer step of transferring the image formed on the electrophotographic photosensitive member to the surface of the recording medium to form a transfer image, and a fixing step of fixing the transfer image transferred to the surface of the recording medium. An image forming method comprising the developer, wherein the developer comprises an electrostatic charge image developing toner containing at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer. It is a forming method.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the toner for developing an electrostatic charge image of the present invention, a method for producing the toner, and an image forming method will be described in detail.
<Toner for electrostatic image development>
The toner for developing an electrostatic image of the present invention is characterized by containing at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer. The toner for developing an electrostatic image of the present invention may contain a reactive polymer, a colorant, a release agent and other components as necessary.
[0018]
-Non-bisphenol-based polyester-
In the present invention, the non-bisphenol-based polyester refers to a polyester resin that does not use bisphenol A and its derivatives as a raw material for the polyester resin. Bisphenol A and its derivatives themselves are poorly biodegradable, and when discarded, they may remain undegraded for a long time. Further, since it has an aromatic ring in the molecule, it may be discolored by light, which may affect the color gamut of the toner.
[0019]
The glass transition point of the non-bisphenol-based polyester used in the present invention is 0 to 50 ° C, preferably 30 to 50 ° C. When the glass transition point of the non-bisphenol-based polyester is less than 0 ° C., the viscoelasticity of the toner becomes too low, and offset at high temperatures is likely to occur.
On the other hand, if the glass transition point of the non-bisphenol-based polyester exceeds 50 ° C., the toner viscoelasticity becomes too high, and the glossiness (glossiness) of the fixed image tends to be lowered.
Further, when the glass transition point of the non-bisphenol-based polyester does not satisfy the above range, the offset property of the fixed image and the gloss property are liable to be lowered.
In addition, in this invention, a glass transition point means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.
[0020]
The non-bisphenol-based polyester is a polycondensate of an alcohol component and a carboxylic acid component. Specific examples of the alcohol component include, for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, and dipropylene. Glycol, isopentyl glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, xylylene glycol, 1,4-cyclohexanedimethanol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, bis -(Β-hydroxyethyl) terephthalate, tris- (β-hydroxyethyl) isocyanate, 2,2,4-trimethylolpentane-1,3-diol and the like. These may be used alone or in combination of two or more.
[0021]
Specific examples of the carboxylic acid component include, for example, malonic acid, succinic acid, glutaric acid, dimer acid, phthalic acid, isophthalic acid, terephthalic acid, isophthalic acid dimethyl ester, terephthalic acid dimethyl ester, terephthalic acid monomethyl ester, tetrahydroterephthale Acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, dimethyltetrahydrophthalic acid, endomethylenehexahydrophthalic acid, naphthalenetetracarboxylic acid, diphenolic acid, trimellitic acid, pyromellitic acid, trimesic acid, cyclopentanedicarboxylic acid, 3 , 3 ′, 4,4′-benzophenonetetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, 2,2-bis- (4-carboxyphenyl) propane, trimellitic anhydride and 4,4 -Diaminophenyl ester Diimide carboxylic acid obtained from styrene, tris- (β-carboxyethyl) isocyanate, isocyanate ring-containing polyimide carboxylic acid, tolylene diisocyanate, xylylene diisocyanate or isophorone diisocyanate trimerization reaction product and isocyanate obtained from trimellitic anhydride Examples thereof include ring-containing polyimide carboxylic acid. These may be used alone or in combination of two or more.
[0022]
The non-bisphenol-based polyester is preferably a reaction product of an aliphatic alcohol, an aromatic dicarboxylic acid, and a trivalent or higher polyvalent monomer. By using such a non-bisphenol-based polyester, the glass transition point of the resin is increased and the offset property is improved.
The non-bisphenol-based polyester can be produced according to a conventional method.
Here, the trivalent or higher polyvalent monomer means a compound containing three or more hydroxyl groups in one molecule or a compound containing three or more carboxyl groups in one molecule.
[0023]
The total acid value and hydroxyl value of the non-bisphenol-based polyester is preferably 5 to 50 mgKOH / g, more preferably 10 to 25 mgKOH / g. When the total of the acid value and the hydroxyl value is 5 to 50 mgKOH / g, it becomes easy to form aggregated particles with a vinyl polymer described later at the time of toner production, and it becomes easy to obtain toner particles having a preferable shape. . As a result, an excellent image can be formed.
In addition, in this invention, an acid value and a hydroxyl value mean the value measured by the method prescribed | regulated by JISK0070.
[0024]
The content of the non-bisphenol-based polyester is preferably 5 to 50% by mass and more preferably 10 to 30% by mass with respect to the total toner mass. When the content of the non-bisphenol-based polyester is 5 to 50% by mass with respect to the total toner mass, a toner having excellent offset properties and excellent gloss properties can be obtained.
[0025]
-Vinyl polymer-
The vinyl polymer used in the present invention is preferably a resin obtained by polymerizing a polymerizable monomer having at least a vinyl double bond, more preferably styrene containing at least an unsaturated carboxylic acid in a repeating unit. -It is preferably an acrylic copolymer resin.
[0026]
Examples of the polymerizable monomer include styrenes such as styrene and parachlorostyrene, vinyl esters such as vinyl naphthalene, vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyrate. Such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl chloroacrylate, methacrylic acid Methylene aliphatic carboxylic esters such as methyl, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, for example vinyl such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether Monomers such as N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone and the like, monomers having an N-containing polar group, methacrylic acid, acrylic acid, cinnamic acid, Examples thereof include vinyl carboxylic acids such as carboxyethyl acrylate.
[0027]
As the vinyl polymer, homopolymers and copolymers of the above monomers, and various waxes can be used together.
[0028]
The glass transition point of the vinyl polymer is preferably 50 to 100 ° C, more preferably 60 to 80 ° C. An image obtained from a toner containing a vinyl polymer having a glass transition point of 50 to 100 ° C. is excellent in offset property and gloss property.
[0029]
The toner for developing an electrostatic charge image of the present invention contains other resins (binder resin and the like) as long as the effects of the present invention are not impaired in addition to the non-bisphenol polyester and the vinyl polymer as the binder resin. May be.
[0030]
-Reactive polymer-
The electrostatic charge image developing toner of the present invention may contain a reactive polymer as required.
The structure of the reactive polymer is not particularly limited, but includes at least one reactive group, and the reactive group undergoes a crosslinking reaction at a temperature higher than the maximum temperature at the time of toner production.
The reactive group is not particularly limited as long as it has the above-described characteristics, but is preferably an organic compound group having a cyclic structure (hereinafter, sometimes referred to as “cyclic reactive group”).
[0031]
In this case, by selecting the type of cyclic reactive group and the number of cyclic reactive groups contained in the reactive polymer, excellent thermal durability and mechanical durability can be achieved even at low temperatures. An image having the property can be obtained. Moreover, the reactive polymer which has a desired characteristic can be obtained by superposing | polymerizing using the polymerizable monomer containing a cyclic reactive group. In addition, the kind of cyclic reactive group contained in the reactive polymer is not limited to one kind, and may be two or more kinds.
[0032]
As such a cyclic reactive group, it is possible to carry out a crosslinking reaction by opening a ring at a temperature of at least a temperature higher than 100 ° C., particularly preferably in a range of 120 ° C. to 220 ° C. which is a general fixing temperature range. In addition, it is not particularly limited as long as it is stable (no crosslinking reaction) at the maximum temperature (100 ° C.) or less at the time of toner production. Specifically, it is any of an epoxy group, an aziridinyl group, and an oxazoline group. Preferably there is.
[0033]
In order to facilitate the crosslinking reaction with these cyclic reactive groups, it is preferable that the toner contains a compound containing a polar group (low molecular compound and / or high molecular compound). The polar group is not particularly limited as long as it has a large polarity, but a carboxyl group is particularly preferable. The polar group may be included in the same reactive polymer together with the cyclic reactive group.
[0034]
The vinyl polymer may be a reactive polymer. When the cyclic reactive group is an epoxy group, examples of the raw material for the vinyl polymer include glycidyl methacrylate (GMA), glycidyl acrylate, 2-methylglycidyl methacrylate, 2-methylglycidyl acrylate, and allyl. Epoxy group-containing monomers such as glycidyl ether, glycidyl p-vinylbenzoate, methyl glycidyl itaconate, glycidyl ethyl maleate, glycidyl vinyl sulfonate, glycidyl β-styrene sulfonate, glycidyl allyl sulfonate, glycidyl methallyl sulfonate Can be used.
[0035]
When the cyclic reactive group is an aziridinyl group, for example, aziridinyl group-containing polymerizable monomers such as methacryloylaziridine, acroylaziridine, 2-aziridinylethyl methacrylate, 2-aziridinylethyl acrylate, etc. When the cyclic reactive group is an oxazoline group, for example, an oxazoline group-containing polymerizable monomer such as 2-isopropenyl-2-oxazoline or 2-vinyl 2-oxazoline may be used. it can.
In the polymerization, one or more of the polymerizable monomers listed above can be used.
[0036]
The reactive polymer can be contained inside the toner or added to the surface of the toner. When the toner is contained in the toner, it may also serve as a binder resin, or may be separate from the binder resin. Moreover, you may serve as another component.
On the other hand, when a reactive polymer is added to the surface of the toner, the reactive polymer can be added to the toner surface as an external additive, and this external additive may also have other functions.
[0037]
-Colorant-
In the present invention, for example, the following colorants can be used as necessary.
Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite.
[0038]
Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, hansa yellow, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, permanent yellow NCG, and the like. be able to.
[0039]
Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK.
[0040]
Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C Naphthol red such as Rose Bengal, Eoxin Red, Alizarin Lake, Pigment Red 146, 147, 184, 185, 155, 238 and 269.
[0041]
Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate.
[0042]
Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
[0043]
Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.
[0044]
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.
[0045]
Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.
[0046]
Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue.
[0047]
The said colorant is used individually by 1 type or in combination of 2 or more types. The colorant is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.
The colorant is added in the range of 4 to 15% by mass with respect to the total mass of the toner constituting solids. By setting the blending amount of the colorant within the above range, it is possible to ensure the color developability during toner fixing.
[0048]
-Release agent-
Specific examples of the release agent used in the present invention include, for example, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones which show a softening point by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearin Fatty acid amides such as acid amides, plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, animal waxes such as beeswax, montan wax, ozokerite, ceresin, Examples thereof include mineral-based and petroleum-based waxes such as paraffin wax, microcrystalline wax, microcrystalline wax, Fischer-Tropsch wax, and modified products thereof.
These waxes are hardly dissolved in a solvent such as toluene at room temperature or very little even if dissolved.
It is desirable to add these release agents in a range of 5 to 25% by mass with respect to the total mass of the solid component of the toner in order to ensure the releasability of the fixed image in the oilless fixing system.
In addition, the electrostatic charge image developing toner of the present invention may contain a polymerizable UV-stable monomer or the like, if necessary, in order to improve the weather resistance of the image.
[0049]
The surface of the toner for developing an electrostatic charge image of the present invention is dried in the same manner as a normal toner for the purpose of imparting fluidity and improving cleaning properties, and then, as an external additive, silica, alumina, titania, calcium carbonate, etc. Binder resin fine particles such as inorganic fine particles, vinyl resin, polyester, and silicone can be added while being sheared in a dry state.
[0050]
On the other hand, an external additive can be attached to the surface of the toner in water. In such a case, when the external additive is an inorganic fine particle, it can be used as an external additive added to a normal toner surface such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and the like. An inorganic additive can be dispersed in water together with an ionic surfactant, a polymer acid, and a polymer base, and an external additive can be attached to the surface of the toner.
[0051]
The apparent weight average molecular weight of the toner for developing an electrostatic charge image of the present invention is preferably 15,000 to 60,000, more preferably 20,000 to 45,000. When the apparent weight average molecular weight is 15,000 or more, the cohesive force of the binder resin is easily improved, and the oilless peelability can be improved. Moreover, if it is 60,000 or less, the smoothness at the time of fixing is excellent, and the glossiness can be improved.
Here, the apparent weight average molecular weight refers to the molecular weight obtained by measuring the THF soluble content of the resin by gel permeation chromatography (GPC).
[0052]
The volume average particle size of the toner for developing an electrostatic charge image of the present invention is preferably from 3 to 9 μm, more preferably from 4 to 8 μm, still more preferably from 4.5 to 7.5 μm. When the volume average particle diameter is 3 μm or more, the toner weight is heavy, so that the force for embedding the metal oxide on the toner surface at the time of collision between the photoconductor and the toner is large, and as a result, the metal oxide remains on the surface of the photoconductor. Can be prevented. If it is 9 μm or less, the fine line reproducibility during development is excellent.
The volume average particle diameter of the toner can be measured with a laser diffraction particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).
[0053]
The volume average particle size distribution index GSDv of the toner of the present invention is preferably 1.30 or less, and more preferably 1.25 or less. When GSDv is 1.30 or less, the resolution is improved and image defects such as toner scattering and fogging hardly occur.
The cumulative volume average particle diameter of the toner for developing an electrostatic charge image of the present invention is, for example, a particle size distribution measured with a measuring instrument such as Coulter Counter TAII (manufactured by Nikka Kisha Co., Ltd.), Multisizer II (manufactured by Nikka Kisha Co., Ltd.). Draw a cumulative distribution from the small diameter side to the particle size range (channel) divided on the basis of the particle size, and set the particle size to be 16% cumulative to the volume D _16v , Number D _16P , The particle size that becomes 50% cumulative is the volume D _50v , Number D _50P , The particle size that is 84% cumulative is the volume D _84v , Number D _84P Is defined. Using these, the volume average particle size distribution index (GSDv) is (D _84v / D _16V ) ^1/2 The number average particle size distribution index (GSDp) is (D _84P / D _16P ) ^1/2 Is calculated as
[0054]
The toner for developing an electrostatic image of the present invention may be used in either a one-component development method or a two-component development method, but is preferably used in a two-component development method combined with a resin-coated carrier. By using a resin-coated carrier as the carrier, it is possible to improve the rise of charge and the deterioration of charge distribution due to the reduction in the particle size of the toner, and the background stain and density unevenness resulting from the decrease in charge amount. The carrier is not particularly limited as long as it is a known carrier, and iron powder carriers, ferrite carriers, surface-coated ferrite carriers, and the like can be used. Each surface-added powder may be used after a desired surface treatment.
[0055]
<Toner production method>
The method for producing a toner for developing an electrostatic charge image according to the present invention comprises an aggregation step of mixing at least the fine particle dispersion of the non-bisphenol polyester and the fine particle dispersion of the vinyl polymer to form aggregated particles, and the aggregated particles And a fusing step of fusing and fusing. When other binder resin, reactive polymer, colorant, release agent and the like are added, each dispersion is prepared and mixed with a fine particle dispersion such as a vinyl polymer in the aggregation step.
[0056]
In the case of the vinyl polymer, it is possible to prepare a fine particle dispersion of the vinyl polymer by performing emulsion polymerization using a vinyl monomer and an ionic surfactant. Further, in the case of the non-bisphenol-based polyester, the non-bisphenol-based polyester synthesized according to a conventional method is dissolved in a solvent that is oily and has a relatively low solubility in water, and a homogenizer or the like together with an ionic surfactant or polymer electrolyte. A fine particle dispersion can be obtained by dispersing in fine particles in water with a disperser and then evaporating the solvent by heating or decompressing. Moreover, when using other binder resins and reactive polymers other than the vinyl polymer and the non-bisphenol polyester, the same method as the method for preparing the fine particle dispersion of the resin described above can be used.
The center diameter (median diameter) of the fine particles in the resin fine particle dispersion thus obtained is preferably 1 μm or less, more preferably 50 to 400 nm, and even more preferably 70 to 350 nm.
In addition, the center diameter of resin fine particles can be measured, for example with a laser diffraction type particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).
[0057]
The zeta potential of the vinyl polymer and non-bisphenol polyester fine particle dispersion at 20 ° C. is preferably −10 to −100 mV, and more preferably −20 to −50 mV. When the zeta potential is within this range, the stability of the emulsion is improved, and further, the ion repulsion is weakened, so that the cohesiveness is improved and the toner productivity is excellent.
[0058]
In the case of the colorant, for example, a dispersion of colorant particles can be prepared using a media-type disperser such as a rotary shearing homogenizer, a ball mill, a sand mill, or an attritor, a high-pressure opposed collision disperser, or the like. Further, these colorants can be dispersed in an aqueous system by a homogenizer using a polar surfactant.
Moreover, OHP transparency and color developability can be ensured by setting the center diameter (median diameter) of the colorant particles in the toner to 100 to 330 nm.
The center diameter of the colorant particles can be measured, for example, with a laser diffraction particle size distribution measuring device (LA-700, manufactured by Horiba, Ltd.).
[0059]
In the case of the mold release agent, the mold release agent is dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, and heated to a melting point or higher, and has a strong shearing ability. Or a pressure discharge type disperser (Gorin homogenizer, manufactured by Gorin Co., Ltd.) to be dispersed in the form of fine particles to prepare a dispersion of particles of 1 μm or less.
The particle size of the obtained release agent particle dispersion was measured, for example, with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). In addition, when using a release agent, after the resin fine particles, colorant particles and release agent particles are aggregated, it is possible to add a resin fine particle dispersion to adhere the resin fine particles to the surface of the aggregated particles. It is desirable from the viewpoint of securing the property.
[0060]
In the present invention, a surfactant can be used for resin emulsion polymerization, pigment dispersion, resin fine particle dispersion, mold release agent dispersion, aggregation, and aggregation particle stabilization. Specifically, sulfate surfactants, sulfonates, phosphates, soaps, and other anionic surfactants, amine salts, quaternary ammonium salts, and other cationic surfactants, polyethylene glycols, It is also effective to use nonionic surfactants such as alkylphenol ethylene oxide adducts and polyhydric alcohols as the dispersing means, and as a dispersion means, general use such as a ball mill, sand mill, dyno mill having a rotating shear homogenizer or media Can be used
[0061]
In the production of the toner for developing an electrostatic charge image according to the present invention, the particles can be adjusted by generating aggregation by pH change in the aggregation process. At the same time, a flocculant may be added as a method for stably and rapidly agglomerating particles or obtaining agglomerated particles having a narrower particle size distribution.
A compound having a monovalent or higher charge is preferable as the flocculant, and specific examples of the compound having a monovalent or higher charge as the flocculant include the above-described ionic surfactants and nonionic (nonionic) surface active agents. Water-soluble surfactants such as hydrochloric acid, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, etc. Metal salt of inorganic acid, aliphatic acid such as sodium acetate, potassium formate, sodium oxalate, sodium phthalate, potassium salicylate, metal salt of aromatic acid, metal salt of phenol such as sodium phenolate, metal salt of amino acid Inorganic acid salts of aliphatic and aromatic amines such as triethanolamine hydrochloride and aniline hydrochloride It is below.
In consideration of the stability of the aggregated particles, the stability of the aggregating agent with respect to heat and time, and removal during washing, a metal salt of an inorganic acid is preferable in terms of performance and use.
Specifically, metal salts of inorganic acids such as magnesium chloride, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, and sodium carbonate.
The amount of these flocculants to be added varies depending on the valence of the charge, but they are all small, in the case of monovalent, about 3% by mass or less, in the case of divalent, about 1% by mass, in the case of trivalent Is about 0.5 mass% or less. Since a smaller amount of the flocculant is preferable, a compound having a higher valence is preferable.
[0062]
The heating temperature in the fusion step is preferably 88 to 98 ° C, more preferably 90 to 96 ° C, and further preferably 92 to 95 ° C. The heating time is preferably 2 to 8 hours, more preferably 3 to 7 hours, and further preferably 4 to 6 hours. When a reactive polymer is used, the heating temperature is preferably equal to or lower than the reaction temperature of the reactive polymer.
[0063]
The toner for developing an electrostatic charge image of the present invention is preferably prepared by an emulsion polymerization aggregation method and has a two-layer structure of a core layer and a shell layer covering the core layer. In particular, an embodiment in which the non-bisphenol polyester and the vinyl polymer are contained as the resin component of the core layer and the vinyl polymer is contained as the resin component of the shell layer is preferable. The vinyl polymer of the core layer and the shell layer may be the same or different, and may contain other binder resins. When the electrostatic charge image developing toner of the present invention has the two-layer structure as described above, the offset property is maintained because the core layer containing the non-bisphenol-based polyester is protected by the shell layer when offset at a high temperature. In addition, the glossiness of the fixed image can be improved due to the low viscosity of the toner.
[0064]
When a toner having a multilayer structure is produced, a toner having a multilayer structure can be obtained by forming agglomerated particles serving as nuclei and then repeating the step of attaching other particles to the surface of the agglomerated particles one or more times. .
For example, in the case of producing a toner having a core / shell structure, a step of forming aggregated particles to be a core layer, and particles made of a binder resin or the like are attached to the surface of the aggregated particles to be the core layer. A toner having a core / shell structure can be obtained through a step of forming aggregated particles provided with a layer to be a layer.
[0065]
In the toner production method of the present invention, the toner of the present invention can be obtained by completing an arbitrary washing step, solid-liquid separation step, and drying step after the fusion step. At this time, it is desirable that the washing process is sufficiently replaced and washed with ion-exchanged water in consideration of the chargeability. Moreover, although there is no restriction | limiting in particular in a solid-liquid separation process, From the point of productivity, suction filtration, pressure filtration, etc. are suitable. Further, the drying process is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.
[0066]
<Image forming method>
The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrophotographic photosensitive member, and developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer. A developing process for forming an image, a transfer process for transferring the image formed on the electrophotographic photosensitive member to the surface of the recording medium to form a transfer image, and fixing the transferred image transferred to the surface of the recording medium And a fixing step, wherein the developer includes the electrostatic image developing toner of the present invention.
[0067]
FIG. 1 is a schematic configuration diagram showing an example of an electrophotographic image forming apparatus to which the image forming method of the present invention is applied. The electrophotographic image forming apparatus includes an electrophotographic photosensitive member 30, a charging roll 31 serving as a charging unit, a laser exposure optical system 32, a developing unit 33, a transfer unit 34, a charge eliminating device 35, and a cleaning blade 36 serving as a mechanical cleaning unit. And fixing rolls 37 and 38.
[0068]
The contact charging method, which is one form of charging means, is to charge the surface of the electrophotographic photosensitive member 30 by applying a voltage to the conductive member brought into contact with the surface of the electrophotographic photosensitive member 30. The conductive member As the shape, a roll shape such as the charging roll 31 in FIG. 1, a brush shape, a blade shape, or a pin electrode shape may be used.
[0069]
The surface of the electrophotographic photosensitive member 30 is uniformly charged by the charging roll 31, and an electrostatic latent image is formed by the laser exposure optical system 32. The developing device 33 has a developer carrier 33a, and a developer layer is formed on the surface of the developer carrier 33a by the developer containing the electrostatic image developing toner of the present invention.
[0070]
The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 30 is developed with toner constituting the developer layer on the surface of the developer carrying member 33a disposed opposite to the electrophotographic photosensitive member 30, thereby forming a toner image. Is done.
[0071]
The toner image formed on the surface of the electrophotographic photosensitive member 30 is electrostatically transferred onto the paper 40 as a transfer material by the transfer unit 34 and fixed by heat and / or pressure by the fixing rolls 37 and 38.
[0072]
The electrophotographic photosensitive member 30 after the toner image on the surface is transferred has the electrostatic latent image remaining on the surface removed by the static eliminator 35, and the residual toner is further removed by a cleaning blade 36 that is a mechanical cleaning means. Is removed.
The mechanical cleaning means directly contacts the surface of the photoreceptor 30 and removes toner, paper dust, dust, and the like adhering to the surface. In addition to a blade type such as the cleaning blade 36, A known type such as a brush or a roll can be applied.
[0073]
Further, by using the developer containing the toner for developing an electrostatic charge image of the present invention as the developer, the image forming method of the present invention can realize excellent glossiness of a fixed image while enabling offset at a high temperature. It becomes.
[0074]
The specific electrophotographic image forming apparatus to which the image forming method of the present invention is applied has been described with reference to the drawings. However, the image forming apparatus to which the present invention can be applied is not limited to the above structure and form. There is no problem in any structure and form as long as the configuration of the present invention can be applied.
[0075]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited at all.
The toner for developing an electrostatic charge image of the present invention is prepared by preparing the following resin fine particle dispersion, colorant particle dispersion, and release agent particle dispersion, respectively, and mixing and stirring them at a predetermined ratio. A polymer is added and ionically neutralized to form agglomerated particles. Next, an inorganic hydroxide is added to adjust the pH in the system from weakly acidic to neutral, and then the mixture is heated to a temperature equal to or higher than the glass transition point of the resin fine particles to fuse and unite. After completion of the reaction, a desired toner is obtained through sufficient washing, solid-liquid separation, and drying processes.
Hereinafter, each preparation method is demonstrated.
[0076]
(Preparation of resin fine particle dispersion (1) for shell layer)
550 parts by mass of styrene
50 parts by mass of n-butyl acrylate
12 parts by mass of acrylic acid
18 parts by weight of dodecanethiol
The above components are mixed and dissolved to prepare a monomer solution.
On the other hand, 14 parts by mass of an anionic surfactant (manufactured by Dow Chemical Co., Ltd., Dowfax) is dissolved in 250 parts by mass of ion-exchanged water, and the above solution is added and dispersed and emulsified in a flask. (Monomer emulsion A)
Furthermore, 1 part by mass of an anionic surfactant (manufactured by Dow Chemical Co., Dowfax) is dissolved in 555 parts by mass of ion-exchanged water and charged into a polymerization flask.
The polymerization flask is sealed, a reflux pipe is installed, and the polymerization flask is heated to 85 ° C. with a water bath while being slowly stirred while injecting nitrogen.
9 parts by mass of ammonium persulfate was dissolved in 43 parts by mass of ion-exchanged water, and dropped into the polymerization flask through a metering pump over 20 minutes, and then the monomer emulsion A was again fed through the metering pump for 200 minutes. Add dropwise.
Thereafter, the polymerization flask is maintained at 85 ° C. for 3 hours while continuing the slow stirring to complete the polymerization. As a result, an anionic resin fine particle dispersion (1) for a shell layer having a fine particle center diameter of 190 nm, a glass transition point of 54.5 ° C., an oxidation of 25 mg KOH / g, and a solid content of 42% was obtained.
[0077]
(Preparation of resin fine particle dispersion (2) for shell layer)
550 parts by mass of styrene
50 parts by mass of ethyl acrylate
18 parts by mass of acrylic acid
18 parts by weight of dodecanethiol
A solution was prepared by mixing and dissolving the above components, and a resin fine particle dispersion for shell layer (2) was obtained in the same manner as the preparation of fine resin particle dispersion for shell layer (1).
As a result, an anionic resin fine particle dispersion (2) for a shell layer having a fine particle central diameter of 190 nm, a glass transition point of 62.0 ° C., an acid value of 30 mgKOH / g, and a solid content of 42% was obtained.
[0078]
(Preparation of resin fine particle dispersion (1) for core layer)
400 parts by mass of styrene
200 parts by weight of n-butyl acrylate
8 parts by mass of acrylic acid
10 parts by weight of glycidyl methacrylate
12 parts by weight of dodecanethiol
The above components are mixed and dissolved to prepare a monomer solution.
On the other hand, 12 parts by mass of an anionic surfactant (manufactured by Dow Chemical Co., Ltd., Dowfax) is dissolved in 250 parts by mass of ion-exchanged water, and the above solution is added and dispersed and emulsified in a flask. (Monomer emulsion B)
Furthermore, 1 part by mass of an anionic surfactant (manufactured by Dow Chemical Co., Dowfax) is dissolved in 555 parts by mass of ion-exchanged water and charged into a polymerization flask.
The polymerization flask is sealed, a reflux pipe is installed, and the polymerization flask is heated to 85 ° C. with a water bath while being slowly stirred while injecting nitrogen.
9 parts by mass of ammonium persulfate was dissolved in 43 parts by mass of ion-exchanged water and dropped into the polymerization flask through a metering pump over 20 minutes, and then the monomer emulsion B was added through the metering pump for 200 minutes. Add dropwise.
Thereafter, the polymerization flask is maintained at 85 ° C. for 3 hours while continuing the slow stirring to complete the polymerization.
As a result, an anionic core particle resin fine particle dispersion (1) having a fine particle center diameter of 220 nm, a glass transition point of 55.0 ° C., an acid value of 40 mg KOH / g, and a solid content of 42% was obtained.
[0079]
(Preparation of resin fine particle dispersion (2) for core layer)
Resin fine particle dispersion for core layer, except that the amount of styrene was changed to 500 parts by mass and the amount of 2-ethylhexyl acrylate was changed to 100 parts by mass instead of n-butyl acrylate in the preparation of resin fine particle dispersion (1) for core layer Prepared in the same manner as in (1) to obtain an anionic core particle resin particle dispersion (2) having a center diameter of 200 nm, a glass transition point of 50.5 ° C., an acid value of 38 mgKOH / g, and a solid content of 42%. It was.
[0080]
(Synthesis of polyester resin A)
480 parts by mass of isophthalic acid
480 parts by mass of terephthalic acid
550 parts by mass of 1,6-hexanediol
1 part by weight of dibutyltin oxide
The above substances are put into a 3 L glass four-necked flask, and a stainless steel stirring rod, a flow-down condenser and a nitrogen introduction tube are attached, and in an electric heating mantle heater at 200 ° C. for 2 hours, then 200 ° C. The reaction was carried out with stirring under reduced pressure (200 mmHg) for 1 hour. The obtained polyester resin A had an acid value of 25 mgKOH / g, a hydroxyl value of 12.5 mgKOH / g, and a glass transition temperature of 38 ° C. The weight average molecular weight (Mw) by GPC was 8500, the number average molecular weight (Mn) was 4300, and the dispersion ratio was Mw / Mn = 2.
The number average molecular weight, weight average molecular weight, and molecular weight distribution of the binder resin were measured by gel permeation chromatography (HLC802A type: manufactured by Tosoh Corporation) at a temperature of 40 ° C., a solvent tetrahydrofuran, a measurement flow rate of 1.0 ml / min, Measurement was performed with a sample concentration of 0.5%, a sample injection amount of 200 μl, and a column GMH6 (double connection). The ratio of the molecular weight peak of the low molecular weight portion to the molecular weight peak of the high molecular weight portion was obtained by separating the peaks having peaks in the molecular weight distribution at the lowest point of the valley, obtaining the respective areas, and using the ratio as the ratio.
[0081]
(Synthesis of polyester resin B)
490 parts by weight of trimellitic anhydride
425 parts by mass of isophthalic acid
1.4-cyclohexanediol 580 parts by mass
1 part by weight of dibutyltin oxide
The reaction was advanced in the same manner as the synthesis of the polyester resin A using the above substances. The obtained polyester resin B had an acid value of 30 mgKOH / g, a hydroxyl value of 10.4 mgKOH / g, and a glass transition temperature of 49 ° C. Moreover, the weight average molecular weight (Mw) by GPC was 11500, the number average molecular weight (Mn) was 6000, and the dispersion ratio was Mw / Mn = 1.9.
[0082]
(Synthesis of polyester resin C)
400 parts by mass of cyclopentanedicarboxylic acid
500 parts by mass of isophthalic acid
500 parts by mass of 1,3-butanediol
1 part by weight of dibutyltin oxide
The reaction was advanced in the same manner as the synthesis of the polyester resin A using the above substances. The obtained polyester resin C had an acid value of 15 mgKOH / g, a hydroxyl value of 8.3 mgKOH / g, and a glass transition temperature of 25 ° C. Moreover, the weight average molecular weight (Mw) by GPC was 10000, the number average molecular weight (Mn) was 4800, and the dispersion ratio was Mw / Mn = 2.1.
[0083]
(Synthesis of polyester resin D)
480 parts by mass of pyromellitic acid
480 parts by mass of terephthalic acid
500 parts by mass of 1,6-hexanediol
1 part by weight of dibutyltin oxide
The reaction was advanced in the same manner as the synthesis of the polyester resin A using the above substances. The obtained polyester resin D had an acid value of 20 mgKOH / g, a hydroxyl value of 10.1 mgKOH / g, and a glass transition temperature of 65 ° C. Moreover, the weight average molecular weight (Mw) by GPC was 14500, the number average molecular weight (Mn) was 7100, and dispersion ratio was Mw / Mn = 2.0.
[0084]
(Preparation of polyester resin dispersion (1))
50 parts by mass of polyester resin A
Anionic surfactant (Dow Fax manufactured by Dow Chemical)
5 parts by mass
200 parts by mass of ion exchange water
The components were heated to 130 ° C. and sufficiently dispersed with a homogenizer (IKA, Ultra Turrax T50), and then dispersed with a pressure discharge type homogenizer (Gorin homogenizer, Gorin), with a center diameter of 160 nm, solid A polyester resin dispersion (1) having an amount of 21.5% was obtained.
[0085]
(Preparation of polyester resin dispersion (2))
50 parts by mass of polyester resin B
5 parts by mass of aqueous ammonia
200 parts by mass of ion exchange water
Polyester resin B was heated to 180 ° C. and added to Cavitron CD1010 (Eurotech Co., Ltd.) at 50 g / min. It sent at the speed of. Next, 0.5% by mass of dilute ammonia water was heated to 160 ° C. with a heat exchanger and 1 L / min. I sent it to the Cavitron at a speed of. The rotor speed is 9000 rpm and the pressure is 7 kg / cm. ² The dispersion obtained at that time was cooled to 50 ° C. and taken out. Furthermore, it was diluted with ion exchange water to prepare a polyester resin dispersion (2) having a solid content of 20%. Further, the pH of this dispersion was 9.0.
[0086]
(Preparation of polyester resin dispersion (3))
A polyester resin C (3) having a center diameter of 170 nm and a solid content of 21.5% was obtained from the polyester resin C in the same manner as the polyester resin dispersion (1).
[0087]
(Preparation of polyester resin dispersion (4))
A polyester resin dispersion (4) having a center diameter of 165 nm and a solid content of 21.5% was obtained from the polyester resin D in the same manner as the polyester resin dispersion (1).
[0088]
(Preparation of colorant particle dispersion (1))
46 parts by mass of cyan pigment (Dainippon Ink & Chemicals, B15: 3)
4 parts by weight of anionic surfactant (Daiichi Kogyo Seiyaku, Neogen R)
200 parts by mass of ion exchange water
The above components are mixed and dissolved, pre-dispersed for 10 minutes with a homogenizer (IKA, Ultra Tarrax), and further dispersed with a sand mill for 2 hours to disperse a Cyan colorant particle having a central diameter of 135 nm and a solid content of 20.0%. (1) was obtained.
[0089]
(Preparation of colorant particle dispersion (2))
In the preparation of the colorant particle dispersion (1), it was prepared in the same manner as the colorant particle dispersion (1) except that a magenta pigment (manufactured by Dainichi Seika Co., Ltd., dimethylquinacridone PR122) was used instead of the cyan pigment. A magenta colorant particle dispersion (2) having a center diameter of 130 nm and a solid content of 20.0% was obtained.
[0090]
(Preparation of release agent particle dispersion)
Paraffin wax (Nippon Seiwa Co., Ltd., HNPO190; melting point 85 ° C)
46 parts by mass
4 parts by weight of anionic surfactant (Dow Chemical Dow Fax)
200 parts by mass of ion exchange water
The components were heated to 95 ° C. and dispersed with a homogenizer (IKA, Ultra Tarrax T50) for 1 hour, and then dispersed with a pressure discharge type homogenizer (Gorin homogenizer, Gorin), with a center diameter of 167 nm, solid A release agent particle dispersion having a content of 20.0% was obtained.
[0091]
(Preparation of toner particles 1)
Resin fine particle dispersion for core layer (1) (63 parts by mass of resin) 150 parts by mass
Polyester resin dispersion (1) (12 parts by mass of resin) 60 parts by mass
Colorant particle dispersion (1) (8.6 parts by mass of pigment) 40 parts by mass
Release agent particle dispersion (release agent 6.45 parts by mass) 30 parts by mass
Polyaluminum chloride 0.15 parts by mass
500 parts by mass of ion exchange water
After thoroughly mixing and dispersing the above components in a round stainless steel flask with a homogenizer (IKA, Ultra Turrax T50), the flask was heated to 48 ° C. with stirring in an oil bath for heating. After holding for a minute, 72 parts by mass (30.24 parts by mass of resin) of resin fine particle dispersion liquid (1) for shell layer was added and gently stirred.
Thereafter, the pH of the system was adjusted to 6.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then heated to 95 ° C. while stirring was continued.
During the temperature increase up to 95 ° C., in the usual case, the pH in the system was lowered to about 5.0 but kept as it was.
After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then solid-liquid separated by Nutsche suction filtration. And it re-dispersed in 3 liters of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This washing operation was repeated 5 times, solid-liquid separation was performed by Nutsche suction filtration, and then vacuum drying was performed for 12 hours to obtain toner particles 1.
[0092]
When the particle size of the toner particles was measured with a Coulter counter, the cumulative volume average particle size D ₅₀ Was 5.6 μm and the volume average particle size distribution index GSDv was 1.25. The shape factor SF1 of the toner particles determined from the shape observation with Luzex was 130 potato shapes.
To 50 parts by mass of the toner particles, 1.2 parts by mass of hydrophobic silica (Cabot, TS720) was added and mixed by a sample mill to obtain an externally added toner.
Then, using a ferrite carrier having an average particle diameter of 50 μm coated with 1% of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd.), the externally added toner is weighed so that the toner concentration becomes 5%. A developer was prepared by stirring and mixing for a minute.
[0093]
(Adjustment of toner particles 2)
Resin fine particle dispersion for core layer (1) (63 parts by mass of resin) 150 parts by mass
Polyester resin dispersion (2) (12 parts by mass of resin) 60 parts by mass
Colorant particle dispersion (1) (8 parts by mass of pigment) 40 parts by mass
Release agent particle dispersion (release agent 10 parts by weight) 50 parts by weight
Polyaluminum chloride 0.2 parts by mass
500 parts by mass of ion exchange water
Toner particles 2 were prepared in the same manner as in the preparation of toner particles 1 using the above-mentioned materials and using resin fine particle dispersion liquid (1) for shell layer. When the particle size of the toner particles 2 was measured with a Coulter counter, the cumulative volume average particle size D ₅₀ Was 5.8 μm and the volume average particle size distribution index GSDv was 1.26. Further, the shape factor SF1 of the toner particles obtained from the shape observation by Luzex was 128 potato shapes.
[0094]
[Example 1]
Using toner particle 1 and using a Fuji Xerox DC1250 remodeling machine, Fuji Xerox J-coated paper was used as the transfer paper, and the process speed was adjusted to 180 mm / sec, and the toner fixing property was examined. The oilless fixability by the PFA tube fixing roll was good, and it was confirmed that the image showed sufficient fixability at 130 ° C. or higher and the transfer paper was peeled off without any resistance. The surface gloss of the image at a fixing temperature of 180 ° C. was as good as 57%, both developability and transferability were good, the uniformity of the image density was high, and high chroma was exhibited. The minimum fixing temperature (130 ° C. in Example 1) was determined by image contamination by cloth rubbing of the image. Also, no hot offset was observed at a fixing temperature of 205 ° C.
The surface gloss of the image was measured using a gloss meter (Glossmeter, Gardner, Inc., Gloss Guard II, incident angle 75 °).
In order to evaluate the blocking property of the image, the image surfaces of two solid images fixed at 5 ° C. fixed at 160 ° C. face each other and overlap each other, and the image surface is 80 g / cm. ² After placing the weight so that it was loaded, left in a constant temperature bath at 60 ° C. for 48 hours, taken out and cooled, the two solid images were peeled off, but they were not adhered at all, and the image defect and gloss There was no change over time.
Further, 20 g of toner not added externally was placed in an aluminum cup, placed in a constant temperature chamber at 50 ° C., stored for 24 hours, and then taken out to confirm the caking state of the toner. However, no change was observed before storage.
[0095]
[Example 2]
In the adjustment of the toner particles 1, the resin fine particle dispersion liquid (1) for the shell layer is used as the fine resin particle dispersion liquid (2) for the shell layer, and the fine resin particle dispersion liquid for the core layer (1) is used. The toner particles were obtained in the same manner as in the adjustment of the toner particles 1 except that the toner particles were changed to
Cumulative volume average particle diameter D of the toner particles ₅₀ Was 5.6 μm, the volume average particle size distribution index GSDv was 1.18, and the shape factor SF1 was 120, which was spherical.
Using the toner particles, an externally added toner was obtained in the same manner as in the preparation of the toner particles 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0096]
[Example 3]
In the adjustment of the toner particles 1, the resin fine particle dispersion for shell layer (1) is changed to the resin fine particle dispersion for shell layer (2), and the colorant particle dispersion (1) is changed to the colorant particle dispersion (2). The toner particles were obtained in the same manner as in the adjustment of the toner particles 1 except that the pH during heating at 95 ° C. was maintained at 4.0.
Cumulative volume average particle diameter D of the toner particles ₅₀ Was 5.5 μm, the volume average particle size distribution index GSDv was 1.17, and the shape factor SF1 was 116, which was spherical.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of toner particle 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0097]
[Example 4]
When the toner particles 2 were used and evaluated in the same manner as in Example 1, the cumulative volume average particle diameter D of the toner particles was ₅₀ Was 5.5 μm, the volume average particle size distribution index GSDv was 1.20, and the shape factor SF1 was 124, which was spherical.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of toner particle 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0098]
[Example 5]
Toner particles 1 were obtained in the same manner as in the adjustment of toner particles 1 except that the polyester resin dispersion was (3).
Cumulative volume average particle diameter D of the toner particles ₅₀ Was 5.6 μm, the volume average particle size distribution index GSDv was 1.20, and the shape factor SF1 was 120, which was spherical.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of toner particle 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0099]
[Comparative Example 1]
The toner particles 1 were prepared in the same manner as the toner particles 1 except that only 200 parts by mass of the core layer resin fine particle dispersion (1) was used without adding the polyester resin dispersion (1). The accumulated volume average particle diameter D of the toner particles ₅₀ Was 5.5 μm, the volume average particle size distribution index GSDv was 1.19, and the shape factor SF1 was 126.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of toner particle 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0100]
[Comparative Example 2]
In the adjustment of the toner particles 2, instead of the core layer resin fine particle dispersion and the shell layer resin fine particle dispersion, the polyester resin dispersion was changed and the polyester resin dispersion (2) was changed to (3). 375 parts by mass for the core layer and 151 parts by mass for the shell layer were added. Except for the changes described above, the toner was converted into a toner by the same method as the adjustment of the toner particles 2, and the cumulative volume average particle diameter D of the toner particles was obtained. ₅₀ Was 5.9 μm, the volume average particle size distribution index GSDv was 1.37, and the shape factor SF1 was 133.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of the toner particle 2, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0101]
[Comparative Example 3]
When the toner particles 1 were prepared in the same manner as the toner particles 1 except that the polyester resin dispersion liquid (1) was changed to the polyester resin dispersion liquid (4), the cumulative volume average particle diameter of the toner particles was adjusted. D ₅₀ Was 5.6 μm, the volume average particle size distribution index GSDv was 1.21, and the shape factor SF1 was 128.
Using this toner particle, an externally added toner was obtained in the same manner as in the preparation of toner particle 1, and a developer was further prepared. The toner fixability was examined in the same manner as in Example 1. The composition of the toner particles is shown in Table 1, and the evaluation results are shown in Table 2.
[0102]
[Table 1]

[0103]
[Table 2]

[0104]
The evaluation criteria for the image density uniformity in Table 2 are the measurement of the density at five locations in the image area using a spectrometric densitometer (X-Rite), and the density difference between the highest density area and the lowest density area is an evaluation index for image density uniformity. It was.
○: The density difference between the highest density part and the lowest density part is less than 0.2.
Δ: The density difference between the highest density part and the lowest density part is 0.2 to 0.3.
X: The density difference between the highest density part and the lowest density part is higher than 0.3.
[0105]
The evaluation criteria for the image blocking property in Table 2 are as follows.
○: Image defect is not observed
Δ: Image defect is less than half of the image plane
×: Image loss is 1/2 or more in the image plane
[0106]
The evaluation criteria for toner caking properties in Table 2 are as follows.
○: Toner lump is not confirmed
Δ: Toner lump is less than 1/2
X: Toner lump is 1/2 or more
[0107]
【The invention's effect】
The present invention can provide an electrostatic image developing toner excellent in high-temperature offset property and glossiness of a fixed image, and a method for producing the same. Furthermore, it is possible to provide an image forming method capable of forming a fixed image having excellent gloss.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of an electrophotographic image forming apparatus to which an image forming method of the present invention is applied.
[Explanation of symbols]
30: Electrophotographic photosensitive member (latent image carrier)
31: Charging roll
32: Laser exposure optical system
33: Developer
33a: developer carrier
34: Transfer means
35: Static eliminator
36: Cleaning blade
37, 38: fixing roll
40: paper

Claims (3)

A toner for developing electrostatic images, comprising at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer. A method for producing a toner for developing an electrostatic charge image, comprising at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer,
It comprises at least an aggregating step of mixing the fine particle dispersion of the non-bisphenol polyester and the fine particle dispersion of the vinyl polymer to form aggregated particles, and a fusion step of fusing the aggregated particles by heating. A method for producing a toner for developing an electrostatic charge image. An electrostatic latent image forming step of forming an electrostatic latent image on the electrophotographic photosensitive member; a developing step of developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer to form an image; Image formation comprising: a transfer step of transferring an image formed on the electrophotographic photosensitive member to the surface of the recording medium to form a transfer image; and a fixing step of fixing the transfer image transferred to the surface of the recording medium A method,
The image forming method, wherein the developer contains a toner for developing an electrostatic image containing at least a non-bisphenol polyester having a glass transition point of 0 to 50 ° C. and a vinyl polymer.

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