JP2007225967A - Toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner which can provide a satisfactory image over a long time even when a charging member is contaminated by an abrasive agent in long-time duration and, further, is excellent in a characteristic of suppressing or preventing both of defective charge and image flow even in a cleanerless image forming method more sever with respect to contamination of the charging member due to the abrasive agent. <P>SOLUTION: The toner comprises at least: a binding resin; a toner particle containing coloring agent; and inorganic fine powder, wherein the inorganic fine powder has an average particle size of a primary particle of 30 to 300 nm, has particles having perovskite crystal, and volume resistivity A (Ω cm) of the inorganic fine powder is 1.0×10<SP>4</SP>≤A≤1.0×10<SP>9</SP>and free ratio B (number%) for the toner is 5≤B≤40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner and an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method, or the like.

  Conventionally, a number of methods are known as electrophotographic methods. Generally, a photoconductive material is used to form an electrostatic latent image on an electrostatic latent image carrier (photoconductor) by various means. Next, the electrostatic latent image is developed with a developer to be visualized, and the toner image is transferred to a transfer material such as paper as necessary, and then the toner image is fixed on the transfer material by heat and pressure. To obtain a copy.

  However, when such an image forming process is repeated many times, particularly in a high humidity environment, ozone generated in the charging process for charging the electrostatic latent image bearing member reacts with nitrogen in the air to generate nitrogen oxides (NOx). It becomes. Further, these nitrogen oxides react with moisture in the air to form nitric acid and adhere to the surface of the latent electrostatic image bearing member, thereby reducing the resistance of the surface of the latent electrostatic image bearing member.

  For this reason, an image flow occurs in the electrostatic latent image bearing member during image formation. There is known a method for improving the image flow by adding particles having an abrasive action to the toner and peeling off the charged product adhering to the surface of the electrostatic latent image bearing member. However, conventionally used abrasives have a large particle size and a broad particle size distribution, and it has been difficult to uniformly polish the surface of the electrostatic latent image bearing member.

  As an improvement of this point, Patent Documents 1 and 2 propose a method of adding abrasive particles (strontium titanate powder) to toner particles. Since the strontium titanate powder used in these methods has a fine particle size and few coarse particles, it has an excellent polishing effect.

However, since the abrasive particles have a small particle size, some of them may slip through the cleaning blade. Conventional abrasive particles have a volume resistance of about 1.0 × 10 ^{10 to} 1.0 × 10 ¹¹ , and if the abrasive particles slipped through the cleaning contaminate (spent) the charging member, image defects due to poor charging are likely to occur. There was a tendency for problems to occur in durability. Therefore, there is an urgent need for long-term durability to prevent the charging member from being contaminated or to make it difficult for image defects to occur even if the charging member is contaminated.

  Also, in recent years, the entire image forming apparatus has been made compact and compatible with ecology by eliminating waste toner. To reduce the amount of toner consumed per page, the transfer residual toner is collected and reused without using the cleaning blade as described above. A cleanerless system has been widely proposed (Patent Document 3 and Patent Document 4). Among them, copiers and printers employing a so-called simultaneous development cleaning system that collects transfer residual toner in a developing device simultaneously with development have been put into practical use. In particular, since this simultaneous development cleaning method does not use a cleaning unit, dramatic progress has been made in terms of ecology by reducing the size of the apparatus and eliminating waste toner.

When such a cleaner-less system is used, since there is no cleaning blade for removing the transfer residual toner, the charging member becomes more and more seriously contaminated, which causes a charging failure. However, in order to suppress the image flow that occurs in a high humidity environment, the surface of the photoreceptor is uniformly polished by attaching abrasive particles to a member that contacts the electrostatic charge latent image carrier such as a charging member and an auxiliary brush. The contamination of the member and the image flow were in opposite directions. In particular, when abrasive particles having a volume resistance of about 1.0 × 10 ^{10 to} 1.0 × 10 ¹¹ are accumulated on the charging member due to long-term durability, the ability to impart charge to the photoreceptor decreases, and a satisfactory image can be obtained. There was a tendency to not. Therefore, even if abrasive particles adhere to the charging member, it has been an urgent task for long-term durability to make it difficult for image defects due to defective charging to occur.

Japanese Patent Laid-Open No. 10-10770 Japanese Patent No. 3047900 Japanese Patent Laid-Open No. 05-053482 JP-A-10-307456

  An object of the present invention is to provide a toner and an image forming method that solve the above-mentioned problems.

  That is, an object of the present invention is to obtain a good image over a long period even if the charging member is contaminated with an abrasive during long-term durability. Another object of the present invention is to provide a toner and an image forming method which are excellent in characteristics for suppressing or preventing both charging failure and image flow even in a cleaner-less image forming method which is more severe for contamination of a charging member by an abrasive. .

An object of the present invention is to provide toner particles containing at least a binder resin and a colorant and at least an inorganic fine powder. The inorganic fine powder has an average primary particle size of 30 to 300 nm, and a perovskite. The volume resistivity value A (Ω · cm) of the inorganic fine powder is 1.0 × 10 ⁴ ≦ A ≦ 1.0 × 10 ⁹ , and the release rate B with respect to the toner. The toner is characterized in that (number%) satisfies 5 ≦ B ≦ 40.

Further, the present invention provides a charging step of charging the electrostatic latent image carrier with contact charging means, an electrostatic latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier, Developing the electrostatic latent image with a developer to form a toner image on the electrostatic latent image carrier, and transferring to transfer the toner image on the electrostatic latent image carrier to an intermediate transfer member or transfer material The toner includes at least inorganic fine particles on a toner surface containing at least a binder resin and a colorant, and the average particle size of primary particles of the inorganic fine particles is 30. Particles having perovskite type crystals of 300 nm to 300 nm, and the volume resistance value A (Ω · cm) of the inorganic fine powder is 1.0 × 10 ⁴ ≦ A ≦ 1.0 × 10 ⁹ , and the toner Liberation rate B (number%) with respect to 5 ≦ B ≦ 40 An image forming method which is characterized in that.

  According to the present invention, both charging failure due to contamination of the charging member and suppression of image flow under high humidity can be achieved. Specifically, in a cleaner-less image forming method that is more severe with respect to contamination of the charging member, even when the charging member is contaminated due to long-term durability by an abrasive whose volume resistance is adjusted to an appropriate range, there is no charging failure. A good image can be provided.

  Furthermore, by adjusting the release rate of the abrasive from the toner to an appropriate range, it is possible to efficiently suppress the image flow with a small amount of abrasive particles, and to provide an image with high image quality and high stability. It becomes possible.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.
First, the inorganic fine powder contained in the toner of the present invention will be described in detail.

  As a result of intensive studies by the present inventors, by performing the above-described image formation using a toner formed by adding inorganic fine powder of perovskite crystal having a specific volume resistance, it is possible to perform image formation during long-term durability. It was found that charging failure and image flow can be compatible.

  In the present invention, an image is formed using a toner to which particles having a fine particle size and a small amount of coarse particles (hereinafter referred to as an abrasive) are added, so that it adheres very thinly to the surface of the latent electrostatic image bearing member. The reason why the charged product can be scraped off is considered as follows. When there is a cleaning step, the toner and the abrasive remaining on the electrostatic latent image bearing member after the transfer step of the image forming process are scraped off by a cleaning blade in contact with the electrostatic latent image bearing member and put into the cleaner. Sent. However, part of the toner and abrasive remains in the vicinity of the cleaning blade. At this time, the released cleaning blade rubs the surface of the latent electrostatic image bearing member with a pressure at which it comes into contact with the latent electrostatic image bearing member, so that the charged product can be removed.

  Further, when a cleaner-less system is used, the toner and the abrasive remaining after the transfer step of the image forming process adhere to the leveling member and the charging member that are in contact with the electrostatic image carrier, and the electrostatic latent image carrier. The charged product can be removed.

  In the present invention, the abrasive added to the toner is preferable because of the high polishing effect of the perovskite crystal inorganic fine powder. The inorganic fine powder of perovskite crystal has an average primary particle size of 30 to 300 nm, more preferably 40 to 250 nm. When the average particle size is less than 30 nm, the polishing effect of the particles in the cleaner part is insufficient. On the other hand, if it exceeds 300 nm, the above polishing effect is too strong, and scratches are generated on the latent electrostatic image bearing member (photosensitive member).

Further, in the present invention, the volume resistance value A (Ω · cm) of the perovskite type crystalline inorganic fine powder is preferably 1.0 × 10 ⁴ ≦ A ≦ 1.0 × 10 ⁹ . When the volume resistance value of the inorganic fine powder is less than 1.0 × 10 ⁴ Ω · cm, the toner charge amount is particularly greatly lowered when the toner is left under high humidity, and the image density changes easily due to durability. Become. On the other hand, when the volume resistivity value of the inorganic fine powder exceeds 1.0 × 10 ⁹ Ω · cm, the charge imparting ability to the electrostatic charge latent image carrier when attached to the charging member, particularly under low humidity. Obstruction, and uneven charging and poor charging are likely to occur.

  In order to adjust the volume resistance value A (Ω · cm) of the perovskite crystal inorganic fine powder, the following two methods are preferable.

In the first method, it is preferable to adjust the molar ratio of the perovskite crystalline inorganic fine powder. For example, strontium titanate, which is a perovskite type crystalline inorganic fine powder, will be described. For strontium titanate, by reducing the molar ratio of SrO / TiO _2, it is possible to reduce the resistance of strontium titanate. The molar ratio of SrO / TiO ₂ can be adjusted to 0.80. In order to reduce the molar ratio of SrO / TiO ₂ , the mixing ratio of the titanium oxide source and the strontium source during the reaction should be adjusted. Thus, the resistance can be adjusted.

  As the second method, it is preferable to treat the surface of the perovskite type inorganic fine powder with a compound such as titanium, aluminum or zirconium. By adjusting these treatment materials and treatment amounts, it is possible to adjust the volume resistance value A of the inorganic fine powder to a preferable range. In addition, after the inorganic fine powder is coated with a metal compound, it can be further treated with a silane coupling agent, a titanium coupling agent, a fatty acid, a fatty acid metal salt or the like in order to improve hydrophobicity and suppress aggregation.

  The titanium, aluminum, and zirconium sources to be surface-treated on the inorganic fine powder of perovskite crystal may be any material that can be handled as an acid or alkaline solution. For example, titanium sources such as titanium sulfate and titanium tetrachloride are used as an aluminum source. As the zirconium source, zirconium oxychloride, zirconium sulfate, zirconium nitrate or the like can be used alone or in any combination.

  In the present invention, the liberation rate of the perovskite crystal inorganic fine powder to the toner particles is preferably 5 to 40% by number, more preferably 10 to 35% by number. Here, the release rate is a percentage of the perovskite crystal inorganic fine powder released from the toner particles, which is determined by a number%, and is measured by a particle analyzer (PT1000: manufactured by Yokogawa Electric Corporation). . In the present invention, the charge product can be effectively removed by setting the liberation ratio to the toner particles to 5 to 40% by number.

  When the release rate of the inorganic fine powder is less than 5% by number, the inorganic fine powder behaves together with the toner, and the ratio of being transferred to the intermediate transfer member or transfer material in the transfer process increases. In this case, it is insufficient to remove the charged product adhering to the surface of the latent electrostatic image bearing member. On the other hand, when the liberation ratio exceeds 40% by number, the inorganic fine powder liberated in the developing device functions as a carrier for imparting charge to the toner, so the developer charge amount due to durability The change becomes large and the density change is likely to occur.

  Furthermore, by using an inorganic fine powder of a perovskite crystal having a substantially cubic and / or cuboid particle shape as an inorganic fine powder of a perovskite crystal suitable for uniformly polishing the electrostatic charge latent image bearing member, The charged product adhering to the surface of the image carrier can be efficiently removed. Since the particle shape of the abrasive is approximately cubic and / or cuboid, the contact area between the abrasive and the surface of the latent electrostatic image bearing member can be increased, and the ridge line of the cube and / or cuboid of the abrasive Since the toner comes into contact with the surface of the latent electrostatic image bearing member, good scraping property of the toner can be obtained.

  Next, the toner used in the present invention will be described.

  The toner used in the present invention may be any toner as long as it contains a binder resin and a colorant.

  As the colorant used for the toner particles in the present invention, any dye or pigment colorant used in conventionally known toners can be used. The method for producing the toner particles of the present invention is not particularly limited, and a kneading and pulverizing method, suspension polymerization method, suspension granulation method, emulsion polymerization method, emulsion aggregation method, dispersion polymerization method and the like are used.

  Hereinafter, a method for producing toner particles by the kneading and pulverization method will be described in detail.

  First, the binder resin that can be used in the present invention will be described.

  As the binder resin used in the present invention, commercially available resins can be used, but (a) a polyester resin, (b) a hybrid resin having a polyester unit and a vinyl copolymer unit, (c) Mixture of hybrid resin and vinyl copolymer, (d) Mixture of polyester resin and vinyl copolymer, (e) Mixture of hybrid resin and polyester resin, and (f) Polyester resin, hybrid resin and vinyl It is a resin selected from a mixture with a copolymer.

  When a polyester resin is used as the binder resin, a polyhydric alcohol and a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride, a polyvalent carboxylic acid ester, or the like can be used as a raw material monomer.

  Specifically, for example, as the dihydric alcohol component, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2 -Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1, 2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Opentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A And hydrogenated bisphenol A.

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

  Divalent acid components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides thereof, alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof, carbon number Examples thereof include succinic acid substituted with 6 to 12 alkyl groups or anhydrides thereof, unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or anhydrides thereof.

  Examples of the trivalent or higher polyvalent carboxylic acid component for forming a polyester resin having a crosslinking site include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4,5-benzenetetracarboxylic acid, and anhydrides and ester compounds thereof.

  Among them, in particular, a bisphenol derivative represented by the following general formula (I) is used as a diol component, and a carboxylic acid component (for example, fumaric acid) composed of a divalent or higher carboxylic acid or an acid anhydride thereof, or a lower alkyl ester thereof. A polyester resin obtained by polycondensation using acid, maleic acid, maleic anhydride, phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, etc.) as an acid component is preferable because it has good charging characteristics as a color toner. .

  In the binder resin contained in the toner used in the present invention, the “hybrid resin” means a resin in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, it is a resin formed by a transesterification reaction between a polyester unit and a vinyl polymer unit obtained by polymerizing a monomer having a carboxylic acid ester group such as (meth) acrylic acid ester, preferably a vinyl polymer. A graft copolymer (or block copolymer) having a trunk polymer and a polyester unit as a branch polymer. In the present invention, “polyester unit” refers to a portion derived from polyester, and “vinyl polymer unit” refers to a portion derived from a vinyl polymer. The polyester monomer constituting the polyester unit is a polyvalent carboxylic acid component and a polyhydric alcohol component, and the vinyl polymer unit is a monomer component having a vinyl group.

  Vinyl monomers for producing vinyl polymer units include styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2, 4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn -Styrene such as dodecylstyrene, p-methoxystyrene, p-chlorostyrene, 3,4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene and derivatives thereof; ethylene, propylene, butylene, isobutylene Styrene unsaturated monoolefins such as butadiene, isoprene, etc. Unsaturated polyenes; vinyl halides such as vinyl chloride, vinyl chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate, ethyl methacrylate, methacryl Propyl acid, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate Α-methylene aliphatic monocarboxylic acid esters such as methyl acrylate, ethyl acrylate, propyl acrylate, acrylic acid-n-butyl, acrylic acid isobutyl, acrylic acid-n-octyl, acrylic acid dode Acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic esters such as phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl methyl ketone, Vinyl ketones such as vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone; Vinyl naphthalenes; Acrylonitrile, methacrylonitrile, acrylamide And acrylic acid or methacrylic acid derivatives.

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

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

  In the toner used in the present invention, the vinyl polymer unit of the binder resin may have a crosslinked structure crosslinked with a crosslinking agent having two or more vinyl groups. Examples of the crosslinking agent used in this case include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; examples of diacrylate compounds linked by an alkyl chain include ethylene glycol diacrylate and 1,3-butylene glycol. Examples include diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, and those obtained by replacing acrylates of the above compounds with methacrylate. The diacrylate compounds linked by an alkyl chain containing an ether bond include, for example, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, poly Examples include tylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate, and those obtained by replacing acrylates of the above compounds with methacrylates; diacrylates linked by a chain containing an aromatic group and an ether bond. Examples of the compounds include polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the like The thing which replaced the acrylate of the compound of this with the methacrylate is mentioned.

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

  In this invention, it is preferable that the monomer component which can react with the component of both resin units is included in any one or both of a vinyl-type polymer unit and a polyester unit. Examples of monomers that can react with the components of the vinyl polymer unit among the monomers constituting the polyester resin unit include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. It is done. Among the monomers constituting the vinyl polymer unit, those capable of reacting with the components of the polyester unit include those having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method of obtaining a reaction product of a vinyl polymer unit and a polyester unit, there is a polymer containing a monomer component capable of reacting with each of the vinyl polymer unit and the polyester unit listed above. A method obtained by carrying out the polymerization reaction of one or both resins is preferred.

  Examples of the polymerization initiator used when producing a vinyl polymer unit that can be used in the present invention include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2,2′-azobis (-2,4-dimethylvaleronitrile), 2,2′-azobis (-2methylbutyronitrile), dimethyl-2,2′-azobisisobuty 1,1′-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo) -isobutyronitrile, 2,2′-azobis (2,4,4-trimethylpentane), 2-phenylazo-2, 4-dimethyl-4-methoxyvaleronitrile, 2,2′-azobis (2-methyl-propane), methyl ethyl ketone peroxide, acetylacetone Ketones, ketone peroxides such as cyclohexanone peroxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydro Peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, deca Noyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxide Sidicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl Peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t -Butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, di-t-butyl peroxyisophthalate, t-butyl peroxyallyl carbonate, t-amyl peroxy 2-ethylhexanoate, di-t-butyl Peroxy hexahydro terephthalate, di -t- butyl peroxy azelate and the like.

  As a manufacturing method which can prepare the hybrid resin used for the toner which can be used for this invention, the manufacturing method shown to the following (1)-(6) can be mentioned, for example.

  (1) A method in which a vinyl polymer, a polyester resin, and a hybrid resin are blended after production, and the blended product is obtained by dissolving and swelling the resin component in an organic solvent (for example, xylene) and then distilling the organic solvent. Manufactured by. The hybrid resin is synthesized by separately producing a vinyl polymer and a polyester resin, then dissolving and swelling in a small amount of an organic solvent, adding an esterification catalyst and an alcohol, and performing a transesterification reaction by heating. The ester compound used can be used.

  (2) A method for producing a polyester unit and a hybrid resin component in the presence of a vinyl polymer after the production thereof. The hybrid resin component is added as necessary to the reaction of a vinyl polymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (polyhydric alcohol, polycarboxylic acid), and the unit and monomer as necessary. Produced by reaction with polyester. Also in this case, an organic solvent can be appropriately used.

  (3) A method for producing a vinyl polymer unit and a hybrid resin component in the presence of a polyester resin after the production. The hybrid resin component is produced by a reaction between a polyester unit (a polyester monomer can be added if necessary) and a vinyl monomer, and a reaction between the unit and the monomer and a vinyl polymer unit added as necessary. . Also in this case, an organic solvent can be appropriately used.

  (4) After the vinyl polymer and the polyester resin are produced, either or both of a vinyl monomer and a polyester monomer (polyhydric alcohol, polycarboxylic acid) are added in the presence of these polymer units, and the added monomer. The hybrid resin component can be produced by carrying out a polymerization reaction under conditions according to the conditions. Also in this case, an organic solvent can be appropriately used.

  (5) After producing the hybrid resin, either one or both of a vinyl monomer and a polyester monomer (polyhydric alcohol, polyvalent carboxylic acid) are added to perform either or both of addition polymerization and condensation polymerization reaction. As a result, a vinyl polymer unit and a polyester unit are produced. In this case, as the hybrid resin component, those produced by the production methods (2) to (4) can be used, and those produced by known production methods can be used as necessary. it can. Furthermore, an organic solvent can be used as appropriate.

  (6) A vinyl polymer unit, a polyester unit and a hybrid resin component are obtained by mixing vinyl monomers and polyester monomers (polyhydric alcohol, polycarboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reactions. Manufactured. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (6), a plurality of types of polymer units having different molecular weights and different degrees of crosslinking can be used for the vinyl polymer unit and the polyester unit. The vinyl polymer or vinyl polymer unit in the present invention means a vinyl homopolymer or vinyl copolymer, a vinyl monopolymer unit or a vinyl copolymer unit.

  Further, the toner used in the present invention preferably contains a wax as a release agent because the fixability can be remarkably improved.

  Examples of the wax that can be used in the present invention include the following. Oxides of aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, and aliphatic hydrocarbon waxes such as oxidized polyethylene wax, or the like Block copolymers of these: waxes mainly composed of fatty acid esters such as carnauba wax, behenyl behenate, and montanic acid ester wax, and those obtained by partially or fully deoxidizing fatty acid esters such as deoxidized carnauba wax Is mentioned. Further, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; polyhydric alcohols such as sorbitol; fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid; and stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, seryl alcohol, Esters of alcohols such as merisyl alcohol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bis stearic acid amide, ethylene biscapric acid Saturated fatty acid bisamides such as amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N ′ dioleyl adipic acid amide, N, N ′ dioleyl Unsaturated fatty acid amides such as sebacic acid amides; Aromatic bisamides such as m-xylene bisstearic acid amide and N, N ′ distearyl isophthalic acid amides; calcium stearate, calcium laurate, zinc stearate, magnesium stearate, etc. Aliphatic metal salts (generally referred to as metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; fatty acids such as behenic acid monoglycerides and many others Price Lumpur partial ester; methyl ester compounds having hydroxyl groups obtained by and hydrogenated vegetable oils and the like.

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

  As the colorant used in the toner used in the present invention, known dyes and / or pigments are used. A pigment alone may be used, but it is preferable to use a dye and a pigment together to improve the clarity when a full-color image forming apparatus is used.

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

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

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

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

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

  In the toner used in the present invention, it is preferable to use a toner obtained by mixing a colorant in advance with the binder resin of the present invention to form a master batch. Then, the colorant can be favorably dispersed in the toner by melt-kneading the colorant master batch and other raw materials (binder resin, wax, etc.).

  When using a resin that can be used in the present invention to masterbatch the colorant, even when a large amount of colorant is used, the dispersibility of the colorant is not deteriorated, and the dispersibility in the toner particles is improved, Excellent color reproducibility such as color mixing and transparency. Further, a toner having a large covering power on the transfer material can be obtained. Further, by improving the dispersibility of the colorant, it is possible to obtain an image with excellent durability stability of toner chargeability and maintaining high image quality.

  The amount of the colorant used in the toner is preferably 0.1 to 15 parts by mass, more preferably 0.5 to 12 parts by mass, and most preferably 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin. This is preferable in terms of color reproducibility and developability.

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

  Negatively chargeable charge control agents include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds having sulfonic acid or carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene Etc. are available. As the positively chargeable charge control agent, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound, or the like can be used. The charge control agent may be added internally or externally to the toner particles.

  In particular, the color toner that can be used in the present invention is preferably an aromatic carboxylic acid metal compound that is colorless, has a high toner charging speed, and can stably maintain a constant charge amount.

  Next, a manufacturing procedure will be described.

  First, in the raw material mixing step, as a toner internal additive, at least a binder resin, a colorant, and a release agent are weighed and mixed and mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Further, the toner raw materials blended and mixed as described above are melt-kneaded to melt the binder resin, and the colorant and the like are dispersed therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. In recent years, single-screw or twin-screw extruders have become mainstream due to the advantage of being capable of continuous production. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd. In general, a twin-screw extruder manufactured by Kay Sea Kay, a co-kneader manufactured by Buss, or the like is used. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading, and then cooled through a cooling step of cooling by water cooling or the like.

  In general, the cooled colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, pulverization is performed with a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nisshin Engineering Co., Ltd. or the like. After that, if necessary, classification is performed using a classifier such as an inertia class elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or centrifugal class turbo plex (manufactured by Hosokawa Micron Co., Ltd.), and the weight average particle diameter A classified product of 3 to 11 μm is obtained.

  If necessary, toner particles may be formed by performing surface modification and spheronization treatment in a surface modification step, for example, a hybridization system manufactured by Nara Machinery Co., Ltd. or a mechano-fusion system manufactured by Hosokawa Micron.

  A method for producing toner particles by suspension polymerization will be described in detail.

  A colorant, a low softening point material such as wax, a polar resin, a charge control agent, and a polymerization initiator are added to the polymerizable monomer, and if necessary, the solution is uniformly dissolved or dispersed by a homogenizer or an ultrasonic disperser. The monomer composition is dispersed in an aqueous phase containing a dispersion stabilizer by a stirrer, a homogenizer or a homomixer. At this time, granulation is preferably performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, stirring may be carried out to such an extent that the particle state of the monomer composition is maintained by the action of the dispersion stabilizer and precipitation of the particles of the monomer composition is prevented. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 to 90 ° C. 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, some water or A part of the aqueous medium may be distilled off. After completion of the reaction, the produced toner particles are recovered by washing and filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 to 3,000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition.

  Toner particle size distribution control and particle size control include pH adjustment of aqueous media during granulation, methods of changing the type and addition amount of poorly water-soluble inorganic salts and dispersants that act as protective colloids, mechanical devices This can be achieved by controlling the peripheral speed of the rotor, the number of passes, the shape of the stirring blade, the stirring conditions, the container shape, or the solid content concentration in the aqueous solution.

  Examples of the polymerizable monomer used for suspension polymerization include styrene; styrene derivatives such as o- (m-, p-) methylstyrene and m- (p-) ethylstyrene; methyl (meth) acrylate, (meta ) Propyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, (meth) acrylate-2-ethylhexyl, Examples include (meth) acrylic acid ester monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide.

  As the polar resin added during polymerization, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a polyester resin, and an epoxy resin are preferably used.

  Examples of the low softening point material used in the present invention include paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof.

  As the charge control agent used in the present invention, a known charge control agent can be used, but a charge control agent having no polymerization inhibitory property and no soluble component in an aqueous medium is particularly preferable. Specific examples of the negative compound include salicylic acid, naphthoic acid, dicarboxylic acid, metal compounds of derivatives thereof, polymer compounds having sulfonic acid in the side chain, boron compounds, urea compounds, silicon compounds, calixarene. . Examples of the positive system include a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, and an imidazole compound. The amount of the charge control agent used is preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  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 polymerization initiators such as azobisisobutylnitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroxy peroxide, 2 Peroxide polymerization initiators such as 1,4-dichlorobenzoyl peroxide and lauroyl peroxide are used. The addition amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used at a ratio of 0.5 to 20% by mass (based on the polymerizable monomer) with respect to the polymerizable monomer. . The kind of the polymerization initiator is slightly different depending on the polymerization method, but may be used alone or mixed with reference to the 10-hour half-life temperature.

  As a dispersant for suspension polymerization, inorganic oxides such as calcium 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, and ferrite. Examples of the organic compound include polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch. These dispersants are preferably used in a proportion of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

  A commercially available dispersant may be used as it is, but in order to obtain dispersed particles having a fine uniform particle size, it can also be obtained by producing an inorganic compound in a dispersion medium under high-speed stirring. For example, in the case of calcium 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.

  In order to refine these dispersants, 0.001 to 0.1 parts by mass of a surfactant may be used in combination with 100 parts by mass of the suspension. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. Examples include sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate.

  A perovskite crystal inorganic fine powder is added to the toner particles obtained by these production methods to obtain the toner of the present invention. The amount of the perovskite crystal inorganic fine powder added to the toner particles is preferably 0.1 to 5.0 parts by mass, more preferably 0.2 to 3.0 parts by mass with respect to 100 parts by mass of the toner particles.

  Furthermore, in the present invention, in order to improve developability and durability, the following inorganic powder can also be added to the toner. For example, oxides of metals such as silicon, magnesium, zinc, aluminum, titanium, cerium, cobalt, iron, zirconium, chromium, manganese, tin, antimony; metal salts such as barium sulfate, calcium carbonate, magnesium carbonate, aluminum carbonate; Examples thereof include clay minerals such as kaolin; phosphoric acid compounds such as apatite; silicon compounds such as silicon carbide and silicon nitride; and carbon powders such as carbon black and graphite.

  For the same purpose, the following organic particles and composite particles may be added to the toner. Resin particles such as polyamide resin particles, silicone resin particles, silicone rubber particles, urethane particles, melamine-formaldehyde particles, acrylic particles; rubber, wax, fatty acid compounds or resins, metals, metal oxides, carbon black Composite particles composed of inorganic particles; Teflon (registered trademark), fluorine resin such as polyvinylidene fluoride; fluorine compound such as carbon fluoride; fatty acid metal salt such as zinc stearate; fatty acid derivative such as fatty acid ester; molybdenum sulfide; Examples include amino acids and amino acid derivatives.

  In the present invention, both a one-component development process and a two-component development process can be used.

  The magnetic carrier that can be used when the two-component development process is included will be described.

  The magnetic carrier that can be used in the present invention is preferably a magnetic carrier in which a coating layer is formed on the surface of a known ferrite particle, filled ferrite particle, or magnetic fine particle dispersed resin core, and particularly preferably a magnetic fine particle dispersed resin core. Magnetic carrier having a coating layer formed on the surface thereof.

In the magnetic carrier that can be used in the present invention, the magnetic fine particles used in the magnetic fine particle dispersed resin core are preferably magnetite fine particles, and are nonmagnetic inorganic compounds for adjusting the true density and magnetic properties of the magnetic carrier. It is preferable to use certain hematite (α-Fe ₂ O ₃ ) fine particles in combination.

  As the binder resin constituting the magnetic fine particle dispersed resin core particles that can be used in the present invention, a thermosetting resin is preferable.

  Thermosetting resins include phenolic resins, epoxy resins, polyamide resins, melamine resins, urea resins, unsaturated polyester resins, alkyd resins, xylene resins, acetoguanamine resins, furan resins, silicone resins, polyimide resins, urethane resins. Is mentioned. These resins may be used alone or in combination of two or more, but preferably contain at least a phenol resin.

The ratio of the binder resin and the magnetic fine particles constituting the core particles in the present invention is preferably binder resin: magnetic fine particles = 1: 99 to 1:50 on a mass basis.
In the present invention, the carrier coating material preferably contains at least a binder resin and fine particles.

  As the binder resin for forming the coating material used for the magnetic carrier that can be used in the present invention, any known resin can be used. Preferably, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, Perfluoropolymers such as polyfluorochloroethylene, polytetrafluoroethylene, polyperfluoropropylene, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and trifluorochloroethylene, tetrafluoro Examples thereof include a copolymer of ethylene and hexafluoropropylene, a copolymer of vinyl fluoride and vinylidene fluoride, and a copolymer of vinylidene fluoride and tetrafluoroethylene.

  The above-mentioned resins can be used alone or in combination. In addition, a curing agent or the like can be mixed with a thermoplastic resin and cured for use.

  In the present invention, a silicone resin can also be used as the coating material resin from the viewpoint of adhesion to the core and prevention of spent. The silicone resin can be used alone, but is preferably used in combination with a coupling agent in order to increase the strength of the coating layer and control the charge to a preferable level. Furthermore, the coupling agent described above is preferably used as a so-called primer agent in which a part of the coupling agent is treated on the surface of the carrier core before coating the resin, and the subsequent coating layer is accompanied by a covalent bond. , It can be formed in a more adhesive state.

  Aminosilane is preferably used as the coupling agent. As a result, an amino group having positive chargeability can be introduced on the surface of the carrier, and negative charge characteristics can be imparted to the toner satisfactorily. Furthermore, in the case of a magnetic substance-dispersed resin carrier, the presence of an amino group activates both the lipophilic treatment agent that is preferably treated with the metal compound and the silicone resin. By further enhancing the properties and at the same time promoting the curing of the resin, a stronger coating layer can be formed.

  During the coating treatment of the coating layer, it is preferable to coat in a reduced pressure state at a temperature of 30 to 80 ° C.

  The coating amount of the resin core forming the coating material is preferably 0.3 to 4.0 parts by mass with respect to 100 parts by mass of the core. Preferably it is 0.4 thru | or 3.5 mass part, More preferably, it is 0.5 mass part thru | or 3.2 mass part.

  The coating resin preferably contains fine particles in order to make the shape of the carrier surface more uniform and / or sharpen the charge distribution of the toner.

  As the fine particles, both organic and inorganic fine particles can be used. However, it is necessary to maintain the shape of the particles when the carrier is coated, and preferably, crosslinked resin particles or inorganic fine particles are preferably used. Can do. Specifically, a crosslinked polymethyl methacrylate resin, a crosslinked polystyrene resin, a melamine resin, a phenol resin, a nylon resin, and inorganic fine particles can be used alone or in combination from silica, titanium oxide, alumina, and the like. Among these, a crosslinked polymethyl methacrylate resin, a crosslinked polystyrene resin, and a melamine resin are preferable from the viewpoint of charge stability.

  These fine particles are preferably used in an amount of 1 to 40 parts by mass with respect to 100 parts by mass of the coating resin. By using it in the above range, charging stability and toner separation can be improved, and image defects can be prevented. When the amount is less than 1 part by mass, the effect of addition of fine particles cannot be obtained, and when the amount exceeds 40 parts by mass, the coating layer lacks during durability, resulting in poor durability.

  The particle diameter of the fine particles preferably has a peak value of 0.08 to 0.50 μm on the basis of the number in order to improve the toner separation. When the thickness is less than 0.08 μm, it is difficult to disperse the fine particles in the coating material. When the thickness exceeds 0.50 μm, the coating layer lacks during durability, resulting in poor durability.

  The coating resin may contain conductive fine particles so as not to reduce the specific resistance of the carrier excessively and to remove residual charges on the surface of the carrier.

  As the conductive particles, particles containing at least one kind of particles selected from carbon black, magnetite, graphite, titanium oxide, alumina, zinc oxide, and tin oxide are preferable. In particular, as a conductive particle, carbon black is preferably used without being able to remove residual charges on the carrier surface with a small addition amount, and having a small particle size and not inhibiting irregularities caused by fine particles on the carrier surface. be able to. The particle size of the carbon black has a peak value of 10 nm to 60 nm (more preferably 15 to 50 nm) on the basis of the number, so that residual charges on the carrier surface can be removed well and desorption from the carrier can be prevented well. This is preferable.

  These conductive fine particles are preferably used in an amount of 1 to 15 parts by mass with respect to 100 parts by mass of the coating resin in order to reduce the specific resistance of the carrier and to remove residual charges on the carrier surface. When the amount is less than 1 part by mass, the effect of removing the residual charge on the carrier surface is hardly exhibited. When the amount exceeds 15 parts by mass, the dispersion in the coating material becomes unstable, and an excessive charge removing effect is obtained. Therefore, the charge imparting ability of the carrier itself may be reduced.

  The magnetic carrier that can be used in the present invention preferably has a number-based average particle size of 10 to 80 μm. Particles having an average particle size of less than 10 μm are likely to adhere to the carrier, and those having an average particle size of more than 80 μm may not be able to be imparted with good charge due to a small specific surface area relative to the toner. In particular, in order to improve image quality and prevent carrier adhesion, the thickness is 15 to 60 μm, preferably 20 to 45 μm.

  As a method for producing a magnetic fine particle-dispersed resin core, there is a method in which a binder resin monomer and magnetic fine particles are mixed and the monomer is polymerized to obtain magnetic fine particle-dispersed core particles. At this time, as monomers used for polymerization, vinyl monomers, bisphenols and epichlorohydrin for forming epoxy resins; phenols and aldehydes for forming phenol resins; urea and aldehydes for forming urea resins Melamine and aldehydes are used. For example, as a method of producing magnetic fine particle dispersed core particles using a curable phenolic resin, magnetic fine particles are placed in an aqueous medium, and phenols and aldehydes are polymerized in the presence of a basic catalyst in the aqueous medium. There is a method of obtaining fine particle dispersed core particles.

  Other methods for producing magnetic fine particle-dispersed resin core particles include thoroughly mixing a vinyl-based or non-vinyl-based thermoplastic resin, magnetic material, and other additives with a mixer before heating rolls, kneaders, and extruders. There is a method of obtaining magnetic fine particle-dispersed core particles by melting and kneading using a kneader such as the above, cooling the mixture, and then pulverizing and classifying. At this time, it is preferable that the obtained magnetic fine particle-dispersed core particles are spheroidized thermally or mechanically and used as the magnetic fine particle-dispersed core particles for the resin carrier. As the binder resin, a thermosetting resin such as a phenol resin, a melamine resin, or an epoxy resin is preferable in terms of excellent durability, impact resistance, and heat resistance. The binder resin is more preferably a phenol resin in order to more suitably express the characteristics of the present invention.

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

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

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

  Examples of the basic catalyst used in the condensation polymerization of phenols and aldehydes include those used in the production of ordinary resol type resins. Examples of such a basic catalyst include aqueous ammonia, hexamethylenetetramine and alkylamines such as dimethylamine, diethyltriamine, and polyethyleneimine. The molar ratio of these basic catalysts to phenols is preferably 0.02 to 0.3.

  Next, the image forming method of the present invention will be described in detail.

  An example of the simultaneous development cleaning method used in the present invention is shown in FIG. 1, but is not necessarily limited thereto. In FIG. 1, an electrophotographic photosensitive member 1 serving as an electrostatic latent image carrier rotates in the b direction. The photosensitive member 1 is charged by a charging device 2 as a charging unit, and a laser beam L is projected onto the charged surface of the photosensitive member 1 by an exposure device 3 as an electrostatic latent image forming unit to form an electrostatic latent image. . Thereafter, the electrostatic latent image is visualized as a toner image by the developing device 4 that is a developing unit, and is transferred to the transfer material P by the transfer device 5 that is a transfer unit. In this transfer unit, the untransferred toner remaining on the surface of the photosensitive member without being transferred passes through the above-described charging unit and electrostatic latent image forming unit, and is again used for development or collected by the developing device.

  Here, each step of the image forming method that can be used in the present invention will be described in more detail.

  The charging step is not particularly limited as long as it is a contact charging unit that charges the surface of the photoconductor to charge the electrophotographic photoconductor. As the charging means, an apparatus for charging the electrophotographic photosensitive member by bringing a conductive roller or blade into contact with the electrophotographic photosensitive member can be used.

  Corona discharge, which is a conventional non-contact charging method, generates a large amount of ozone that reacts with nitrogen in the air to form nitrogen oxides (NOx), and these nitrogen oxides react with moisture in the air to form nitric acid. It adheres to the surface of the photoreceptor and tends to reduce the resistance of the surface of the photoreceptor. On the other hand, in the contact charging method, the amount of ozone generated is remarkably small, and the change in the resistance of the photoreceptor surface due to the charged product is small. Further, the contact charging method is more preferable because the charged product that causes the image flow can be efficiently removed by the polishing action of the inorganic fine particles contained in the transfer residual toner in the contact area with the photoreceptor.

  The contact charging method includes a discharge charging mechanism such as a roller charging method and a direct injection charging mechanism such as a magnetic brush charging method.

  The discharge charging mechanism is a mechanism in which the surface of the member to be charged is charged by a discharge phenomenon that occurs in the gap between the contact charging member and the member to be charged. Since the discharge charging system has a constant discharge threshold value for the contact charging member and the member to be charged, it is necessary to apply a voltage larger than the potential of the member to be charged to the contact charging member. In addition, the amount of generation is much smaller than that of a corona charger, but in principle, a charged product is generated.

  As a contact charging member by discharge, a roller charging method (roller charging device) using a conductive roller (charging roller) is preferable in terms of discharge stability and is widely used. The discharge charging roller may be formed in a roller shape using a conductive or medium resistance rubber material or foam as a base layer, and the surface thereof may be made of a high resistance layer. In this configuration, the discharge phenomenon occurs in a gap of several tens of μm that is slightly away from the contact portion between the roller and the member to be charged. Therefore, in order to stabilize the discharge phenomenon, a layer on the roller surface (hereinafter referred to as a surface layer) is flat, has an average surface roughness Ra of 1.0 μm or less, and has a surface with high roller hardness. Preferably it is.

The volume resistance value C (Ω · cm) of the charging member used in the present invention is preferably 1.0 × 10 ⁴ ≦ C ≦ 1.0 × 10 ⁹ , more preferably 5.0 × 10 ⁴ ≦ C ≦ 1. 0.0 × 10 ⁸ .

Further, when the volume resistance value of the inorganic fine powder of the perovskite crystal is A (Ω · cm) and the volume resistance value of the charging member is C (Ω · cm), 10 ⁻¹ ≦ A / C ≦ 10 is perovskite type. This is more preferable for preventing poor charging due to the crystalline inorganic fine powder.

  In the electrostatic latent image forming step, a known exposure apparatus can be used as the exposure means. For example, a semiconductor laser or a light emitting diode is used as the light source, and a scanning optical system unit including a polygon mirror, a lens, and a mirror can be used.

  The development process is mainly divided into a one-component contact development method that does not require a carrier and a two-component development method that includes a toner and a carrier, and any of them can be used. In the present invention, a two-component development method is preferably used.

  As a two-component development method, a magnetic brush of a two-component developer having a nonmagnetic toner and a magnetic carrier is formed on a developer carrier (development sleeve) containing a magnet, and the magnetic brush is formed with a developer layer thickness. After coating with a regulating member to a predetermined layer thickness, the magnetic brush is transported to a developing area facing the photoreceptor, and the magnetic brush is applied while applying a predetermined developing bias between the photoreceptor and the developing sleeve in the developing area. Is a method in which the electrostatic latent image is visualized as a toner image by bringing the toner close to or in contact with the surface of the photoreceptor.

  As described above, by bringing the magnetic brush close to or in contact with the surface of the photoconductor, the deposits on the surface of the photoconductor can be reduced, and the surface of the photoconductor can be reduced by the inorganic fine particles contained in the toner. This is preferably used because it can effectively remove the deposits.

  Examples of the magnetic carrier that can be used in such a two-component developer include an iron powder carrier, a ferrite carrier, and a magnetic fine particle dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin. In the iron powder carrier, since the specific resistance of the carrier itself is low, the charge of the electrostatic latent image leaks through the carrier, and the electrostatic latent image may be disturbed, thereby causing an image defect. Also, in the ferrite carrier, although the specific resistance of the carrier itself is relatively high, the magnetic brush tends to be stiff due to the large saturation magnetization, and the magnetic brush has uneven spots on the toner image. There is. Therefore, a magnetic fine particle dispersed resin carrier in which magnetic fine particles are dispersed in a binder resin is preferably used. The magnetic fine particle-dispersed resin carrier has a relatively higher specific resistance than that of a ferrite carrier, has a lower saturation magnetization, and a lower true specific gravity, thereby preventing electrostatic latent image charge leakage and a rigid magnetic brush. Therefore, it is preferable in that a good toner image free from image defects and unevenness in stitches can be formed.

  In the transfer process, the toner image on the surface of the photoconductor is transferred to the transfer material without contact with the photoconductor, such as corona transfer means, or a roller or an endless belt-shaped transfer member is brought into contact with the photoconductor. There are methods for transferring a toner image on the body surface onto a transfer material, and any method can be used.

  In the present invention, as in the charging step, a large amount of ozone is not generated, and a contact type transfer roller, a resin belt, or an elastic belt-like transfer member is preferably used from the viewpoint of suppression of charged products and low power. It is done.

  In the image forming method of the present invention, as shown in FIG. 2, the transfer residual toner on the photosensitive member is leveled after the transfer and before the charging step, thereby improving the recovery rate of the transfer residual toner during development. Therefore, it is preferable to further include a leveling step 6 having a bias applying means for the purpose of uniformizing the charging polarity of the transfer residual toner.

  In the leveling step 6, when the toner is negatively charged, it is preferable to apply a bias for negatively charging the transfer residual toner to reduce adhesion of the transfer residual toner to the charging member in the charging step. This improves the recovery rate of the transfer residual toner during development. Further, as the leveling member, a brush-like member is preferably used. Furthermore, it is preferable to provide a plurality of such leveling members because the transfer residual toner adheres to the charging member and the recovery rate of the transfer residual toner during development increases.

<Measurement of average particle size of inorganic fine powder>
About the average particle diameter of the inorganic fine powder of the perovskite type crystal | crystallization in this invention, 100 particle diameters were measured from the photograph image | photographed with the magnification of 50,000 times with the electron microscope, and the average was calculated | required. The particle size was determined as (a + b) / 2, where a is the longest side of the primary particles and b is the shortest side.

<Measurement of liberation rate of inorganic fine powder>
The liberation rate is based on the simultaneous emission of carbon atoms, which are constituent elements of the binder resin, and the emission of constituent atoms of the perovskite crystalline inorganic fine powder. When the volume A, “emission volume of constituent atoms of perovskite-type crystalline inorganic fine powder emitting simultaneously with carbon atoms” is defined as emission volume B, it is defined as obtained by the following formula.

  The above liberation rate is measured with a particle analyzer according to the principle described in “Japan Hardcopy 97 Papers” on pages 65-68 (publisher: Electrophotographic Society, issue date: July 9, 1997). Specifically, in the apparatus, fine particles such as toner are introduced into the plasma one by one, and the element of the luminescent material, the number of particles, and the particle size of the particles can be known from the emission spectrum of the fine particles.

  Here, “emitted simultaneously with carbon atoms” in the emission volume B means 2.6 msec. From the emission of carbon atoms. The emission of constituent atoms of the perovskite crystalline inorganic fine powder emitted within. The subsequent light emission of the constituent atoms of the perovskite crystal inorganic fine powder is only the light emission of the constituent atoms of the perovskite crystal inorganic fine powder. In the present invention, the light emission of the constituent atoms of the perovskite type crystalline inorganic fine powder emitted simultaneously with the carbon atoms is measured by measuring the perovskite type crystalline inorganic fine powder adhering to the toner particle surface, and the constituent atoms of the perovskite type crystalline inorganic fine powder are measured. Only the emission of light means that the perovskite-type crystalline inorganic fine powder released from the toner particles is measured, and the release rate is obtained using these.

  As a specific measurement method, helium gas containing 0.1% by volume of oxygen was used, and measurement was performed at 23 ° C. in an environment with a humidity of 60%. Wet one is used for measurement. The channel 1 measures carbon atoms (measurement wavelength 247.860 nm), and the channel 2 measures constituent atoms of the inorganic fine powder (for example, strontium atoms in the case of strontium titanate: measurement wavelength 407.770 nm). Sampling is performed so that the number of light emission of carbon atoms is 1,000 to 1,400, and scanning is repeated until the number of light emission of carbon atoms reaches 10,000 or more in total, and the number of light emission is integrated. At this time, in the distribution in which the number of light emission of carbon atoms is taken on the vertical axis and the cube root voltage of the carbon atom is taken on the horizontal axis, the distribution has a maximum and further has no valley. Sampling and measurement. Based on this data, the noise cut level of all elements is set to 1.50 V, and the liberation rate is calculated using the above formula.

<Measurement of volume resistivity of perovskite crystalline inorganic fine powder>
The volume resistance value R (Ω · cm) of the perovskite crystal inorganic fine powder was measured using the apparatus shown in FIG.

In the measurement method, 5.0 g of a sample is weighed, a steel electrode is applied to the lower part of a PVC pipe having an inner diameter of about 2.6 cm, and the sample is put in the PVC pipe. Next, a steel electrode is applied to the top of the PVC pipe, and a 2 mm thick Teflon (registered trademark) plate is laid on the top and bottom of the steel electrode. A load of 8 kg / cm ² is applied using a hydraulic press. At this time, the thickness t (cm) of the sample portion is measured. In a pressurized state, the resistance value r (Ω) when a voltage of 100 V is applied is measured. The volume resistance value R was calculated from ((2.6 / 2) ² π / t) r.

<Volume resistance measurement of charging roller and conductive fiber brush>
The volume resistance values of the conductive fibers of the charging roller and the conductive fiber brush were measured using the apparatus shown in FIG. A voltage of 100 V is applied while applying a load of 4.9 N (500 g) to both ends of the charging member. The volume resistance value at that time was measured.

<Measurement of molecular weight by GPC (toner)>
The molecular weight of the chromatogram by gel permeation chromatograph (GPC) is measured under the following conditions.

Resin prepared by stabilizing the column in a heat chamber at 40 ° C., and flowing tetrahydrofuran (THF) as a solvent at a flow rate of 1 ml / min to the column at this temperature to adjust the sample concentration to 0.05 to 0.6% by mass. Measurement is performed by injecting 50 to 200 μl of a THF sample solution. An RI (refractive index) detector is used as the detector. As the column, in order to accurately measure the molecular weight region of 10 ^{3 to} 2 × 10 ⁶ , it is preferable to combine a plurality of commercially available polystyrene gel columns. For example, μ-styragel 500, 10 ³ , 10 ⁴ manufactured by Waters A combination of 10 ^{5 and} a combination of shodex KA-801, 802, 803, 804, 805, 806, and 807 manufactured by Showa Denko are preferable.

In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Chemical Co. Manufactured by Toyo Soda Kogyo Co., Ltd. and having molecular weights of 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , It is appropriate to use 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶ , and use at least about 10 standard polystyrene samples.

<Measurement of maximum endothermic peak of wax>
The maximum endothermic peak of the wax and toner can be measured according to ASTM D3418-82 using a differential scanning calorimeter (DSC measuring device) and DSC2920 (TA Instruments Japan).

  As a measuring method, 5 to 20 mg, preferably 10 mg of a measurement sample is accurately weighed. This is put in an aluminum pan, and an empty aluminum pan is used as a reference, and measurement is performed at a temperature rising rate of 10 ° C./min and normal temperature and normal humidity within a measurement temperature range of 30 to 200 ° C. In this temperature raising process, an endothermic peak in the temperature range of 30 to 200 ° C. is obtained. When there are a plurality of peaks, the highest endothermic peak is the one having the highest height from the baseline in the region above the endothermic peak due to the resin.

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

  As a measurement method, 0.1 to 5 ml of a surfactant (preferably alkylbenzenesulfone hydrochloride) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is dispersed for about 1 to 3 minutes with an ultrasonic disperser, and the volume and number of the sample are measured for each channel by the measuring device using a 100 μm aperture as the aperture. The volume distribution and the number distribution are calculated. From these obtained distributions, the weight average particle diameter of the sample is determined. As channels, 2.00 to 2.52 μm; 2.52 to 3.17 μm; 3.17 to 4.00 μm; 4.00 to 5.04 μm; 5.04 to 6.35 μm; 6.35 to 8. 00 μm; 8.00 to 10.08 μm; 10.08 to 12.70 μm; 12.70 to 16.00 μm; 16.00 to 20.20 μm; 20.20 to 25.40 μm; 25.40 to 32.00 μm; 13 channels of 32-40.30 μm are used.

<Measurement of particle size of fine particles in carrier coating resin>
The particle size of the fine particles is 500 or more random particles having a particle size of 5 nm or more by scanning electron microscope (50,000 times) obtained by dissolving a coating material from a carrier in a solvent such as toluene. Extract and measure the major and minor axes with a digitizer. The average is the particle size, with the mode diameter that becomes the peak of the particle size distribution of 500 or more particles (from the column histogram separated every 10 nm). The average particle size is calculated.

  Hereinafter, the present invention will be described in more detail with reference to specific production examples and examples, but the present invention is not limited thereto. “Part” and “%” are based on mass unless otherwise specified.

<Production Example 1 of Perovskite Crystalline Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.5 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.5, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 1.0-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.5 mol / liter in terms of SrTiO ₃ . The slurry was heated to 80 ° C. at 10 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 80 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

A 4.0 mass% titanium sulfate solution and a sodium hydroxide aqueous solution were simultaneously added dropwise at a liquid temperature of 75 ° C. with respect to the solid content of the slurry so that the pH was 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 125 nm were obtained. The treated strontium titanate fine particles were used as inorganic fine powder (A-1). Table 1 shows the physical properties of the inorganic fine powder (A-1).

Moreover, the photograph image | photographed by the magnification of 50,000 times with the electron microscope of this inorganic fine powder (A-1) is shown in FIG. Fine particles that look like a rectangular parallelepiped or cubic are strontium titanate fine particles treated with TiO ₂ .

<Production Example 2 of Perovskite Crystalline Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.7 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.5, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 1.0-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.7 mol / liter in terms of SrTiO ₃ . The slurry was heated to 70 ° C. at a rate of 6 ° C./hour in a nitrogen atmosphere, and reacted for 8 hours after reaching 70 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

A 4.0 mass% titanium sulfate solution and a sodium hydroxide aqueous solution were simultaneously added dropwise at a liquid temperature of 75 ° C. with respect to the solid content of the slurry so that the pH was 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 290 nm were obtained. The treated strontium titanate fine particles were used as inorganic fine powder (A-2). Table 1 shows the physical properties of the inorganic fine powder (A-2).

<Production Example 3 of Perovskite Crystalline Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.5 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 6.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 1.0-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Furthermore, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ . The slurry was heated to 85 ° C. at 13 ° C./hour in a nitrogen atmosphere, and reacted for 3 hours after reaching 85 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

A 4.0 mass% titanium sulfate solution and a sodium hydroxide aqueous solution were simultaneously added dropwise at a liquid temperature of 75 ° C. with respect to the solid content of the slurry so that the pH was 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 35 nm were obtained. The treated strontium titanate fine particles were used as inorganic fine powder (A-3). Table 1 shows the physical properties of the inorganic fine powder (A-3).

<Production Example 4 of Perovskite Type Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 0.95-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.5 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 80 ° C. at 9 ° C./hour in a nitrogen atmosphere, and reacted for 4.5 hours after reaching 80 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

The slurry was simultaneously added dropwise at a liquid temperature of 75 ° C. with respect to the slurry solid content so that a 15.0 mass% titanium sulfate solution and an aqueous sodium hydroxide solution had a pH of 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 125 nm were obtained. The treated strontium titanate fine particles are used as inorganic fine powder (A-4). Table 1 shows the physical properties of the inorganic fine powder (A-4).

<Production Example 5 of Perovskite Type Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

0.80-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.5 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 80 ° C. at 9 ° C./hour in a nitrogen atmosphere, and reacted for 6 hours after reaching 80 ° C. After the reaction, the reaction mixture was cooled to room temperature, the supernatant was removed, washed repeatedly with pure water, and then filtered with Nutsche. The obtained cake was dried to obtain strontium titanate fine particles having an average primary particle size of 125 nm. The strontium titanate fine particles were used as inorganic fine powder (A-5). Table 1 shows the physical properties of the inorganic fine powder (A-5).

<Production Example 6 of Perovskite Type Inorganic Fine Powder>
The hydrous titanium oxide obtained by hydrolysis by adding aqueous ammonia to the aqueous titanium tetrachloride was washed with pure water, and 0.30% sulfuric acid was added to the hydrous titanium oxide slurry as SO _{3 with} respect to the hydrous titanium oxide. Added. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant liquid reached 50 μS / cm.

0.98-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ .

  The slurry was heated to 75 ° C. at a rate of 10 ° C./hour in a nitrogen atmosphere, and reacted for 5 hours after reaching 75 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Then, after repeatedly washing with pure water and filtering with Nutsche, the obtained cake was dried, sintered at 1200 ° C. for 1 hour, and then crushed to obtain strontium titanate fine particles via a sintering process.

Next, the obtained strontium titanate was dispersed in water, and a 6.0 mass% sodium aluminate solution and an aqueous sodium hydroxide solution were simultaneously added dropwise at a liquid temperature of 75 ° C. so that the pH was 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. Strontium titanate fine particles treated with Al ₂ O _{3 having} an average primary particle size of 270 nm were obtained. The treated strontium titanate fine particles are used as inorganic fine powder (A-6). Table 1 shows the physical properties of the inorganic fine powder (A-6).

<Production Example 7 of Perovskite Type Inorganic Fine Powder>
The hydrous titanium oxide obtained by hydrolysis by adding aqueous ammonia to the aqueous titanium tetrachloride was washed with pure water, and 0.30% sulfuric acid was added to the hydrous titanium oxide slurry as SO _{3 with} respect to the hydrous titanium oxide. Added. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 0.6 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant liquid reached 50 μS / cm.

A 1.0-fold molar amount of Ca (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel, followed by replacement with nitrogen gas. Further, distilled water was added so as to be 0.8 mol / liter in terms of CaTiO ₃ .

  The slurry was heated to 65 ° C. at 7 ° C./hour in a nitrogen atmosphere, and reacted for 6 hours after reaching 65 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

The slurry was simultaneously added dropwise at a liquid temperature of 65 ° C. with respect to the slurry solid content so that 2.5% by mass of zirconium sulfate and an aqueous sodium hydroxide solution had a pH of 6.5. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. Calcium titanate fine particles treated with ZrO _{2 having} an average primary particle size of 210 nm were obtained. The treated calcium titanate fine particles are designated as inorganic fine powder (A-7). Table 1 shows the physical properties of the inorganic fine powder (A-7).

<Comparative Production Example 1 of Perovskite Crystalline Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 3.5 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion to adjust the pH of the dispersion to 7.5, and washing was repeated until the electrical conductivity of the supernatant reached 90 μS / cm.

0.97-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.3 mol / liter in terms of SrTiO ₃ . The slurry was heated to 90 ° C. at 30 ° C./hour in a nitrogen atmosphere, and reacted for 2.5 hours after reaching 90 ° C. After the reaction, the reaction mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

The slurry was simultaneously added dropwise at a liquid temperature of 70 ° C. to a slurry solid content so that a 3.0% by mass titanium sulfate solution and an aqueous sodium hydroxide solution had a pH of 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 25 nm were obtained. The strontium titanate fine particles were used as comparative inorganic fine powder (a-1). Table 1 shows the physical properties of the comparative inorganic fine powder (a-1).

<Comparative Production Example 2 of Perovskite Crystalline Inorganic Fine Powder>
The hydrous titanium oxide slurry obtained by hydrolyzing the aqueous titanyl sulfate solution was washed with an alkaline aqueous solution. Next, hydrochloric acid was added to the hydrous titanium oxide slurry to adjust the pH to 1.0 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 5.0, and washing was repeated until the electrical conductivity of the supernatant reached 90 μS / cm.

0.97-fold molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Furthermore, distilled water was added so as to be 0.6 mol / liter in terms of SrTiO ₃ . The slurry was heated to 65 ° C. at 5 ° C./hour in a nitrogen atmosphere, and reacted for 8 hours after reaching 65 ° C. After the reaction, the reaction mixture was cooled to room temperature, the supernatant was removed, and washing was repeated with pure water.

  Then, after repeatedly washing with pure water and filtering through Nutsche, the obtained cake was dried, sintered at 1100 ° C. for 1 hour, and then crushed to obtain strontium titanate fine particles via a sintering process.

Next, the obtained strontium titanate was dispersed in water, and a 3.0 mass% titanium sulfate solution and an aqueous sodium hydroxide solution were simultaneously added dropwise at a liquid temperature of 70 ° C. so that the pH was 6.0. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. TiO ₂ -treated strontium titanate fine particles having an average primary particle size of 315 nm were obtained. The treated strontium titanate fine particles were used as comparative inorganic fine powder (a-2). Table 1 shows the physical properties of the comparative inorganic fine powder (a-2).

<Comparative Production Example 3 of Perovskite Crystalline Inorganic Fine Powder>
Hydrous titanium oxide obtained by hydrolysis by adding ammonia water to an aqueous solution of titanium tetrachloride was washed with pure water until the electrical conductivity of the supernatant reached 90 μS / cm.

1.1 times the molar amount of Sr (OH) ₂ .8H ₂ O was added to the hydrous titanium oxide, and the mixture was placed in a SUS reaction vessel and purged with nitrogen gas. Further, distilled water was added so as to be 0.3 mol / liter in terms of SrTiO ₃ . The slurry was heated to 90 ° C. at 9 ° C./hour in a nitrogen atmosphere, and reacted for 6 hours after reaching 90 ° C. After the reaction, the reaction solution was cooled to room temperature, and the supernatant was removed. Then, washing was repeated with pure water, followed by filtration with Nutsche. The obtained cake was treated with 2.5% by mass of silicone oil and then dried to obtain strontium titanate fine particles having an average primary particle size of 180 nm. The silicone oil-treated strontium titanate fine particles were used as comparative inorganic fine powder (a-3). Table 1 shows the physical properties of the comparative inorganic fine powder (a-3).

<Comparative Production Example 4 of Perovskite Type Inorganic Fine Powder>
The strontium titanate fine particles obtained in Production Example 1 of perovskite inorganic fine powder were dispersed in water, and at a liquid temperature of 70 ° C., a 21.0 mass% sodium aluminate solution and an aqueous sodium hydroxide solution had a pH of 5.5. It was dripped simultaneously so that it might become. After completion of dropping, the liquid temperature was cooled, washed repeatedly with pure water, filtered through Nutsche, and the resulting cake was dried. Strontium titanate fine particles treated with Al ₂ O ₃ having an average primary particle size of 125 nm were used as comparative inorganic fine powder (a-4). Table 1 shows the physical properties of the comparative inorganic fine powder (a-4).

<Comparative Production Example 5 of Perovskite Type Inorganic Fine Powder>
500 g of calcium carbonate and 400 g of titanium oxide were wet-mixed in a ball mill for 7 hours and then filtered and dried. The mixture was molded at a pressure of 980 kPa (10 kg / cm ² ) and sintered at 1100 ° C. for 2 hours. This was mechanically pulverized to obtain calcium titanate fine particles having an average particle diameter of 450 nm primary particles treated with 4.5% by mass of silicone oil. The silicone oil-treated calcium titanate fine particles were used as comparative inorganic fine powder (a-5). Table 1 shows the physical properties of the comparative inorganic fine powder (a-5).

<Production Example 1 of Toner Particles>
30 parts by mass of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, 10 parts by mass of polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Put 20 parts by mass of terephthalic acid, 3 parts by mass of trimellitic anhydride, 27 parts by mass of fumaric acid and dibutyltin oxide into a 4 liter glass four-necked flask, and add four thermometers, stirring rods, condensers and nitrogen inlet tubes. The flask was attached to a neck flask, and this four-neck flask was placed in a mantle heater. Under a nitrogen atmosphere, reaction was carried out at 200 ° C. for about 5.0 hours to obtain a polyester resin.

-100 mass parts of said polyester resin-C.I. I. Pigment Blue 15: 3 7 parts by mass, 3,5-di-t-butylsalicylic acid aluminum compound 0.6 parts by mass, paraffin wax 5 parts by mass Henschel mixer (FM-75 type, Mitsui Miike Chemical Co., Ltd.) The mixture was melted and kneaded in a biaxial extruder set at a temperature of 130 ° C. while sucking with a vent port connected to a suction pump. This melt-kneaded product was roughly crushed with a hammer mill to obtain a 1 mm mesh pass crushed product. Further, after finely pulverizing with a jet mill, classification was performed with an air classifier (Elbow Jet Lab EJ-L3, manufactured by Nippon Steel Mining Co., Ltd.) to obtain toner particles (B-1).

<Toner Particle Production Example 2>
After adding 450 parts by mass of 0.1M Na ₃ PO ₄ aqueous solution to 710 parts by mass of ion-exchanged water and heating to 65 ° C., using a TK homomixer (manufactured by Special Machine Industries) at 10,000 rpm. Stir. To this, 68 parts by mass of 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

on the other hand,
Styrene 100 parts by mass n-butyl acrylate 20 parts by mass C.I. I. Pigment Blue 15: 3 (colorant) 8 parts by mass, 3,5-di-t-butylsalicylic acid aluminum compound 0.9 part by mass, saturated polyester (polar resin) 7 parts by mass, ester wax (melting point 70 ° C.) 15 parts by mass Part The above material was heated to 60 ° C., and uniformly dissolved and dispersed at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In this, 7 parts by mass of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into an aqueous medium, and stirred at 10,000 rpm for 10 minutes with a TK homomixer in an N ₂ atmosphere at 60 ° C. to granulate the polymerizable monomer composition. Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. and reacted for 10 hours. After the completion of the polymerization reaction, the residual monomer is distilled off under reduced pressure. After cooling, hydrochloric acid is added to dissolve Ca ₃ (PO ₄ ) _{2 and the} like, followed by filtration, washing with water, and drying to produce toner particles (B-2 )

<Production Example 3 of Toner Particles>
Dispersion liquid (M-1)
-Styrene 350 mass parts-n-butyl acrylate 100 mass parts-Acrylic acid 25 mass parts-t-dodecyl mercaptan 10 mass parts The above composition was mixed and melt | dissolved, and it prepared as a monomer mixture.

100 parts by mass of a paraffin wax dispersion having a melting point of 78 ° C. (solid content concentration 30%, dispersed particle size 0.14 μm, wax Mw = 500, Mn = 380)
Anionic surfactant 1.2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ 0.5 parts by weight of nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd .: Nonipol 400)
-Ion exchange water 1530 mass parts The said composition is disperse | distributed in a flask and a heating is started, performing nitrogen substitution. When the liquid temperature reached 70 ° C., a solution prepared by dissolving 6.56 parts by mass of potassium persulfate with 350 parts by mass of ion-exchanged water was added thereto. While maintaining the liquid temperature at 70 ° C., the monomer mixture was charged and stirred, and the liquid temperature was raised to 80 ° C. and emulsion polymerization was continued for 6 hours. After that, the liquid temperature was adjusted to 40 ° C. M-1) was obtained. Thus, the particle diameter in the obtained dispersion was 0.16 μm in average particle diameter, 60 ° C. in glass transition point of solid content, 15,000 in weight average molecular weight (Mw), and 12 in peak molecular weight. 000. Paraffin wax was contained in the polymer by 6%, and as a result of observing a thin piece of this solid content with a transmission electron microscope, it was confirmed that the polymer particles included the wax particles.

Dispersion (M-2)
Styrene 350 parts by mass n-butyl acrylate 100 parts by mass Acrylic acid 25 parts by mass The above ratios were mixed and dissolved to prepare a monomer mixture.

100 parts by mass of a Fischer-Tropsch wax dispersion with a melting point of 105 ° C. (solid content concentration 30%, dispersion particle size 0.15 μm, wax Mw = 1200, Mn = 790)
Anionic surfactant 1.7 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
・ 0.5 parts by weight of nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd .: Nonipol 400)
-Ion exchange water 1530 mass parts The said composition is disperse | distributed in a flask and a heating is started, performing nitrogen substitution. When the liquid temperature reached 65 ° C., a solution prepared by dissolving 5.85 parts by mass of potassium persulfate with 300 parts of ion-exchanged water was added thereto. While maintaining the liquid temperature at 65 ° C., the monomer mixture was added and stirred, and the liquid temperature was raised to 75 ° C. and emulsion polymerization was continued for 8 hours. After that, the liquid temperature was adjusted to 40 ° C. M-2) was obtained. Thus, the particle diameter in the obtained dispersion liquid was an average particle diameter of 0.16 μm, a glass transition point of solid content of 63 ° C., and a weight average molecular weight (Mw) of 700,000. The hydrocarbon wax was contained in the polymer by 6%, and as a result of observing a thin piece of this solid content with a transmission electron microscope, it was confirmed that the wax particles were encapsulated.

Dispersion (M-3)
・ C. I. Pigment Blue 15: 3 12 parts by mass / Anionic surfactant 2 parts by mass (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC)
-Ion exchange water 78 mass parts The above was mixed, and it disperse | distributed using the sand grinder mill, and obtained the colorant dispersion liquid (M-3).

  300 parts by weight of the dispersion liquid (M-1), 150 parts by weight of the dispersion liquid (M-2) and 25 parts by weight of the dispersion liquid (M-3) were added to 1 liter of Separa equipped with a stirrer, a cooling tube and a thermometer. It put into the bull flask and stirred. As a flocculant, 180 parts by mass of a 10% sodium chloride aqueous solution was dropped into this mixed solution, and the flask was heated to 54 ° C. while stirring the inside of the flask. After maintaining at 48 ° C. for 1 hour, it was confirmed by observation with an optical microscope that aggregated particles having a diameter of about 5 μm were formed.

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

<Toner Production Example 1>
To 100 parts by mass of toner particles (B-1), 1.5% by mass of inorganic fine particles (A-1) shown in Table 1 and 0.8% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g are added. Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) was mixed at a rotation speed of 35 times / second for 5 minutes to obtain a toner (C-1). The liberation rate of the inorganic fine particles (A-1) was 21% by number. Table 2 shows the physical properties of the toner (C-1).

<Toner Production Example 2>
To 100 parts by mass of toner particles (B-1), 0.9% by mass of inorganic fine particles (A-1) shown in Table 1 and 0.8% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g are added. Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) was mixed at a rotational speed of 35 times / second for 7 minutes to obtain a toner (C-2). The liberation rate of the inorganic fine particles (C-2) was 6% by number. Table 2 shows the physical properties of the toner (C-2).

<Toner Production Example 3>
Only 100% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g is added to 100 parts by mass of the toner particles (B-2), and a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) At 35 rpm for 5 minutes. Thereafter, 3.3% by mass of inorganic fine particles (A-1) shown in Table 1 were added, and the rotation speed was 35 times / second for 1 minute using a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.). Additional mixing was performed to obtain a toner (C-3). The liberation rate of the inorganic fine particles (A-1) was 39% by number. Table 2 shows the physical properties of Toner (C-3).

<Toner Production Example 4>
To 100 parts by mass of toner particles (B-2), 1.5% by mass of inorganic fine particles (A-2) shown in Table 1 and 0.8% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g are added. Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) was mixed at a rotation speed of 35 times / second for 5 minutes to obtain a toner (C-4). The liberation rate of the inorganic fine particles (A-2) was 32% by number. Table 2 shows the physical properties of the toner (C-4).

<Toner Production Example 5>
A toner (C-5) was obtained in the same manner as in Toner Production Example 1 except that the inorganic fine powder (A-3) was used. The liberation rate of the inorganic fine particles (A-3) was 13% by number. Table 2 shows the physical properties of Toner (C-5).

<Toner Production Example 6>
A toner (C-6) was obtained in the same manner as in Toner Production Example 1 except that the inorganic fine powder (A-4) was used. The liberation rate of the inorganic fine particles (A-4) was 20% by number. Table 2 shows the physical properties of the toner (C-6).

<Toner Production Example 7>
A toner (C-7) was obtained in the same manner as in Toner Production Example 1 except that the inorganic fine powder (A-5) was used. The liberation rate of the inorganic fine particles (A-5) was 26% by number. Table 2 shows the physical properties of Toner (C-7).

<Toner Production Example 8>
A toner (C-8) was obtained in the same manner as in Toner Production Example 4 except that the inorganic fine powder (A-6) was used. The liberation rate of the inorganic fine particles (A-6) was 34% by number. Table 2 shows the physical properties of Toner (C-8).

<Toner Production Example 9>
A toner (C-9) was obtained in the same manner as in Toner Production Example 1 except that the inorganic fine powder (A-7) was used. The liberation rate of the inorganic fine particles (A-7) was 29% by number. Table 2 shows the physical properties of Toner (C-9).

<Toner Production Example 10>
To 100 parts by mass of toner particles (B-3), 1.2% by mass of inorganic fine particles (A-1) shown in Table 1 and 0.9% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g are added. Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) was mixed at a rotational speed of 35 times / second for 5 minutes to obtain a toner (C-10). The liberation rate of the inorganic fine particles (A-1) was 17% by number. Table 2 shows the physical properties of Toner (C-10).

<Comparative Toner Production Example 1>
To 100 parts by mass of toner particles (B-1), 0.2% by mass of inorganic fine particles (A-1) shown in Table 1 and 0.8% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g are added. Then, a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) was mixed for 8 minutes at a rotation speed of 35 times to obtain a comparative toner (c-1). The liberation rate of the inorganic fine particles (A-1) was 4% by number. Table 2 shows the physical properties of the comparative toner (c-1).

<Production Example 2 for Comparative Toner>
Only 100% by mass of hydrophobic silica having a BET specific surface area of 150 m ² / g is added to 100 parts by mass of the toner particles (B-2), and a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.) At 35 rpm for 5 minutes. Thereafter, 3.3% by mass of the inorganic fine particles (A-1) shown in Table 1 were added, and the rotation speed was 25 times / second for 1 minute using a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Co., Ltd.). Additional mixing was performed to obtain a comparative toner (c-2). The liberation rate of the inorganic fine particles (A-1) was 41% by number. Table 2 shows the physical properties of the comparative toner (c-2).

<Comparative Toner Production Example 3>
A comparative toner (c-3) was obtained in the same manner as in Toner Production Example 1 except that the comparative inorganic fine powder (a-1) was used. The liberation rate of the comparative inorganic fine particles (a-1) was 26% by number. Table 2 shows the physical properties of the comparative toner (c-3).

<Comparative Toner Production Example 4>
A comparative toner (c-4) was obtained in the same manner as in Toner Production Example 4 except that the comparative inorganic fine powder (a-2) was used. The liberation rate of the comparative inorganic fine particles (a-2) was 30% by number. Table 2 shows the physical properties of the comparative toner (c-4).

<Comparative Toner Production Example 5>
A comparative toner (c-5) was obtained in the same manner as in Toner Production Example 1 except that the comparative inorganic fine powder (a-3) was used. The liberation rate of the comparative inorganic fine particles (a-3) was 23% by number. Table 2 shows the physical properties of the comparative toner (c-5).

<Comparative Toner Production Example 6>
A comparative toner (c-6) was obtained in the same manner as in Toner Production Example 1 except that the comparative inorganic fine powder (a-4) was used. The liberation rate of the comparative inorganic fine particles (a-4) was 14% by number. Table 2 shows the physical properties of the comparative toner (c-6).

<Comparative Toner Production Example 7>
A comparative toner (c-7) was obtained in the same manner as in Toner Production Example 1 except that the comparative inorganic fine powder (a-5) was used. The liberation rate of the comparative inorganic fine particles (a-5) was 15% by number. Table 2 shows the physical properties of the comparative toner (c-7).

<Manufacture example 1 of a magnetic carrier>
A magnetic fine particle dispersed resin core was prepared using the following materials.

-Phenol 10 parts by mass-Formaldehyde solution (37% by mass aqueous solution) 6 parts by mass-Magnetite particles 74 parts by mass-Hematite particles 10 parts by mass The above materials, 5 parts by mass of 30% by mass ammonia water, and 10 parts by mass water are placed in a flask. While stirring and mixing, the temperature was raised to 85 ° C. at a rate of 3 ° C./min, and a polymerization reaction was carried out at 85 ° C. for 3 hours to cure. Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Subsequently, this was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C. to obtain a magnetic fine particle dispersed resin core (R-1) in which magnetic fine particles were dispersed.

  Next, 4 parts by mass of a methyl methacrylate macromer having an ethylenically unsaturated group at one end and a weight average molecular weight of 4800, 44 parts by mass of a monomer having the following compound (d) as a unit, and 52 parts by mass of methyl methacrylate were added to a reflux condenser. , A thermometer, a nitrogen suction tube, and a four-necked flask equipped with a mixing method stirrer, 100 parts by weight of toluene, 100 parts by weight of methyl ethyl ketone, and 2.4 parts by weight of azobisisovaleronitrile were added, The graft copolymer solution (solid content 35 mass%) was obtained by maintaining at 80 ° C. for 10 hours.

  With respect to 30 parts by mass of the obtained graft copolymer solution, 0.8 part by mass of melamine resin (number average particle diameter 0.25 μm), 1.5 parts by mass of carbon black (number average particle diameter 35 nm), 100 parts by mass of toluene. The part was stirred with a homogenizer to obtain a coating material (L-1).

While stirring 100 parts by mass of the magnetic fine particle-dispersed resin core (R-1) prepared above while continuously applying shear stress, the coating material (L-1) is gradually added to volatilize the solvent at 75 ° C. Then, the resin coating was performed on the core surface. The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 3 hours, pulverized, and then classified with a sieve having an aperture of 76 μm. The average particle size was 38 μm, the specific resistance was 6.0 × 10 ⁹ Ω · cm magnetic carrier (D-1) was obtained.

<Manufacture example 2 of a magnetic carrier>
A magnetic fine particle dispersed resin core was prepared using the following materials.

-Phenol 10 parts by mass-Formaldehyde solution (37% by mass aqueous solution) 6 parts by mass-Magnetite particles 64 parts by mass-Hematite particles 20 parts by mass The above materials, 5 parts by mass of 30% by mass ammonia water and 10 parts by mass of water are placed in a flask. While stirring and mixing, the temperature was raised to 85 ° C. at a rate of 3 ° C./min, and a polymerization reaction was carried out at 85 ° C. for 3 hours to cure. Then, after cooling to 30 degreeC and adding water, the supernatant liquid was removed, the precipitate was washed with water, and then air-dried. Next, this was dried under reduced pressure (5 hPa or less) at a temperature of 60 ° C. to obtain a magnetic fine particle dispersed resin core (R-2) in a state where magnetic fine particles were dispersed.

Next, 20 parts by mass of toluene, 20 parts by mass of butanol, 10 parts by mass of water, and 40 parts by mass of ice are placed in a four-necked flask, and a mixture 40 having a molar ratio of CH ₃ SiCl ₃ and SiCl ₂ of 40 is mixed with stirring. After adding a mass part and a catalyst and stirring for 30 minutes, the condensation reaction was performed at 65 degreeC for 2 hours. Thereafter, the siloxane was thoroughly washed with water and dissolved in a toluene-methyl ethyl ketone-butanol mixed solvent to prepare a silicone varnish having a solid content of 10%.

  In this silicone varnish, with respect to 100 parts by mass of siloxane solids, 2.0 parts by mass of ion-exchanged water and 3.0 parts by mass of the following curing agent

と、２．０質量部の下記アミノシランカップリング剤
（ＣＨ₃）₂Ｎ−Ｃ₃Ｈ₆−Ｓｉ−（ＯＣＨ₃）₃ （へ）
を同時添加し、コート材（Ｌ−２）を得た。

And 2.0 parts by mass of the following aminosilane coupling agent (CH ₃ ) ₂ N—C ₃ H ₆ —Si— (OCH ₃ ) ₃ (to)
Were simultaneously added to obtain a coating material (L-2).

While stirring 100 parts by mass of the magnetic fine particle dispersed resin core (R-2) prepared above while continuously applying shear stress, the coating material (L-2) is gradually added to volatilize the solvent at 75 ° C. Then, the resin coating was performed on the core surface. The resin-coated magnetic carrier particles were heat-treated with stirring at 100 ° C. for 3 hours, pulverized, and then classified with a sieve having an aperture of 76 μm, an average particle size of 40 μm, a specific resistance of 8.1 × 10 ¹⁰ Ω · cm magnetic carrier (D-2) was obtained.

<Manufacture example 3 of a magnetic carrier>
A magnetic fine particle dispersed resin core was prepared using the following materials.

MnO and 25.0 mol%, MgO of 3.0 mol%, Fe ₂ O ₃ the 70.5Mol% and SrCO ₃ to 5 hours triturated with 1.5 mol% wet ball mill, and mixed, dried, 3 at 900 ° C. Temporary firing was performed after holding the time. This was pulverized with a wet ball mill for 7 hours to 2 μm or less. A dispersant and a binder (polyvinyl alcohol) were added to the slurry by several weight%, and then granulated and dried by a spray dryer to obtain a granulated product having a volume average particle size of about 42 μm. This granulated product was put in an electric furnace, and held at 1200 ° C. for 3 hours in a mixed gas in which the oxygen concentration in nitrogen gas was adjusted to 2.0 vol%, and then subjected to main firing. Thereafter, it was crushed and further sieved to obtain a magnetic carrier core (R-3) having a volume average particle size of 42 μm.

next,
Straight silicone (KR255 manufactured by Shin-Etsu Chemical Co., Ltd. (in terms of solid content)) 100 parts by mass Silane coupling agent (γ-aminopropylethoxysilane) 8 parts by mass Carbon black 10 parts by mass The above components are mixed with 300 parts by mass of xylene. The magnetic carrier resin coating solution (L-3) was used. While stirring using a fluidized bed heated to 70 ° C. using this resin coating solution (L-3), the magnetic carrier core (R-3) is 12.0% by mass based on the straight silicone resin. The coating and solvent removal operations were performed. Furthermore, using an oven, treatment was performed at 230 ° C. for 2.5 hours, and pulverization and classification using a sieve were performed to obtain a magnetic carrier (D-3).

<Example 1>
First, a developer was prepared. To 90 parts by mass of the magnetic carrier (D-1), 10 parts by mass of the toner (C-1) was added and mixed with a tumbler mixer to obtain a developer.

Next, a full color copier IRC3220N manufactured by Canon Inc. was used as an image forming apparatus for carrying out the image forming method of the present invention. The two-component developer of the apparatus was filled with 200 g of the developer, and the charging roller was modified to a charging roller having a volume resistance C of 5.0 × 10 ⁶ . The development bias is adjusted so that the amount of toner applied to the initial transfer material (paper) is 0.55 mg / cm ^2, and while supplying toner (C-1), normal temperature and normal humidity (NN) (23 ° C., 50% RH), high temperature and high humidity (HH) (35 ° C., 90% RH), low temperature and low humidity (NL) (23 ° C., 5% RH), durable image output (A4 horizontal, 10% printing ratio, 100,000 1 to 4). The evaluation items and evaluation criteria are shown below. The obtained evaluation results are shown in Table 3.

[Evaluation item]
Evaluation 1 <Image density>
After the endurance image was printed, the fixed image when the solid image was fixed at 180 ° C. was subjected to density measurement with a densitometer X-Rite 500 type, and the average value of 6 points was taken as the image density.
A: 1.50 or more: Very good.
B: 1.35 or more and less than 1.50: Good.
C: 1.20 or more and less than 1.35: Slightly bad, but at a level that does not cause any practical problems.
D: Less than 1.20: Practical problem.

Evaluation 2 <Transfer efficiency>
After the durable image was printed, the transfer residual toner on the surface of the photoreceptor when the solid image was transferred was taped with a polyester tape. The transferability was evaluated from the difference between the density of the material peeled off and pasted on the paper and the density of the tape just pasted on the paper.
For the density measurement, a densitometer X-Rite 500 type was used, and an average value of 6 points was taken as a residual toner density.
A: Less than 0.5: Very good.
B: 0.5 or more and less than 1.0: Good.
C: 1.0 or more and less than 2.0: Slightly bad, but at a level where there is no practical problem.
D: 2.0 or more: Practical problem.

Evaluation 3 <Image Flow>
After the endurance image was printed, the intermediate transfer member was released from the photosensitive member in each environment, only the photosensitive member was rotated for 30 minutes while applying a charging bias, stopped, and left as it was for 24 hours. Thereafter, the developing unit and the intermediate transfer member were returned to normal, and a character pattern with a printing ratio of 5% was drawn until the image flow disappeared. The following ranking was performed according to the number of images that could not be recognized.
A: Less than 10 sheets B: 10 sheets or more less than 30 sheets C: 30 sheets or more less than 50 sheets D: 50 sheets or more

Evaluation 4 <Charging performance>
After the durability image was printed, the charging performance of the charging roller was evaluated from the difference between the value obtained by applying a constant AC voltage and measuring the charging AC current value of the charging roller and the charging AC current value of the new charging roller.
A: Less than 0.10 mA: very good.
B: 0.10 mA or more and less than 0.30 mA: Good.
C: 0.30 mA or more and less than 0.50 mA: Slightly bad, but at a level where there is no practical problem.
D: 0.50 mA or more: This is a practical problem.

Evaluation 5 <Drum scratch>
After the endurance image was printed, the state of scratches on the electrostatic charge latent image carrier (drum) was evaluated.
A: There are no scratches or minor (1 μm or less).
B: Although there are scratches of 2 μm or less, there is no problem with the image.
C: There is a scratch of 2 μm or more, which is a problem on the image.

<Examples 2 to 13>
In Example 1, in place of the toner (C-1) and the carrier (D-1), a combination of toner and carrier as shown in Table 3 was used. And evaluation 1-4 was performed. The evaluation results are shown in Table 3.

  In Example 12, the same evaluation was performed without a leveling step as shown in FIG.

  Further, in Example 13, the leveling step 6 was modified to the cleaning blade unit 7 as shown in FIG.

<Comparative Examples 1-7>
In Example 1, in place of the toner (C-1) and the carrier (D-1), an image is printed out in the same manner as in Example 1 except that the combination of toner and carrier as shown in Table 4 is used. Evaluation 1-4 was performed. The evaluation results are shown in Table 4.

It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is a schematic diagram showing an example of an image forming apparatus using the image forming method of the present invention. It is the schematic of the apparatus used for the measurement of the volume resistance value of inorganic fine powder. It is the schematic of the apparatus used for the measurement of the volume resistance value of a charging member. It is the image which drew the electron micrograph (50,000 times magnification) of the inorganic fine powder (A-1) shown in manufacture example 1 of the perovskite type crystal inorganic fine powder.

Explanation of symbols

4c developing sleeve 4d regulating blade 4f conveying screw S1 charging bias applying means S2 developing bias applying means S3 transfer bias applying means

Claims (10)

In a toner particle containing at least a binder resin and a colorant, and a toner having at least an inorganic fine powder,
The inorganic fine powder has particles having perovskite crystals with an average primary particle diameter of 30 to 300 nm, and the volume resistivity A (Ω · cm) of the inorganic fine powder is 1.0 ×. A toner characterized by 10 ⁴ ≦ A ≦ 1.0 × 10 ⁹ , and a liberation rate B (number%) with respect to the toner is 5 ≦ B ≦ 40.   The toner according to claim 1, wherein the inorganic fine powder has a cubic shape and / or a rectangular parallelepiped shape.   The toner according to claim 1, wherein the inorganic fine powder is a strontium titanate fine powder.   4. The toner according to claim 1, wherein the inorganic fine powder is added in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of toner particles. A charging step of bringing a contact charging means into contact with the electrostatic latent image carrier and charging; an electrostatic latent image forming step of forming an electrostatic latent image on the charged electrostatic latent image carrier; and At least a development step of developing with a developer to form a toner image on the electrostatic latent image carrier and a transfer step of transferring the toner image on the electrostatic latent image carrier to an intermediate transfer member or transfer material In the image forming method,
The toner is a toner containing at least inorganic fine particles on a toner surface containing at least a binder resin and a colorant, and particles having perovskite crystals whose average primary particle size is 30 to 300 nm. And the volume resistance value A (Ω · cm) of the inorganic fine powder is 1.0 × 10 ⁴ ≦ A ≦ 1.0 × 10 ⁹ and the liberation rate B (number%) with respect to the toner is 5 An image forming method, wherein ≦ B ≦ 40.   6. The image forming method according to claim 5, wherein the inorganic fine powder has a cubic shape and / or a rectangular parallelepiped shape.   7. The image forming method according to claim 5, wherein the inorganic fine powder is strontium titanate fine powder. 6. A volume resistance value of the inorganic fine powder is A (Ω · cm), and a volume resistance value of the charging member is C (Ω · cm). 8. The image forming method according to any one of 7 above.
10 ⁻¹ ≦ A / C ≦ 10   9. The image forming method according to claim 5, wherein the inorganic fine powder is added in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the toner particles.   In the image forming method, a toner image is formed on the electrostatic latent image carrier, and at the same time, a developing simultaneous recovery step of recovering the toner remaining on the electrostatic latent image carrier after transfer, and after charging and before charging. The image forming method according to claim 5, further comprising a leveling step of leveling the toner remaining on the electrostatic latent image carrier and applying a bias.

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