JP4206355B2 - Electrostatic latent image developing carrier and electrostatic latent image developing developer - Google Patents

Description

  The present invention relates to an electrostatic latent image developing carrier and an electrostatic latent image developing developer used in an image forming apparatus using an electrophotographic system.

  In recent years, printing apparatuses using an electrophotographic method have been rapidly colorized and printing speed has been increased. Conventionally, the two-component development method has been widely used in full-color image forming apparatuses because it is suitable for high-speed printing and can easily handle non-magnetic toner. However, the two-component developing device requires a developer storage volume in addition to the toner storage volume and needs to be equipped with a stirring mechanism as compared with the one-component developing device, so that the developing device tends to be large and complicated. There is a drawback. In a full-color printing apparatus, it is necessary to provide a developing device for each color in the apparatus. Therefore, it is essential to reduce the size of each developing unit. For this reason, it is necessary to reduce the amount of developer.

  The carrier in the developer is repeatedly subjected to mechanical friction and impact in the developing device by friction with toner, a rubbing member such as a sleeve and a blade, a regulating member and a stirring and conveying member such as a screw and paddle. Decreasing the amount of developer means an increase in the chance of friction between the toner and the carrier per the number of printed sheets, and an increase in the frequency with which the carrier passes through the developing portion. As a result, the fatigue of the carrier in the developing unit rapidly proceeds. . Combined with higher printing speed, carrier durability, especially wear resistance of the film on the surface of the carrier and prevention of contamination of the carrier surface due to toner and other components (spent), and quick charging over a long period of time Maintaining it has become more important than ever.

In recent digital copying machines and printers, negative-positive development is often performed using a negatively charged photosensitive member, and negatively charged toner is often used. Many examples are known in which a carrier film contains an organic compound containing nitrogen to negatively charge the toner. For example, as described in Patent Document 1, an example of using an aminosilane coupling agent mixed with a silicone resin, or as an example of internally adding a certain acid amide as described in Patent Document 2, As described in Patent Document 3, an amino compound such as melamine or guanamine or a derivative thereof is internally added. As a measure for preventing spent by toner, for example, as described in Patent Document 4, there is an example in which a low surface energy material such as silicone oil having releasability is internally added to the film.
Japanese Patent Laid-Open No. 2004-77568 JP 2004-85739 A JP 2001-265065 A JP 2003-21935 A

  However, the oil component described above improves the hydrophobicity of the surface and is effective in improving the initial spent property. However, the oil component oozes out to the surface layer due to the film formation process and the change of the carrier over time. There has been a problem that the chargeability of the developer over time varies greatly.

  The present invention has been made in consideration of the above-described circumstances, and provides a carrier for developing an electrostatic latent image that has excellent durability of a film formed into a film and has stable chargeability regardless of the use atmosphere. Therefore, it is an object of the present invention to provide a developer for developing an electrostatic latent image that prevents change over time, has excellent spent properties, and has stable charging performance over a long period of time.

In order to solve the above-described problems, the invention described in claim 1 is a carrier for developing an electrostatic latent image in which a resin coating layer is provided on the surface of a magnetic powder constituting a core material, and the resin The coating layer is CF ₃ (CF ₂ ) _n —NH (R ₁ OR ₂ ) (where R ₁ is a saturated alkylene group having 1 or 2 carbon atoms, and R ₂ is an alkyl group having 1 or 2 carbon atoms. And n is a positive integer.) A composition comprising a compound containing a repeating unit represented by formula (1) and / or a composition containing a condensation product of the compound is formed into a film. An electrostatic latent image developing carrier characterized by the above.

The invention according to claim 2 is characterized in that the composition is a compound having a structure containing a repeating unit represented by CF ₃ (CF ₂ ) ₁₆ —NH (CH ₂ OCH ₃ ) and / or a condensation product of the compound. It is characterized by comprising.

  The invention according to claim 3 is the electrostatic latent image developing carrier according to claim 1 or 2, wherein the composition contains a silanol and / or a condensation product of a silicone compound having a group to be hydrolyzed. It is characterized by being made.

  According to a fourth aspect of the present invention, in the electrostatic latent image developing carrier according to the third aspect, the composition contains a condensation product of a methyl silicone compound having a molecular weight of 1,000 to 100,000. It is characterized by that.

  The invention according to claim 5 is the electrostatic latent image developing carrier according to any one of claims 1 to 4, wherein the composition contains fine particles of metal oxide. It is characterized by.

  According to a sixth aspect of the present invention, in the electrostatic latent image developing carrier according to the fifth aspect, the metal oxide fine particles are alumina fine particles.

  According to a seventh aspect of the present invention, in the electrostatic latent image developing carrier according to the sixth aspect, the alumina fine particles are contained in a range of 1 wt% to 70 wt% with respect to the total weight of the composition. It is characterized by that.

  According to an eighth aspect of the present invention, in the electrostatic latent image developing carrier according to the sixth or seventh aspect, the alumina fine particles have an average particle diameter of 0.01 μm to 0.7 μm.

The invention according to claim 9 is the electrostatic latent image developing carrier according to any one of claims 1 to 8, wherein the composition has a volume resistivity of 10 ⁻² Ωcm to 10 ⁸ Ωcm. It is characterized by containing a low resistance substance.

  Invention of Claim 10 contains the carrier for electrostatic latent image development of any one of Claims 1-9, binder resin, and a coloring agent, and with respect to the said carrier for electrostatic latent image development And an electrostatic latent image developing developer comprising a toner having a relatively negative chargeability.

  According to an eleventh aspect of the present invention, in the electrostatic latent image developing developer according to the tenth aspect, the toner contains a chromatic colorant.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the carrier for electrostatic latent image development which is excellent in spent property, the durability of a film | membrane, and excellent in the time-dependent stability of charging.

  The carrier for developing an electrostatic latent image of the present invention is a carrier for developing an electrostatic latent image in which a resin coating layer is provided on the surface of a magnetic powder constituting a core material, and a specific compound is contained in the resin coating layer. A composition comprising the above is formed into a film. The component contained in the resin coating layer is, for example, a compound obtained by methoxymethylating an amino group in a fluorinated aliphatic amine.

  When oil components such as conventional silicone oil compounds and amino-modified silicone oils are included in the film, the amount of charge due to temperature and humidity changes as described above, However, depending on the film formation conditions, the oil is likely to be unevenly distributed on the surface layer. Although there is a problem that changes occur, a fluorinated aliphatic amine having an amine structure excellent in positive chargeability and imparting spent resistance and having an alkoxyalkylated terminal primary amine as a hydrophobizing agent is used. As a result, it becomes possible to react the component that is the main structure of the film with the modified oil component, uneven distribution during production, and change in charge amount due to oil seepage over time. It was found that there is less electrostatic latent image carrier obtained.

The modified oil component is, for example, CF ₃ (CF ₂ ) _n —NH (R ₁ OR ₂ ) (where R ₁ is a saturated alkylene group having 1 or 2 carbon atoms, and R ₂ has 1 carbon atom) Or an alkyl group of 2 and n is a positive integer.), Which is a compound having a structure containing a repeating unit represented by the following formula: Is obtained by methoxymethylation of the amine. Among the aliphatic amines used here, a compound obtained from a fluorinated aliphatic amine having 17 carbon atoms is preferably used since it has excellent spent properties.

  For example, the following method can be used for alkoxyalkylation of a fluorinated aliphatic amine. Hereinafter, the method of methoxymethylation is illustrated. For example, a fluorinated aliphatic amine is dissolved in methanol, and an aqueous formaldehyde solution is dropped into this solution while keeping the liquidity basic as necessary. By refluxing at 30 ° C. to 60 ° C. for about 1 hour while cooling as necessary so as not to cause an excessive increase in temperature due to heat of reaction, a solution of a methoxymethylated fluorinated aliphatic amine is obtained.

  The methoxymethylated fluorinated aliphatic amine thus obtained is mixed or dispersed in the resin coating layer of the electrostatic latent image developing carrier as a charge control agent to constitute the core material of the electrostatic latent image developing carrier. Applied to magnetic powder.

  A conventionally known resin composition can be used as a component contained in the resin coating layer in the electrostatic latent image developing carrier. Especially, it is preferable to contain the condensation product of the silicone compound which has a silanol and / or the group hydrolyzed.

As a component contained in the resin coating layer in the carrier for developing an electrostatic latent image, methyl silicone resin and methyl phenyl silicone resin are more preferably used. The methylsilicone resin is generally a co-polymer formed by combining a compound containing a structural unit represented by SiO ₂ , CH ₃ SiO _3/2 (CH ₃ ) ₂ SiO, (CH ₃ ) ₃ SiO _1/2 and a derivative thereof. It is a coalescence. The methylphenyl silicone resin is generally CH ₃ SiO _3/2 , (CH ₃ ) ₂ SiO, C ₆ H ₅ SiO _3/2 , (C ₆ H ₅ ) (CH ₃ ) SiO, (C ₆ H ₅ ) _2. It is a polymer formed by combining SiO structural units and derivatives thereof. Examples of such resins include, for example, KR271, KR272, KR282, KR252, KR255, KR152 (manufactured by Shin-Etsu Chemical Co., Ltd.), SR2400, SR2406 (manufactured by Toray Dow Corning Silicone) as straight silicone resins. . In particular, methyl silicone resin is more preferably used for reasons such as low spent property and small environmental fluctuation of charge amount.

  In addition, a modified silicone resin is also preferably used. Examples include epoxy-modified silicone, acrylic-modified silicone, phenol-modified silicone, urethane-modified silicone, polyester-modified silicone, alkyd-modified silicone, and the like. Specific examples of the modified silicone resin include epoxy modified product: ES-1001N, acrylic modified silicone: KR-5208, polyester modified product: KR-5203, alkyd modified product: KR-206, urethane modified product: KR-305 ( As mentioned above, Shin-Etsu Chemical Co., Ltd.), epoxy-modified product: SR2115, alkyd-modified product: SR2110 (manufactured by Toray Dow Corning Silicone), and the like.

  The molecular weight of the silicone resin is preferably 1000 to 100,000. This is because if the molecular weight of the methyl silicone resin is less than 1000, defects such as brittleness of the film after curing tend to occur, and conversely, if it is greater than 100,000, the viscosity of the coating solution increases too much during coating, and the coating film This is because the uniformity of the film cannot be sufficiently obtained, or the film density may not be sufficiently increased after curing. The molecular weight of the silicone resin is more preferably about 1000 to 20000.

  Furthermore, in the present invention, as the resin that can be contained in the resin coating layer, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer are used. Polymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer) Copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer) , Styrene-ethyl methacrylate copolymer, styrene-meta Styrenic resins such as butyl acrylate copolymer, styrene-phenyl methacrylate copolymer, styrene-α-chloromethyl acrylate copolymer, styrene-acrylonitrile-acrylate copolymer, epoxy resin, polyester Examples thereof include one or more of resin, polyethylene resin, polypropylene resin, ionomer resin, polyurethane resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyamide resin, phenol resin, polycarbonate resin, melamine resin and the like. Moreover, it is also possible to use what mixed these illustrated 1 type, or 2 or more types of resin, and the said silicone resin.

  As a material to be contained in the resin coating layer, metal oxide fine particles different from the resin component can be further contained, and an appropriate content and particle diameter are selected with respect to the thickness of the film formed. As a result, the strength of the film can be remarkably improved. As such fine particles, conventionally known materials can be used alone or in combination, and typically include silica, titanium oxide, alumina and the like. Among these, alumina fine particles are preferably used in order to charge the toner negatively.

  The content of the metal oxide fine particles is appropriately selected depending on the material constituting the film formed, but is preferably in the range of 1 to 70% by weight. If the amount is less than 1% by weight, the effect of improving the strength of the film is not sufficient. On the other hand, if the amount exceeds 70% by weight, the particles are likely to be detached from the film, which may cause a problem in durability. Because.

  The average particle diameter of the metal oxide fine particles depends on the thickness of the film, but is preferably in the range of 0.01 to 0.7 μm. The particle diameter of the metal oxide fine particles used for the thickness of the film is appropriately selected. As used herein, the film thickness refers to the volume of the resin component that does not include the fine particle component of the resin coating layer component included in the carrier for developing an electrostatic latent image, and the magnetic fine powder that constitutes the core material. The value divided by the surface area.

  The surface area of the magnetic powder constituting the core material is obtained by calculating the weight average particle diameter and calculating the surface area of the corresponding sphere, and the average particle diameter of the fine particles contained with respect to the film thickness is 0.01 to 1. A double particle size range is preferred. This is because if it is less than 0.01 times, the effect of improving the film strength by filling the particles is not recognized, and conversely, if it is more than 1 times, particles are likely to be detached from the film.

Further, in order to make the electric resistance of the electrostatic latent image developing carrier appropriate, it is possible to contain a conductive substance in the resin coating layer of the electrostatic latent image developing carrier. As the conductive material here, a known conductive material can be used. Examples of the conductive material, for example, conductive ZnO, metal powder such as Al, SnO ₂ doped with SnO ₂ and various elements made by various methods, borides, e.g. TiB _2, ZnB _2, MoB ₂ and silicon carbide and conductive polymers (polyacetylene, polyparaphenylene, poly (para-phenylene sulfide), polypyrrole), etc., most preferably conductive carbon black.

  The carrier for developing an electrostatic latent image of the present invention functions as a developer that is agitated with toner and used in a two-component development system. The toner used by mixing with the electrostatic latent image developing carrier of the present invention preferably exhibits a relatively negative chargeability when frictionally charged with the electrostatic latent image developing carrier.

  In the developer for developing an electrostatic latent image of the present invention, examples of the toner used by mixing with the carrier for developing an electrostatic latent image can be all those prepared by a conventionally known production method. . That is, a binder resin mainly composed of a thermoplastic resin contains a colorant, fine particles, a charge control agent, a release agent, etc., kneading and pulverizing methods, various polymerization methods, granulating methods, etc. The toner can be an amorphous or spherical toner prepared by various toner manufacturing methods. Either magnetic toner or non-magnetic toner can be used.

  As the binder resin contained in the toner, the following can be used alone or in combination. Examples of styrene-based binder resins include styrene such as polystyrene and polyvinyltoluene, and homopolymers of substituted styrene, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene- Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methacrylic acid Butyl copolymer, styrene-α-chloromethacrylic acid methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, Styrene-isoprene copolymer, steel Styrene copolymers such as styrene-maleic acid copolymers and styrene-maleic acid ester copolymers; acrylic binders such as polymethyl methacrylate and polybutyl methacrylate, and others, polyvinyl chloride, polyvinyl acetate , Polyethylene, polypropylene, polyester, polyurethane, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, Examples include paraffin wax. Further, the polyester resin can further reduce the melt viscosity while ensuring the stability during storage of the toner, as compared with the styrene-based or acrylic-based resin. Such a polyester resin can be obtained, for example, by a polycondensation reaction between an alcohol and a carboxylic acid.

  Examples of the alcohol include diols such as polyethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol, neopentyl glycol, 1,4-butenediol, , 4-bis (hydroxymethyl) cyclohexane, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, polyoxypropylenated bisphenol A, and the like, and these are saturated or unsaturated having 3 to 22 carbon atoms. Divalent alcohol units substituted with saturated hydrocarbon groups, other divalent alcohol units, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaesitol dipenta D Ritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, tri Mention may be made of trihydric or higher alcohol monomers such as methylolethane, trimethylolpropane and 1,3,5-trihydroxymethylbenzene.

  Examples of the carboxylic acid used to obtain the polyester resin include monocarboxylic acids such as palmitic acid, stearic acid, and oleic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. Acids, adipic acid, sebacic acid, malonic acid, divalent organic acid monomers in which these are substituted with saturated or unsaturated hydrocarbon groups having 3 to 22 carbon atoms, anhydrides of these acids, lower alkyl esters and Dimer from linolenic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1, 2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl 2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid embol trimer acid, trivalent or higher polyvalent carboxylic acid monomers such as anhydrides of these acids The body can be mentioned.

  Epoxy resins include polycondensates of bisphenol A and epochorhydrin, such as epomic R362, R364, R365, R366, R367, R369 (above, Mitsui Petrochemical Co., Ltd.), Epotot YD-011, YD-012, YD-014, YD-904, YD-017 (above, manufactured by Tohto Kasei Co., Ltd.) Epcots 1002, 1004, 1007 (above, manufactured by Shell Chemical Co., Ltd.) Is mentioned.

  Colorants that can be used in the developer for developing an electrostatic latent image of the present invention include carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, phthalocyanine blue, Hansa Yellow G, rhodamine 6G, lake. Any conventionally known dyes such as calco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dyes, monoazo dyes, disazo dyes and dyes can be used alone or in combination. It is also possible to make a magnetic toner by adding a magnetic material to the toner.

  As the magnetic material, fine powders such as ferromagnetic materials such as iron and cobalt, magnetite, hematite, Li-based ferrite, Mn—Zn-based ferrite, Cu—Zn-based ferrite, Ni—Zn ferrite, and Ba ferrite can be used.

  A so-called charge control agent can be used for the purpose of sufficiently controlling the triboelectric chargeability of the toner. As the charge control agent here, all known ones can be used. For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary Examples thereof include ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Nitronine-based dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal complex E- 84, E-89 of a phenol-based condensate (manufactured by Orient Chemical Industry Co., Ltd.), TP-302 of a quaternary ammonium salt molybdenum complex, TP-415 (manufactured by Hodogaya Chemical Industry Co., Ltd.), quaternary ammonium Copy charge PSY VP2038 of salt, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinaclide And azo pigments, and other high molecular compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium salt.

  As the release material, low molecular weight polypropylene, low molecular weight polyethylene, carnauba wax, microcrystalline wax, jojoba wax, rice wax, montanic acid wax and the like can be used alone or in combination, but are not limited thereto. is not.

Additives can be added to the toner. In order to obtain a good image, it is important to impart sufficient fluidity to the toner. As additives, it is generally effective to externally add hydrophobized metal oxide fine particles or lubricant fine particles as fluidity improvers, and metal oxides, organic resin fine particles, metal soaps, etc. Can be used. Specific examples of these additives include lubricants such as Teflon (R) and zinc stearate, abrasives such as cerium oxide and silicon carbide, and inorganic oxides such as SiO ₂ and TiO ₂ whose surfaces are hydrophobized. And fluidity-imparting agents, those known as anti-caking agents, and surface-treated products thereof. In order to improve the fluidity of the toner, hydrophobic silica is particularly preferably used.

  The weight average particle diameter Dt of the toner used in the developer for developing an electrostatic latent image of the present invention is preferably 9.0 to 4.0 μm, and more preferably 7.5 to 4.5 μm. The ratio of the toner to the electrostatic latent image developing carrier is preferably 2 to 25 parts by weight of toner per 100 parts by weight of the carrier, and more preferably 4 to 15 parts by weight of toner per 100 parts by weight of the carrier.

  Examples will be specifically described below. The present invention is not limited to the embodiments exemplified herein.

(Production of compound 1 for resin coating layer)
10 parts of a compound having a structure represented by CF ₃ (CF ₂ ) ₃ NH ₂ was dissolved in 10 parts of methanol, and then cooled in an ice bath. While maintaining the liquid temperature at 0 ° C. or lower, 2 parts of an aqueous formaldehyde (37 wt%) solution was added dropwise. After completion of heat generation during mixing, the mixture was stirred at 25 ° C. for 1 hour to obtain a solution of compound 1 for resin coating layer.

(Production of compound 2 for resin coating layer)
10 parts of a compound having a structure represented by CF ₃ (CF ₂ ) ₁₆ NH ₂ was dissolved in 10 parts of methanol, and then cooled in an ice bath. While maintaining the liquid temperature at 30 ° C. or lower, 0.4 part of an aqueous formaldehyde (37 wt%) solution was added dropwise. After the heat generation during mixing was completed, the mixture was stirred at 25 ° C. for 1 hour to obtain a solution of compound 2 for resin coating layer.

(Manufacture of carrier A for electrostatic latent image development)
The following solutions were added to a stirrable glass container equipped with a refluxer and refluxed at 60 ° C. for 3 hours to obtain a mixed solution.
Methyl silicone resin toluene solution (molecular weight 15000, solid content 20% by weight, curing temperature 120 ° C.) 100 parts Toluene 100 parts Isopropanol 100 parts Resin coating layer compound 1 solution 10 parts

  After cooling the obtained mixed solution, 1 part of carbon black (BlackParls 2000 manufactured by Cabot Specialty Chemicals Inc.) was added and dispersed with a homogenizer.

  To the obtained dispersion, 1 part of dibutyltin diacetate-toluene solution (40% by weight solution) and 0.02 part of γ-aminoethylaminopropyltrimethoxysilane were added as a catalyst to obtain a coating liquid.

  A powder obtained by applying the obtained coating solution to a ferrite core material having a volume average particle diameter of 38 μm and a magnetic moment of 76 emu / g at 1000 gauss, which is a magnetic fine powder, was obtained using a fluidized bed dryer.

  The obtained powder was heated at 230 ° C. for 2 hours and then dried to obtain an electrostatic latent image developing carrier A having a film thickness of 0.6 μm. The thickness of the film was adjusted by the coating amount of the coating liquid on the ferrite core material.

The electrostatic latent image developing carrier A was filled in a cell having parallel electrodes with a gap of 2 mm and an electrode area of 100 mm ² , and volume resistivity at applied voltages of 100 V and 500 V was measured. The volume resistivity of this carrier A was LogR14.2 Ωcm (50 V / mm) and 13.4 Ωcm (250 V / mm).

(Manufacture of carrier B for developing electrostatic latent image)
The same operation as the production of the electrostatic latent image developing carrier A described above was repeated except that the resin coating layer compound 2 was used in place of the resin coating layer compound 1, and the electrostatic latent image development carrier B was Obtained. The film thickness of the electrostatic latent image developing carrier B was 0.61 μm, and the volume resistivity was LogR 14.1 Ωcm (50 V / mm) 13.8 Ωcm (250 V / mm).

(Manufacture of carrier C for developing electrostatic latent image)
To the obtained dispersion, 20 parts of alumina particles having an average particle size of 0.1 μm were added to the solid content, and the coating liquid obtained by stirring and dispersing with a homogenizer was used. The same operation as the production of the electrostatic latent image developing carrier B was repeated to obtain an electrostatic latent image developing carrier C.

(Manufacture of particles of carrier D for electrostatic latent image development)
To the obtained dispersion liquid, 60 parts of alumina particles having an average particle diameter of 0.2 μm were further added to the solid content, and the coating liquid obtained by stirring and dispersing with a homogenizer was used. The same operation as the production of the electrostatic latent image developing carrier B was repeated to obtain an electrostatic latent image developing carrier D.

(Manufacture of electrostatic latent image developing carrier E particles)
The electrostatic latent image described above except that a compound having a structure represented by CH ₃ (CH ₂ ) ₃ NH ₂ was used instead of the compound having a structure represented by CF ₃ (CF ₂ ) ₃ NH _2. The same operation as the production of the developing carrier A was repeated to obtain an electrostatic latent image developing carrier E.

Example 1
93 parts of electrostatic latent image developing carrier A and 7 parts of magenta toner for IPSIO Color 8000 were mixed to obtain a developer. This developer is loaded into the IPSIO Color 8000, an image area ratio of 12%, and 1000 continuous printing is performed using a character image pattern. Then, a part of the developer is taken out, and then a continuous printing test of 100,000 sheets. Went. The developer charge amount was measured before starting use, after printing 1000 sheets, and at the end of continuous printing. Further, the background stain of the image at the end of printing 100,000 sheets and the charge amount of the developer were similarly evaluated.

  The charge amount of the developer was determined based on the blow-off method by collecting a small amount of developer from the sleeve of the developing device. The film thickness of the electrostatic latent image developing carrier was determined by crushing the carrier and observing a cross-sectional image with a scanning electron microscope. The spent amount was measured by adding 10 g of methyl ethyl ketone to 1 g of the electrostatic latent image developing carrier obtained by removing the toner from the electrostatic latent image developing carrier after printing 100,000 sheets and stirring 500 times. Then, the supernatant liquid was taken out and the transmittance was measured with a spectrophotometer. The measurement was performed using a cell having an optical path length of 1 cm in the wavelength range of 400 nm to 800 nm, and the spent amount was compared with the maximum peak value in the measurement wavelength region.

  The evaluation of the background stain was a visual evaluation, and was evaluated in four stages: ◎: very good, ○: good, Δ: slightly bad, x: bad (x is an unacceptable level).

(Examples 2 to 4, Comparative Example 1)
Except for using the electrostatic latent image developing carriers B to E in place of the electrostatic latent image developing carrier A, the same operations as in Example 1 were repeated to obtain Examples 2 to 4 and Comparative Example 1. .

  The evaluation results of Examples 1 to 4 and Comparative Example 1 are shown in Table 1.

  From Table 1, Examples 1-4 have an initial developer charge amount, an initial background stain, a developer charge amount after running 1000 sheets, a developer charge amount after printing 100,000 sheets, and 100,000 sheets as compared with Comparative Example 1. It was revealed that the background after printing, the film wear rate, and the amount of toner spent after 100,000 sheets were excellent.

Claims (11)

A carrier for developing an electrostatic latent image in which a resin coating layer is provided on the surface of a magnetic powder constituting a core material, and the resin coating layer includes CF ₃ (CF ₂ ) _n —NH (R ₁ OR ₂ (Wherein R ₁ is a saturated alkylene group having 1 or 2 carbon atoms, R ₂ is an alkyl group having 1 or 2 carbon atoms, and n is a positive integer). A carrier for developing an electrostatic latent image, which is a film formed of a composition comprising a compound having a structure containing units and / or a condensation product of the compound. The composition contains a compound having a structure containing a repeating unit represented by CF ₃ (CF ₂ ) ₁₆ —NH (CH ₂ OCH ₃ ) and / or a condensation product of the compound. The electrostatic latent image developing carrier according to claim 1.   3. The electrostatic latent image developing carrier according to claim 1, wherein the composition contains a condensation product of a silicone compound having a silanol and / or a group to be hydrolyzed.   4. The electrostatic latent image developing carrier according to claim 3, wherein the composition contains a condensation product of a methyl silicone compound having a molecular weight of 1,000 to 100,000.   The electrostatic latent image developing carrier according to claim 1, wherein the composition contains fine particles of a metal oxide.   6. The electrostatic latent image developing carrier according to claim 5, wherein the metal oxide fine particles are alumina fine particles.   The carrier for electrostatic latent image development according to claim 6, wherein the alumina fine particles are contained in the range of 1% by weight to 70% by weight with respect to the total weight of the composition.   The carrier for electrostatic latent image development according to claim 6 or 7, wherein the alumina fine particles have an average particle diameter of 0.01 µm to 0.7 µm. The electrostatic composition according to claim 1, wherein the composition contains a low-resistance material having a volume resistivity of 10 ⁻² Ωcm to 10 ⁸ Ωcm. Carrier for developing latent images.   The carrier for developing an electrostatic latent image according to claim 1, a binder resin, and a colorant, and having a negative chargeability relative to the carrier for developing an electrostatic latent image. A developer for developing an electrostatic latent image, comprising a toner.   The developer for developing an electrostatic latent image according to claim 10, wherein the toner contains a chromatic colorant.