JP4051018B2 - Toner for electrostatic image development - Google Patents

Description

  The present invention relates to a toner for developing an electrostatic image used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, etc., an external additive for toner contained in the toner, and the toner It relates to the manufacturing method.

  Patent Document 1 discloses a developer charging capability using an electrostatic charge image developer comprising a toner and a carrier containing hydrophobic silica having an average particle diameter of 5 to 15 nm and hydrophobic silica having an average particle diameter smaller than 5 nm. A technique for suppressing the decrease in the above is disclosed.

  Patent Document 2 contains an external additive containing a silicon compound having a number average particle size of 1 to 30 nm and a silicon compound having a number average particle size of 30 nm or more and having a number distribution peak in a specific particle size range. A technique for stabilizing the fluidity of a toner under high temperature and high humidity is disclosed.

Japanese Patent Application Laid-Open No. 9-24062 (Claim 1, [0006]) JP 11-265092 A (Claim 1, [0040], [0077])

  According to the present invention, even when an image is formed by a copying apparatus or a printer at a high temperature, the toner can flow smoothly and the image can be stably formed without filming on the roll blade. It is an object of the present invention to provide a toner for developing a charge image, an external additive for toner contained in the toner, and a method for producing the toner.

  The present inventors have found that the above problem can be achieved when a specific surface treatment is applied to silica having different particle size ranges.

That is, the present invention
(1) A toner external additive containing the first component, the second component, and the third component having the following requirements [1] to [4]:
[1] First component: BET specific surface area of 35 to 65 m ² / g and formula (I):

(Wherein R ^{1 to} R ⁶ are each independently an alkyl group having 1 to 5 carbon atoms)
Silica to which a silane coupling agent represented by formula (1) is attached, wherein the total amount of carbon in the total amount of silica is 0.7 to 3.3% by weight [2] Second component: BET specific surface area is 105 to Silica having 155 m ² / g and having a silane coupling agent represented by the formula (I) attached thereto, wherein the total amount of carbon in the total amount of silica is 1.2 to 6.0% by weight [3] Third component: BET specific surface area of 105 to 155 m ² / g and formula (II):

(Wherein, R ⁷ is an alkyl group or 1 to 5 carbon atoms chlorine atom, R ⁸ is a methyl or ethyl group, R ⁹ and R ¹⁰ are each independently EnsoHara child)
Silica to which a silane coupling agent represented by formula (1) is attached, wherein the total amount of carbon in the total amount of silica is 0.5 to 2.5% by weight [4] First component, second component and third component Component weight ratio (first component / second component / third component) = 5 to 35/5 to 35/30 to 70
(2) An electrostatic charge image developing toner containing a binder resin, a colorant, a wax and an external additive, wherein the external additive for toner according to (1) is used as the external additive. The present invention relates to a toner for developing a charge image, and (3) a method for producing a toner for developing an electrostatic image according to (2), comprising a step of melt kneading a raw material containing a binder resin, a colorant and a wax.

  The toner containing the toner external additive of the present invention adopts an oil-less fixing method because the toner flows well even at a high temperature exceeding 40 ° C. and filming on the roll blade is suppressed. Even when an image is formed at a high speed by a small copying machine, printer or the like, an excellent effect that an image can be stably formed is exhibited.

  In recent electrostatic image developing apparatuses such as copying machines and printers, an oilless fixing method has been remarkably spread in order to achieve cost reduction / miniaturization, and a demand for high speed has become normal.

  Thus, as a result of examining technical problems that occur when the apparatus is downsized, the present inventors have found that the following problems are important.

(1) If a recent downsized apparatus operates at a high speed, the temperature in the apparatus may rise to around 50 ° C. Therefore, it is necessary to maintain the fluidity of the toner under such a high temperature.
(2) When the developing roll is rotated at a high speed in order to print a toner containing a large amount of wax for oilless fixing at a high speed, filming of the wax component occurs on the blade, resulting in poor toner transportability. In some cases, particularly when the developing roll is made of a material having no elasticity such as aluminum, it is necessary to suppress this phenomenon.

  Conventionally, as a technique for stabilizing the fluidity of the toner, a method of externally adding inorganic or organic fine particles is known. However, the toner fluidity is stabilized at a high temperature exceeding 40 ° C. No external additives are designed from the viewpoint of deterring.

  The oilless fixing toner needs to contain a large amount of wax, and the wax may be exposed on the surface of the toner particles. In particular, the amount of the wax exposed on the surface of the pulverized toner tends to increase. is there.

  In the process of adhering the toner to the developing roll, the present inventors have contacted the toner surface wax with each other when the toner particles approached each other, thereby inhibiting the fluidity of the toner, or bringing the toner close to the blade surface. At this time, it was estimated that the toner filmed on the blade because the wax on the toner surface also contacted the blade surface.

  Therefore, the present inventors considered that the fluidity of the toner and the suppression of filming on the blade can be simultaneously designed by coating the toner surface with an appropriate external additive.

  The toner external additive of the present invention contains the first component, the second component, and the third component having the above requirements [1] to [4].

  The particles constituting the external additive of the present invention need to contain silica from the viewpoint of maintaining the chargeability of the toner, and the first component, the second component, and the third component are all silica. It consists of

The external additive of the present invention must contain a large particle size component from the viewpoint of preventing leakage of toner from the developing device, particularly between the developing roll and the blade. From such viewpoints, BET specific surface area of the silica particles contained as the first component is a 35~65m ² / g, preferably from ^{40~60m 2 / g, 45~55m 2 /} g is more preferable. Here, the BET specific surface area is a value measured by a method based on JIS Z8830.

Further, the external additive of the present invention needs to contain a small particle size component from the viewpoint of toner fluidity, filming suppression, and streak generation suppression. From such viewpoints, BET specific surface area of the silica particles contained as the second component and the third component is 105~155m ² / g, preferably from ^{115~145m 2 / g, 125~135m 2 /} g is more preferable.

  The particles constituting the external additive of the present invention preferably impart appropriate water repellency and slipperiness from the viewpoint of fluidity at high temperatures and suppression of filming. :

The particles to which the silane coupling agent represented by the formula (1) is attached, wherein the total amount of carbon in the total amount of the particles is 0.7 to 3.3% by weight, preferably 0.7 to 3.0% by weight, more preferably The particles need to be 0.8 to 2.8% by weight. On the other hand, the small particle size component is a particle to which the silane coupling agent represented by the formula (I) is attached, and the total carbon amount in the total amount of the particle is 1.2 to 6.0% by weight, preferably 1 From 4 to 5.5% by weight, more preferably from 1.5 to 5.0% by weight of particles of formula (II):

The particles to which the silane coupling agent represented by the formula (1) is attached, wherein the total amount of carbon in the total amount of the particles is 0.5 to 2.5% by weight, preferably 0.6 to 2.3% by weight, more preferably It is necessary that particles of 0.7 to 2.0% by weight are used in combination.

  The silane coupling agent represented by the formula (I) is effective in improving the fluidity of the particles, but the silane coupling agent represented by the formula (I) is attached to all the small particle size components. The fluidity becomes excessive and toner leakage occurs. Therefore, in the external additive of the present invention, by using particles in which the silane coupling agent represented by the formula (II) is attached to a part of the small particle size component, moderate fluidity without deteriorating filming. Can be granted.

  The total carbon amount indicating the degree of adhesion of the silane coupling agent to silica may be within the above range, and the mode of adhesion of the silane coupling agent to the silica surface may be chemical adsorption, even if it is due to chemical bonding. Alternatively, adhesion by physical adsorption or the like (see Iwanami chemistry, 4th edition, page 302) may be used. Here, the total carbon amount is a value measured by a carbon analyzer “EMIA-110 type” manufactured by Horiba.

In formula (I), R < ¹ > -R < ⁶ > is respectively independently a C1-C5 alkyl group or an alkoxy group. The number of carbon atoms of the alkyl group and alkoxy group is preferably 1 to 3, and more preferably 1 or 2, from the viewpoint of fluidity of the toner when externally added to the toner. R ^{1 to} R ⁶ may be the same or different, but are preferably all the same.

  Accordingly, examples of the silane coupling agent represented by the formula (I) used for the silica of the first component and the second component include hexamethyldisilazane, hexaethyldisilazane, hexamethoxydisilazane, hexaethoxydisilazane, and the like. Among them, hexamethyldisilazane is preferable.

In the formula (II), R ⁷ is an alkyl group having 1 to 5 carbon atoms, an alkoxy group or a chlorine atom, and an alkyl group having 1 to 5 carbon atoms is preferable from the viewpoint of reactivity with silica. R ⁸ is a methyl group or an ethyl group, and is preferably a methyl group from the viewpoint of fluidity of the toner when externally added to the toner. R ⁹ and R ¹⁰ are each independently a chlorine atom, a bromine atom or an iodine atom, and preferably a chlorine atom from the viewpoint of production cost.

  Accordingly, examples of the silane coupling agent represented by the formula (II) used for the third component silica include dichlorodimethylsilane, dichlorodiethylsilane, and trichloromethylsilane. Among these, dichlorodimethylsilane is Particularly preferred.

  In the external additive of the present invention, the weight ratio of the first component, the second component, and the third component (first component / second component / third component) prevents toner leakage due to the first component, and depends on the second component. Considering prevention of streaks on the developing roll and optimization and retention of the toner adhesion amount on the developing roll by the third component, respectively, it is 5 to 35/5 to 35/30 to 70, preferably 10 to 30. / 10-30 / 40-70, more preferably 15-25 / 15-25 / 55-65.

  The external additive of the present invention may appropriately contain other components as long as the effects of the present invention are not impaired. The content of the other component is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably 0% by weight in the total amount of the external additive of the present invention.

  The content of the external additive of the present invention in the toner is 1.5 with respect to 100 parts by weight of the toner (untreated toner) before being processed with the external additive from the viewpoint of preventing toner leakage and streaking. Part by weight or more is preferable, 1.8 parts by weight or more is more preferable, and 2.0 parts by weight or more is more preferable. Further, from the viewpoint of preventing toner leakage, it is preferably 4.5 parts by weight or less, more preferably 4.0 parts by weight or less with respect to 100 parts by weight of untreated toner. Therefore, from these viewpoints, the total content of the external additive of the present invention is preferably 1.5 to 4.5 parts by weight, more preferably 1.8 to 4.0 parts by weight, and 2.0 to 3. 5 parts by weight is more preferable.

  The present invention further provides an electrostatic charge image developing toner containing a binder resin, a colorant and a wax in addition to the external additive of the present invention.

  Examples of the binder resin include polyester, styrene-acrylic resin, a mixed resin of polyester and styrene-acrylic resin, a hybrid resin having two or more resin components, and the like, from the viewpoint of a balance between durability and transparency. Polyester is preferred.

  The content of the polyester in the binder resin is preferably 50 to 100% by weight, and more preferably 70 to 100% by weight. The hybrid resin is preferably a resin in which a condensation polymerization resin such as polyester, polyester / polyamide or polyamide and an addition polymerization resin such as vinyl polymerization resin are partially chemically bonded.

  The raw material monomer of the polyester is not particularly limited, and a known alcohol component and a known carboxylic acid component such as carboxylic acid, carboxylic acid anhydride, or carboxylic acid ester are used.

  Examples of the alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane. Bisphenol A alkylene (2 to 3 carbon atoms) oxide (average added mole number 1 to 16) adduct, ethylene glycol, propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or alkylene thereof (C2-C4) oxide (average addition mole number 1-16) adduct etc. are mentioned.

  The carboxylic acid component includes dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, adipic acid and succinic acid, alkyl groups having 1 to 20 carbon atoms such as dodecenyl succinic acid and octenyl succinic acid, or carbon. Trivalent or higher polyvalent carboxylic acids such as succinic acid, trimellitic acid and pyromellitic acid substituted with alkenyl groups of 2 to 20, anhydrides of these acids and alkyls of these acids (1 to 3 carbon atoms) ) Esters and the like. Among these, from the viewpoint of the negative chargeability of the resin, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, anhydrides of these acids and alkyls of those acids (1 carbon number) -3) Aromatic polyvalent carboxylic acid compounds such as esters are preferred, terephthalic acid, trimellitic acid, anhydrides of these acids and alkyls of those acids Number 1-3) ester is more preferred carbon.

  The content of the aromatic polyvalent carboxylic acid compound is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, and still more preferably 40 to 95 mol% in the carboxylic acid component.

  The polyester can be produced, for example, by subjecting an alcohol component and a carboxylic acid component to condensation polymerization at a temperature of 180 to 250 ° C. in an inert gas atmosphere, if necessary, using an esterification catalyst.

  The softening point of the polyester is preferably 80 to 165 ° C, and the glass transition point is preferably 50 to 85 ° C.

  In the present invention, the polyester is preferably an amorphous polyester from the viewpoint of durability. In the present invention, “amorphous” means that the ratio of the softening point to the maximum peak temperature of the heat of fusion (softening point / peak temperature) is greater than 1.3 and 4 or less, preferably 1.5-3. Say.

  Furthermore, from the viewpoint of kneading and melting by an open roll type kneader, the polyester is preferably a non-crosslinked polyester, and the content of the non-crosslinked polyester is preferably 30% by weight or more in the total amount of the polyester, and 50% by weight. % Or more is more preferable, 60% by weight or more is more preferable, and 100% by weight is particularly preferable. In the present invention, “non-crosslinked polyester” means that the total content of trivalent or higher polyvalent monomers (trivalent or higher polyhydric alcohol and / or trivalent or higher polyvalent carboxylic acid compound) is the total raw material monomer. Medium means 5 mol% or less.

  As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like can be used, and these can be used alone or in admixture of two or more. Either color toner or full color toner may be used. The content of the colorant is preferably 1 to 40 parts by weight and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  Examples of the wax include known waxes such as polypropylene wax, polyethylene wax, Fischer-Tropsch wax, and ester wax. Among these, polyethylene wax and ester wax are preferable from the viewpoint of dispersibility of the wax during toner production. Are preferred, and ester waxes are more preferred.

  The ester wax may be a natural wax such as carnauba wax, montan wax, candelilla wax, rice wax or the like, or a synthetic wax. Among these, carnauba wax is preferable.

  The melting point of the wax is preferably 60 to 100 ° C., more preferably 70 to 90 ° C., from the viewpoint of toner durability.

  The acid value of the wax is preferably 1 to 10 mgKOH / g, more preferably 1 to 8 mgKOH / g, from the viewpoint of dispersibility of the colorant and environmental characteristics.

  The content of the wax is preferably 2 to 15 parts by weight and more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the binder resin.

  The toner of the present invention is further added with a charge control agent, a fluidity improver, a conductivity modifier, an extender pigment, a reinforcing filler such as a fibrous substance, an antioxidant, an anti-aging agent, and a cleaning property improver. An agent may be appropriately contained.

  Examples of the charge control agent include a nigrosine dye, a triphenylmethane dye containing a tertiary amine as a side chain, a quaternary ammonium salt compound, a polyamine resin, a positive charge control agent such as an imidazole derivative, a metal-containing azo dye, Examples include aromatic hydroxycarboxylic acid metal complexes, copper phthalocyanine dyes, metal complexes of salicylic acid alkyl derivatives, and negatively chargeable charge control agents such as benzyl acid boron compounds, which are used independently depending on the chargeability of the toner. Or may be used as a mixture. The content of the charge control agent is preferably 0.5 to 3 parts by weight with respect to 100 parts by weight of the binder resin.

  The toner of the present invention can be produced through a step of melt-kneading a raw material containing a binder resin, a colorant, a wax and, if necessary, an additive such as a charge control agent. The melting method includes a biaxial kneading method, an open roll kneading method, etc., but it is preferable to use an open roll kneader from the viewpoint that each raw material component can be highly dispersed. Not only is it possible to contain a large amount of wax that is indispensable as a toner for less fixing, but when a charge control agent is used as a raw material, the charge control agent is highly dispersed, so that uniform charge is imparted. An excellent effect is achieved.

  The raw material used for melt-kneading is preferably a premixed binder resin, colorant, wax, charge control agent, etc. using a Henschel mixer, etc., but the colorant, wax and charge control agent are the same as the binder resin in advance. Or you may mix with another raw material in the state which melt-kneaded with dissimilar resin and processed the masterbatch.

  The open roll type kneader used in the present invention is one having at least two rolls and an open melt kneading section, and uses a kneader having at least two rolls of a heating roll and a cooling roll. It is preferable. Such an open roll type kneader can easily dissipate kneading heat generated during melt kneading. Moreover, it is preferable that an open roll type kneader is a continuous type from a viewpoint of production efficiency.

  Further, in the open roll type kneader, the two rolls are arranged close to each other in parallel, and the gap between the rolls is preferably 0.01 to 5 mm, more preferably 0.05 to 2 mm. Further, the structure, size, material, and the like of the roll are not particularly limited, and the roll surface may be any of smooth, corrugated, uneven and the like.

  The open roll kneader is preferably a two-roll kneader having two rolls with different rotational speeds. The rotation speed of the roll is preferably 2 to 100 m / min. The rotation speed of the cooling roll is preferably 2 to 100 m / min, more preferably 10 to 60 m / min, and further preferably 15 to 50 m / min. The two rolls preferably have different rotational speeds, and the ratio of the rotational speeds of the two rolls (cooling roll / heating roll) is preferably 1/10 to 9/10. ˜8 / 10 is more preferable.

  60-150 degreeC is preferable and the difference of the temperature of a heating roll and a cooling roll has more preferable 80-120 degreeC. In addition, the temperature of a roll can be adjusted with the temperature of the heat medium passed through the inside of the roll, and the inside of the roll may be divided into two or more and a heat medium having a different temperature may be passed through each roll.

  In order to make the kneaded material easily stick to the heating roll, the temperature on the raw material input side of the heating roll is higher than the softening point of the binder resin and the melting point of the wax, and the temperature of the cooling roll is the softening point of the binder resin. It is preferable that the temperature is adjusted lower than any of the melting points of the wax and the wax.

  The temperature on the raw material charging side of the heating roll is preferably higher than any of the softening point of the binder resin and the melting point of the wax, and is preferably 0 to 80 ° C. higher than the higher temperature. It is preferably 5 to 50 ° C., particularly preferably. Further, the temperature of the cooling roll is preferably lower than any of the softening point of the binder resin and the melting point of the wax, more preferably 0 to 80 ° C. lower than the lower one of the temperatures, It is particularly preferable that the temperature is 40 to 80 ° C.

  After the melt-kneading, it is preferable that the obtained kneaded product is cooled until reaching a pulverizable hardness, if necessary, and then mechanically pulverized in the pulverization step. In the pulverization process, a mechanical pulverizer such as a collision plate pulverizer, a turbo mill, a kryptron type, or the like can be used. Among these, from the viewpoint of the adhesion of silica during the external additive treatment, the collision A plate grinder is preferred.

  After the pulverization step, toner can be obtained by classification as necessary. The volume average particle of the toner of the present invention is preferably 3 to 15 μm.

  The external additive of the present invention can be added to the coarsely pulverized product obtained at the toner production stage or the surface of the toner using a Henschel mixer or the like. The external additive to be added may be added in advance by mixing the first component, the second component and the third component, or each component may be added separately.

  The toner containing the external additive of the present invention may be manufactured by any manufacturing method such as a spray drying method, a microcapsule method, and a polymerization method in addition to the mechanical pulverization method. From the viewpoint of silica adhesion during the treatment, a toner produced by a mechanical pulverization method is preferred.

  When the toner of the present invention contains a magnetic fine powder, it is used alone as a developer, and when it does not contain a magnetic fine powder, it is used as a non-magnetic one-component developing toner or mixed with a carrier to develop a two-component system. The developing agent is not particularly limited and can be used in any developing method. From the viewpoint of preventing filming on the charging blade and streaking on the developing roll, the toner of the present invention is a non-magnetic one component. It can be particularly suitably used as a developing toner.

[Total carbon content]
The amount of carbon in the sample is measured using a carbon analyzer “EMIA-110 type” (manufactured by Horiba Seisakusho).

[Softening point]
Measured according to ASTM E28-67.

[Acid value and hydroxyl value]
It is measured by the method of JIS K0070.

[Maximum heat melting temperature, glass transition point and melting point]
Using a differential scanning calorimeter (Seiko Denshi Kogyo Co., Ltd., DSC210), the temperature was raised to 200 ° C., and a sample cooled from that temperature to 0 ° C. at a temperature lowering rate of 10 ° C./min was measured at a temperature rising rate of 10 ° C./min. And determine the maximum peak temperature of the heat of fusion. Note that the maximum peak temperature is the melting point for wax. Further, the glass transition point is defined as the temperature at the intersection of an extended line of the baseline below the maximum peak temperature in the amorphous resin and a tangent showing the maximum slope from the peak rising portion to the peak apex.

Resin production example 1
10800 g of propylene oxide adduct of bisphenol A (average addition mol number: 2.2 mol), 4300 g of ethylene oxide adduct of bisphenol A (average addition mol number: 2.0 mol), 5040 g of terephthalic acid and n-dodecenyl succinic anhydride 700 g was stirred at 230 ° C. in a nitrogen atmosphere, and when the water produced by the reaction stopped flowing out, 2112 g of trimellitic anhydride was added and reacted until the softening point reached 147 ° C. The obtained resin is designated as polyester A. Polyester A had a softening point of 147 ° C., a glass transition point of 74 ° C., a maximum peak temperature of heat of fusion of 81 ° C., an acid value of 25 mgKOH / g, and a hydroxyl value of 26 mgKOH / g.

Resin production example 2
12250 g of propylene oxide adduct of bisphenol A (average addition mole number: 2.2 mol), 21125 g of ethylene oxide adduct of bisphenol A (average addition mole number: 2.0 mol), 14940 g of terephthalic acid and 15 g of dibutyltin oxide, The mixture was stirred at 230 ° C. in a nitrogen atmosphere until the softening point reached 121 ° C. The obtained resin is designated as polyester B. Polyester B had a softening point of 121 ° C, a glass transition point of 66 ° C, a maximum peak temperature of heat of fusion of 71 ° C, an acid value of 3.4 mgKOH / g, and a hydroxyl value of 23.4 mgKOH / g.

Examples 1-4 and Comparative Examples 1-11
2880 g of polyester A, 4320 g of polyester B, 288 g of colorant “Pigment Blue 15: 3” (manufactured by Dainichi Seika Kogyo Co., Ltd.), 15 g of colorant “Pigment Green 7” (manufactured by Dainichi Seika Kogyo Co., Ltd.), charge control The agent “LR-147” (manufactured by Nippon Carlit Co., Ltd.) and a hydroxy acid ester-containing mold release agent “Carnauba wax C1” (obtained from Hiroyuki Kato, melting point: 88 ° C.) 504 g were put into a Henschel mixer, The mixture was stirred for 15 minutes to obtain a mixture. The obtained mixture was melt-kneaded using an open roll type continuous kneader to obtain a kneaded product.

  The open roll type continuous kneader used has a roll outer diameter of 0.14 m and an effective roll length of 0.8 m, and the operating conditions are a heating roll (front roll) rotational speed of 33 m / min and a cooling roll (rear roll) The rotation speed of the roll was 11 m / min, and the roll gap was 0.1 mm. The heating and cooling medium temperatures in the roll are 150 ° C. on the raw material input side of the heating roll, 115 ° C. on the kneaded material discharge side, 35 ° C. on the raw material input side of the cooling roll, and the kneaded material discharge side. Was set to 30 ° C.

  The kneaded product is roughly crushed in a rotoplex, and the coarsely pulverized product is further pulverized and classified using a collision plate type pulverizer (IDS-2 type, manufactured by Nippon Pneumatic Industry Co., Ltd.) and a dispersion separator to obtain a volume average particle. An untreated toner having a particle size of about 8.0 μm was obtained.

  The used amount of external additive shown in Table 1 was added to 100 parts by weight of the obtained untreated toner, and the mixture was mixed with a Henschel mixer at 3000 r / min for 10 minutes to obtain a cyan toner.

Test example
(1) 210 g of toner is put into a developer (manufactured for BEAMSTAR 4120 for Hitachi) manufactured by Hitachi, Ltd., and is not set in the printer, and the developing roll is kept at room temperature (25 ° C.) for 2 hours at a rotation speed of 320 r / min. Rotated under environment.
The following evaluation criteria were observed by visually observing the state of toner adhesion to the developing roll after 1 minute (initial) from the start of rotation and the end of rotation, as well as the occurrence of streaks on the developing roll and the state of toner leakage after the rotation. Evaluated according to. The results are shown in Table 1.

(2) The developing roll was placed in a constant temperature bath at 50 ° C., and the same test was performed in a high temperature (50 ° C.) environment. The results are shown in Table 1. However, the observation of the adhesion state of the toner to the developing roll 1 minute after the start of rotation (initial stage) is not performed.

[Evaluation criteria for filming occurrence]
○: The developing roll cannot be seen at all (filming does not occur and the toner supply is normal)
Δ: Slightly developing roll can be confirmed from the toner layer (development density is not affected, but filming is slightly occurring)
X: A state where the developing roll is clearly exposed (filming occurs and toner supply is reduced)

[Evaluation criteria for streaks]
○: Within 1 △: 2 to 3 ×: 3 or more

[Evaluation criteria for toner leakage]
○: No toner leakage from between the developing roll and the blade.
Δ: Toner slightly leaks from between the developing roll and the blade.
X: The toner leaked from between the developing roll and the blade is slightly accumulated.

  From the above results, it can be seen that in the example, the fluidity is not impaired in both the room temperature environment and the high temperature environment, the occurrence of filming is suppressed, and the toner having the streak prevention and the toner leakage prevention is obtained. .

  The toner for developing an electrostatic image containing the external additive of the present invention is suitably used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like.

Claims (5)

An external additive for toner containing a first component, a second component, and a third component having the following requirements [1] to [4].
[1] First component: BET specific surface area of 35 to 65 m ² / g and formula (I)

(Wherein R ^{1 to} R ⁶ are each independently an alkyl group having 1 to 5 carbon atoms)
Silica to which a silane coupling agent represented by formula (1) is attached, wherein the total amount of carbon in the total amount of silica is 0.7 to 3.3% by weight [2] Second component: BET specific surface area is 105 to Silica having 155 m ² / g and having a silane coupling agent represented by the formula (I) attached thereto, wherein the total amount of carbon in the total amount of silica is 1.2 to 6.0% by weight [3] Third component: BET specific surface area of 105 to 155 m ² / g and formula (II):

(Wherein, R ⁷ is an alkyl group or 1 to 5 carbon atoms chlorine atom, R ⁸ is a methyl or ethyl group, R ⁹ and R ¹⁰ are each independently EnsoHara child)
Silica to which a silane coupling agent represented by formula (1) is attached, wherein the total amount of carbon in the total amount of silica is 0.5 to 2.5% by weight [4] First component, second component and third component Component weight ratio (first component / second component / third component) = 5 to 35/5 to 35/30 to 70   An electrostatic charge image developing toner containing a binder resin, a colorant, a wax, and an external additive, wherein the external additive contains the toner external additive according to claim 1 as the external additive. toner.   The method for producing a toner for developing an electrostatic charge image according to claim 2, further comprising a step of melt-kneading a raw material containing a binder resin, a colorant and a wax.   The manufacturing method of Claim 3 which performs a melt-kneading process using an open roll-type kneader.   The manufacturing method of Claim 3 or 4 which has the process of grind | pulverizing the obtained melt-kneaded material mechanically after melt-kneading.