JP4072557B2 - Toner production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production method of toner high in transfer efficiency by effectively eliminating in a short time the unreacted polymerizable monomer remaining in toner particles produced by suspension polymerization method. <P>SOLUTION: The colored polymerized particles are obtained by polymerizing the polymerizable monomer composition at least containing a polymerizable monomer and coloring agent in a water-based dispersal medium, then washed, and dehydrated, and the obtained wet colored polymerizable monomer particles are dried with hot air. After removing the water-based dispersal medium until it reaches &ge;0.1%, and &lt;1%, the colored polymerizable particles are added with a metallic compound of alkylsalicylic acid, and dried under reduced pressure while agitating until the remaining amount of the unreacted polymerizable monomer in the colored polymer particles becomes &le;200ppm, then the toner particles coated with the metallic compound of alkylsalicylic acid are characteristically obtained. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a toner for developing an electrostatic charge image in an image forming method such as electronic printing, or a toner for forming a toner fixed image in a toner jet type image forming method. The present invention relates to a component developer.

  Conventionally, as an electrophotographic method, as described in Patent Document 1 and Patent Document 2, many methods are known. In general, a photoconductive material is used, and a toner image is formed by developing an electrostatic charge image on a photoreceptor using toner by various means. If necessary, the toner image is transferred to a transfer material such as paper. Thereafter, the image is fixed by heating, pressure, heating pressure, solvent vapor or the like to obtain a copy image or a printed image.

  Conventionally, toners used for these purposes have generally been produced by melt-mixing a colorant composed of a dye / pigment in a thermoplastic resin and uniformly dispersing it, and then producing a toner having a desired particle size using a pulverizer and classifier. It was.

  Although these production methods can produce fairly good toners, there are certain limitations, i.e., limited choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being finely pulverized with economically possible production equipment. However, if the resin colorant dispersion is made brittle to satisfy these requirements, the particle size range of the particles formed when actually pulverized at high speed tends to be widened. It is included in the problem.

  Further, such a highly brittle material is susceptible to further pulverization or powdering when used for development in a copying machine or the like. Also, with this method, it is difficult to completely disperse solid fine particles such as a colorant in the resin. Depending on the degree of dispersion, an increase in fog, a decrease in image density, color mixing, and transparency Care must be taken to disperse as it will cause defects. Further, exposure of the colorant to the fracture surface may cause a change in development characteristics.

  On the other hand, in order to overcome the problems of the toner by these pulverization methods, Patent Document 3, Patent Document 4, and Patent Document 5 propose a toner production method by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, a polar resin, a release agent, and other additives are uniformly dissolved or dissolved. After dispersing, the monomer composition component is dispersed in an aqueous medium containing a dispersant using an appropriate stirrer to polymerize the polymerization monomer. After completion of the polymerization, the mixture is filtered, washed with water and dried to obtain a toner having a desired particle size.

  Since this method does not include a pulverization step, the toner particles do not need to be brittle, a soft material can be used, and the colorant is not exposed to the surface of the toner particles. Has triboelectric charging. Since the classification process can be omitted, cost saving effects such as saving energy, shortening manufacturing time, and improving process yield are great.

  On the other hand, in the suspension polymerization method, including the suspension polymerization method toner, the reaction form of the polymer increases as the polymerization proceeds, the viscosity of the polymerization reaction system increases, and it becomes difficult to move radicals and polymerizable monomers. Many polymerizable monomer components tend to remain therein. In particular, in the case of a suspension polymerization method toner, the polymerizable monomer system contains components such as dyes, pigments (particularly carbon black), charge control agents, and magnetic substances that may inhibit the polymerization reaction. Since it exists in a large amount other than the body, unreacted polymerizable monomers are likely to remain.

  If these toner particles contain many components that act as a solvent for the binder resin as well as the polymerizable monomer, the fluidity of the toner is lowered and the image quality is deteriorated, and the blocking resistance is lowered. . In addition to the performance directly related to toner, especially when using an organic semiconductor as the photoconductor, there are problems associated with photoconductor degradation such as memory ghosting and image blur, in addition to toner fusing to the photoconductor drum. May cause dots. In addition to the matters related to the performance of the product, there is a problem in that the polymerizable monomer component volatilizes and generates a bad odor at the time of fixing.

  In order to improve the above, it is possible to produce a further improvement effect on the image quality by reducing the residual amount of the polymerizable monomer present in the toner particles to 500 ppm or less as in Patent Document 6. Proposed.

  Furthermore, along with the downsizing and personalization of copying machines, printers, etc., restrictions on the apparatus have increased, the burden on the above-mentioned problems has increased, and interest in the environment has increased, and the polymerizability present in the toner particles has increased. It is preferable to reduce the residual amount of monomer to 200 ppm or less, and more preferably to 100 ppm or less.

  As a method for setting the residual amount of polymerizable monomer in the toner particles to 200 ppm or less, a known means for promoting consumption of polymerizable monomer used when the binder resin is produced by suspension polymerization is used. Can do. For example, as a method of removing the unreacted polymerizable monomer, a method of washing with a highly volatile organic solvent that does not dissolve the toner binder resin but dissolves the polymerizable monomer and / or the organic solvent component; A method of washing with acid or alkali; a solvent component that does not dissolve the foaming agent or polymer is put into the polymer system, and the resulting toner is made porous, thereby volatilizing the internal polymerizable monomer and / or organic solvent component. And a method of volatilizing the main synthetic monomer and / or organic solvent component under dry conditions, but it is possible to select a solvent such as elution of toner constituents due to a decrease in toner capsule properties and the residual property of the solvent. Since it is difficult, the method of volatilizing a polymerizable monomer and / or an organic solvent component under dry conditions is most preferable.

  Conventionally, the drying method of toner particles after solid-liquid separation of the suspension after the polymerization reaction has been improved. For example, Patent Document 7 proposes a method in which toner particles are suspended and suspended in a gas and dried while forming a fluidized bed. Further, a method for drying toner particles using a fluidized bed dryer is proposed in Patent Document 8, Patent Document 9, and the like.

  The toner particle drying method using the fluidized bed dryer can efficiently dry the toner. However, since the unreacted polymerizable monomer described above generally has a boiling point higher than that of water, it can be effectively removed only after the removal of moisture is almost completed. However, it cannot be removed effectively without sufficient reduction drying. However, when moisture is removed, particles with charging properties such as toner particles cause adhesion to the wall surface of the fluid chamber, and further, the particles adhered to the wall surface of the fluid chamber peel in a lump state, As a whole, problems such as non-removable removal of the unreacted polymerizable monomer, or the inability to recover the entire amount after the treatment occur.

  Further, Patent Document 10 discloses that the toner particles or the suspension after solid-liquid separation of the suspension after the polymerization reaction is dispersed as it is in a granular form in a hot air stream and sent in parallel with the hot air stream. A method of instantaneous drying has been proposed.

  This method of drying toner particles by a hot air stream can remove water efficiently and continuously. However, the above-mentioned unreacted polymerizable monomer can hardly be removed by instantaneous drying.

  Further, Patent Document 11 and the like propose a method of drying using a vacuum drying apparatus.

  However, in this drying method, after removing the water by evaporation, further removal of the unreacted polymerizable monomer requires not only a very long drying time, but also the inside of the apparatus during the removal of the water. The toner is tightened and aggregated due to the vacuum state to form a compacted state. The formation of this compacted state becomes prominent when the moisture content becomes 5% or less, and the cohesive force between the powders suddenly increases from the increase in the powder temperature. When this compacted state is formed, adhesion and fusion are caused on the apparatus wall surface, the agitating blade in the apparatus, etc., and stable operation is hindered. Further, the toner is agglomerated due to aggregation between the toners.

  In addition, the electrostatic image developing toner has various chemical substances added to improve the image quality and achieve other required characteristics, and in particular, various kinds of resolution, density uniformity, fog, etc. For the purpose of improving image characteristics, various fine powders are widely added to improve the fluidity and chargeability of toner.

  However, if the toner is agglomerated due to aggregation between the toners, the external additive does not uniformly adhere to the toner surface when the toner is externally added in a later step, which causes a problem in performance as a developer.

  On the other hand, in order to obtain a full-color image, an image forming method using an intermediate transfer member has been proposed. Patent Document 12 discloses a full-color image device using a drum-shaped intermediate transfer member, and Patent Document 13 discloses a toner. There has been proposed a method in which the toner image formed in Step 1 is transferred to an intermediate transfer member, and the toner image on the intermediate transfer member is further transferred to a transfer material.

  However, in a system using an intermediate transfer member, it is necessary to transfer the toner image once from the photosensitive member to the intermediate transfer member, and then transfer the toner image again onto the transfer material from the intermediate transfer low. Need to be increased.

US Patent 2,297,691 Japanese Patent Publication No.43-24748 Japanese Patent Publication No. 36-10231 Japanese Patent Publication No.42-10799 Japanese Patent Publication No. 51-14895 JP-A-7-92736 JP-A-63-124055 Japanese Patent Laid-Open No. 4-31966 JP-A-8-179562 JP-A-6-324517 Japanese Patent Application Laid-Open No. 8-160662 US Pat. No. 5,187,526 JP 59-15739 A

  An object of the present invention is to provide a toner production method in which toner particles obtained by a direct polymerization method are uniformly dried with unreacted polymerizable monomers and dried efficiently.

  Another object of the present invention is to provide a method for producing a toner capable of obtaining a high-quality image free from image defects caused by the remaining unreacted polymerizable monomer.

  Another object of the present invention is to provide a method for producing a toner having high transfer efficiency and capable of obtaining an image having good environmental characteristics.

  In the present invention, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in an aqueous dispersion medium to produce colored polymer particles, which are then washed and dehydrated. The wet colored polymer particles are dried using hot air to remove the aqueous dispersion medium to a water content of 0.1% or more and less than 1.0%, and then the metal particles of alkyl salicylic acid are added to the colored polymer particles. While stirring these, the metal compound of alkylsalicylic acid is obtained by drying under reduced pressure until the remaining amount of the unreacted polymerizable monomer remaining in the colored polymer particles is 200 ppm or less. The present invention relates to a toner manufacturing method characterized in that toner particles covering the particle surface are obtained.

  The formation process and significance of the present invention will be described.

  As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors polymerized a polymerizable monomer composition containing at least a polymerizable monomer and a colorant in an aqueous dispersion medium. Then, after producing colored polymer particles, washing, dewatering, and drying the resulting colored polymer particles in a wet state using hot air, the water content is 0.1% or more and 1.0%. After substantially removing the aqueous dispersion medium to less than the above, by adding a metal compound of alkylsalicylic acid to the colored polymer particles and drying them under reduced pressure, stable operation of the dryer is not hindered. In addition, since the occurrence of lumps due to aggregation between toners is suppressed and the external additive can be uniformly adhered in the subsequent process, the performance as a developer is not impaired in the drying stage of the wet toner, and the toner particles Unreacted remaining in The toner particles in which the monomer is easily removed, the residual amount thereof is 200 ppm or less, the impurities of the metal compound of the alkyl salicylic acid are removed, and the metal particle of the alkyl salicylic acid coats the toner particle surface are efficient. The inventors have found that they can be obtained well and have reached the present invention.

  In the fluidized bed dryer used in the conventional method for producing polymerized toner, in order to remove the remaining amount of the unreacted polymerizable monomer to 200 ppm or less, the water content is reduced to 0.1% or less (as water content). After removal, it is necessary to continue drying, and as described above, when moisture is removed, particles with charging properties such as toner particles cause adhesion to the wall surface of the fluid chamber, and Particles adhering to the wall surface of the fluid chamber are peeled off in a lump state, and as a whole, removal of unreacted polymerizable monomer becomes non-uniform, performance deterioration as a developer, and workability Caused the problem of decline.

  In addition, when drying is performed using a (vacuum) reduced pressure drying method from the beginning, a very long drying time is required, and when water is removed, lumps due to aggregation of toners occur. When lumps occur, the external additive does not uniformly adhere to the toner surface when externally adding to the toner in a later step, causing a problem in performance as a developer. Moreover, it is difficult to remove the unreacted polymerizable monomer remaining in the particles from the inside of the agglomerated dust, which becomes non-uniform and causes the problems described above.

  According to the present invention, toner particles obtained by suspension polymerization are efficiently removed in a short time from unreacted polymerizable monomers remaining in the toner particles to obtain toner particles having high transfer efficiency. The manufacturing method of can be provided.

  Next, the present invention will be described in detail with reference to preferred embodiments.

  As the polymerizable monomer used when the toner of the present invention is produced by the polymerization method, a styrene monomer and a vinyl polymerizable monomer capable of radical polymerization are used. As the vinyl polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  Monofunctional polymerizable monomers include α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenyl Styrene derivatives such as styrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl Acrylate, n-oct Acrylic polymerizable monomers such as til acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate , Ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n -Nonyl methacrylate, diethyl phosphate ethyl methacrylate, di Methacrylic polymerizable monomers such as tylphosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl esters such as vinyl acetate, vinyl propionate, vinyl acetate, vinyl benzoate, vinyl formate; vinyl methyl ether, vinyl ethyl Examples thereof include vinyl ethers such as ether and vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropyl ketone.

  As polyfunctional polymerizable monomers, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2′-bis (4- (acryloxy-diethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate Triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol Dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4- (methacryloxy-diethoxy) phenyl) propane, Examples include 2,2′-bis (4- (methacryloxy / polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether, and the like.

  In the present invention, a styrene monomer and the above monofunctional polymerizable monomer alone or in combination of two or more thereof, or the above monofunctional polymerizable monomer and polyfunctional polymerizable monomer. Are used in combination. The polyfunctional polymerizable monomer can also be used as a crosslinking agent.

  As the polymerization initiator used in the polymerization of the polymerizable monomer described above, an oil-soluble initiator and / or a water-soluble initiator is used. For example, as the oil-soluble initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile) Azo compounds such as 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide Oxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, dicumylper Kisaido, t- butyl hydroperoxide, di -t- butyl peroxide, peroxide-based initiators cited such as cumene hydroperoxide.

  Water-soluble initiators include ammonium persulfate, potassium persulfate, 2,2′-azobis (N, N′-dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloric acid Salts, sodium azobis (isobutylamidine) hydrochloride, sodium 2,2′-azobisisobutyronitrile sulfonate, ferrous sulfate or hydrogen peroxide.

  In the present invention, in order to control the polymerization degree of the polymerizable monomer, a chain transfer agent, a polymerization inhibitor and the like can be further added and used.

  When suspension polymerization is used as the toner production method of the present invention, the dispersant used is, for example, an inorganic oxide such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate. , Calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic substance, ferrite and the like. As the organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like can be dispersed in an aqueous phase. These dispersants are preferably used in an amount of 0.2 to 10.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  Commercially available dispersants may be used as they are, but in order to obtain dispersed particles having a fine and uniform particle size, the inorganic compound can be produced in a dispersion medium under high-speed stirring. For example, in the case of tricalcium phosphate, a dispersant preferable for the suspension polymerization method can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring.

  Moreover, you may use together 0.001-0.1 mass part surfactant for refinement | miniaturization of these dispersing agents. Specifically, commercially available nonionic, anionic and cationic surfactants can be used, such as sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pendadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate. , Calcium oleate and the like.

  A well-known thing can be used as a coloring agent used by this invention.

  For example, examples of the black pigment include carbon black, aniline black, nonmagnetic ferrite, and magnetite.

  Examples of the yellow pigment include yellow iron oxide, navel yellow, naphthol yellow S, hanzer yellow G, hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartrazine lake.

  Examples of the orange pigment include permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, and indanthrene brilliant orange GK.

  Examples of red pigments include Bengala, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red C, Lake D, Brilliant Carmine 6B, Brilliant Carmine 3B, Eoxin Lake, Rhodamine Lake B, and Alizarin Lake. It is done.

  Examples of the blue pigment include alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, first sky blue, and indanthrene blue BG.

  Examples of purple pigments include Fast Violet B and Methyl Violet Lake.

  Examples of the green pigment include Pigment Green B, Malachite Green Lake, Final Yellow Green G, and the like.

  Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide.

  These colorants can be used alone or in combination and further in the form of a solid solution.

  The colorant used in the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. The added amount of the colorant is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the resin. When a magnetic material is used as the black colorant, it is preferably used at 30 to 150 parts by mass with respect to 100 parts by mass of the resin, unlike other colorants.

  As the colorant when the toner for developing an electrostatic charge image of the present invention is used as a translucent color toner, a cyan colorant, a magenta colorant, and a yellow colorant as shown below can be used.

  As the cyan colorant, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds, and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 and the like can be used particularly preferably.

  As the magenta colorant, condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds are used. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, 254 are particularly preferred.

  As the yellow colorant, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180, etc. are preferably used.

  These colorants can be used alone or in combination and further in the form of a solid solution. The colorant is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin or monomer.

  In the present invention, in order to produce toner particles using a polymerization method, it is necessary to pay attention to the polymerization inhibition property and water phase transfer property of the colorant. If necessary, surface modification may be performed by subjecting the surface of the colorant to a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since dyes and carbon black often have polymerization inhibiting properties, care must be taken when using them.

  A preferred method for treating the dye includes a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance. The obtained colored polymer is added to the polymerizable monomer composition. About carbon black, you may process with the substance (for example, organosiloxane etc.) which reacts with the surface functional group of carbon black besides the process similar to the said dye.

  Examples of the polymerization initiator used in the present invention include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane- 1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or diazo polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy Peroxide-based polymerization initiators such as carbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide are used. The addition amount of the polymerization initiator varies depending on the target degree of polymerization, but generally 0.5 to 20% by mass is added to the monomer. The kind of the polymerization initiator is slightly different depending on the polymerization method, but can be used alone or in combination with reference to the 10-hour half-life temperature.

  In order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.

  Examples of negative charge control include compounds containing a carboxy group (for example, alkylsalicylic acid metal chelates), metal complex dyes, fatty acid soaps, naphthenic acid metal salts, and the like. In particular, alkylsalicylic acid coordinated with aluminum, zinc or zirconia. Is a white crystal powder, and is therefore preferably used as a full-color toner.

  Examples of the releasing agent (offset preventing agent) include aliphatic hydrocarbons, aliphatic metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, various waxes and the like. Among these, aliphatic hydrocarbons having a weight average molecular weight of about 1000 to 10,000 are preferable. Specifically, one or a combination of two or more of low molecular weight polypropylene, low molecular weight polyethylene, paraffin wax, a low molecular weight olefin polymer composed of an olefin unit having 4 or more carbon atoms is suitable.

  The release agent is used at a ratio of 0.1 to 15 parts by mass with respect to 100 parts by mass of the binder resin. The toner of the present invention is polymerized by dissolving in a monomer in a suspension polymerization method. The toner thus obtained forms a release agent layer in the central portion.

  The addition amount of the resin having a polar group is preferably in the range of 1 to 20 parts by mass, more preferably 2.5 to 15 parts by mass with respect to 100 parts by mass of the binder resin in the toner particles. When the amount is less than 1 part by mass, the function as an upper layer of the toner particles is deteriorated. When the amount exceeds 20 parts by mass, the upper layer formed on the toner particles becomes excessive, and the charging stability of the toner tends to be reduced.

  Among resins having a polar group, a polyester resin or a derivative thereof is preferable. The composition of a typical polyester resin is as follows.

  As an alcohol component of the polyester resin, ethylene glycol, propylene glycol, butanediol, diethylene glycol, triethylene glycol, pentanediol, hexanediol, neopentyl glycol, hydrogenated bisphenol A, or bisphenol represented by the following formula (I) Derivatives, and diols represented by the following (II) are exemplified.

（式中、Ｒはエチレン又はプロピレン基であり、ｘ及びｙはそれぞれ１以上の整数であり、かつｘ＋ｙの平均値は２〜１０である。）

(In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 10.)

  The particle size of the toner of the present invention is preferably 3 to 35 μm, and more preferably 5 to 25 μm. The surface of the toner of the present invention can be coated with a surface treatment agent (fluidizing agent) to improve fluidity and chargeability. As the surface treatment agent, various conventionally known materials such as inorganic fine particles and fluororesin particles can be used. In particular, a silica-based surface treatment agent containing hydrophobic or hydrophilic silica fine particles, for example, ultrafine particulate anhydrous silica or Colloidal silica or the like is preferably used.

  In the method for producing the toner of the present invention, the polymerizable monomer composition is polymerized to form colored polymer particles, and then washed, and the resulting slurry containing the colored polymer particles is dehydrated and obtained. The wet colored polymer particles obtained are used as a dry raw material. When the wet colored polymer particles are used as a dry raw material, the wet colored polymer particles before drying have a water content from the viewpoint of fluidity as a powder. It is preferable that it is 40% or less. Furthermore, 30% or less is more preferable. The term “moisture content” as used herein refers to the moisture content moisture content, that is, the ratio of the moisture mass to the total mass (the sum of the dry toner mass and the moisture mass), and is a value determined by a heat loss method at 105 ° C. Using.

  The toner particles having such a moisture content can be easily obtained by a normal solid-liquid separation means (for example, filtration), but in order to obtain such a moisture content, preliminary drying may be performed.

  In the present invention, for example, a loop type as shown in FIG. 1 may be used as an apparatus for instantaneously drying such a material to be dried in a hot air stream while being fed in parallel with a high-speed hot air stream. The air dryer etc. which have the following drying pipe 2 are mentioned, However It does not restrict | limit in particular.

  In the hot air dryer shown in FIG. 1, the compressed air heated to a predetermined temperature in the hot air generator 1 is discharged at supersonic speed by the air flow dispersion unit 3, and the material to be dried supplied from the slurry or wet particle supply device 6 is discharged. , Dispersed and dried instantaneously (0.5 to 10 seconds) in the loop type airflow drying tube 2. The airflow outlet 4 is placed inside a loop type airflow drying tube to classify the dried product and the undried product by the Coanda effect. The dried product is separated from the airflow by the cyclone 5 and is removed from the system from the outlet 7. Can be put out.

  Further, the coarse particles in the particles coming out of the drying tube 2 are separately classified by a classifier and returned to the material to be dried supplying apparatus 6, and only particles having a certain particle size range are supplied to the cyclone 5 to obtain desired toner particles. By obtaining, classification and drying can be performed continuously. In addition to the loop type described above, the drying tube type of the air dryer is a straight tube type, with an enlarged inner cylinder to increase the residence time, and deposits on the bottom of the horizontal tube by giving vortex motion to the particles. Various types of drying tubes, such as a model that prevents the occurrence of the problem, can be used, but an air dryer having a loop-type drying tube as shown in FIG. 1 is most preferable.

  In the present invention, it is preferable to use compressed air heated to 40 to 150 ° C., preferably 60 to 120 ° C., for drying with a hot air stream. When the heating temperature is lower than 40 ° C., the drying efficiency is lowered. When the heating temperature is higher than 150 ° C., the toner is fused.

  As an apparatus for instantly drying such a material to be dried (wet particles) preferably used in the present invention in a high-speed hot air stream and sending it in parallel with the hot air stream, a flash is specifically used. Examples include jet dryers (manufactured by Seishin Company) and flash dryers (manufactured by Hosokawa Micron).

  In addition, as a device for suspending and suspending such an object to be dried (wet particles) preferably used in the present invention to form a fluidized bed and drying it, a fluidized bed dryer (Okawara Seisakusho) or a vibrating fluidized bed Examples include dryers (manufactured by Chuo Kako Co., Ltd.).

  In the toner production method of the present invention, drying with hot air was performed as described above so that the water content of the colored polymer particles was in the range of 0.1% to less than 1.0%. Thereafter, a metal compound of alkyl salicylic acid is added to the colored polymer particles after the primary drying, and the mixture is stirred under reduced pressure until the remaining amount of the unreacted polymerizable monomer is 200 ppm or less.

  The metal compound of alkyl salicylic acid used in the present invention finally coats the surface of the toner and serves to improve transfer efficiency, but its primary particle size is as small as 0.2 μm or less, and the colored weight after primary drying is finished. There is an effect of imparting fluidity to the coalesced particles or suppressing aggregation. Therefore, after adding such a metal compound of alkyl salicylic acid to the colored polymer particles, by performing drying under reduced pressure while stirring them, the colored polymer particles are adhered to each other in a reduced-pressure dryer. Unreacted polymerizable monomer remaining in the toner particles because it circulates without causing aggregation and adhesion between the particles and the device, and further receives heat from the outer wall of the dryer uniformly and efficiently. The residual amount of can be reduced to 200 ppm or less. At the same time, alkylsalicylic acid, which is an impurity contained in the metal compound of alkylsalicylic acid, can be sublimated and reduced.

  Furthermore, when the dried colored polymer particles are taken out from the reduced pressure drier after the drying, the fluidity is good and there is no adhesion to the inside of the apparatus, so that it can be taken out well.

  A vacuum dryer equipped with a stirring mechanism used after substantially removing the aqueous dispersion medium used in the method for producing a toner of the present invention is an apparatus capable of drying colored polymer particles in a vacuum (= depressurized) drying state. If there is, it can be used without particular limitation. In the present invention, for example, an agitating / decompressing dryer having an aspect as shown in FIGS. 2 and 3 is preferably used. These will be described below.

  The vacuum drying apparatus shown in FIG. 2 is arranged on the inner peripheral surface of the container 32 while a screw type stirring member 35 connected via a drive arm 34 to a drive apparatus 33 arranged on the upper part of the inverted conical container 32 rotates. It is configured to swirl along, and repeatedly agitates and disperses while lifting the processing raw material in the container 32 upward from below, and can be efficiently stirred and mixed throughout the container 32. A raw material supply port 36 and an exhaust port 37 are provided at the upper part of the container 32, and a product take-out port 38 is provided at the lower side with a take-out valve 39 connected thereto. An airtight lid 16 is attached to the raw material supply port 36, and the bag filter 10 is connected to the exhaust port 37.

  A jacket 11 is attached around the container 32. The jacket 11 is provided with a steam supply port 12, a cooling water supply port 13, and a discharge port 14. The steam supply port 12 is not shown in the figure. However, a steam generating boiler is connected, and a cooling water pump 16 is connected to the cooling water supply port 13.

  In addition, the steam inlets 17 of the container 32 are provided at two positions above and below the container 32, and the supply amount on the lower side is increased so as to obtain a stirring effect of the raw material at the time of injection. It is connected to a steam generating boiler 19 via an accumulator 18. The accumulator 18 is used to quickly feed saturated or superheated steam into the container 32, and is indispensable to finish heating the raw material in the container 32 in a short time. The container 32 can be decompressed by the vacuum pump 28 from the exhaust port 37 via the bag filter 10 and the cold trap 20.

  The bag filter 10 is partitioned into two upper and lower chambers by a partition plate 21, a tubular filter cloth 22 is suspended on the lower side, and an exhaust port 23 and a filter connected to the cold trap 20 on the upper side. A cleaning nozzle 24 is disposed at a position above the center of the cloth 22 and the filter cloth 22 is reversely cleaned by intermittently injecting high-pressure air from the compressor 25. Further, an accumulator 27 is provided between the filter 26 and the cleaning nozzle 24. This accumulator 27 compensates for the shortage of high-pressure air supply on the compressor 25 side, sends a constant amount of high-pressure air to the cleaning nozzle 24 in a stable state with little pressure fluctuation, and the flow rate of air passing through the filter 26 and The passage speed is kept substantially constant, and the filtration effect by the filter 26 is stabilized.

  The gas is supplied from the gas supply port 30 as a carrier gas for suppressing blocking of toner particles in the lower part of the inside of the apparatus and efficiently evaporating adhering moisture or residual polymerizable monomer from the particle surface. work. Therefore, it is preferable to supply gas from the viewpoint of improving efficiency.

  The humidified air exhausted from the bag filter 10 is sent to the cold trap 20 and condensed, moisture and the like are discharged as drain, and the air is exhausted from the vacuum pump 28. Further, a pump 29 for feeding cooling water is connected to the cold trap 20.

  The type of gas introduced into the container 32 is not particularly limited, and an inert gas such as nitrogen or air is used.

  The vacuum drying apparatus in FIG. 3 is configured such that a ribbon blade 40 having a double spiral structure rotates on a drive device 33 disposed on the upper part of an inverted conical container 32, and the processing raw material in the container 32 is moved downward. Stirring and dispersion are repeatedly imparted while being lifted upwards, and the entire container 32 can be efficiently stirred and mixed. Since other parts are common to the vacuum drying apparatus of FIG.

  Specific examples of the stirring depressurization dryer used after substantially removing the aqueous dispersion medium preferably used in the present invention include a Nauter mixer (manufactured by Hosokawa Micron), Ribocorn (manufactured by Okawara Seisakusho), SV mixer (shinko bread Tech).

  In the toner production method of the present invention, the alkyl salicylic acid metal compound to be added to the colored polymer particles when dried with the above-described stirring reduced pressure drier is a low crystalline or amorphous alkyl salicylic acid. A metal complex salt, a metal complex, or a mixture of a metal complex salt and a metal complex is preferable.

  If the metal complex salt or metal complex of alkylsalicylic acid is low crystalline or amorphous, the toner surface can be finally uniformly coated, and the metal complex or metal complex of alkylsalicylic acid coated on the toner surface is transferred. To prevent toner charge leakage (a phenomenon in which the charge amount of the toner decreases due to discharge generated between the toner or the photoconductor and the transfer material, or a reverse polarity), and friction between the photoconductor and the toner This increases the charge amount of the toner and increases the electrostatic adhesion force with the transfer material, so that the transfer efficiency is improved. When the metal complex salt or metal complex of alkylsalicylic acid or a mixture of the metal complex salt and the metal complex is a crystalline substance, it is hard because it is a crystal, and does not coat the toner, but the crystal is embedded in the toner. Further, even if the addition amount is increased, the toner is embedded unevenly, and the entire toner cannot be covered uniformly. Further, when the crystal is large, it cannot be embedded in the toner. Therefore, leakage of toner charge cannot be prevented, and a phenomenon called “retransfer” in which the toner transferred onto the transfer material returns to the photoreceptor cannot be prevented.

  Furthermore, in the method for producing a toner of the present invention, the alkylsalicylic acid metal compound added to the colored polymer particles when drying with the above-described stirring decompression dryer is particularly an aluminum or zirconium compound as a central metal. Therefore, the effect of preventing retransfer is great and the transfer efficiency is high. This is considered to be due to the fact that an aluminum or zirconium compound of oxycarboxylic acid improves the chargeability of the toner, a large charge amount is obtained, and the coatability of the toner is good.

  In addition, when the primary particle size of the metal compound of the alkyl salicylic acid is larger than 0.2 μm, the effect of improving the fluidity of the toner is reduced, so that the particle size is preferably 0.2 μm or less. Is more preferable.

  The toner used in the present invention has a finer particle diameter, specifically a weight average diameter measured by a Coulter counter of 4 μm in order to faithfully develop finer latent image dots for higher image quality. A toner having a number variation coefficient of 35% or less at ˜8 μm is most preferable. In a toner having a weight average diameter of less than 4 μm, a large amount of untransferred toner is generated on the photosensitive member or the intermediate transfer member due to poor transfer efficiency, which causes image unevenness due to fogging or transfer failure. Further, when the weight average diameter of the toner exceeds 8 μm, fusion to the member is likely to occur, and when the number variation coefficient of the toner exceeds 35%, the tendency further increases and becomes a problem.

  As the low softening point substance used in the toner according to the present invention, a compound having a main maximum peak value measured according to ASTM D3418-8 of 40 to 90 ° C. is preferable. When the maximum peak is less than 40 ° C., the self-aggregation force of the low softening point substance becomes weak, and as a result, the high temperature offset resistance becomes weak, which is not preferable for a full color toner. On the other hand, if the maximum peak exceeds 90 ° C., the fixing temperature increases, and it becomes difficult to appropriately smooth the surface of the fixed image, which is not preferable from the viewpoint of color mixing. Furthermore, in the case of obtaining a toner by a direct polymerization method, granulation and polymerization are carried out in an aqueous system, so if the temperature at the maximum peak value is high, a low softening point substance mainly precipitates during granulation and inhibits the suspension system. Therefore, it is not preferable.

  For example, DSC-7 manufactured by Perkin Elmer is used to measure the temperature of the maximum peak value. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium. For the sample, an aluminum pan is used, an empty pan is set for control, and the measurement is performed at a heating rate of 10 ° C./min.

  Specifically, paraffin wax, polyolefin wax, Fischer tropish wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof can be used. Preferably, the ester wax having one or more long-chain ester moieties having 10 or more carbon atoms represented by the following general structural formula has an effect on high-temperature offset resistance without impairing the transparency of OHP. preferable. Specific structural formulas of typical ester wax compounds preferable for the present invention are shown as general structural formula 1), general structural formula 2) and general structural formula 3) below.

（式中、ａ及びｂは０〜４の整数を示し、ａ＋ｂは４であり、Ｒ₁及びＲ₂は炭素数が１〜４０の有機基を示し、且つＲ₁とＲ₂との炭素数差が１０以上である基を示し、ｎ及びｍは０〜１５の整数を示し、ｎとｍが同時に０になることはない。）

(Wherein, a and b represent an integer of 0 to 4, a + b is 4, R ₁ and R ₂ represent an organic group having 1 to 40 carbon atoms, and the carbon number of R ₁ and R _2. A group having a difference of 10 or more, n and m are integers of 0 to 15, and n and m are not 0 at the same time.)

（式中、ａ及びｂは０〜４の整数を示し、ａ＋ｂは４であり、Ｒ₁は炭素数が１〜４０の有機基を示し、ｎ及びｍは０〜１５の整数を示し、ｎとｍが同時に０になることはない。）

(In the formula, a and b represent an integer of 0 to 4, a + b represents 4, R ₁ represents an organic group having 1 to 40 carbon atoms, n and m represent an integer of 0 to 15; And m are never 0 at the same time.)

（式中、ａ及びｂは０〜３の整数を示し、ａ＋ｂは３以下であり、Ｒ₁及びＲ₂は炭素数が１〜４０の有機基を示し、且つＲ₁とＲ₂との炭素数差が１０以上である基を示し、Ｒ₃は炭素数が１以上の有機基を示し、ｎ及びｍは０〜１５の整数を示し、ｎとｍが同時に０になることはない。）

(In the formula, a and b represent integers of 0 to 3, a + b is 3 or less, R ₁ and R ₂ represent an organic group having 1 to 40 carbon atoms, and carbons of R ₁ and R _2. A group having a number difference of 10 or more, R ₃ represents an organic group having 1 or more carbon atoms, n and m represent an integer of 0 to 15, and n and m are not 0 at the same time.)

  The ester wax preferably used in the present invention preferably has a hardness of 0.5 to 5.0. The hardness of the ester wax is a value obtained by measuring a Vickers hardness using, for example, a dynamic ultra-micro hardness meter (DUH-200) manufactured by Shimadzu Corporation after preparing a cylindrical sample having a diameter of 20 mmφ and a thickness of 5 mm. Measurement conditions are as follows: a load of 0.5 g and a load speed of 9.67 mm / second are displaced by 10 μm and held for 15 seconds, and the resulting dent shape is measured to determine the Vickers hardness. A low softening point material having a hardness of less than 0.5 increases the pressure dependency and process speed dependency of the fixing device, and the high temperature offset effect tends to be insufficient. Since the stability is poor and the self-cohesive force of the release agent itself is small, the high-temperature offset resistance tends to be insufficient. Specific compounds include the following compounds.

  In recent years, the need for full-color double-sided images has increased, and when a double-sided image is formed, the heating part of the fixing unit is also used when the toner image on the transfer paper first formed on the front side forms the next image on the back side. It is necessary to sufficiently consider the high-temperature offset resistance of the toner. Therefore, in the present invention, it is desirable to add a large amount of a low softening point substance. Specifically, it is preferable to add 5 to 40% by mass of a low softening point substance in the toner. When the amount is less than 5% by mass, sufficient high-temperature offset resistance is not exhibited, and the image on the back side tends to exhibit an offset phenomenon at the time of fixing a double-sided image. On the other hand, when the amount exceeds 40% by mass, coalescence of toner particles is likely to occur during granulation, and a product having a wide particle size distribution is likely to be generated, which is inappropriate for the present invention.

  As the method for producing the toner particles of the present invention, the suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842 is directly used. It is possible to produce toner using a method of producing toner.

  In the present invention, a so-called seed polymerization method in which a monomer is further adsorbed to the obtained polymer particles and then polymerized using a polymerization initiator can be suitably used in the present invention.

  Further, in the present invention, considering that a large amount of a low softening point substance is contained in the toner from the viewpoint of fixability, it is inevitably necessary to encapsulate the low softening point substance in the outer shell resin. As a specific method for embedding the low softening point substance, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than the main monomer, and a small amount of a resin or monomer having a large polarity. Is added to obtain a toner having a so-called core-shell structure in which a low softening point substance is coated with an outer shell resin. Toner particle size distribution control and particle size control can be achieved by changing the type and amount of dispersion-inhibiting inorganic salts and protective colloids and mechanical equipment conditions such as rotor speed, number of passes, A predetermined toner of the present invention can be obtained by controlling the stirring conditions such as the shape of the stirring blades, the container shape, or the solid content concentration in the aqueous solution.

  In the present invention, as a specific method for measuring the tomographic plane of the toner, the toner is sufficiently dispersed in a room temperature curable epoxy resin, and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. After staining with ruthenium tetroxide and, if necessary, osmium tetroxide, a flaky sample was cut out using a microtome equipped with diamond teeth, and the tomographic morphology of the toner was measured using a transmission electron microscope (TEM). In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to provide contrast between materials by utilizing a slight difference in crystallinity between the low softening point substance used and the resin constituting the outer shell. A typical example is shown in FIG. It was clearly observed that the low softening point material was encapsulated by the outer shell resin.

  In the toner manufacturing method of the present invention, the toner can be specifically manufactured by the following manufacturing method.

  That is, a release agent composed of a low softening point substance, a colorant, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and the mixture is uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser or the like. The monomer system is dispersed in an aqueous phase containing a dispersion stabilizer by a normal stirrer, clear mixer, homomixer, homogenizer or the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the monomer droplets have a desired toner particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. The polymerization is preferably carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and in order to remove unreacted polymerizable monomers and by-products that cause odor during toner fixing, the latter half of the reaction, or the completion of the reaction. A part of the aqueous medium may be distilled off later. In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

  After completion of the reaction, the produced colored polymer particles (toner particles) are recovered by washing and filtration, and the wet colored polymer particles are dried by the drying method of the present invention described above to obtain a metal compound of alkyl salicylic acid. A toner having a toner surface coated thereon is obtained.

  In the present invention, the toner particles having the toner surface coated with the dried metal compound of alkylsalicylic acid obtained as described above further imparts mechanical impact force, and the adhesion state of the metal compound of alkylsalicylic acid to the toner particles. Is preferably adjusted. That is, it is preferable to adjust the adhesion state of the external additive to the toner particles by applying a mechanical impact force with a dry mixer such as a Henschel mixer. More specifically, the peripheral speed of the high-speed rotary blade of the Henschel mixer and the processing time are adjusted to adjust the adhesion state of the external additive to the toner particles.

  Further, at this time, it is preferable to add an external additive such as a fluidity-imparting agent, a chargeability-imparting agent, or an abrasive as necessary, and simultaneously or additionally process it.

  When a two-component developer is prepared by mixing a toner and a carrier, the mixing ratio is 2 to 15% by mass, preferably 4 to 13% by mass as the toner concentration in the developer. Results. When the toner concentration is less than 2% by mass, the image density tends to be low, and when it exceeds 15% by mass, fogging or in-machine scattering tends to occur, and the useful life of the developer tends to decrease.

As a developing method using the toner and the carrier according to the present invention, for example, development can be performed using a developing means as shown in FIG. Specifically, it is preferable to perform development in a state where the magnetic brush is in contact with the latent image carrier, for example, the photosensitive drum 501 while applying an alternating electric field. The distance (SD distance) B between the developer carrying member (developing sleeve) 511 and the photosensitive drum 501 is 100 to 1000 μm in terms of preventing carrier adhesion and improving dot reproducibility. If it is narrower than 100 μm, the supply of developer tends to be insufficient, and the image density becomes low, and if it exceeds 1000 μm, the magnetic lines from the magnetic pole S ₁ spread and the density of the magnetic brush decreases, resulting in poor dot reproducibility and magnetic coating. The force that restrains the carrier is weakened, and carrier adhesion is likely to occur.

  The voltage between the peaks of the alternating electric field is preferably 300 to 3000 V, and the frequency is 500 to 10000 Hz, preferably 1000 to 7000 Hz, which can be appropriately selected depending on the process. In this case, a triangular wave, a rectangular wave, a sine wave, a waveform with a changed duty ratio, an intermittent alternating superimposed electric field, or the like can be selected and used as the waveform. When the applied voltage is lower than 300 V, it is difficult to obtain a sufficient image density, and the fog toner in the non-image portion may not be recovered well. If the voltage exceeds 5000 V, the latent image may be disturbed via the magnetic brush, resulting in a decrease in image quality.

  By using a two-component developer with well-charged toner, the anti-fogging voltage (Vback) can be lowered and the primary charge of the photoreceptor can be lowered, thus extending the life of the photoreceptor. it can. Vback is 200 V or less, more preferably 150 V or less, although it depends on the development system.

  The contrast potential is preferably 100 V to 400 V so that a sufficient image density is obtained.

  When the frequency is lower than 500 Hz, although related to the process speed, when the toner in contact with the electrostatic image carrier is returned to the developing sleeve, sufficient vibration is not applied and fogging is likely to occur. If it exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is likely to deteriorate.

  What is important in the developing method of the present invention is that the contact width of the magnetic brush on the developing sleeve 511 with the photosensitive drum 501 in order to obtain a sufficient image density, excellent dot reproducibility, and development without carrier adhesion ( The development nip C) is preferably 3 to 8 mm. If the development nip C is narrower than 3 mm, it is difficult to satisfactorily satisfy a sufficient image density and dot reproducibility. If the development nip C is wider than 8 mm, developer packing occurs and the operation of the machine stops or the carrier adheres. It is difficult to sufficiently suppress As a method for adjusting the developing nip, the nip width is appropriately adjusted by adjusting the distance A between the developer regulating member 515 and the developing sleeve 11 or by adjusting the distance B between the developing sleeve 511 and the photosensitive drum 501.

  In the image forming method of the present invention, three or more developing devices for magenta, cyan and yellow are used in the output of a full color image in which color reproducibility is particularly important, and the developer and the developing method of the present invention are used. In particular, when combined with a development system that forms a digital latent image, the dot latent image can be developed faithfully without being affected by the magnetic brush and without disturbing the latent image. Even in the transfer process, a high transfer rate can be achieved by using a toner having a fine particle size distribution that has been finely powder-cut. Therefore, high image quality can be achieved in both the halftone part and the solid part.

  In addition to the improvement of the initial image quality, the use of the two-component developer according to the present invention reduces the share of the developer in the developing device, and the effect of the present invention does not deteriorate the image quality even when copying many sheets. Can fully demonstrate.

  In order to obtain a more tightened image, it is preferable to have a developing device for magenta, cyan, yellow, and black, and a tight image can be obtained by performing black development last.

  The image forming method of the present invention will be described with reference to the accompanying drawings.

  In FIG. 5, a magnetic brush made of magnetic particles 523 is formed on the surface of the conveying sleeve 522 by the magnetic force of the magnet roller 521, and this magnetic brush is brought into contact with the surface of the electrostatic charge image carrier (photosensitive drum) 501. The drum 501 is charged. A charging bias is applied to the conveying sleeve 522 by a bias applying unit (not shown). By irradiating the charged photosensitive drum 501 with laser light 524 by an exposure device (not shown), a digital electrostatic charge image is formed. The electrostatic charge image formed on the photosensitive drum 501 includes a magnet roller 512, and the toner 519a in the developer 519 carried on the developing sleeve 511 to which a developing bias is applied by a bias applying device (not shown). Developed.

The developing device 504 is partitioned into a developer chamber R ₁ and a stirring chamber R ₂ by a partition wall 517, and developer conveying screws 513 and 514 are installed, respectively. Above the agitating chamber R ₂ , a toner storage chamber R ₃ containing replenishing toner 518 is installed, and a supply port 520 is provided below the storage chamber R ₃ .

The developer transport screw 513 rotates to transport the developer in the developer chamber R ₁ in one direction along the longitudinal direction of the developing sleeve 511 while stirring. The partition wall 517 is provided with openings (not shown) on the front side and the back side of the drawing, and the developer conveyed to one side of the developer chamber R ₁ by the screw 513 passes through the opening of the partition wall 517 on one side. It is fed into the stirring chamber R ₂ and delivered to the developer conveying screw 514. In the direction of rotation the screw 513 and the opposite of the screw 514, the developer in the stirring chamber R _2, stirring the toner supplied from the developer chamber R ₁ from the passed developer and toner storage chamber R _3, with mixing Then, the inside of the stirring chamber R ₂ is conveyed in the direction opposite to that of the screw 513, and fed into the developer chamber R ₁ through the other opening of the partition wall 517.

In order to develop the electrostatic image formed on the photosensitive drum 1, the developer 519 in the developer chamber R ₁ is pumped up by the magnetic force of the magnet roller 512 and is carried on the surface of the developing sleeve 511. The developer carried on the developing sleeve 511 is conveyed to a regulating blade 515 as the developing sleeve 511 rotates, and is regulated to a thin developer layer having an appropriate layer thickness, and then the developing sleeve 511, the photosensitive drum 501, and the like. Reaches the opposite development area. A magnetic pole (development pole) N ₁ is located at a position corresponding to the development area of the magnet roller 512, and the development pole N ₁ forms a development magnetic field in the development area, and the developer spikes by this development magnetic field. Thus, a developer magnetic brush is generated in the development region. Then, the magnetic brush comes into contact with the photosensitive drum 501, and the toner adhering to the magnetic brush and the toner adhering to the surface of the developing sleeve 511 are transferred to the electrostatic charge image area on the photosensitive drum 501 by the reverse development method. The electrostatic image is developed and a toner image is formed.

The developer that has passed through the developing region is returned to the developing device 504 as the developing sleeve 511 rotates, and is peeled off from the developing sleeve 511 by the repulsive magnetic field between the magnetic poles S ₁ and S ₂ , and the developer chamber R ₁ and the agitation are stirred. It falls into the chamber R ₂ and is collected.

T / C ratio of the developer 519 in the developing device 504 by the developing of the (toner and mixing ratio of the carrier, i.e., toner concentration in the developer) When reduced are consumed by developing the toner 518 from the toner storage chamber R ₃ The stirring chamber R ₂ is replenished in an amount that is suitable for the amount, and the T / C of the developer 519 is maintained at a predetermined amount. To detect the T / C ratio of the developer 519 in the container 504, a toner concentration detection sensor that measures a change in the magnetic permeability of the developer using the inductance of the coil is used. The toner concentration detection sensor has a coil (not shown) therein.

  The regulating blade 515 that is disposed below the developing sleeve 511 and regulates the layer thickness of the developer 519 on the developing sleeve 511 is a nonmagnetic blade 515 made of a nonmagnetic material such as aluminum or SUS316. The distance between the end portion and the surface of the developing sleeve 511 is 300 to 1000 μm, preferably 400 to 900 μm. If this distance is less than 300 μm, the magnetic carrier is clogged in the meantime, and the developer layer is likely to be uneven, and it is difficult to apply the developer necessary for good development, and a developed image with low density and unevenness is formed. Easy to be. In order to prevent non-uniform application (so-called blade clogging) due to unnecessary particles mixed in the developer, this distance is preferably 400 μm or more. If it is larger than 1000 μm, the amount of developer applied on the developing sleeve 511 increases, and it is difficult to regulate the predetermined developer layer thickness, and the adhesion of magnetic carrier particles to the photosensitive drum 501 increases and the developer is circulated and regulated. Development regulation by the blade 515 is weakened, and toner tribo is lowered and fogging is easily caused.

  Even when the developing sleeve 511 is rotated in the direction of the arrow, the magnetic carrier particle layer moves slowly as it moves away from the sleeve surface due to the balance between the restraining force based on magnetic force and gravity and the conveying force in the moving direction of the developing sleeve 511. Become. Some fall under the influence of gravity.

Therefore, the magnetic carrier particle layer is transported in the direction of the magnetic pole N ₁ as the sleeve is closer to the sleeve by appropriately selecting the arrangement position of the magnetic poles N and the fluidity and magnetic characteristics of the magnetic carrier particles, thereby forming a moving layer. Due to the movement of the magnetic carrier particles, the developer is transported to the development area along with the rotation of the developing sleeve 511 and is used for development.

  Further, the developed toner image is transferred onto a transfer material (recording material) 525 being conveyed by a transfer blade 527 which is a transfer device to which a transfer bias is applied by a bias applying device 526 and transferred onto the transfer material. The toner image thus fixed is fixed on the transfer material by a fixing device (not shown). In the transfer process, transfer residual toner that is not transferred to the transfer material and remains on the photosensitive drum 501 is adjusted in charge in the charging process and collected during development.

  FIG. 6 is a schematic view in which the image forming method of the present invention is applied to a full-color image forming apparatus.

  The full-color image forming apparatus main body is provided with a first image forming unit Pa, a second image forming unit Pb, a third image forming unit Pc, and a fourth image forming unit Pd. It is formed on a transfer material through development and transfer processes.

  The configuration of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.

  The first image forming unit Pa includes an electrophotographic photosensitive drum 761a having a diameter of 30 mm as an electrostatic charge image carrier, and the photosensitive drum 761a is rotationally moved in the direction of arrow a. Reference numeral 762a denotes a primary charger serving as a charging unit, and is arranged such that a magnetic brush formed on the surface of a sleeve having a diameter of 16 mm comes into contact with the surface of the photosensitive drum 761a. 767a is a laser beam for forming an electrostatic charge image on the photosensitive drum 761a whose surface is uniformly charged by the primary charger 762a, and is irradiated by an exposure device (not shown). Reference numeral 763a denotes a developing device as developing means for developing an electrostatic image carried on the photosensitive drum 761a to form a color toner image, and holds color toner. 764a is a transfer blade as transfer means for transferring the color toner image formed on the surface of the photosensitive drum 761a to the surface of the transfer material (recording material) conveyed by the belt-like transfer material carrier 768. The transfer blade 764a is in contact with the back surface of the transfer material carrier 768 and can apply a transfer bias.

  The first image forming unit Pa first uniformly charges the photosensitive drum 761a with the primary charger 762a, forms an electrostatic charge image on the photosensitive member with the exposure device 767a, and converts the electrostatic charge image into a color toner with the developing device 763a. The developed toner image is brought into contact with the back side of a belt-shaped transfer material carrier 768 that carries and conveys the transfer material at the first transfer portion (contact position between the photoconductor and the transfer material). The image is transferred onto the surface of the transfer material by applying a transfer bias from the transfer blade 764a.

  When the toner is consumed by development and the T / C ratio decreases, the decrease is detected by a toner concentration detection sensor 785 that measures the change in the magnetic permeability of the developer using the inductance of the coil, and the amount of consumed toner is calculated. Accordingly, replenishment toner 765 is replenished. The toner concentration detection sensor 785 has a coil (not shown) inside.

  This image forming apparatus has the same configuration as that of the first image forming unit Pa, and the second image forming unit Pb, the third image forming unit Pc, and the fourth image forming unit having different color toner colors held in the developing device. The image forming unit Pd is provided with four image forming units. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the transfer material is sequentially performed at the transfer portion of each image forming unit. In this step, the color toners are superimposed on each other by moving the transfer material once on the same transfer material while aligning the registration. When the transfer is completed, the transfer material is separated from the transfer material carrier 768 by the separation charger 769. Then, it is sent to the fixing device 770 by a conveying means such as a conveying belt, and a final full-color image is obtained by only one fixing.

  The fixing device 770 includes a pair of a fixing roller 771 having a diameter of 40 mm and a pressure roller 772 having a diameter of 30 mm. The fixing roller 771 includes heating means 775 and 776 therein.

  The unfixed color toner image transferred onto the transfer material passes through the pressure contact portion between the fixing roller 771 and the pressure roller 772 of the fixing device 770 and is fixed onto the transfer material by the action of heat and pressure. The

  In FIG. 6, a transfer material carrier 768 is an endless belt-like member, and this belt-like member is moved in the direction of arrow e by a drive roller 780. 779 is a transfer belt cleaning device, 781 is a belt driven roller, and 782 is a belt static eliminator. Reference numeral 783 denotes a pair of registration rollers for conveying the transfer material in the transfer material holder to the transfer material carrier 768.

  As the transfer means, a contact transfer means capable of directly applying a transfer bias by contacting the back surface of the transfer material carrier such as a roller-shaped transfer roller is used instead of the transfer blade contacting the back surface of the transfer material carrier. It is possible.

  Further, a non-contact transfer unit that performs transfer by applying a transfer bias from a corona charger arranged in a non-contact manner on the back side of a transfer material carrier that is generally used instead of the contact transfer unit described above. It is also possible to use.

  However, it is more preferable to use the contact transfer means in that the amount of ozone generated when the transfer bias is applied can be controlled.

  In the image forming method of the present invention, a toner image obtained by developing an electrostatic charge image formed on a latent image carrier can be transferred to a recording material via an intermediate transfer member.

  That is, this image forming method includes a step of transferring a toner image formed by developing an electrostatic charge image formed on an electrostatic charge image carrier to an intermediate transfer member, and a toner image transferred to the intermediate transfer member as a recording material. And a step of transferring to the substrate.

  An example of an image forming method using an intermediate transfer member will be specifically described with reference to FIG.

  In the apparatus system shown in FIG. 7, the cyan developer 854-1, the magenta developer 854-2, the yellow developer 854-3, and the black developer 854-4 have cyan developer and magenta toner having cyan toner, respectively. A magenta developer, a yellow developer having a yellow toner, and a black developer having a black toner have been introduced. An electrostatic latent image is formed on a photosensitive member 851 as a latent image holding member by a latent image forming unit 853 such as a laser beam. The electrostatic image formed on the photosensitive member 851 is developed with these developers by a developing method such as a magnetic brush developing method, a non-magnetic one-component developing method, or a magnetic jumping developing method, and each color toner image is formed on the photosensitive member 851. Is done. The photosensitive member 851 is a photosensitive drum or photosensitive belt having a conductive substrate 851b and a photoconductive insulating material layer 851a such as amorphous selenium, cadmium sulfide, zinc oxide, an organic photoconductor, and amorphous silicon formed on the conductive substrate 851b. is there. The photoconductor 851 is rotated in the direction of the arrow by a driving device (not shown). As the photoreceptor 851, a photoreceptor having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

  The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generation material and a substance having charge transport performance in the same layer, or a functional separation type photosensitive layer having the charge generation layer as a component. There may be. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated in this order on a conductive substrate is one preferred example.

  As the binder resin for the organic photosensitive layer, polycarbonate resin, polyester resin, and acrylic resin have good cleaning properties, and poor cleaning, fusion of toner to the photoreceptor, and filming of external additives are unlikely to occur.

  In the charging step, there are a non-contact type method using a photoconductor 851 using a corona charger and a contact type method using a contact charging member such as a roller. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 7 is preferably used.

  The charging roller 852 as a primary charging member has a basic configuration of a central cored bar 852b and a conductive elastic layer 852a that forms the outer periphery thereof. The charging roller 852 is pressed against the surface of the photoconductor 851 with a pressing force, and is driven to rotate as the photoconductor 851 rotates.

  As a preferable process condition when using the charging roller, when the contact pressure of the roller is 5 to 500 g / cm and an AC voltage is superimposed on a DC voltage, AC voltage = 0.5 to 5 kVpp, AC Frequency = 50 Hz to 5 kHz, DC voltage = ± 0.2 to ± 5 kV.

  Other contact charging members include a method using a charging blade and a method using a conductive brush. These contact charging members are effective in that a high voltage is unnecessary and generation of ozone is reduced.

  The material of the charging roller and charging blade as the contact charging member is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the releasable coating, nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), and fluorine acrylic resin can be applied.

  The toner image on the photosensitive member is transferred to an intermediate transfer member 855 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The intermediate transfer body 855 includes a pipe-shaped conductive core metal 855b and a medium-resistance elastic body layer 855a formed on the outer peripheral surface thereof. The core metal 855b may be a plastic surface provided with a conductive layer (for example, conductive plating).

Medium resistance elastic layer 855a is made of elastic material such as silicone rubber, fluororesin rubber, chloroprene rubber, urethane rubber, EPDM (ethylene propylene diene terpolymer), carbon black, zinc oxide, tin oxide, carbonized It is a solid or foamed meat layer in which a conductivity imparting material such as silicon is blended and dispersed to adjust the electric resistance value (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm.

  The intermediate transfer member 855 is disposed in parallel with the photosensitive member 851 so as to be in contact with the lower surface portion of the photosensitive member 851, and rotates in the counterclockwise direction of the arrow at the same peripheral speed as the photosensitive member 851.

  The first color toner image formed and supported on the surface of the photosensitive member 851 passes through the transfer nip where the photosensitive member 851 and the intermediate transfer member 855 are in contact with each other, and is applied to the transfer nip region by the transfer bias applied to the intermediate transfer member 855. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer member 855 by the formed electric field.

  The untransferred toner on the photoconductor 851 that has not been transferred to the intermediate transfer body 855 is cleaned by the photoconductor cleaning member 858 and collected in the photoconductor cleaning container 859.

  A transfer unit is disposed in parallel with the intermediate transfer member 855 and brought into contact with the lower surface of the intermediate transfer member 855. The transfer unit 857 is, for example, a transfer roller or a transfer belt, and has the same circumference as the intermediate transfer member 855. Rotates clockwise at the speed of the arrow. The transfer unit 857 may be disposed so as to be in direct contact with the intermediate transfer member 855, or a belt or the like may be disposed between the intermediate transfer member 855 and the transfer unit 857.

  In the case of the transfer roller, a basic core 857b and a conductive elastic layer 857a that forms the outer periphery thereof are used as a basic configuration.

  Common materials can be used for the intermediate transfer member and the transfer roller. By setting the volume resistivity of the elastic layer of the transfer roller to be smaller than the volume resistivity of the elastic layer of the intermediate transfer member, the voltage applied to the transfer roller can be reduced, and a good toner image is formed on the transfer material. In addition, the transfer material can be prevented from being wrapped around the intermediate transfer member. In particular, the volume specific resistance value of the elastic layer of the intermediate transfer member is particularly preferably 10 times or more than the volume specific resistance value of the elastic layer of the transfer roller.

  The hardness of the intermediate transfer member and the transfer roller is measured according to JIS K-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to a range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is harder than the hardness of the elastic layer of the intermediate transfer member. Those having a value of ˜80 degrees are preferable for preventing the transfer material from being wound around the intermediate transfer member. When the hardness of the intermediate transfer member and the transfer roller are reversed, a recess is formed on the transfer roller side, and the transfer material is likely to be wound around the intermediate transfer member.

  The transfer means 857 is rotated at a constant speed or a peripheral speed different from that of the intermediate transfer body 855. The transfer material 856 is conveyed between the intermediate transfer body 855 and the transfer means 857, and at the same time, a bias having a polarity opposite to the frictional charge of the toner is applied to the transfer means 857 from the transfer bias means. The toner image is transferred to the surface side of the transfer material 856.

  The transfer residual toner on the intermediate transfer member that has not been transferred to the transfer material 856 is cleaned by the intermediate transfer member cleaning member 860 and collected in the intermediate transfer member cleaning container 862. The toner image transferred to the transfer material 856 is fixed to the transfer material 856 by the heat fixing device 861.

  As the material of the transfer roller, the same material as that of the charging roller can be used. As a preferable transfer process condition, the contact pressure of the roller is 2.94 to 490 N / m (3 to 500 g / cm) (more preferably Is 19.6 to 294 N / m), and the DC voltage is ± 0.2 to ± 10 kV.

  If the linear pressure as the contact pressure is less than 2.94 N / m, it is not preferable because transfer of the transfer material and transfer failure are likely to occur.

For example, the conductive elastic layer 857b of the transfer roller 857 is blended and dispersed with an elastic material such as polyurethane rubber or EPDM (ethylene propylene diene terpolymer) with a conductivity imparting agent such as carbon black, zinc oxide, tin oxide or silicon carbide. Thus, it is a solid or foamed meat layer whose electric resistance value (volume resistivity) is adjusted to a medium resistance of 10 ⁶ to 10 ¹⁰ Ω · cm.

  The various measurement methods used in the present invention are listed below.

<Measurement of toner particle size distribution>
The particle size distribution of the toner can be measured by various methods. In the present invention, the particle size distribution was performed using a Coulter counter.

  A Coulter Counter TA-II type (manufactured by Coulter Co., Ltd.) was used as a measuring device, and an electrolyte solution was connected by connecting an interface (manufactured by Nikka) and a CX-1 personal computer (manufactured by Canon) that output number average distribution and volume average distribution Prepare 1% NaCl aqueous solution using primary sodium chloride.

  As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzenesulfonate 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 electrolyte in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Using the Coulter counter TA-II, 100 μm aperture is used as an aperture, and particles of 2 to 40 μm on the basis of the number are used. The particle size distribution is measured, and various values are obtained therefrom.

<Measurement of residual amount of polymerizable monomer remaining in toner particles>
The remaining amount of the polymerizable monomer and the organic solvent remaining in the toner particles was measured by gas chromatography using an internal standard method under the following conditions using 0.2 g of toner dissolved in 4 ml of THF. .

G. C. Condition measuring device: Shimadzu GC-15A (with capillary)
Carrier: N ₂ , 2 kg / cm ² 50 ml / min split ratio 1:60, linear velocity 30 mm / sec
Column: ULBON HR-1 50m x 0.25mm
Sample volume: 2 μl
Indication substance: Toluene

<Measurement of triboelectric charge amount of toner>
1.6 g of toner and 18.4 g of magnetic carrier are placed in a 50 cc polyethylene container and left open in each environment for one day. In a high-temperature and high-humidity environment, the sample is sealed after being left standing, and then left for another 2 hours to prevent condensation of the sample. Mix for 60 seconds with a turbula mixer, put this mixed powder (developer) in a metal container with a 625 mesh conductive screen at the bottom, and suck it with a suction machine. The triboelectric charge amount is obtained from the potential accumulated in the connected capacitor. At this time, the suction pressure is 250 mmHg. By this method, the triboelectric charge amount is calculated using the following formula.
Q (mC / kg) = (C × V) × (W ₁ −W ₂ ) ⁻¹
(W ₁ is the weight before suction, W ₂ is the weight after suction, C is the capacity of the capacitor, and V is the potential accumulated in the capacitor.)

  Further, the triboelectric charge amount of the developer toner at the time of durability was measured by sampling 1 g of the developer on the developing sleeve and using the above measuring apparatus without mixing and stirring.

  Next, the present invention will be described more specifically with reference to examples and comparative examples.

<Example 1>
First, 450 parts by mass of 0.1 mol / liter-Na ₃ PO ₄ aqueous solution was added to 710 parts by mass of ion-exchanged water and heated to 60 ° C., and then 3,500 using a clear mixer (manufactured by M Technique). Stir at rev / min. To this was added 68 parts by mass of a 1.0 mol / liter-CaCl ₂ aqueous solution to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, as a dispersoid, first, C.V. I. Pigment Red 122, an aluminum dialkyl salicylate compound and 100 parts by mass of a styrene monomer were dispersed for 3 hours using an attritor (manufactured by Mitsui Miike Chemical Industries) to obtain a colorant dispersion. Next, the rest of the following formulation was added to the colorant dispersion, heated to 60 ° C., and dissolved and mixed for 30 minutes. In this, 8 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was dissolved to prepare a polymerizable monomer composition.
-Styrene monomer 165 mass parts-n-butyl acrylate 35 mass parts-C.I. I. Pigment Red 122 15 parts by mass / saturated polyester 15 parts by mass / dialkyl salicylate compound 2 parts by mass / compound (1) 25 parts by mass (DSC peak temperature 59.4 ° C., Vickers hardness 1.5)

The polymerizable monomer composition was put into the aqueous dispersion medium and granulated for 15 minutes while maintaining the rotation speed. Then, the stirrer is changed from a high-speed stirrer to a propeller stirring blade, the internal temperature is raised to 60 ° C., polymerization is continued at 50 rpm for 5 hours, and then the internal temperature is raised to 80 ° C. for 8 hours. Was continued. After completion of the polymerization, the slurry was cooled, diluted hydrochloric acid was added, and Ca ₃ (PO ₄ ) ₂ was dissolved, followed by filtration and washing with water to obtain wet colored polymer particles having a water content of 20%.

  The obtained wet colored polymer particles were pulverized and then dried using a continuous instantaneous air dryer (flash dryer FJD-4: manufactured by Seishin Enterprise Co., Ltd.). As drying conditions, 90 ° C. air was blown at a linear velocity of 16.5 m / sec, and wet colored polymer particles were continuously supplied at 20 kg / hr. The water content of the colored polymer particles after the completion of such primary drying was measured and found to be 0.1%. At this time, the amount of the polymerizable monomer remaining in the colored polymer particles, that is, the content of the colored polymer particles was 620 ppm. There was no occurrence of lumps due to aggregation of the colored polymer particles, and the passing rate of a sieve having an aperture of 149 μm was 96%. The passing rate here is a value obtained by the following equation.

  Next, 30 kg of the taken out primary dry colored polymer particles and 45 g of the aluminum complex of amorphous dialkylsalicylic acid were put into a Nauter type vacuum dryer (NXV-1 type: manufactured by Hosokawa Micron Corporation) with a capacity of 100 liters and stirred. The solution was dried under reduced pressure. As drying conditions, the jacket heating temperature was 50 ° C., the degree of vacuum was 2 to 5 kPa, and nitrogen gas was supplied from the bottom at 5.0 N liters / min to perform drying for 3 hours. After completion of drying, the discharge of the dry colored polymer particles from the outlet was good, and the entire amount could be easily taken out. Moreover, there was almost no adhesion on the wall surface and stirring blade in the dryer. The content of the polymerizable monomer remaining in the extracted colored polymer particles was 25 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 96%.

  The surface of the colored polymer particles (toner particles) was coated with a metal compound of alkyl salicylic acid.

  The weight average particle diameter of the colored polymer particles was 6.5 μm. For the colored polymer particles, a schematic diagram of a tomographic photograph of the colored polymer particles using a transmission electron microscope is shown in FIG. 4, and the compound (1), which is a low softening point substance, was covered with an outer shell resin. The structure was shown.

  Next, the obtained colored polymer particles were stirred for 5 minutes with a Henschel mixer (manufactured by Mitsui Miike Chemical Co., Ltd.), and then hydrophobic with an average particle size of 0.005 μm with respect to 100 parts by mass of the obtained colored polymer particles. 1.5 parts by mass of silica was added and further mixed with a Henschel mixer to obtain the toner of this example.

  Using this toner, an image-printing test was conducted in an environment of 23 ° C./65% RH using a Canon color laser jet printer Color Laser Giotto-2030 modified with an intermediate transfer member. Even in sheet durability, there was no change in the image density after the durability and after the durability, and a high-quality image without voids was obtained. The transfer efficiency determined by the following method was 98%.

[Transfer efficiency]
A solid image of 10 cm ² is formed on the photoreceptor, and the amount of toner on the photoreceptor (W1) and the amount of toner on the paper after transfer (W2) are used, and the ratio between the two: W2 / W1 × 100 (% ).

  Further, problems such as toner fusion and memory ghost did not occur on the photoconductor which is an organic semiconductor. Further, when an image was formed on an OHP sheet, an image with good transparency was obtained.

  In addition, when a similar image printing test was performed in an environment of 30 ° C./80% RH, similar results were obtained. Further, after standing for 7 days in the middle of an environment of 30 ° C./80% RH, a similar image output test was performed. As a result, a high-quality image with no change in image density and without omission was obtained.

<Example 2>
20 kg of the colored polymer particles obtained by the primary drying obtained by the continuous instantaneous air dryer obtained in Example 1 and 30 g of the aluminum complex of amorphous dialkylsalicylic acid were used in a 50 liter ribocorn vacuum dryer (RD-). 50 type: manufactured by Okawara Seisakusho Co., Ltd.), and under reduced pressure drying at a jacket heating temperature of 50 ° C. and a vacuum degree of 0.7 to 2 kPa for 2 hours while stirring. After completion of drying, the discharge of the colored polymer particles from the outlet was good, and the entire amount could be easily taken out. Moreover, there was almost no adhesion on the wall surface and stirring blade in the dryer. The content of the polymerizable monomer remaining in the extracted toner particles was 38 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 95%. The surface of the colored polymer particles (toner particles) was coated with a metal compound of alkyl salicylic acid.

  After stirring the obtained colored polymer particles for 5 minutes with a Henschel mixer, 1.5 parts by mass of hydrophobic silica having an average particle size of 0.005 μm was added to 100 parts by mass of the obtained colored polymer particles. The toner was further mixed with a Henschel mixer.

  Further, using this toner, image output evaluation similar to that in Example 1 was performed, and as a result, a good image was obtained as in Example 1. The transfer efficiency in an environment of 23 ° C./65% RH was 97%.

<Comparative Example 1>
30 kg of the primary dry colored polymer particles dried by the continuous instantaneous air flow dryer obtained in Example 1 were added to the same vacuum dryer as in Example 1 (NXV-1 type) without adding an amorphous aluminum complex of dialkyl salicylic acid. Was dried under reduced pressure with stirring at a jacket heating temperature of 50 ° C. and a degree of vacuum of 2 to 5 kPa for 3 hours. At this time, the content of the polymerizable monomer remaining in the colored polymer particles was 230 ppm. Furthermore, it dried under reduced pressure, stirring similarly for 2 hours. After completion of drying, the dried colored polymer particles were discharged from the outlet. As a result, there was adhesion on the wall surface and stirring blade in the dryer, and about 3 kg remained in the dryer. The content of the polymerizable monomer remaining in the extracted colored polymer particles was 40 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 94%.

  To 100 parts by mass of the colored polymer particles taken out first, 0.1 part by mass of an amorphous aluminum complex of dialkylsalicylic acid was added and stirred for 5 minutes with a Henschel mixer, and then a hydrophobic particle having an average particle diameter of 0.005 μm. 1.5 parts by mass of functional silica was added and further mixed with a Henschel mixer to obtain a toner.

  Further, the same image output evaluation as in Example 1 was performed, and a good image was obtained in the same manner as in Example 1. The transfer efficiency was 96%. However, a similar image output test was performed after leaving the sample for 30 days in an environment of 30 ° C./80% RH, and as a result, a temporary increase in image density was observed immediately after being left for 7 days.

  Further, after the drying under reduced pressure, only the colored polymer particles remaining in the dryer were similarly evaluated as the toner, and the image density was evaluated in an environment of 30 ° C./80% RH. A decrease was observed.

<Comparative example 2>
To 100 parts by mass of the colored polymer particles first taken out in Comparative Example 1, 1.5 parts by mass of hydrophobic silica having an average particle diameter of 0.005 μm was added without adding an aluminum complex of amorphous dialkylsalicylic acid. The toner was then mixed with a Henschel mixer.

  Further, the same image output evaluation as that in Example 1 was performed. As a result, the image density was low and the image was missing. The transfer efficiency was a low value of 65%.

<Comparative Example 3>
The primary dry colored polymer particles (water content 0.1%, amount of polymerizable monomer remaining in the colored polymer particles 620 ppm) dried in the continuous instantaneous air dryer obtained in Example 1 were reduced in pressure. Without drying, 0.1 parts by mass of an amorphous aluminum complex of dialkyl salicylic acid was added to 100 parts by mass of the colored polymer particles in the same manner as in Comparative Example 1, and after stirring for 5 minutes with a Henschel mixer, the average particles Toner was added by adding 1.5 parts by mass of hydrophobic silica having a diameter of 0.005 μm and further mixing with a Henschel mixer.

  Further, when the same image output test as that of Example 1 was performed, solid portion white spots due to poor transfer occurred from about 500 sheets, and the image density decreased from about 2,000 sheets. Image defects due to toner fusion to the photoreceptor occurred at about 1,500 sheets in an 80% RH environment.

<Comparative Example 4>
About 30 kg of wet colored polymer particles having a water content of 20% obtained in Example 1 were crushed and then dried under reduced pressure while stirring using a Nauter type vacuum dryer (NXV-1 type) having a capacity of 100 liters. . Drying was performed for 6 hours at a jacket heating temperature of 50 ° C. and a degree of vacuum of 2 to 5 kPa. At this time, the moisture content of the toner particles was measured to be 0.3%, and the content of the polymerizable monomer remaining in the colored polymer particles was 340 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 77%. Further, after discharging the dried colored polymer particles, there was about 4 kg of adhesion in the dryer, and a part of the adhesion was caused on the stirring blade and the apparatus wall surface.

  The obtained colored polymer particles were pulverized, and then the same operation as in Comparative Example 1 was performed to obtain a toner.

  Further, as a result of the same image output test as in Example 1, solid portion white spots due to transfer failure occurred at about 1,000 sheets, and the image density decreased from about 4,000 sheets. Image defects due to toner fusion to the photoreceptor occurred at about 3,000 sheets in an 80% RH environment.

<Example 3>
First, the same aqueous dispersion medium as in Example 1 was prepared.

On the other hand, under the dispersoid system, among the following formulations, grafted carbon black, zinc complex salt of crystalline dialkyl salicylic acid and 100 parts by mass of styrene monomer were dispersed for 3 hours using an attritor to obtain a colorant dispersion. . Next, the rest of the following formulation was added to the colorant dispersion, heated to 60 ° C., and dissolved and mixed for 30 minutes. In this, 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was dissolved to prepare a polymerizable monomer composition.
Styrene monomer 170 parts by weight 2-ethylhexyl acrylate 30 parts by weight Grafted carbon black 20 parts by weight Saturated polyester 20 parts by weight Crystalline dialkyl salicylic acid zinc complex 3 parts by weight Compound (1) 30 parts by weight

The polymerizable monomer composition obtained above was put into the aqueous dispersion medium and granulated for 12 minutes while maintaining the rotation speed. After that, the stirrer is changed from a high-speed stirrer to a propeller stirring blade, the internal temperature is raised to 60 ° C. and polymerization is continued at 50 rpm for 6 hours, then the internal temperature is raised to 80 ° C. and polymerization is carried out for 8 hours. Was continued. After the completion of the polymerization, the slurry was cooled and diluted hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , followed by filtration and washing with water to obtain wet colored polymer particles having a water content of 18%.

  Next, the obtained wet colored polymer particles having a water content of 18% were crushed and then dried using a continuous instantaneous air dryer (flash dryer FJD-4) in the same manner as in Example 1. As drying conditions, 90 ° C. air was blown at a linear velocity of 16.5 m / sec, and wet colored polymer particles were continuously supplied at 35 kg / hr. The water content was measured and found to be 0.1%. At this time, the amount of the polymerizable monomer remaining in the colored polymer particles, that is, the content of the colored polymer particles was 600 ppm. There was no occurrence of lumps due to the aggregation of the colored polymer, and the passing rate of the sieve having an aperture of 149 μm was 96%.

  Next, 30 kg of the taken out primary dry colored polymer particles and 3 g of amorphous dialkyl salicylic acid zirconium complex were put into a Nauter type vacuum dryer (NXV-1 type: manufactured by Hosokawa Micron Corporation) with a capacity of 100 liters and stirred. The solution was dried under reduced pressure. As drying conditions, the jacket heating temperature was 50 ° C., the degree of vacuum was 2 to 5 kPa, and nitrogen gas was supplied from the bottom at 5.0 N liters / min to perform drying for 3 hours. After completion of drying, the discharge of the dry colored polymer particles from the outlet was almost good, and the entire amount could be easily taken out. Further, the adhesion on the wall surface of the dryer and the stirring blade was very small. The content of the polymerizable monomer remaining in the extracted colored polymer particles was 45 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 93%. The weight average particle diameter of the colored polymer particles was 7.3 μm. A schematic diagram of a tomographic photograph of the colored polymer particles is shown in FIG. The compound (1), which is a low softening point material, showed a structure covered with an outer shell tree. The surface of the colored polymer particles (toner particles) was coated with a metal compound of alkyl salicylic acid.

  After stirring the obtained colored polymer particles for 5 minutes with a Henschel mixer, 0.8 part by mass of hydrophobic silica having an average particle size of 0.005 μm was added to 100 parts by mass of the obtained colored polymer particles. The toner was further mixed with a Henschel mixer.

  Further, using this toner, image output evaluation similar to that in Example 1 was performed, and as a result, a good image was obtained as in Example 1. The transfer efficiency in an environment of 23 ° C./65% RH was 95%.

<Comparative Example 5>
30 kg of the primary dry colored polymer particles dried in the continuous instantaneous air flow dryer obtained in Example 3 were not added with a zirconium complex of amorphous dialkylsalicylic acid, and the same vacuum dryer (RD-50 type) as in Example 3. ), And dried under reduced pressure for 4 hours at a jacket heating temperature of 50 ° C. and a vacuum degree of 0.7 to 2 kPa. After the drying was completed, the dried toner particles were discharged from the outlet. As a result, there was adhesion on the wall surface and the stirring blade in the dryer, and about 3 kg remained in the dryer, and a discharge operation was necessary. The content of the polymerizable monomer remaining in the extracted toner particles was 80 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 87%.

  After adding 0.01 parts by mass of a non-crystalline dialkyl salicylic acid zirconium complex to 100 parts by mass of the colored polymer particles extracted first, and stirring for 5 minutes with a Henschel mixer, the hydrophobic particle having an average particle diameter of 0.005 μm 0.8 parts by mass of functional silica was added and further mixed with a Henschel mixer to obtain a toner.

  Further, the same image output evaluation as in Example 1 was performed, and a good image was obtained in the same manner as in Example 1. The transfer efficiency was 94%. However, a similar image output test was performed after leaving the sample for 30 days in an environment of 30 ° C./80% RH, and as a result, a temporary increase in image density was observed immediately after being left for 7 days.

<Example 4>
First, the same aqueous dispersion medium as in Example 1 was prepared.

On the other hand, as a dispersoid system, grafted carbon black, a zinc complex salt of crystalline dialkyl salicylic acid and 100 parts by mass of a styrene monomer were dispersed for 3 hours using an attritor to obtain a colorant dispersion. Next, the rest of the following formulation was added to the colorant dispersion, heated to 60 ° C., and dissolved and mixed for 30 minutes. In this, 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator was dissolved to prepare a polymerizable monomer composition.
Styrene monomer 170 parts by weight 2-ethylhexyl acrylate 30 parts by weight Grafted carbon black 20 parts by weight Saturated polyester 20 parts by weight Amorphous dialkylsalicylic acid aluminum complex 0.5 part by weight Compound (1) 30 parts by mass

The polymerizable monomer composition obtained above was put into the aqueous dispersion medium and granulated for 15 minutes while maintaining the rotation speed. Thereafter, the stirrer is changed from a high-speed stirrer to a propeller stirring blade, the internal temperature is raised to 60 ° C., polymerization is continued at 50 rpm for 6 hours, and then the internal temperature is raised to 80 ° C. for 6 hours. Was continued. After completion of the polymerization, the slurry was cooled and diluted hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , followed by filtration and washing with water to obtain wet colored polymer particles having a water content of 22%.

  Next, about 40 kg of wet colored polymer particles having a water content of 22% were pulverized and then dried using a fluidized bed dryer (FBS-5 type: manufactured by Okawara Seisakusho). As drying conditions, air at 50 ° C. was blown at a linear velocity of 0.4 m / second, and after 2 hours, the colored polymer particles were taken out and the water content was measured. As a result, it was 0.3%. Further, at this time, the content of the polymerizable monomer remaining in the colored polymer particles was 750 ppm, but there was no generation of lumps due to toner aggregation, and the passing rate of the streaks having a mesh size of 149 μm was 96%. Met.

  Next, 30 kg of the primary dry colored polymer particles taken out and 120 g of the amorphous aluminum complex of dialkylsalicylic acid were charged into a 100 liter Nauter type vacuum dryer (NXV-1 type: manufactured by Hosokawa Micron Corporation) and stirred. The solution was dried under reduced pressure. As drying conditions, the jacket heating temperature was 50 ° C., the degree of vacuum was 2 to 5 kPa, and nitrogen gas was supplied from the bottom at 5.0 N liters / min to perform drying for 3 hours. After completion of drying, the discharge of the dry colored polymer particles from the outlet was good, and the entire amount could be easily taken out. Moreover, there was almost no adhesion on the wall surface and stirring blade in the dryer. The content of the polymerizable monomer remaining in the extracted colored polymer particles was 28 ppm. Further, the passing rate of the sieve having an aperture of 149 μm was 96%. The surface of the colored polymer particles (toner particles) was coated with a metal compound of alkyl salicylic acid.

  The weight average particle diameter of the colored polymer particles was 6.8 μm.

  After stirring the obtained colored polymer particles for 5 minutes with a Henschel mixer, 1.2 parts by mass of hydrophobic silica having an average particle size of 0.005 μm was added to 100 parts by mass of the obtained colored polymer particles. The toner was further mixed with a Henschel mixer.

  Further, using this toner, image output evaluation similar to that in Example 1 was performed, and as a result, a good image was obtained as in Example 1. The transfer efficiency in an environment of 23 ° C./65% RH was 98%.

<Comparative Example 6>
About 40 kg of the wet colored polymer particles obtained from the water-containing toner having a water content of 22% obtained in Example 4 were crushed and dried using a fluidized bed dryer (FBS-5 type: manufactured by Okawara Seisakusho). It was. As drying conditions, air at 50 ° C. was blown at a linear velocity of 0.4 m / second, and after 4 hours, the colored polymer particles were taken out and the water content was measured. As a result, it was 0.1%. Further, although the content of the polymerizable monomer remaining in the colored polymer particles was 180 ppm, there was an occurrence of lumps due to the aggregation of the colored polymer particles, and the passing rate of a sieve having an aperture of 149 μm was 85%. Met. In addition, an adhesion layer of colored polymer particles was observed on the inner wall of the dryer. The adhesion layer of the colored polymer particles was taken out and the water content was measured. The result was 0.1%, but the content of the polymerizable monomer remaining in the toner particles was 320 ppm.

  To 100 parts by mass of the obtained colored polymer particle particles, 1.2 parts by mass of hydrophobic silica having an average particle diameter of 0.005 μm was added and mixed with a Henschel mixer to obtain a toner.

  Further, when the same image output test as in Example 1 was performed, solid white spots due to poor transfer occurred from about 1,500 sheets of durability, and about 4,500 sheets in an environment of 30 ° C./80% RH. As a result, image defects due to toner fusion to the photoreceptor occurred.

It is the schematic which shows an example of the system of the apparatus which disperse | distributes the to-be-dried material (wet particle | grains or slurry) used for this invention to a granular form in a hot airflow, and instantaneously dries while sending in parallel with a high-speed hot airflow. is there. It is a schematic sectional drawing which shows an example of the pressure-reduction-type drying apparatus and apparatus system which are used for this invention. It is a schematic sectional drawing which shows an example of the pressure-reduction-type drying apparatus and apparatus system which are used for this invention. 3 is a schematic diagram illustrating a cross section of the toner of Example 1. FIG. It is a schematic diagram showing a suitable example of the image forming method of the present invention. It is a schematic explanatory drawing which shows the example of a full-color image formation method. It is a schematic explanatory drawing which shows the other example of the image forming apparatus for enforcing the image forming method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-air generator 2 Airflow drying pipe 3 Airflow dispersion | distribution part 4 Airflow extraction port 5 Cyclone 6 To-be-dried material supply apparatus 7 Dry goods extraction port 10 Bag filter 11 Jacket 12 Steam supply port 13 Cooling water supply port 14 Discharge port 15 Pump 16 Manhole DESCRIPTION OF SYMBOLS 17 Steam inlet 18 Accumulator 19 Boiler 20 Cold trap 21 Partition plate 22 Filter cloth 23 Outlet 24 Washing nozzle 25 Compressor 26 Filter 28 Vacuum pump 29 Pump 30 Gas inlet 31 Mixer 32 Container 33 Drive device 34 Drive arm 35 Stirring member 36 Raw material supply port 37 Exhaust port 38 Outlet 39 Extraction valve 40 Ribbon blade type stirring member 501 Electrostatic charge image carrier (photosensitive drum)
504 Developing device 511 Developer carrier (developing sleeve)
512 Magnet Roller 513, 514 Developer Conveying Screw 515 Regulating Blade 517 Partition 518 Replenisher Toner 519 Developer 519a Toner 519b Carrier 520 Replenishment Port 521 Magnet Roller 522 Conveying Sleeve 523 Magnetic Particles 524 Laser Light 525 Transfer Material (Recording Material)
526 Bias applying means 527 Transfer blade 528 Toner density detection sensor 761a Photosensitive drum 762a Primary charger 763a Developer 764a Transfer blade 765a Replenishing toner 767a Laser light 768 Transfer material carrier 769 Separation charger 770 Fixing device 771 Fixing roller 772 Roller 773 Web 775,776 Heating means 779 Transfer belt cleaning device 780 Drive roller 781 Belt driven roller

Claims (8)

  A polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in an aqueous dispersion medium to form colored polymer particles, and then washed, dehydrated, and obtained wet color. After removing the aqueous dispersion medium to a moisture content of 0.1% or more and less than 1.0% by drying the polymer particles using hot air, a metal compound of alkyl salicylic acid is added to the colored polymer particles, While stirring these, drying is performed under reduced pressure until the remaining amount of the unreacted polymerizable monomer remaining in the colored polymer particles is 200 ppm or less, and the metal compound of alkyl salicylic acid covers the toner particle surface. A method for producing toner, comprising obtaining toner particles.   2. The toner production according to claim 1, wherein the drying using the hot air is performed by dispersing the colored polymer particles in a wet state in the form of powder in a hot air stream and feeding the polymer particles in parallel with the hot air stream. Method.   2. The method for producing a toner according to claim 1, wherein the drying using the hot air is performed by suspending and suspending the colored polymer particles in a wet state to form a fluidized bed and drying.   4. The toner manufacturing method according to claim 1, wherein the drying under reduced pressure is performed under gas supply.   The method for producing a toner according to claim 4, wherein the drying under reduced pressure is performed by supplying a gas in such an amount that the pressure in the dryer is maintained at 13 kPa or less.   6. The metal compound of the alkyl salicylic acid is a low crystalline or non-crystalline metal salicylic acid metal complex salt or a metal complex, or a mixture of a metal complex salt and a metal complex. Toner manufacturing method.   The toner particles contain 5 to 40% by mass of a low softening point substance, and the low softening point substance is encapsulated in an outer shell resin layer by a toner tomographic surface measurement method using a transmission electron microscope. The method for producing a toner according to claim 1, wherein:   8. The method for producing a toner according to claim 1, wherein the toner particles contain an ester wax having at least one long-chain ester portion having 10 or more carbon atoms as a low softening point substance. .

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