JP4597031B2 - Replenishment developer and development method - Google Patents

Description

  The present invention relates to a replenishment developer and a developing method used in an electrophotographic system, an electrostatic recording system, and an electrostatic printing system.

  In the electrophotographic method, a uniformly charged image forming body is exposed to light to form a latent image, the latent image is developed into a toner image, and then the toner image is transferred to a transfer material such as recording paper. Is done. When the transfer material carrying the toner image passes through the fixing device, the toner is fixed on the transfer material. In developing a latent image, a one-component or two-component development method is used, and the development method is adopted in accordance with these characteristics. The two-component development method is said to be excellent in high image quality and high durability.

  In the normal two-component development method, the toner in the developing device is consumed, and the replenishment of the shortage is performed with new toner, but the carrier is used continuously, so the development characteristics are deteriorated due to the deterioration of the carrier. There is a problem that the operation of periodically changing the developer in the developing device occurs. In response to this technical problem, a proposal has been made to replenish the replenishment toner and carrier at a fixed ratio, gradually replace the carrier in the developing device, whose development performance has deteriorated, with a new carrier, and eliminate these maintenance work. (For example, refer to Patent Document 1).

  However, in the developing method described in Patent Document 1, since the replenishment developer containing the carrier is replenished, there is a problem in the mixing property between the developer in the developing device and the replenishment developer. For example, when the mixing property is deteriorated, the charge amount of the developer may be uneven, and the development characteristics may be deteriorated.

  In recent years, with the development of IT, there is a demand for means for outputting further high-definition images such as lowercase letters, photographs or color originals in a wide range of fields from offices to homes. Heavy users are demanding performance (high durability) that does not deteriorate image quality even when a large number of copies or prints are made. In addition, small offices and homes are required to provide high-quality images, and from the viewpoint of space saving, downsizing the device, reusing waste toner or adopting a waste tonerless system, and energy saving There is a demand for a lower fixing temperature. Furthermore, there is a strong demand for outputting transfer images to various transfer materials (media), and various studies have been conducted from various viewpoints in order to achieve these objects.

  The mainstream of electrophotographic process development systems that output full-color images has shifted from rotary development systems to tandem development systems in which a plurality of photosensitive drums that can easily cope with higher speeds are arranged. The tandem development system is a system that performs batch transfer onto a transfer material using an intermediate transfer member or the like, and enables image output to various media. Parts in the tandem development system are miniaturized, and a cleanerless system has been proposed in order to miniaturize the apparatus itself. Of course, the developer used in the tandem development system also needs to cope with high image quality, high speed, high durability, and downsizing.

  Therefore, a resin-impregnated ferrite carrier produced by impregnating a porous ferrite core material with 5 to 25% by mass of resin instead of a conventional iron powder carrier or ferrite carrier (see, for example, Patent Document 2) or a magnetic material A magnetic material-dispersed resin carrier in which fine particles are dispersed in a binder resin has been proposed (see, for example, Patent Document 3).

  The resin-impregnated ferrite carrier has a high resin content and a low specific gravity. Therefore, if the particle size distribution is appropriately controlled, it can be a carrier for a two-component developer that is excellent in durability and can form high-quality images. . However, there is a tendency that irregularly shaped particles due to generation of fine powder or coalescence of carriers are likely to exist.

  On the other hand, the magnetic substance-containing resin carrier has a sharper particle size distribution than the resin-impregnated ferrite carrier, and is particularly easy to spheroidize because it is produced by a polymerization method. Therefore, it is suitably used as a means for improving image quality. Further, since the true specific gravity is small, it is advantageous for toner spent and has the advantage of excellent durability.

  However, especially in a system using an intermediate transfer body, non-spherical carrier particles are fragile and more likely to adhere to the surface of the photoreceptor. When the magnetic material or broken particles adhere to the surface of the photosensitive member, the intermediate transfer member is scratched, resulting in poor superimposition of the toner image on the intermediate transfer member, and image defects are likely to become more prominent.

  Therefore, there is a proposal to improve the chargeability, durability, ability to prevent carrier adhesion, etc. by coating the carrier surface with a resin containing fine powder and controlling the amount of fine powder contained in the resin and the strength of magnetization. (For example, refer to Patent Document 4).

Japanese Patent Publication No. 2-21591 JP 2003-156877 A Japanese Patent No. 3284488 JP 2002-91090 A

  It is an object of the present invention to provide a two-component development method in which a developer for replenishment containing at least a toner and a magnetic carrier is developed while being replenished to a developing device, and at least the excess carrier in the developing device is discharged from the developing device. In the developer for replenishment for use, the developer for replenishment in which the developer in the developer and the developer for replenishment are efficiently mixed in the developing unit, and high durability and high image quality can be obtained, and It is to provide a developing method.

  As a result of intensive studies, the present inventors have found that the developer in the developer and the developer for replenishment are efficiently used in the developer by using the developer for replenishment containing a specific toner and carrier. It was found that high durability and high image quality can be obtained by mixing well.

That is, the above object can be achieved by using the replenishment developer and the developing method described in the following (1) to ( 5 ).

(1) To be used in a two-component developing method in which a developer for replenishment containing at least a toner and a magnetic carrier is developed while being replenished to the developing device, and at least the excess carrier inside the developing device is discharged from the developing device. Developer for replenishment,
The replenishment developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the magnetic carrier,
The toner is
i) obtained by an emulsion aggregation method obtained through a process of agglomerating at least polymer fine particles and colorant fine particles to form a fine particle aggregate and an aging step of causing fusion between the fine particles of the fine particle aggregate. Yes,
ii) The weight average diameter (D4) is 3.0 μm to 11.0 μm,
iii) The proportion of particles having an equivalent circle diameter of 0.6 μm to 2.0 μm is 30% by number or less,
iv) The average circularity of particles having an equivalent circle diameter of 2.0 μm or more is 0.940 to 0.985,
The magnetic carrier is
i) 50% particle size (D50) based on volume distribution is 15 to 70 μm,
ii) The true specific gravity is 2.5 to 4.2 g / cm ³ ,
iii) Ri 1000 / 4π (kA / m is 40 to 70 Am ² / kg der intensity of magnetization under the magnetic field),
iv) The replenishing developer , wherein the magnetic carrier has an average circularity of 0.850 to 0.950 and contains 90% by number or more of particles having a circularity of 0.80 or more .

( 2 ) The molecular weight distribution measured by gel permeation chromatography (GPC) of the THF soluble matter in the toner has a main peak in the region of molecular weight 10,000 to 100,000 (1) The developer for replenishment according to (4 ) .

( 3 ) The developer for replenishment according to any one of (1) and (2) , wherein the polymer fine particles contain at least a styrene copolymer.

( 4 ) Any one of (1) to ( 3 ), wherein the magnetic carrier is a magnetic substance-containing resin carrier obtained by polymerizing a monomer for forming a binder resin in the presence of a magnetic substance. The developer for replenishment according to 1.

( 5 ) A developing method in which a developer for replenishment containing toner and a magnetic carrier is developed while being replenished to the developing device, and the excess carrier inside the developing device is discharged from the developing device, ( 4 ) A developing method using the developer for replenishment according to any one of ( 4 ).

  By using the replenishment developer and the development method of the present invention, the developer in the developer and the replenishment developer can be efficiently mixed in the developing unit, and high durability and high image quality can be obtained. . Specifically, for a long period of time, there is little fluctuation in the chargeability of the toner, dot reproducibility is good, and an image with little fogging can be obtained.

  The replenishment developer of the present invention is characterized by containing at least a toner and a magnetic carrier. As a result, it is possible to maintain the performance of the developer in the developing unit by supplying toner and new carrier to the developing unit and discharging at least the excess carrier from the developing unit.

  The replenishment developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the magnetic carrier. By using a replenishment developer having a blending ratio in this range, it is possible to maintain stable developer performance over a long period of time, there is little variation in toner charging property, dot reproducibility is good, and fogging Fewer images can be obtained.

  When the blending ratio of the toner is less than 2 parts by mass, the amount of toner to be replenished becomes relatively small, the charge amount of the toner becomes uneven, and image defects such as white streaks occur. When the amount exceeds 50 parts by mass, the carrier replenishment effect is difficult to be obtained, the performance of the developer is lowered, the durability is deteriorated, the dot reproducibility is also deteriorated, and the fog is increased.

  The toner used in the replenishment developer of the present invention includes at least a step of agglomerating polymer fine particles and colorant fine particles to form a fine particle aggregate and a ripening step of causing fusion between the fine particles of the fine particle aggregate. It is obtained by the obtained emulsion aggregation method.

  As the polymer used for the polymer fine particles, known resins are used. For example, homopolymers of styrene derivatives such as polystyrene and polyvinyltoluene; styrene-propylene copolymers, styrene-vinyltoluene copolymers, Styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylamino acrylate Ethyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-octyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer Coalescence, styrene-vinylmethyl -Ter copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester Styrene copolymer such as copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin Terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, and aromatic petroleum resin. These resins may be used alone or in combination.

  Among these, a polymer preferably used for the polymer fine particles of the present invention is a resin having a styrene copolymer and a polyester unit.

  The following are mentioned as a polymerizable monomer used for a styrene-type copolymer. For example, styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p- tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, Styrene and its derivatives such as 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; and styrene and derivatives thereof such as butadiene and isoprene. Saturated polyenes; vinyl chloride, vinylidene chloride, vinyl bromide, fluorine Vinyl halides such as vinyl; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-methacrylate Α-methylene aliphatic monocarboxylic acid esters such as octyl, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate Propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-acrylate Acrylic esters such as lorethyl and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole; N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

  In addition, unsaturated dibasic acids such as maleic acid, citraconic acid, itaconic acid, alkenyl succinic acid, fumaric acid, mesaconic acid; maleic anhydride, citraconic anhydride, itaconic anhydride, alkenyl succinic anhydride, etc. Unsaturated dibasic acid anhydride; maleic acid methyl half ester, maleic acid ethyl half ester, maleic acid butyl half ester, citraconic acid methyl half ester, citraconic acid ethyl half ester, citraconic acid butyl half ester, itaconic acid methyl half ester, Alkenyl succinic acid half ester, fumaric acid methyl half ester, mesaconic acid methyl half ester unsaturated dibasic acid half ester; dimethylmaleic acid, dimethyl fumaric acid unsaturated dibasic acid ester; acrylic acid, meta Α, β-unsaturated acids such as rillic acid, crotonic acid and cinnamic acid; α, β-unsaturated acid anhydrides such as crotonic acid anhydride and cinnamic acid anhydride, the α, β-unsaturated acid and lower fatty acids And monomers having a carboxyl group such as alkenylmalonic acid, alkenylglutaric acid, alkenyladipic acid, acid anhydrides and monoesters thereof.

  Further, acrylic acid or methacrylic acid esters such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate; 4- (1-hydroxy-1-methylbutyl) styrene, 4- (1-hydroxy-1) -Methylhexyl) Monomers having a hydroxy group such as styrene.

In the present invention, a resin having a polyester unit is also preferably used.
The above-mentioned “polyester unit” means a part derived from polyester. Specifically, as a component constituting the polyester unit, a divalent or higher alcohol monomer component and a divalent or higher carboxylic acid, a divalent or higher valent acid, Examples include acid monomer components such as carboxylic acid anhydrides and divalent or higher carboxylic acid esters.

  For the toner used in the present invention, a resin having a polycondensation portion using a component constituting these polyester units as a part of a raw material can be used.

  For example, as a dihydric or higher alcohol monomer component, specifically, as a dihydric alcohol monomer component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene ( 3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -poly Alkylene oxide adducts of bisphenol A such as oxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, Ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1, -Propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol , Polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.

  Examples of the trivalent or higher alcohol monomer component include sorbit, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.

  Divalent carboxylic acid monomer components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof; And succinic acid substituted with an alkyl group or alkenyl group having 6 to 18 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid, or anhydrides thereof.

  Examples of the trivalent or higher carboxylic acid monomer component include trimellitic acid, pyromellitic acid, polyvalent carboxylic acid such as benzophenone tetracarboxylic acid and its anhydride, and the like.

  Examples of other monomers include polyhydric alcohols such as oxyalkylene ethers of novolak type phenol resins.

  The polymer fine particles used in the present invention may be fine particles emulsified and dispersed in an aqueous solvent. The polymer fine particles obtained by emulsion polymerization of the above polymerizable monomer, or a polymer polymerized in advance. The emulsified fine particles are preferably emulsified and dispersed.

  As the surfactant used in emulsion polymerization and emulsion dispersion, at least one selected from known cationic surfactants, anionic surfactants, and nonionic surfactants can be used. Two or more of these surfactants may be used in combination. Among these, it is particularly preferable to mainly use an anionic surfactant.

  Specific examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and the like. Specific examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, and the like. Further, specific examples of the nonionic surfactant include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose, and the like. Can be mentioned.

  As the polymerization initiator, persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate, and redox initiators combining these persulfates as a component with a reducing agent such as acidic sodium sulfite, hydrogen peroxide, Water-soluble polymerization initiators such as 4,4'-azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, and the like, and a reducing agent such as ferrous salt, which contains these water-soluble polymerizable initiators as one component; A combined redox initiator system, benzoyl peroxide, 2,2'-azobis-isobutyronitrile, and the like are used. These polymerization initiators may be added to the polymerization system before, simultaneously with the addition of the monomer, or after the addition, and these addition methods may be combined as necessary.

  In addition, a known chain transfer agent can be used as necessary. Specific examples of such a chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropyl xanthogen, carbon tetrachloride, Examples include trichlorobromomethane, octanethiol, stearylthiol and the like. The chain transfer agent may be used alone or in combination of two or more.

  Moreover, you may use the following crosslinking agents for molecular weight adjustment of a polymer.

  Examples of the crosslinking agent include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; diacrylate compounds linked by an alkyl chain such as ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1, Examples include 4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate, and methacrylates in which the acrylates of the above compounds are replaced by methacrylates; Examples of the diacrylate compounds linked by a chain include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, and polyethylene glycol. Examples include 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and those obtained by replacing the acrylate of the above compound with methacrylate; as diacrylate compounds linked by a chain containing an aromatic group and an ether bond. For example, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the above compounds The thing which replaced the acrylate with the methacrylate is mentioned.

  Polyfunctional cross-linking agents include pentaerythritol triacrylate, trimethylol ethane triacrylate, trimethylol propane triacrylate, tetramethylol methane tetraacrylate, oligoester acrylate, and acrylates of the above compounds replaced with methacrylate; triallylcia Examples include nurate and triallyl trimellitate.

  As the colorant used for the colorant fine particles, known dyes and / or pigments are used. Although the pigment alone may be used, it is more preferable from the viewpoint of the image quality of the full-color image to improve the sharpness by using the dye and the pigment together. These colorant fine particles are obtained by emulsifying and dispersing in the resin component using the surfactant.

  Examples of the color pigment for magenta toner include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48: 2, 48: 3, 48: 4, 49, 50, 51, 52, 53, 54, 55, 57: 1, 58, 60, 63, 64, 68, 81: 1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, C.I. I. Pigment violet 19, C.I. I. Bat red 1, 2, 10, 13, 15, 23, 29, 35, etc. are mentioned.

  Examples of the magenta toner dye include C.I. I solvent red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C.I. I. Disper thread 9, C.I. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, C.I. I. Basic dyes such as basic violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28 may be mentioned.

Examples of the color pigment for cyan toner include C.I. I. Pigment Blue 1, 2, 3, 7, 15: 2, 15: 3, 15: 4, 16, 17, 60, 62, 66; I. Bat Blue 6, C.I. I. Examples thereof include Acid Blue 45 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on a phthalocyanine skeleton having a structure represented by the following formula (1).

  Examples of the colored pigment for yellow include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal compounds, methine compounds, and allylamide compounds. Specifically, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 155, 168, 174, 180, 181, 185, 191, C.I. I. Bat yellow 1, 3, 20 and the like. In addition, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6 and Solvent Yellow 162 can also be used.

  As the black colorant, carbon black, iron oxide, and those which are toned in black using the yellow / magenta / cyan colorant shown above can be used.

  In the toner of the present invention, fine particles obtained by emulsifying and dispersing wax can be used in addition to the polymer fine particles and the colorant fine particles.

  Examples of the wax used include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax. Oxides of these, or block copolymers thereof; some waxes based on fatty acid esters such as carnauba wax, behenyl behenate wax, montanate wax, and fatty acid esters such as deoxidized carnauba wax Or what deoxidized all is mentioned. In addition, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brandic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; polyhydric alcohols such as sorbitol; fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid; and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, Esters of alcohols such as merisyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bis stearic acid amide, ethylene biscapric acid Saturated fatty acid bisamides such as amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N ′ dioleyl adipic acid amide, N, N ′ dioleyl Unsaturated fatty acid amides such as sebacic acid amides; Aromatic bisamides such as m-xylene bisstearic acid amide and N, N ′ distearyl isophthalic acid amides; calcium stearate, calcium laurate, zinc stearate, magnesium stearate, etc. Aliphatic metal salts (generally referred to as metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides and many others Price Lumpur partial ester; methyl ester compounds having hydroxyl groups obtained by and hydrogenated vegetable oils and the like.

  Examples of the wax particularly preferably used in the present invention include aliphatic hydrocarbon waxes and esterified products which are esters of fatty acids and alcohols. For example, low molecular weight alkylene polymer obtained by radical polymerization of alkylene under high pressure with Ziegler catalyst or metallocene catalyst under low pressure; alkylene polymer obtained by thermally decomposing high molecular weight alkylene polymer; synthesis containing carbon monoxide and hydrogen A synthetic hydrocarbon wax obtained from the distillation residue of hydrocarbons obtained from the gas by the age method or by hydrogenating them is preferred. Further, those obtained by fractionating hydrocarbon wax by press sweating, solvent method, vacuum distillation or fractional crystallization are more preferably used. The hydrocarbon as a base is synthesized by the reaction of carbon monoxide and hydrogen using a metal oxide catalyst (mostly two or more multi-component systems) [for example, the Jintol method, the Hydrocol method (the fluidized catalyst bed Hydrocarbon compounds synthesized by use); hydrocarbons with up to several hundred carbon atoms obtained by the age method (using the identified catalyst bed) from which a large amount of wax-like hydrocarbons can be obtained; alkylene such as ethylene by Ziegler catalyst Polymerized hydrocarbons are preferred because they are linear hydrocarbons with little branching, small and long saturation. In particular, a wax synthesized by a method that does not rely on polymerization of alkylene is also preferred from its molecular weight distribution. Paraffin wax is also preferably used.

  Further, the wax used for the toner has a peak temperature of a maximum endothermic peak existing in a temperature range of 30 to 200 ° C. in an endothermic curve at the time of temperature rise measured by a differential scanning calorimetry (DSC) apparatus. It is preferable to be in the range of ° C. More preferably, it is in the range of 65 to 105 ° C, and particularly preferably in the range of 65 to 100 ° C.

  When the peak temperature of the maximum endothermic peak of the wax is in the range of 60 to 110 ° C., moderate fine dispersibility in the toner particles can be achieved, which is preferable in order to exhibit the effects of the present invention. On the other hand, when the peak temperature of the maximum endothermic peak is less than 60 ° C., the blocking resistance of the toner deteriorates. Conversely, when the peak temperature of the maximum endothermic peak exceeds 110 ° C., the fixability tends to deteriorate.

  The number average particle size of these emulsified dispersed fine particles (polymer fine particles, colorant fine particles, wax dispersed fine particles) is preferably 0.05 to 3 μm, more preferably 0.1 to 1 μm, and particularly preferably 0.1 to 0. 5 μm. The number average particle diameter can be measured using a fine particle measuring apparatus (for example, UPA manufactured by Microtrack). If the particle size is smaller than 0.05 μm, it is difficult to control the aggregation rate, which is not preferable. On the other hand, if the particle size is larger than 3 μm, the particle size of the toner obtained by agglomeration becomes too large, so that it is unsuitable for applications requiring high resolution as a toner.

  These emulsified and dispersed fine particles can be aggregated by adding an aggregating agent such as an electrolyte to the emulsified dispersion while stirring as necessary, and further heating to form fine particle aggregates.

The flocculant used may be either an organic salt or an inorganic salt, but a monovalent or divalent or higher polyvalent metal salt is preferably used. Specific examples of such salts include NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) _{3 and the} like.

  In adding the flocculant, the temperature of the mixed dispersion is preferably kept at 40 ° C. or lower. When an electrolyte is added under conditions where the temperature exceeds 40 ° C., rapid aggregation occurs, which may make it difficult to control the particle size, and the bulk density of the obtained particles may be problematic. Thereafter, the mixture is heated to produce aggregated particles. Stirring may be carried out in a reaction tank having a conventional well-known stirrer such as a paddle wing, squid wing, three receding wings, Max blend wing, full zone wing, double helical, etc., homogenizer, homomixer, Henschel mixer, etc. Can also be used.

  The particle size growth by the aggregation process is carried out until particles having substantially the same size as the toner particles are obtained, but can be controlled relatively easily by adjusting the pH and temperature of the dispersion. The value of pH varies depending on the type and amount of emulsifier used and the target particle size of the toner, so it cannot be uniquely defined. However, when an anionic surfactant is mainly used, the pH is usually 2 to 6, and the cationic surface activity. When the agent is used, a pH of about 8 to 12 is usually used.

Next, the aging process will be described.
The toner of the present invention can be obtained after the step of forming the fine particle aggregate, followed by a aging step for causing fusion between the fine particles of the fine particle aggregate.
That is, following the agglomeration step, in order to increase the stability of the fine particle aggregate obtained in the agglomeration step, the agglomerated particles are held for a predetermined time at a temperature higher than the glass transition temperature (Tg) of the polymer primary particles. Fusion can occur between them. The aging step can be performed using a stirrer similar to the stirrer used in the aggregation step.

  The toner particles obtained through each of the above steps are obtained by solid-liquid separation according to a known method, collecting the toner particles, and then washing and drying the toner particles as necessary.

  In addition, a known charge control agent can be used for the toner of the present invention in order to stabilize the chargeability. The charge control agent varies depending on the type of charge control agent and the physical properties of other toner constituent materials, but generally 0.1 to 10 parts by mass per 100 parts by mass of the resin is preferably contained in the toner. It is more preferable that -5 mass parts is contained. As such a charge control agent, there are known one that controls the toner to be negatively charged and one that controls the toner to be positively charged. One or two kinds of various kinds of charge control agents are used depending on the kind and use of the toner. The above can be used.

  Examples of the negatively chargeable charge control agent include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds having sulfonic acid or carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixes. Arene etc. can be used. As the positively chargeable charge control agent, a quaternary ammonium salt, a polymer compound having a quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, or the like can be used. The charge control agent may be added internally or externally to the toner.

  In particular, the charge control agent is preferably an aromatic metal carboxylic acid compound that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount.

  In the present invention, for the purpose of improving the performance of the toner, external additives such as a fluidizing agent, a transfer aid, and a charge stabilizer can be mixed with the toner particles using a mixer such as a Henschel mixer. .

  As the fluidizing agent, any fluidizing agent can be used as long as it can increase the fluidity before and after the addition. For example, fluorinated resin powder such as vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, titanium oxide fine powder, alumina fine powder, wet process silica, fine process silica such as dry process silica, silane compound, and organic Examples include treated silica that has been surface-treated with a silicon compound, a titanium coupling agent, silicone oil, and the like.

For example, the dry process silica is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is called dry process silica or fumed silica, and is manufactured by a conventionally known technique. For example, a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen tank is used, and the basic reaction formula is the following formula (2).
(2): SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. . The particle size is preferably within the range of 0.001 to 2 μm as the average primary particle size, and particularly preferably, silica fine powder within the range of 0.002 to 0.2 μm is used.

  In the case of titanium oxide fine powder, fine particles of titanium oxide obtained by low-temperature oxidation (thermal decomposition, hydrolysis) of sulfuric acid method, chlorine method, volatile titanium compounds such as titanium alkoxide, titanium halide and titanium acetylacetonate are used. As the crystal system, any of anatase type, rutile type, mixed crystal type thereof, and amorphous type can be used.

  And if it is alumina fine powder, buyer method, improved buyer method, ethylene chlorohydrin method, underwater spark discharge method, organoaluminum hydrolysis method, aluminum alum pyrolysis method, ammonium aluminum carbonate pyrolysis method, aluminum chloride flame Alumina fine powder obtained by a decomposition method is used. As the crystal system, α, β, γ, δ, ξ, η, θ, κ, χ, ρ type, mixed crystal type, amorphous type, α, δ, γ, θ, mixed crystal can be used. A mold or an amorphous material is preferably used.

  More preferably, the surface of the fine powder is subjected to a hydrophobic treatment with a coupling agent or silicone oil.

  The method of hydrophobizing the surface of the fine particles is a method of chemically or physically treating with an organosilicon compound that reacts or physically adsorbs with the fine particles.

  A preferable method for the hydrophobic treatment is a method in which silica fine particles produced by vapor phase oxidation of a silicon halogen compound are treated with an organosilicon compound. Examples of organosilicon compounds used in such methods are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane. , Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyl Dimethylpolysiloxane containing 2 to 12 siloxane units per molecule, each having a hydroxyl group bonded to Si addressed to one terminal unit, such as tildisiloxane, 1,3-diphenyltetramethyldisiloxane There is. These are used alone or in a mixture of two or more.

  The content of the fine particles is preferably 0.8 to 8.0 parts by mass, and more preferably 1.0 to 4.0 parts by mass with respect to 100 parts by mass of the toner.

Furthermore, the replenishment developer of the present invention can be efficiently mixed with the developer in the developing device by using the toner having the following constitution, and high durability and high image quality can be obtained.

  The toner of the present invention has a weight average diameter (D4) of 3.0 μm to 11.0 μm. The weight average diameter (D4) of the toner of the present invention is preferably 4.0 μm to 10.0 μm, and more preferably 4.5 μm to 9.0 μm. When the weight average diameter (D4) of the toner in the replenishment developer is within this range, an image with good dot reproducibility can be obtained. When the weight average diameter (D4) of the toner is less than 3.0 μm, the specific surface area of the toner increases, the amount of the surface existing on the carrier in the replenishment developer increases, and the developer is replenished into the developer. The miscibility with the inner carrier deteriorates and the uniformity deteriorates. On the other hand, when the weight average diameter (D4) of the toner exceeds 11.0 μm, the dot reproducibility deteriorates and high image quality cannot be achieved.

  The toner of the present invention is characterized in that the ratio of ultrafine powder having an equivalent circle diameter of 0.6 μm to 2.0 μm is 30% by number or less. The amount of ultrafine powder is preferably 20% by number or less, and more preferably 10% by number or less. When the amount of ultrafine powder is 30% by number or less, the mixing property with the developer in the developing device is good. When the amount of super fine powder exceeds 30%, the amount of super fine powder present in the carrier in the developer for replenishment increases, and when replenished into the developer, the mixing with the carrier in the developer is poor. And uniformity is deteriorated. This is because the ultrafine toner powder obtained by the emulsion aggregation method is an emulsified particle. This is because the emulsified particles have very high surface adhesion because the polymerization initiator and the surfactant are localized on the particle surface, and the carrier and other charging members are easily contaminated.

  In addition, once the ultra fine powder adheres to the carrier, the amount of adhesion increases due to van der Waals force and mirror power, and when the emulsified particles adhere to the carrier surface, the emulsified particles become difficult to separate and are replenished into the developer. In such a case, it is difficult to perform efficient charging. This is due to the emulsified particles adhering and covering the surface of the carrier, and as a result, scattering, fogging, and the like are deteriorated.

  In addition, it is preferable that the average circularity of toner particles having an equivalent circle diameter of 2.0 μm or more is 0.910 to 1.000. Use of a material within the above range is preferable because both transferability and developability can be achieved. If the average circularity of the toner is lower than 0.910, the transfer efficiency may be lowered, and the toner charge distribution may be non-uniform, resulting in an image defect.

  Further, in the molecular weight distribution measured by gel permeation chromatography (GPC) of the THF-soluble matter in the toner, it is preferable to have at least a main peak in the region of molecular weight 10,000 to 100,000. By having at least a main peak in this range, a toner excellent in developability and fixability can be obtained. In addition, toner deterioration in the developing unit is reduced by increasing the toner fastness. When the main peak molecular weight is less than 10,000, the fixability is improved, but the storage stability and the stress resistance in the developing device are weakened, and the developability may be lowered, which is not preferable. When the main peak molecular weight exceeds 100,000, the fixing property is deteriorated, which is not preferable.

  The magnetic carrier used for the replenishment developer of the present invention has a volume distribution basis 50% particle size (D50) of 15 to 70 μm, preferably 20 to 70 μm, and more preferably 25 to 60 μm. When the 50% particle size (D50) based on the volume distribution of the magnetic carrier is within this range, an image with good dot reproducibility can be obtained over a long period without fogging. When the 50% particle size (D50) based on the volume distribution of the magnetic carrier is less than 15 μm, the specific surface area of the carrier increases and the mixing with the toner is improved, but the carrier may adhere to the photoreceptor during development. . When the 50% particle size (D50) based on the volume distribution of the magnetic carrier exceeds 70 μm, the stress applied to the toner increases and the developability may be deteriorated.

The true specific gravity of the magnetic carrier is 2.5 to 4.2 g / cm ³ , preferably 2.7 to 4.1 g / cm ³ , and more preferably 3.0 to 4.0 g / cm ³ . When the true specific gravity of the magnetic carrier is within this range, an image with good dot reproducibility can be obtained over a long period of time without fogging. When the true specific gravity of the magnetic carrier is less than 2.5 g / cm ^{3, the} magnetic carrier is easily developed on the photoconductor during development, and carrier adhesion may occur. When the true specific gravity of the magnetic carrier exceeds 4.2 g / cm ³ , the dot reproducibility during development deteriorates, and further, stress on the developer in the developing device increases and the carrier may be deteriorated.

The magnetization intensity of the magnetic carrier is 40 to 70 Am ² / kg under a magnetic field of 1000 / 4π (kA / m). When the magnetization intensity of the magnetic carrier is within this range, an image with good dot reproducibility can be obtained over a long period of time. When the magnetic carrier has a magnetization intensity of less than 40 Am ² / kg, it tends to be developed on the photoreceptor during development, and carrier adhesion may occur. When the magnetization intensity of the magnetic carrier exceeds 70 Am ² / kg, dot reproducibility during development deteriorates, and further, stress on the developer in the developing device increases and the carrier may be deteriorated.

  In addition, the magnetic carrier of the present invention preferably contains 90% by number or more of particles having an average circularity of 0.850 to 0.950 and a circularity of 0.800 or more. The average circularity is preferably 0.870 to 0.930, and more preferably 0.880 to 0.920. The average circularity is a coefficient representing the shape of the roundness of the particle, and is obtained from the maximum diameter of the particle and the measured particle projected area. If the average circularity is 1.000, it indicates a perfect sphere (perfect circle), and the smaller the value, the longer the shape or the more irregular the shape.

  When the average circularity is 0.850 to 0.950, the magnetic carrier of the present invention has sufficient carrier strength, excellent chargeability to the toner, hardly damages the toner, hardly causes toner spent, and is durable. Excellent in properties. When the average circularity is less than 0.850, it means that the particles have an irregular shape. In this case, the charge imparting property to the toner may deteriorate, which is not preferable. On the other hand, when the average circularity exceeds 0.950, the specific surface area of the carrier becomes small, and the charge imparting property may be lowered. Further, when 90% by number or more of particles having a circularity of 0.80 or more are contained, it is preferable because the toner has uniform charge imparting properties. When the number of particles having a circularity of 0.80 or more is less than 90% by number, the charge imparting property is deteriorated, and further, the mixing property in the developing device is deteriorated.

  The magnetic carrier is not particularly limited as long as the above physical properties are satisfied. For example, a so-called resin-impregnated carrier in which a porous magnetic body (including porous ferrite) is impregnated with a resin may be used, or a magnetic body-containing resin carrier in which a magnetic body is dispersed in a resin may be used. .

  Among the above magnetic carriers, it is preferable to use a magnetic substance-containing resin carrier in which a magnetic substance is dispersed in a resin.

  As a method for producing the magnetic substance-containing resin carrier, there is a method obtained by polymerizing monomers constituting the resin in the presence of the magnetic substance.

  At this time, as monomers used for polymerization, in addition to vinyl monomers, bisphenols and epichlorohydrin for forming epoxy resins; phenols and aldehydes for forming phenol resins; urea resins are formed Urea and aldehydes for forming a melamine, and melamine and aldehydes for forming a melamine resin are used.

  For example, as a method for producing a magnetic substance-containing resin carrier using a phenol resin, phenols and aldehydes are polymerized in an aqueous medium containing phenols, aldehydes and a magnetic substance in the presence of a basic catalyst. Thus, a magnetic substance-containing resin carrier can be obtained. When a magnetic substance-containing resin carrier is manufactured by this method, the average circularity is easily adjusted to the above range, which is a preferable manufacturing method.

  As the resin for forming the magnetic substance-containing resin carrier used in the present invention, a phenol resin is preferable. Examples of phenols for producing the phenol resin include phenol, alkylphenols such as m-cresol, p-tert-butylphenol, o-propylphenol, resorcinol, bisphenol A, and a part of benzene nucleus or alkyl group, or Examples thereof include compounds having a phenolic hydroxyl group such as halogenated phenols, all of which are substituted with chlorine atoms or bromine atoms. Of these, phenol (hydroxybenzene) is more preferable.

  Examples of aldehydes for producing the phenol resin include formaldehyde and furfural in the form of either formalin or paraaldehyde. Of these, formaldehyde is particularly preferable.

  The molar ratio of aldehydes to phenols is preferably 1 to 4, particularly preferably 1.2 to 3. If the molar ratio of aldehydes to phenols is less than 1, particles are difficult to produce, and even if they are produced, the resin does not easily cure, so the strength of the particles produced tends to be weak. On the other hand, when the molar ratio of aldehydes to phenols is larger than 4, unreacted aldehydes remaining in the aqueous medium after the reaction tend to increase.

  Examples of the basic catalyst used in the condensation polymerization of phenols and aldehydes include those used in the production of ordinary resol type resins. Examples of such basic catalysts include aqueous ammonia, hexamethylenetetramine, and alkylamines such as dimethylamine, diethyltriamine, and polyethyleneimine. The molar ratio of these basic catalysts to phenols is preferably 0.02 to 0.30.

  As another method for producing the above magnetic substance-containing resin carrier, a vinyl-type or non-vinyl-type thermoplastic resin, a magnetic substance, and other additives are sufficiently mixed by a mixer, and then a heating roll, a kneader, and an extruder. There is a method in which a magnetic material-containing resin carrier core is obtained by melting and kneading using a kneader such as the above, and cooling and then pulverizing and classifying. At this time, it is preferable that the obtained magnetic substance-containing resin carrier core is thermally or mechanically spheroidized and used as a magnetic substance-containing resin carrier.

  The amount of the magnetic substance used in the magnetic substance-containing resin carrier is 70 to 95% by mass (more preferably 80 to 92% by mass) with respect to the magnetic substance-containing resin carrier. It is preferable for reducing the size and ensuring sufficient mechanical strength. Furthermore, in order to adjust the magnetic properties of the magnetic carrier, a part of the magnetic substance contained in the magnetic substance-containing resin carrier may be replaced with a nonmagnetic inorganic compound.

  In addition, the nonmagnetic inorganic compound has a specific resistance value larger than that of the magnetic material, and the number average particle size of the nonmagnetic inorganic compound is larger than the number average particle size of the magnetic material to increase the specific resistance value of the magnetic carrier. Is preferable.

  The magnetic substance is contained in an amount of 30 to 99% by mass based on the total amount of the magnetic substance and the nonmagnetic inorganic compound, thereby adjusting the strength of magnetization of the magnetic substance-containing resin carrier to prevent carrier adhesion, It is preferable when adjusting the specific resistance value of the magnetic substance-containing resin carrier.

In the magnetic substance-containing resin carrier, the magnetic substance is preferably magnetite fine particles, or magnetic ferrite fine particles containing at least an iron element, and the nonmagnetic inorganic compound is hematite (α-Fe ₂ O ₃ ). Fine particles are more preferable in terms of making the dispersibility in the carrier uniform and adjusting the magnetic properties and true specific gravity of the carrier.

  The number average particle diameter of the magnetic material is preferably 0.02 to 2 μm from the viewpoint of making the state of the particle surface of the magnetic carrier uniform. The nonmagnetic inorganic compound preferably has a number average particle diameter of 0.05 to 5 μm, and the nonmagnetic inorganic compound has a particle diameter of 1.1 times or more larger than that of the magnetic substance. It is preferable for increasing the surface resistance value.

  The surface of the magnetic substance-containing resin carrier is preferably coated with a coating material from the viewpoint of charge imparting properties and releasability. As a resin for forming the coating material, an insulating resin is preferably used. The insulating resin that can be used in this case may be a thermoplastic resin or a thermosetting resin.

Specific examples of the resin for forming the coating material include thermoplastic resins such as polystyrene, polymethyl methacrylate, acrylic resins such as styrene-acrylic acid copolymers, styrene-butadiene copolymers, and ethylene. -Vinyl acetate copolymer, polyvinyl chloride, polyvinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, polyvinyl pyrrolidone, petroleum resin, cellulose, cellulose acetate, Cellulose derivatives such as cellulose nitrate, methylcellulose, hydroxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, novolak resin, low molecular weight polyethylene, saturated alkyl Riesuteru resin, polyethylene terephthalate, polybutylene terephthalate, polyarylates such aromatic polyester resins, polyamide resins, polyacetal resins, polycarbonate resins, polyethersulfone resins, polysulfone resins, polyphenylene sulfide resins, polyether ketone resins.
Thermosetting resins include phenolic resins, modified phenolic resins, maleic resins, alkyd resins, epoxy resins, acrylic resins, or unsaturated polyesters obtained by polycondensation of maleic anhydride, terephthalic acid and polyhydric alcohols, urea Resin, melamine resin, urea-melamine resin, xylene resin, toluene resin, guanamine resin, melamine-guanamine resin, acetoguanamine resin, gliptal resin, furan resin, silicone resin, polyimide, polyamideimide resin, polyetherimide resin, polyurethane resin Is mentioned.

  The above-mentioned resins can be used alone or in combination. In addition, a curing agent or the like can be mixed with a thermoplastic resin and cured for use. As a particularly preferable form, it is preferable to use a resin having a higher release property for a toner having a small particle diameter and containing a release agent.

  Furthermore, it is preferable that the coating material contains particles having conductivity and particles having charge controllability. Such a coating material contains the resin forming the coating material, or the monomer forming the resin with conductive particles or charge controllable particles, and the resin or monomer is magnetized by an appropriate method. It is preferable to coat the body-containing resin carrier. These particles are important in terms of soft and quick charging to a toner having a small particle size and low temperature fixability.

The conductive particles preferably have a specific resistance of 1 × 10 ⁸ Ωcm or less, and more preferably have a specific resistance of 1 × 10 ⁶ Ωcm or less. Specifically, the conductive particles are preferably particles containing at least one kind of particles selected from carbon black, magnetite, graphite, zinc oxide, and tin oxide. In particular, as the particles having conductivity, carbon black having good conductivity is preferable in terms of improving the charge imparting property (rise of charge amount) to the toner.

  It is preferable that the conductive particles have a number average particle size of 1 μm or less in order to prevent the particles from falling off from the carrier and to function as a uniform conductive site.

  The particles having charge controllability include organometallic complex particles, organometallic salt particles, chelate compound particles, monoazo metal complex particles, acetylacetone metal complex particles, hydroxycarboxylic acid metal complex particles, and polycarboxylic acid. Examples include metal complex particles and polyol metal complex particles. A charge control agent dispersed in the toner particles may be used. In order to improve the charge imparting property to the toner, it is possible to use resin particles having a functional group or inorganic particles treated with a treatment agent having a functional group. preferable.

  Specifically, the particles having charge controllability include polymethyl methacrylate resin particles, polystyrene resin particles, melamine resin particles, phenol resin particles, nylon resin particles, silica particles, titanium oxide particles, and The particles preferably contain at least one kind of particles selected from alumina particles. Further, in the case of inorganic particles, it is preferable to use them after being treated with various coupling agents in order to develop charge controllability and conductivity.

  The particles having charge controllability preferably have a number average particle diameter of 0.01 to 1.5 μm from the viewpoint of functioning as a uniform charging site.

  The coating amount of the resin forming the coating material on the magnetic substance-containing resin carrier is 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the magnetic substance-containing resin core. And, it is preferable for enhancing the durability of the magnetic carrier. The blending amount of the conductive particles and the charge controllable particles is preferably 0.1 to 30 parts by mass in total with respect to 100 parts by mass of the resin forming the coat layer material.

  When adding more than 30 parts by mass of the above conductive particles or charge controllable particles, the particles are difficult to disperse in the resin forming the coating material, and the particles are detached from the magnetic carrier. There is. In particular, when carbon black is added, the toner may be contaminated with carbon black or the member may be contaminated as the durability increases.

  When the toner and the magnetic carrier are mixed and used as a two-component developer in the developing device, the mixing ratio of the toner and the magnetic carrier is 0.02 parts by mass to 0.0. It is preferably used in the range of 35 parts by mass, more preferably 0.04 parts by mass to 0.25 parts by mass, and particularly preferably 0.05 parts by mass to 0.20 parts by mass. If the mixing ratio of the toner and the magnetic carrier is less than 0.02 parts by mass with respect to 1 part by mass of the magnetic carrier, the image density tends to decrease, and if it exceeds 0.35 parts by mass, fogging and scattering in the apparatus are likely to occur.

  In the present invention, the replenishment developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the magnetic carrier, and the toner and carrier in the replenishment developer are contained in the developer. In the above range, it is preferable because the developer can be uniformly and efficiently mixed and the developer has a uniform charge distribution.

A suitable method for measuring physical properties related to the present invention will be described below.

<Measurement of toner particle size distribution>
As a measuring device, Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Inc.) is used. As the electrolytic solution, an about 1% NaCl aqueous solution is used. As the electrolytic solution, an electrolytic solution prepared using primary sodium chloride or, for example, ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan) can be used.

  As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of the sample are measured for each channel by the measuring apparatus using a 100 μm aperture as the aperture. Volume distribution and number distribution are calculated. From these obtained distributions, the weight average particle diameter (D4) of the sample is determined. As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32.00-40.30 μm are used.

<Measurement of average circularity of toner and amount of super fine powder>
The equivalent circle diameter, circularity, and frequency distribution of the toner are used as a simple method for quantitatively expressing the shape of the toner particles. In the present invention, the flow type particle image measuring apparatus “FPIA-2100 type” is used. ”(Manufactured by Sysmex Corporation), and calculation is performed using the following formulas (3) to (4).
(3): equivalent circle diameter = (particle projected area / π) ^1/2 × 2
(4): Circularity = (perimeter of a circle having the same area as the particle projection area) / (perimeter of the particle projection image)
Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define. The measurement uses the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm).
In the present invention, the circularity is an index indicating the degree of unevenness of the toner particles, and is 1.000 when the toner particles are completely spherical. The more complicated the surface shape, the smaller the circularity.

The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

  In addition, “FPIA-2100”, which is a measuring apparatus used in the present invention, calculates the circularity of each particle, and then calculates the average circularity. 1.0 is divided into classes equally divided every 0.01, and the average circularity is calculated using the center value of the division points and the number of measured particles.

  As a specific measuring method, 10 ml of ion-exchanged water from which impure solids have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, followed by further measurement. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled at 23 ° C. ± 0.5 ° C. so that the temperature inside the flow type particle image analyzer FPIA-2100 is 26 to 27 ° C. Preferably, autofocus is performed using 2 μm latex particles every 2 hours.

  To measure the shape of the toner particles, the flow type particle image measuring device is used, and the concentration of the dispersion is readjusted so that the color toner particle concentration at the time of measurement is 3000 to 10,000 particles / μl. Measure more than one. After the measurement, this data is used to cut data less than 2 μm, and the average circularity of the toner particles is obtained.

  Furthermore, “FPIA-2100”, which is a measuring apparatus used in the present invention, improves the magnification of the processed particle image as compared with “FPIA-1000” conventionally used for calculating the shape of the toner. Further, the accuracy of toner shape measurement has been improved by improving the processing resolution of the captured image (256 × 256 → 512 × 512), thereby achieving more reliable capture of fine particles. Therefore, when it is necessary to measure the shape more accurately as in the present invention, the FPIA 2100 that can obtain information on the shape more accurately is more useful.

<Measurement of molecular weight by GPC (toner)>
The molecular weight of the chromatogram by gel permeation chromatograph (GPC) is measured under the following conditions.
Resin prepared by stabilizing the column in a heat chamber at 40 ° C., and flowing tetrahydrofuran (THF) as a solvent at a flow rate of 1 ml / min to the column at this temperature to adjust the sample concentration to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 to 200 μl of a THF sample solution. An RI (refractive index) detector is used as the detector. As a column, in order to accurately measure a molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, μ-styragel 500, 103, 104, 105 manufactured by Waters And combinations of shodex KA-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko KK are preferable.
In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Manufactured by Toyo Soda Kogyo Co., Ltd. and having molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples.

<Measurement of maximum endothermic peak of wax>
The maximum endothermic peak of the wax and toner can be measured according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device) and DSC2920 (TA Instruments Japan).
As a measuring method, 5 to 20 mg, preferably 10 mg of a measurement sample is accurately weighed. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rising rate of 10 ° C./min and normal temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature raising process, an endothermic peak in the temperature range of 30 to 200 ° C. is obtained. When there are a plurality of peaks, the highest endothermic peak is the one having the highest height from the baseline in the region above the endothermic peak due to the resin.

<Carrier particle size distribution and circularity>
The carrier volume distribution standard 50% particle size (D50) and average circularity are measured as follows using, for example, a multi-image analyzer (manufactured by Beckman Coulter).
A solution obtained by mixing about 1% NaCl aqueous solution and glycerin at 50% by volume: 50% by volume is used as the electrolytic solution. Here, the NaCl aqueous solution may be prepared using primary sodium chloride, and may be, for example, ISOTON (registered trademark) -II (manufactured by Coulter Scientific Japan). Glycerin may be a special grade or first grade reagent.
To the electrolytic solution (about 30 ml), 0.1 to 1.0 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is dispersed for about 1 minute with an ultrasonic disperser to obtain a dispersion.

Using a 200 μm aperture and a 20 × lens as the aperture, the equivalent circle diameter and circularity are calculated under the following measurement conditions.
Average luminance within measurement frame: 220 to 230, measurement frame setting: 300, SH (threshold): 50, binary level: 180

The electrolytic solution and the dispersion liquid are put into a glass measuring container, and the concentration of carrier particles in the measuring container is set to 5 to 10% by volume. Stir the contents of the glass measuring container at the maximum stirring speed. The sample suction pressure is 10 kPa. When the carrier specific gravity is large and the sedimentation is likely to occur, the measurement time is 15 to 30 minutes. Further, the measurement is interrupted every 5 to 10 minutes to replenish the sample solution and the electrolytic solution-glycerin mixed solution.
The number of measurements is 2000. After the measurement is finished, the main body software removes a defocused image, aggregated particles (multiple simultaneous measurements), etc. on the particle image screen.
The circularity and equivalent circle diameter of the carrier are calculated by the following formula.
Circularity = (4 × Area) / (MaxLength ² × π)
Circle equivalent diameter = √ (4 · Area / π)

Here, “Area” is the projected area of the binarized carrier particle image, and “MaxLength” is defined as the maximum diameter of the carrier particle image. The equivalent circle diameter is represented by the diameter of a perfect circle when “Area” is the area of the perfect circle. The equivalent circle diameter is divided into 4 to 100 μm in 256, and is used by logarithmically displaying on a volume basis. Using this, the 50% particle size (D50) based on volume distribution is obtained. The average circularity is obtained by adding the circularity of each particle and dividing by the total number of particles.
FIG. 1 shows an example of a graph of measurement results. The “arithmetic average value” in the “circularity arithmetic statistical value” section in the figure indicates the average circularity.

<True specific gravity of carrier>
The true specific gravity of the carrier particles of the present invention can be measured using a dry automatic densimeter autopycnometer (manufactured by Yuasa Ionics).

<Strength of magnetization of carrier>
The intensity of magnetization of the carrier of the present invention can be measured by the following procedure using an oscillating magnetic field type magnetic property automatic recording device BHV-30 manufactured by Riken Denshi Co., Ltd. The cylindrical plastic container is filled with the carrier sufficiently densely, while an external magnetic field of 10,000 / 4π (kA / m) (10000 Oersted) is created, and in this state, the magnetization moment of the carrier filled in the container is measured. . Further, the actual mass of the carrier filled in the container is measured to determine the magnetization strength (Am ² / kg) of the carrier.

(Example)
Specific examples of the present invention will be described below, but the present invention is not limited to these examples.

[Example 1 of toner production by emulsion aggregation method]
Dispersion A
-Styrene 350 parts by mass-n-butyl acrylate 100 parts by mass-Acrylic acid 25 parts by mass-t-dodecyl mercaptan 10 parts by mass

The above composition was mixed and dissolved to prepare a monomer mixture.
-100 parts by weight of paraffin wax dispersion with a melting point of 78 ° C. (solid content concentration 30%, dispersed particle size 0.14 μm, wax Mw = 500, Mn = 380)
・ Anionic surfactant 1.2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ 0.5 parts by weight of nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd .: Nonipol 400)
・ Ion-exchanged water 1530 parts by mass

  The above composition is dispersed in a flask, and heating is started while performing nitrogen substitution. When the liquid temperature reached 70 ° C., a solution prepared by dissolving 6.56 parts by mass of potassium persulfate with 350 parts by mass of ion-exchanged water was added thereto. While maintaining the liquid temperature at 70 ° C., the monomer mixture is charged and stirred, the liquid temperature is raised to 80 ° C. and emulsion polymerization is continued for 6 hours. After that, the liquid temperature is adjusted to 40 ° C. and then filtered and dispersed. Liquid A was obtained. Thus, the particle diameter in the obtained dispersion was 0.16 μm in average particle diameter, 60 ° C. in glass transition point of solid content, 15,000 in weight average molecular weight (Mw), and 12 in peak molecular weight. 000. Paraffin wax was contained in the polymer by 6%, and as a result of observing a thin piece of this solid content with a transmission electron microscope, it was confirmed that the polymer particles included the wax particles.

Dispersion B
-Styrene 350 mass parts-n-butyl acrylate 100 mass parts-Acrylic acid 25 mass parts or more of the composition was mixed and dissolved, and prepared as a monomer mixture.

-100 parts by mass of a Fischer-Tropsch wax dispersion with a melting point of 105 ° C. (solid content concentration 30%, dispersion particle size 0.15 μm, wax Mw = 1200, Mn = 790)
Anionic surfactant 1.7 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ 0.5 parts by weight of nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd .: Nonipol 400)
・ Ion-exchanged water 1530 parts by mass

  The above composition is dispersed in a flask, and heating is started while performing nitrogen substitution. When the liquid temperature reached 65 ° C., a solution prepared by dissolving 5.85 parts by mass of potassium persulfate with 300 parts of ion-exchanged water was added thereto. While maintaining the liquid temperature at 65 ° C., the monomer mixture was added and stirred, the liquid temperature was raised to 75 ° C., and emulsion polymerization was continued for 8 hours. After that, the liquid temperature was adjusted to 40 ° C. Liquid B was obtained. Thus, the particle diameter in the obtained dispersion was 0.16 μm in average particle diameter, 63 ° C. in glass transition point of solid content, and 700,000 in weight average molecular weight (Mw). Fischer-Tropsch wax was contained in the polymer at 6%, and as a result of observing a thin piece of the solid content with a transmission electron microscope, it was confirmed that the wax particles were encapsulated.

Dispersion C
・ C. I. Pigment Blue 15: 3 12 parts by mass / Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion-exchanged water 78 parts by mass The above composition was mixed and dispersed using a sand grinder mill to obtain a colorant dispersion C.

  300 parts by mass of the dispersion A, 150 parts by mass of the dispersion B, and 25 parts by mass of the dispersion C were put into a 1-liter separable flask equipped with a stirrer, a cooling tube, and a thermometer and stirred. As a flocculant, 180 parts by mass of a 10% sodium chloride aqueous solution was dropped into this mixed solution, and the flask was heated to 54 ° C. while stirring the inside of the flask. After maintaining at 48 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles having a diameter of about 5 μm were formed.

  In the subsequent fusion process, after adding 3 parts by mass of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC), the stainless steel flask was sealed and stirring was continued using a magnetic seal. While heating to 100 ° C., it was held for 3 hours. Then, after cooling, the reaction product was filtered, washed thoroughly with ion exchange water, and then dried to obtain toner particles 1.

For 100 parts of the toner particles, 0.7 part of hydrophobic silica (hexamethyldisilazane 10% treatment) having a BET specific surface area of 200 m ² / g and hydrophobic titanium oxide (hexamethyldisulfate) having a primary particle diameter of 80 nm. 0.7 parts of silazane 5% treatment) was added and dry mixed.

  The toner 1 obtained in Production Example 1 has a weight average particle diameter (D4) of 5.5 μm, a ratio of equivalent circle diameter (number basis) of 0.6 μm to 2.0 μm of 15%, an average circularity of 0.958, and gel permeation chromatography. The peak molecular weight by graphy (hereinafter referred to as GPC) is 12,000, and Mw is 210,000. Table 1 shows the physical properties of Toner 1 thus obtained.

[Example 2 of toner production by emulsion aggregation method]
In Toner Production Example 1, the 10% sodium chloride aqueous solution was changed to 220 parts in the aggregation step, the heating temperature was changed to 80 ° C., and the holding time was changed to 2 hours in the fusing step. Got.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  Toner 2 obtained in Toner Production Example 2 has a weight average particle diameter (D4) of 5.5 μm, a ratio of equivalent circle diameter (number basis) of 0.6 μm to 2.0 μm of 10%, an average circularity of 0.940, and a peak by GPC. The molecular weight is 12,000 and Mw is 210,000. Table 1 shows the physical properties of Toner 2 thus obtained.

[Example 3 of toner production by emulsion aggregation method]
In Toner Production Example 1, the 10% sodium chloride aqueous solution was changed to 300 parts in the aggregation step, the heating temperature was changed to 120 ° C., and the holding time was changed to 5 hours in the fusing step. Got.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  Toner 3 obtained in Toner Production Example 3 has a weight average particle diameter (D4) of 5.5 μm, a circle equivalent diameter (number basis) of 0.6 μm to 2.0 μm of 5%, an average circularity of 0.985, and a peak by GPC. The molecular weight is 12,000 and Mw is 210,000. Table 1 shows the physical properties of Toner 3 thus obtained.

[Example 4 of toner production by emulsion aggregation method]
In Toner Production Example 1, toner particles 4 were obtained in the same manner except that potassium persulfate at the time of producing dispersion A was changed to 4.1 parts by mass.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  Toner 4 obtained in Toner Production Example 4 has a weight average particle diameter (D4) of 5.5 μm, a circle equivalent diameter (number basis) of 0.6 μm to 2.0 μm of 29%, an average circularity of 0.961, and a peak by GPC. The molecular weight is 50,000 and Mw is 250,000. Table 1 shows the physical properties of Toner 4 thus obtained.

[Example 5 of toner production by emulsion polymerization method]
Ethylene glycol 10.0 mol, terephthalic acid 3.0 mol, 1,10-decanedicarboxylic acid 7.0 mol, and dibutyltin oxide 0.2 g were put into a glass 4-liter four-necked flask. A thermometer, a stirring rod, a condenser, and a nitrogen introducing tube were attached to the four-necked flask, and the four-necked flask was placed in a mantle heater. Next, after the inside of the four-necked flask was replaced with nitrogen gas, the temperature was gradually raised to 200 ° C. while stirring and reacted for 4 hours to obtain a polyester resin. As for the molecular weight of this polyester resin by GPC, the peak molecular weight was 15500, and the weight average molecular weight (Mw) was 81500.

  100 parts by weight of the obtained polyester resin and 20 parts by weight of a paraffin wax dispersion having a melting point of 98 ° C. used in Production Example 1 were put into 880 parts by weight of ion-exchanged water and stirred with a sand grinder mill while being heated to 90 ° C. Resin dispersion A was prepared.

450 parts by weight of this polyester resin dispersion A and 25 parts of dispersion C used in Production Example 1 were put into a 1 liter separable flask equipped with a stirrer, a cooling tube and a thermometer and stirred. To this mixed solution, 180 parts of a 10% aqueous sodium chloride solution was added dropwise as a flocculant, and the mixture was heated to 54 ° C. while stirring the inside of the flask in a heating oil bath. After maintaining at 48 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles having a diameter of about 5 μm were formed.
In the subsequent fusion process, after adding 3 parts by mass of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC), the stainless steel flask was sealed and stirring was continued using a magnetic seal. While heating to 100 ° C., it was held for 3 hours. Then, after cooling, the reaction product was filtered, washed thoroughly with ion exchange water, and then dried to obtain toner particles 5.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  The toner 5 obtained in Toner Production Example 5 has a weight average particle diameter (D4) of 5.5 μm, a circle equivalent diameter (number basis) of 0.6 μm to 2.0 μm, a ratio of 15%, an average circularity of 0.970, and a peak by GPC. The molecular weight is 155000 and Mw is 81500. Table 1 shows the physical properties of Toner 5 thus obtained.

[Example 6 of toner production by emulsion aggregation method]
In Toner Production Example 1, the 10% sodium chloride aqueous solution was changed to 100 parts in the aggregation step, the heating temperature was changed to 80 ° C., and the holding time was changed to 2 hours in the fusing step. Got.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  The toner 6 obtained in Toner Production Example 6 has a weight average particle diameter (D4) of 4.2 μm, a ratio of equivalent circle diameter (number basis) of 0.6 μm to 2.0 μm is 31%, an average circularity of 0.930, GPC Has a peak molecular weight of 12,000 and Mw of 210,000. Table 1 shows the physical properties of Toner 6 thus obtained.

[Example 7 of toner production by emulsion aggregation method]
In Toner Production Example 1, the 10% sodium chloride aqueous solution was changed to 80 parts in the aggregation step, the heating temperature was changed to 75 ° C., and the holding time was changed to 1 hour in the fusing step. Got.

To 100 parts of the toner particles, 0.7 part of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 part of hydrophobic titanium oxide having a primary particle diameter of 80 nm were added and dry mixed.

  The toner 7 obtained in Toner Production Example 7 has a weight average particle diameter (D4) of 2.9 μm, a ratio of equivalent circle diameter (number basis) of 0.6 μm to 2.0 μm of 40%, an average circularity of 0.940, GPC Has a peak molecular weight of 12,000 and Mw of 210,000. Table 1 shows the physical properties of Toner 7 thus obtained.

[Production Example 8 of Toner by Grinding Method]
・ Styrene-n-butyl acrylate copolymer resin (copolymerization ratio 80:20, Mw 14,000) 50 mass parts ・ Styrene-n-butyl acrylate copolymer resin (copolymerization ratio 80:20, Mw 300,000) 50 mass parts・ C. I. Pigment Blue 15: 3 4 parts by mass, 2 parts of a Fischer-Tropsch wax having a melting point of 105 ° C., 2 parts of a paraffin wax having a melting point of 78 ° C.

The above mixture was dry-mixed and then melt-kneaded and pulverized to obtain toner particles 8. To 100 parts of the toner particles 8, 0.7 parts of hydrophobic silica having a BET specific surface area of 200 m ² / g and 0.7 parts of hydrophobic titanium oxide having a number average primary particle diameter of 80 nm are added and dried. Mixed. Toner 8 obtained in Toner Production Example 8 has a weight average particle diameter of 5.8 μm, a ratio of equivalent circle diameter (number basis) of 0.6 μm to 2.0 μm is 35%, an average circularity of 0.920, a peak molecular weight by GPC of 12, 000, Mw is 210,000. Table 1 shows the physical properties of Toner 8 thus obtained.

[Magnetic carrier production example 1]
For magnetite powder having a number average particle size of 0.30 μm and (magnetization strength of 75 Am ² / kg under a magnetic field of 10,000 / 4π (kA / m)) and hematite powder having a number average particle size of 0.30 μm, respectively. 4.0% by mass of a silane coupling agent (3- (2-aminoethylaminopropyl) trimethoxysilane) was added and mixed and stirred at 100 ° C. or higher in a container to treat each fine particle.

・ Phenol 10 parts by mass ・ Formaldehyde solution 6 parts by mass (formaldehyde 40%, methanol 10%, water 50%)
・ Processed magnetite 75 parts by mass ・ Processed hematite 9 parts by mass

  The above material, 5 parts by weight of 28% ammonia water, and 20 parts by weight of water are placed in a flask. While stirring and mixing, the temperature is raised to 85 ° C. for 30 minutes and polymerized for 3 hours to produce a phenol resin. Cured. Thereafter, the cured phenol resin was cooled to 30 ° C., water was further added, the supernatant was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 mmHg or less) at a temperature of 60 ° C. to obtain a spherical magnetic substance-containing resin carrier core in which the magnetic substance was dispersed.

  As a coating material, a copolymer of methyl methacrylate and perfluorooctyl acrylate (copolymerization ratio (mass% ratio) 8: 2, weight average molecular weight 45,000) is used, and this is 100 mass of the magnetic material dispersed resin core at the time of coating. A carrier coat solution containing 10% by mass of a copolymer of methyl methacrylate and perfluorooctyl acrylate was prepared using a mixed solvent of methyl ethyl ketone and toluene as a solvent so as to be 1 part by mass with respect to parts. In addition, 0.5 parts by mass of melamine resin (number average particle size 0.2 μm) and 1.0 part by mass of carbon black (number average particle size 30 nm, DBP oil absorption 50 ml / 100 g) may be added to the carrier coat solution using a homogenizer. Mix. Next, the magnetic material-dispersed resin core is added to the mixed solution, and the solvent is volatilized at 70 ° C. while continuously applying shear stress to the mixed solution, and the methyl methacrylate and perfluorooctyl acrylate are applied to the surface of the magnetic material-dispersed resin core. And a copolymer.

The resin-coated magnetic material-dispersed resin core coated with a copolymer of methyl methacrylate and perfluorooctyl acrylate is heat-treated by stirring at 100 ° C. for 2 hours, cooled, crushed, and classified with a 200 mesh sieve. A magnetic carrier having a number average particle diameter of 35 μm, a true specific gravity of 3.73 g / cm ³ , a magnetization strength of 55 Am ² / kg, an average circularity of 0.900, and a ratio of 94% by number of particles having a circularity of 0.80 or more. 1 was obtained. Table 2 shows the physical properties of the magnetic carrier 1 obtained.

[Magnetic Carrier Production Example 2]
A mixture of Fe ₂ O ₃ ; 73.5 mol%, MnO; 5.0 mol%, MgO; 21.5 mol% was mixed for 10 hours using a ball mill. The obtained mixture was calcined at 800 ° C. for 2 hours, and the calcined mixture was pulverized with a ball mill. The average particle size of the obtained pulverized product was 0.2 μm.
Water (300% by mass with respect to the pulverized product), polyvinyl alcohol (3% by mass with respect to the pulverized product), and CaCO ₃ (3% by mass with respect to the pulverized product) are added to the obtained pulverized product, and further a spray dryer. Was granulated. The granulated product was sintered at 980 ° C. for 10 hours, then pulverized and further classified to obtain a Mn—Mg ferrite carrier core. The average particle diameter (D50) of this Mn—Mg ferrite carrier core was 50 μm.

T unit in which all organic groups are methyl groups: 12 parts by mass of siloxane formulated so that D units in which all organic groups are methyl groups = 85: 15, and 0.3 parts by mass of γ-aminopropyltrimethoxysilane, A mixed solution of 200 parts by mass of toluene was added to 100 parts by mass of the carrier core, and the solvent was removed by drying under reduced pressure while stirring and mixing with a solution vacuum kneader. The obtained particles were baked at 140 ° C. for 2 hours to obtain a magnetic carrier 2. The magnetic carrier 2 has an average particle diameter (D50) of 50 μm, a true specific gravity of 3.7 g / cm ³ , a magnetization strength of 52 Am ² / kg, an average circularity of 0.843, and a circularity of 0.80 or more. A magnetic carrier 2 having a ratio of 88% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 2 obtained.

[Magnetic Carrier Production Example 3]
A mixture of Fe ₂ O ₃ ; 80 mol%, MnO; 4.0 mol%, MgO; 16 mol% was mixed for 10 hours using a ball mill. The obtained mixture was calcined at 800 ° C. for 2 hours, and the calcined mixture was pulverized with a ball mill. The average particle size of the obtained pulverized product was 0.2 μm.
Water (300% by mass with respect to the pulverized product), polyvinyl alcohol (2% by mass with respect to the pulverized product) and CaCO ₃ (3% by mass with respect to the pulverized product) are added to the obtained pulverized product, and further a spray dryer. Was granulated. The granulated product was sintered at 980 ° C. for 10 hours, then pulverized and further classified to obtain a Mn—Mg ferrite carrier core. The average particle diameter (D50) of this Mn—Mg ferrite carrier core was 50 μm.

T unit in which all organic groups are methyl groups: 12 parts by mass of siloxane formulated so that D units in which all organic groups are methyl groups = 85: 15, and 0.3 parts by mass of γ-aminopropyltrimethoxysilane, A mixed solution of 200 parts by mass of toluene was added to 100 parts by mass of the carrier core, and the solvent was removed by drying under reduced pressure while stirring and mixing with a solution vacuum kneader. The obtained particles were baked at 140 ° C. for 2 hours to obtain a magnetic carrier 3. The magnetic carrier 3 has an average particle diameter (D50) of 50 μm, a true specific gravity of 4.1 g / cm ³ , a magnetization strength of 50 Am ² / kg, an average circularity of 0.815, and a circularity of 0.80 or more. A magnetic carrier 3 having a ratio of 86% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 3 obtained.

[Magnetic Carrier Production Example 4]
A mixture of Fe ₂ O ₃ ; 50 mol%, MnO; 10.0 mol%, MgO; 40 mol% was mixed for 10 hours using a ball mill. The obtained mixture was calcined at 800 ° C. for 2 hours, and the calcined mixture was pulverized with a ball mill. The average particle size of the obtained pulverized product was 0.2 μm.
To the obtained pulverized product, water (300% by mass with respect to the pulverized product), polyvinyl alcohol (10% by mass with respect to the pulverized product), and CaCO ₃ (3% by mass with respect to the pulverized product) are added. Was granulated. The granulated product was sintered at 980 ° C. for 10 hours, then pulverized and further classified to obtain a Mn—Mg ferrite carrier core. The average particle diameter (D50) of this Mn—Mg ferrite carrier core was 50 μm.

T unit in which all organic groups are methyl groups: 12 parts by mass of siloxane formulated so that D units in which all organic groups are methyl groups = 85: 15, and 0.3 parts by mass of γ-aminopropyltrimethoxysilane, A mixed solution of 200 parts by mass of toluene was added to 100 parts by mass of the carrier core, and the solvent was removed by drying under reduced pressure while stirring and mixing with a solution vacuum kneader. The obtained particles were baked at 140 ° C. for 2 hours to obtain a magnetic carrier 4. The average particle diameter (D50) of the magnetic carrier 4 is 50 μm, the true specific gravity is 2.6 g / cm ³ , the magnetization strength is 42 Am ² / kg, the average circularity is 0.830, and the ratio of particles having a circularity of 0.80 or more. Of 75% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 4 obtained.

[Magnetic Carrier Production Example 5]
A magnetic carrier 5 was obtained in the same manner as in Carrier Production Example 1 except that it was produced using only 84 parts by mass of the treated magnetite. The magnetic carrier 5 has an average particle diameter (D50) of 35 μm, a true specific gravity of 4.1 g / cm ³ , a magnetization strength of 67 Am ² / kg, an average circularity of 0.948, and a circularity of 0.80 or more. A magnetic carrier 5 having a ratio of 92% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 5 obtained.

[Magnetic Carrier Production Example 6]
A magnetic carrier 6 was obtained in the same manner as in Carrier Production Example 1 except that the production was changed to 42 parts by mass of treated magnetite and 42 parts by mass of treated hematite. The magnetic carrier 6 has an average particle diameter (D50) of 35 μm, a true specific gravity of 3.2 g / cm ³ , a magnetization strength of 42 Am ² / kg, an average circularity of 0.920, and a circularity of 0.80 or more. A magnetic carrier 6 having a ratio of 90% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 6 obtained.

[Magnetic Carrier Production Example 7]
These metal oxide particles were weighed so that the molar ratio was Fe ₂ O ₃ ; 80 mol%, MnO; 4.0 mol%, MgO; 16 mol%, and mixed using a ball mill. The obtained mixed powder was calcined, pulverized by a ball mill, further granulated by a spray dryer, sintered, and further classified to obtain a Mn—Mg ferrite carrier core. The average particle diameter (D50) of this Mn—Mg ferrite carrier core was 50 μm.

T unit in which all organic groups are methyl groups: 12 parts by mass of siloxane formulated so that D units in which all organic groups are methyl groups = 85: 15, and 0.3 parts by mass of γ-aminopropyltrimethoxysilane, A mixed solution of 200 parts by mass of toluene was added to 100 parts by mass of the carrier core, and the solvent was removed by drying under reduced pressure while stirring and mixing with a solution vacuum kneader. The obtained particles were baked at 140 ° C. for 2 hours to obtain a magnetic carrier 7. The magnetic carrier 7 has an average particle diameter (D50) of 50 μm, a true specific gravity of 4.8 g / cm ³ , a magnetization strength of 88 Am ² / kg, an average circularity of 0.800, and a circularity of 0.800 or more. A magnetic carrier 7 having a ratio of 71% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 7 obtained.

[Magnetic Carrier Production Example 8]
A magnetic carrier 8 was obtained in the same manner except that the carrier production example 7 was changed to Fe ₂ O ₃ = 50 mol%, CuO = 25 mol%, and ZnO = 25 mol%. The magnetic carrier 8 has an average particle diameter (D50) of 50 μm, a true specific gravity of 4.3 g / cm ³ , a magnetization strength of 75 Am ² / kg, an average circularity of 0.826, and a circularity of 0.800 or more. A magnetic carrier 8 having a ratio of 86% by number was obtained. Table 2 shows the physical properties of the magnetic carrier 8 obtained.

[Magnetic Carrier Production Example 9]
A mixture of Fe ₂ O ₃ ; 50 mol%, MnO; 10.0 mol%, MgO; 40 mol% was mixed for 10 hours using a ball mill. The obtained mixture was calcined at 800 ° C. for 2 hours, and the calcined mixture was pulverized with a ball mill. The average particle size of the obtained pulverized product was 0.2 μm.
Water (300% by mass with respect to the pulverized product), polyvinyl alcohol (10% by mass with respect to the pulverized product) and CaCO ₃ (5% by mass with respect to the pulverized product) are added to the obtained pulverized product, and further a spray dryer. Was granulated. The granulated product was sintered at 980 ° C. for 10 hours, then pulverized and further classified to obtain a Mn—Mg ferrite carrier core. The average particle diameter (D50) of this Mn—Mg ferrite carrier core was 50 μm.

T unit in which all organic groups are methyl groups: 12 parts by mass of siloxane formulated so that D units in which all organic groups are methyl groups = 85: 15, and 0.3 parts by mass of γ-aminopropyltrimethoxysilane, A mixed solution of 200 parts by mass of toluene was added to 100 parts by mass of the carrier core, and the solvent was removed by drying under reduced pressure while stirring and mixing with a solution vacuum kneader. The obtained particles were baked at 140 ° C. for 2 hours to obtain a magnetic carrier 4. The average particle diameter (D50) of the magnetic carrier 4 is 50 μm, the true specific gravity is 2.4 g / cm ³ , the magnetization strength is 38 Am ² / kg, the average circularity is 0.768, and the ratio of particles having a circularity of 0.800 or more. As a result, 70% by number of magnetic carriers 9 were obtained. Table 2 shows the physical properties of the magnetic carrier 9 obtained.

<Example 1>
The starting developer 1 was obtained by mixing 10 parts by mass of the toner 1 obtained in Toner Production Example 1 and 90 parts by mass of the magnetic carrier 1 obtained in Magnetic Carrier Production Example 1 with a V-type mixer. Similarly, 85 parts by mass of the toner 1 obtained in Toner Production Example 1 and 15 parts by mass of the magnetic carrier 1 obtained in Magnetic Carrier Production Example 1 are mixed with a V-type mixer to obtain a replenishment developer 1. It was. Table 3 shows the blending ratio of the toner with respect to 1 part by mass of the magnetic carrier of the obtained developer 1 for start and developer 1 for replenishment.

  Using these start developer 1 and replenishment developer 1, Canon full color copier, iRC6800 remodeling machine (laser spot diameter reduced, enabling 1200 dpi output) normal temperature and normal humidity (NN) (23 ° C, 50% RH), high temperature and high humidity (HH) (35 ° C, 90% RH), normal temperature and low humidity (NL) (23 ° C, 5% RH) Printing ratio, 100,000 sheets). The items for image output evaluation after 100,000 sheets are passed and the evaluation criteria are shown below.

(1) Dot reproducibility (end of life and after 100,000 sheets)
A halftone image was formed using the developer and the modified machine, this image was visually observed, and the dot reproducibility of the image was evaluated based on the following criteria. The formed halftone image is a halftone image when the 48th density in the 256 gradation display in which 0 is solid white and 256 is solid black.
A: Smooth and smooth.
B: I don't feel a lot of rustling.
C: Although there is a slight feeling of roughness, it is at a level where there is no practical problem.
D: Strong feeling of roughness.

(2) Fog (early endurance and after 100,000 sheets)
The average reflectance Dr (%) of plain paper before image printing was measured by a reflectometer (“REFLECTOMETER MODEL TC-6DS” manufactured by Tokyo Denshoku Co., Ltd.).
At the beginning of the endurance, a solid white image was printed on plain paper by changing Vd every 50V so that Vback was 0V to 300V. Further, after endurance output, a solid white image (Vback: 150 V) was drawn on plain paper. The reflectivity Ds (%) of the imaged solid white image was measured. The fog (%) was calculated from the obtained Dr and Ds (initial and subsequent durability) using the following formula. The obtained fog was evaluated according to the following evaluation criteria.
Fog (%) = Dr (%)-Ds (%)
(Evaluation criteria)
A: 0.5% or less B: 0.6-1.0% or less C: 1.1-2.0% or less D: 2.1% or more

(3) Carrier adhesion (initial durability and after 100,000 sheets)
A halftone image is formed on the paper using the developer and the modified machine, and the number of carriers present is counted with an optical microscope within an area of 1 cm ² on the halftone image.
A: 0 to 5 pieces: Very inconspicuous and very good.
B: 6-10 pieces: Good.
C: 11-20 pieces: Although black spots are visible, it is at a level where there is no practical problem.
D: 21 or more: One morning cleaning failure occurs.
In the durability evaluation, the evaluation results of (1) to (3) are shown in Tables 4-1, 4-2, and 4-3.

<Examples 2, 3, 4, Reference Examples 5 to 9, Examples 10, 11, Reference Example 12 > and <Comparative Examples 1 to 9>
The same evaluations (1) to (3) as in Example 1 were performed with the combinations and blending ratios of the magnetic carrier and the toner shown in Table 3.

  The evaluation results of (1) to (3) are shown in Tables 4-1, 4-2, and 4-3 for the initial durability and after 100,000 sheets, respectively.

  By using the replenishment developer containing the toner and carrier peculiar to the present invention, the developer in the development unit and the replenishment developer are efficiently mixed in the development unit, resulting in high durability and high image quality. Can be suitably used for a wide range of electrophotographic systems, electrostatic recording systems, and electrostatic printing systems.

The measurement results of the circularity and equivalent circle diameter of the carrier are shown.

Claims (5)

For replenishment for use in a two-component development method in which at least developer and developer containing toner and magnetic carrier are developed while being replenished to the developer, and at least the excess carrier inside the developer is discharged from the developer. A developer,
The replenishment developer contains 2 to 50 parts by mass of toner with respect to 1 part by mass of the magnetic carrier,
The toner is
i) obtained by an emulsion aggregation method obtained through a process of agglomerating at least polymer fine particles and colorant fine particles to form a fine particle aggregate and an aging step of causing fusion between the fine particles of the fine particle aggregate. Yes,
ii) The weight average diameter (D4) is 3.0 μm to 11.0 μm,
iii) The proportion of particles having an equivalent circle diameter of 0.6 μm to 2.0 μm is 30% by number or less,
iv) The average circularity of particles having an equivalent circle diameter of 2.0 μm or more is 0.940 to 0.985,
The magnetic carrier is
i) 50% particle size (D50) based on volume distribution is 15 to 70 μm,
ii) the true specific gravity is 2.5 to 4.2 g / cm ³ ;
iii) The magnetization intensity under a magnetic field of 1000 / 4π (kA / m) is 40 to 70 Am ² / kg,
iv) The replenishing developer , wherein the magnetic carrier has an average circularity of 0.850 to 0.950 and contains 90% by number or more of particles having a circularity of 0.80 or more . In the molecular weight distribution measured by the THF-soluble matter of the gel permeation chromatography (GPC) of the toner, according to claim 1, characterized in that it has a main peak in the region of molecular weight of 10,000 to 100,000 Developer for replenishment. Replenishing developer according to claim 1 or 2, wherein the polymer particles, characterized in that it contains at least styrene copolymer. Replenishment according to any one of claims 1 to 3, wherein the magnetic carrier is a magnetic substance-containing resin carrier obtained by polymerization of a magnetic material presence of monomers for forming the binder resin Developer. A developing method for discharging developed while replenishing a replenishment developer containing a toner and a magnetic carrier in the developing device, and the carrier becomes excessive developing device within the developing device, one of the claims 1 to 4 A developing method using the developer for replenishment according to claim 1.

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