JP2009031543A - Toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner that can stably give images of high resolution and high definition for a long period of time regardless of an environment. <P>SOLUTION: The toner comprises at least toner particles and inorganic fine powder, wherein the inorganic fine powder has at least an average particle size of 50 to 1,000 nm, shows a maximum peak at least at 32.80 degrees in Bragg angle (2θ±0.20 degrees) by CuKα characteristic X-ray diffraction, and contains a compound oxide expressed by formula:(SrO)<SB>1-x</SB>(MO)<SB>x</SB>(TiO<SB>2</SB>). In the formula, M represents a metal element selected from a group consisting of Mg and Ca; and X ranges from 0.01 to 0.20. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toner used in electrophotography, electrostatic recording, and magnetic recording.

  Conventionally, many methods are known as electrophotographic methods. In general electrophotography, a photoconductive substance is used to form an electrical latent image on an image carrier (photoreceptor) by various means, and then toner is supplied to the latent image. There is known a method of obtaining a toner image by visualizing a toner image, transferring the toner image to a transfer material such as paper as necessary, and fixing the toner image on the transfer material by heat / pressure to obtain a copy. Yes.

  In this fixing process, various types of fixing devices have been developed so far, for example, a heat roller system in which a transfer material is sandwiched and conveyed by a pair of rotating members, and an unfixed toner image is fixed by heat and pressure, An on-demand type fixing device combining a ceramic heater with a small heat capacity and a film has been put into practical use.

  However, in both the heat roller method and the on-demand method, the transfer material and the upper fixing roller or the fixing film and the fixing member such as the lower fixing roller (pressure roller) are frictionally charged or the transfer material is charged on the transfer material. An electric field that attracts the toner to the fixing member is generated, and a part of the toner is transferred onto the fixing member, and the toner image on the transfer paper is disturbed or a stain occurs.

  As a countermeasure against these electrostatic offsets, means for forcibly forming an electric field for preventing offset between fixing members has been proposed. However, due to the influence of these electric fields, a local high electric field is generated on the surface of the fixing member, and a discharge phenomenon thereby causes destruction of a pinhole or the like on the surface of the fixing member (especially the pressure roller). However, the phenomenon that the electrostatic offset deteriorates easily occurs.

  For the purpose of preventing electrostatic offset, a method of adding inorganic fine powder and organic fine particles to toner particles has been proposed (Patent Document 1). However, these methods can suppress a certain amount of electrostatic offset property, but in a low-humidity environment and a transfer material such as dry paper, an offset prevention electric field is still necessary, and pinhole leakage of the fixing member can be prevented. Can not. In addition, a method of adding strontium titanate particles having a small particle diameter or composite particles of strontium titanate and strontium carbonate to toner particles has been proposed (see Patent Document 2 and Patent Document 3). The particles used in these methods are effective in preventing filming and fusing by toner on the electrostatic latent image bearing member. However, at the same time, the particles used in these methods do not have the effect of preventing pinhole leakage in the fixing process.

  As described above, in order to stably obtain high-resolution and high-definition images over a long period of time regardless of the environment, not only has stable charging ability and excellent development characteristics, but also excessive peripheral members. Toners having auxiliary performance such as a charge suppression effect are desired.

  Conventionally, in order to cope with such a problem, efforts have been made to solve the problem by countermeasures from the toner side, but the current situation is that no fundamental countermeasure has been taken.

JP 2002-372800 A Japanese Patent Laid-Open No. 10-10770 JP 2003-15349 A

  An object of the present invention is to provide a developer that solves the above problems. In other words, the object of the present invention is that there is no occurrence of electrostatic offset in the fixing process, there is no occurrence of image damage due to pinhole leakage of the fixing member, and high resolution and high definition images are obtained over a long period of time regardless of the environment. To provide a toner that can be stably obtained.

  In order to achieve the above-mentioned object, the present inventors have studied the constituent materials used in the toner, and as a result, have toner particles containing at least a binder resin and the inorganic fine powder of the present invention. It has been found that there is no occurrence of electrostatic offset in the fixing step, and pinhole leakage due to excessive charging of the fixing member can be prevented.

That is, the present invention is as follows.
(1) A toner comprising toner particles and inorganic fine powder,
The inorganic fine powder has an average particle size of at least 50 nm to 1000 nm, and has a maximum peak at 32.50 deg of Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction,
The following formula [SrO] _1-X [MO] _X [TiO ₂ ]
[Wherein M represents a metal element selected from the group consisting of Mg and Ca. X is 0.01 to 0.20. ]
A toner comprising a complex oxide represented by the formula:
(2) The inorganic fine powder has a peak at 40.00 deg of the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction, and the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction. The intensity level (I _a ) of the maximum peak at 32.50 deg and the intensity level (I _b ) of the peak at 40.00 deg with a Bragg angle (2θ ± 0.20 deg) of the following formula 0.15 <(I _b ) / ( I _a ) <0.50
A toner characterized by satisfying

  According to the present invention, there is no occurrence of image disturbance due to electrostatic offset, the life of the fixing member is increased, and high-resolution, high-definition images can be stably obtained over a long period of time regardless of the environment. Can do.

  The toner of the present invention includes at least toner particles containing a binder resin and composite inorganic fine powder.

  As the binder resin for the toner particles contained in the toner of the present invention, a polyester resin, a vinyl copolymer resin, an epoxy resin, or a binder resin including a hybrid resin having a vinyl polymer unit and a polyester unit. Is preferred.

  When a polyester-based resin is used as the binder resin, alcohol and carboxylic acid, carboxylic acid anhydride, carboxylic acid ester, or the like is used as a raw material monomer.

  Specific examples of the dihydric alcohol component include 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-bis Alkylene oxide adducts of bisphenol A such as (4-hydroxyphenyl) propane and 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, neopentyl Recall, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, hydrogen Added bisphenol A and the like are included.

  Examples of trihydric or higher alcohol components 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. Is included.

  Examples of carboxylic acid components include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or anhydrides; alkyl dicarboxylic acids such as succinic acid, dodecenyl succinic acid, adipic acid, sebacic acid and azelaic acid or anhydrides thereof. Succinic acid substituted with an alkyl group having 6 to 12 carbon atoms or an anhydride thereof; unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid or the anhydride 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. The amount of the trivalent or higher polyvalent carboxylic acid component is preferably 0.1 to 1.9 mol% based on the total monomer.

  Among these, in particular, a bisphenol derivative represented by the following general formula (1) 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.

  In addition, when a vinyl copolymer resin is used as the binder resin, examples of the vinyl monomer for producing the vinyl resin include the following. Styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert- Butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-chloro styrene, 3, Styrene derivatives such as 4-dichlorostyrene, m-nitrostyrene, o-nitrostyrene, p-nitrostyrene; unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; C such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride Vinyl halides; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, methacryl Methacrylic acid esters such as dodecyl acid, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, propyl acrylate, n-acrylate Butyl, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc. Acrylic esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N -N-vinyl compounds such as vinyl indole and N-vinyl pyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide.

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

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

  The vinyl copolymer 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; ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5 -Diacrylate compounds linked by alkyl chains such as pentanediol diacrylate, 1,6 hexanediol diacrylate, neopentyl glycol diacrylate and the like, and acrylates of the above compounds replaced with methacrylate; diethylene glycol diacrylate, triethylene Glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 400 diacrylate, polyethylene glycol # 600 diacrylate, dipropylene glycol diacrylate Diacrylate compounds linked by an alkyl chain containing an ether bond such as a rate, and those obtained by replacing the acrylate of the above compound with methacrylate; polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane Diacrylate compounds such as diacrylate, polyoxyethylene (4) -2,2-bis (4-hydroxyphenyl) propane diacrylate and the like, and diacrylate compounds linked by a chain containing an ether bond and acrylates of the above compounds The thing replaced with a methacrylate is contained.

  Examples of 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; Allyl cyanurate and triallyl trimellitate are included.

  Examples of the polymerization initiator used for producing the vinyl copolymer resin include 2,2′-azobisisobutyronitrile and 2,2′-azobis (4-methoxy-2,4-dimethyl). Valeronitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2 methylbutyronitrile), dimethyl-2,2′-azobisisobutyrate, 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 peroxide, cyclohexanone Ketone peroxides such as 2-oxide, 2,2-bis (t-butylperoxy) butane, t-butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di- -T-butyl peroxide, t-butyl cumyl peroxide, di-cumyl peroxide, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyl peroxide, octanoyl peroxide, decanoyl peroxide, Lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-trioyl peroxide, di-isopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, di-n- Propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate, di-methoxyisopropyl peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, t-butylperoxide Oxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxyneodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxylaurate, t-butyl peroxybenzoate, t-butylperoxyisopropyl carbonate, di-t-butylperoxyisophthalate, t-butylperoxyallyl carbonate, t-amylperoxy 2-ethylhexanoate, di-t-butylperoxyhexahydro Terephthalate, include di -t- butyl peroxy azelate.

  Further, when a hybrid resin having a polyester unit and a vinyl polymer unit is used as the binder resin, even better durability can be expected. The “hybrid resin component” in the present invention means a resin component in which a vinyl polymer unit and a polyester unit are chemically bonded. Specifically, the hybrid resin component is 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. A graft copolymer (or a block copolymer) in which a vinyl polymer is a trunk polymer and a polyester unit is a branch polymer is preferable.

  In the present invention, “polyester unit” refers to a portion derived from polyester, and “vinyl copolymer unit” refers to a portion derived from a vinyl copolymer. The polyester monomer constituting the polyester unit is the polyvalent carboxylic acid component and the polyhydric alcohol component described above, and the monomer constituting the vinyl copolymer unit is the monomer component having the vinyl group described above.

  When a hybrid resin is used as the binder resin, it is preferable that a monomer component capable of reacting with both resin components is contained in the vinyl polymer component and / or the polyester resin component. Examples of monomers that can react with the vinyl polymer component among the monomers constituting the polyester resin component include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, or anhydrides thereof. Examples of monomers that can react with the polyester resin component among monomers constituting the vinyl polymer component include vinyl monomers having a carboxyl group or a hydroxy group, and acrylic acid or methacrylic acid esters.

  As a method for obtaining a reaction product of a vinyl polymer and a polyester resin, that is, a hybrid resin, either a polymer containing a monomer component capable of reacting with each of the vinyl polymer and the polyester resin mentioned above is used. A method obtained by polymerizing one or both resins is preferred.

  Examples of the method for producing the hybrid resin contained in the toner particles contained in the developer of the present invention include the following production methods (1) to (6).

  (1) This is a method obtained by blending after producing a vinyl polymer, a polyester resin and a hybrid resin component. The blend is produced by dissolving and swelling in an organic solvent (for example, xylene) and then distilling off the organic solvent. As a hybrid resin component, a vinyl polymer and a polyester resin are separately manufactured, dissolved and swollen in a small amount of an organic solvent, an esterification catalyst and an alcohol are added, and a transesterification reaction is performed by heating. Synthesized ester compounds can be used.

  (2) This is a method for producing a hybrid resin having a vinyl polymer unit and a polyester unit by producing a vinyl polymer and then reacting a polyester resin and / or a hybrid resin component in the presence thereof. The hybrid resin component is produced by a reaction between a vinyl polymer unit (a vinyl monomer can be added if necessary) and a polyester monomer (alcohol, carboxylic acid) and / or polyester unit. Also in this case, an organic solvent can be appropriately used.

  (3) A method for producing a hybrid resin having a polyester unit and a vinyl polymer unit by reacting a vinyl polymer and / or a hybrid resin component in the presence of the polyester resin after producing the polyester resin. 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 / or vinyl polymer unit. Also in this case, an organic solvent can be appropriately used.

  (4) After producing a vinyl polymer resin and a polyester resin, a vinyl monomer and / or a polyester monomer (alcohol, carboxylic acid) are added and reacted in the presence of these polymer units. A hybrid resin having a coalesced unit and a polyester unit is produced. Also in this case, an organic solvent can be appropriately used.

  (5) After producing a hybrid resin component having a vinyl polymer unit and a polyester unit, a vinyl monomer and / or polyester monomer (alcohol, carboxylic acid) is added to perform addition polymerization and / or condensation polymerization reaction. Thus, a hybrid resin having a vinyl polymer unit and a polyester unit is 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 a known production method can be used as necessary. Furthermore, an organic solvent can be used as appropriate.

  (6) A hybrid resin having a vinyl polymer unit and a polyester unit is produced by mixing a vinyl monomer and a polyester monomer (alcohol, carboxylic acid, etc.) and continuously performing addition polymerization and condensation polymerization reaction. Furthermore, an organic solvent can be used as appropriate.

  In the production methods (1) to (5) above, a hybrid resin may be produced using a plurality of vinyl polymer units and polyester units having different molecular weights and different degrees of crosslinking.

  The glass transition temperature of the binder resin is preferably 40 to 90 ° C, more preferably 45 to 85 ° C. The acid value of the binder resin is preferably 1 to 40 mgKOH / g.

  A release agent can be added to the toner particles contained in the toner of the present invention as necessary.

  Examples of release agents that can be used in the present invention include the following. Aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; aliphatic hydrocarbon waxes or oxides thereof Block copolymers; waxes mainly composed of fatty acid esters such as carnauba wax, sazol wax, and montanic acid ester wax; and fatty acid esters such as deoxidized carnauba wax partially or wholly deoxidized included. Further, saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as pracidic acid, eleostearic acid, and valinalic acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, and seryl alcohol Saturated alcohols such as melyl alcohol; long-chain alkyl alcohols; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; methylene bis stearic acid amide, ethylene biscaprin Saturated fatty acid bisamides such as acid amide, ethylene bislauric acid amide, hexamethylene bis stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N′-dioleyl Unsaturated fatty acid amides such as dipinamide, N, N-dioleyl sebacic acid amide; aromatic bisamides such as m-xylenebisstearic acid amide, N, N-distearylisophthalic acid amide; calcium stearate, laur Fatty acid metal salts such as calcium phosphate, zinc stearate and magnesium stearate (generally called metal soap); waxes grafted to aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid A partially esterified product of a fatty acid such as behenic acid monoglyceride and a polyhydric alcohol; a methyl ester compound having a hydroxyl group obtained by hydrogenation of vegetable oil or the like; Among these release agents, one or more release agents may be contained in the toner particles as necessary.

  A preferable addition amount of the release agent is 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass per 100 parts by mass of the binder resin.

  In addition, these release agents can usually be contained in the toner particles by dissolving the resin in a solvent, increasing the temperature of the resin solution, adding and mixing with stirring, or mixing at the time of kneading.

  In the toner of the present invention, a charge control agent can be used as necessary in order to further stabilize the chargeability. Examples of charge control agents include:

  An organometallic complex or a chelate compound is effective as the negative charge control agent for controlling the toner to be negative charge. Examples of negative charge control agents include monoazo metal complexes, aromatic hydroxycarboxylic acid metal complexes, and aromatic dicarboxylic acid metal complexes. Others include aromatic hydroxycarboxylic acids, aromatic mono and polycarboxylic acids and metal salts thereof, anhydrides or esters thereof, or phenol derivatives of bisphenol.

  Examples of positive charge control agents for controlling the toner to be positively charged include modified products of nigrosine and fatty acid metal salts, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc. Quaternary ammonium salts thereof, and onium salts such as phosphonium salts thereof and their chelating pigments, such as triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, Phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanic acid, ferrocyanic compound, etc.), diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide and dibutyltin as metal salts of higher fatty acids , Dioctyl tin borate, include diorgano tin borate such as dicyclohexyl tin borate.

  A preferable content of the charge control agent is 0.5 to 10 parts by mass per 100 parts by mass of the binder resin. When the amount of the charge control agent is less than 0.5 parts by mass, sufficient charging characteristics may not be obtained, and when it exceeds 10 parts by mass, the compatibility with other materials deteriorates or the humidity decreases. Undercharging may cause overcharging, which is not preferable.

  Magnetic particles can be added to the toner particles contained in the toner of the present invention as necessary. The magnetic material is preferably a magnetic oxide such as magnetite, maghematite, ferrite, or a mixture thereof.

  Examples of the magnetic material include lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, sulfur, germanium, titanium, zirconium, tin, lead, zinc, calcium, barium, vanadium, chromium, manganese, cobalt, copper, Magnetism containing at least one element selected from the group consisting of nickel, gallium, indium, silver, palladium, gold, platinum, tungsten, molybdenum, niobium, osmium, strontium, yttrium, technetium, ruthenium, rhodium, bismuth, etc. Contains iron oxide. Of these, lithium, beryllium, boron, magnesium, aluminum, silicon, phosphorus, germanium, titanium, zirconium, tin, sulfur, calcium, barium, vanadium, chromium, manganese, cobalt, copper, nickel, strontium, bismuth and zinc are preferred. . Particularly preferred is magnetic iron oxide containing an element selected from magnesium, aluminum, silicon, phosphorus and zirconium as a different element. These elements may be incorporated into the iron oxide crystal lattice, may be incorporated into the iron oxide as oxides, or may be present on the surface as oxides or hydroxides. It is preferable to be contained in iron oxide.

The number average particle diameter of these magnetic materials is preferably 0.05 or more and less than 1.0 μm, more preferably 0.1 or more and less than 0.5 μm. The BET specific surface area by the nitrogen adsorption of the magnetic material is preferably 2 to 40 m ² / g, more preferably 4 to 20 m ² / g. A preferable magnetic property of the magnetic material is that the saturation magnetization measured with a magnetic field of 795.8 kA / m is 10 to 200 Am ² / kg, and more preferably 70 to 100 Am ² / kg. A preferable residual magnetization is 1 to 100 Am ² / kg, and more preferably 2 to 20 Am ² / kg. A preferable coercive force is 1 to 30 kA / m, and more preferably 2 to 15 kA / m. A preferable content of the magnetic material is 20 to 200 parts by mass with respect to 100 parts by mass of the binder resin.

  To the toner particles contained in the toner of the present invention, a colorant can be added as necessary. Any appropriate pigment or dye can be used as the colorant.

  Examples of the pigment include carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine yellow, alizarin yellow, bengara, phthalocyanine blue and the like. A preferable addition amount of the pigment is 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  Examples of the dye include azo dyes, anthraquinone dyes, xanthene dyes, methine dyes, and the like. A preferable addition amount of the dye is 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the binder resin.

  As described above, the toner of the present invention contains inorganic fine powder.

  The inorganic fine powder is a mixed crystal of strontium titanate, calcium titanate, and / or magnesium titanate. Due to the components having different charging capabilities, the toner particles are alleviated and made uniform, thereby suppressing the occurrence of electrostatic offset. Further, the inorganic fine powder conveyed by the toner remains on the surface of the fixing member to some extent and suppresses local charging of the surface of the fixing member due to friction between the fixing member and a transfer member such as paper and the fixing member. It is possible to prevent the fixing member from being broken. The main component strontium titanate has a stable crystal structure and is present as a solid solution with calcium titanate and / or magnesium titanate, so that the particle strength is high. Even in environments where mechanical stress is strong, such as under pressure on the fixing member in the fixing process, the structure does not change, and electrostatic offset can be suppressed over a long period of time, or the fixing member can be overcharged. The effect of suppressing the occurrence of the leak discharge phenomenon can be maintained.

The composite inorganic fine powder contained in the toner of the present invention has a peak at a Bragg angle (2θ ± 0.20 deg) of 32.50 deg in a CuKα characteristic X-ray diffraction pattern,
And the following formula [SrO] _1-X [MO] _X [TiO ₂ ]
[Wherein M represents a metal element selected from the group consisting of Mg and Ca. X is 0.01 to 0.20. ]
The present invention relates to a toner comprising the composite oxide represented by

  The strontium titanate crystal has a (1,1,0) plane peak in the vicinity of 32.40 deg, and the calcium titanate crystal has a (1,2,1) plane peak in the vicinity of 33.10 deg. Has a peak on the (1,0,4) plane at 32.80 deg. When the particles have a solid solution state, the X-ray diffraction peak is similar to a substance having a high concentration. That is, the inorganic fine powder of the present invention contains strontium titanate as a main component, and suppresses the electrostatic offset as described above by allowing calcium titanate or magnesium titanate to be present in a solid solution state. Demonstrate the effect of preventing destruction of holes.

The inorganic fine powder of the present invention has a peak at 40.00 deg of the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction, and the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction. ) Of the maximum peak at 32.50 deg (I _a ) and the peak intensity level (I _b ) at 40.00 deg of the Bragg angle (2θ ± 0.20 deg) are expressed by the following formula: 0.15 <(I _b ) / (I _a ) <0.50
It is preferable to satisfy

  The strontium titanate crystal has a (1,1,1) plane peak at a peak intensity ratio of 30% in the vicinity of 40.0 deg with respect to 32,40 deg which is a 1,1,0) plane peak. In contrast, calcium titanate crystals and magnesium titanate have no peak in the vicinity of 40.0 deg.

Therefore, the ratio of the intensity level (I _a ) of the maximum peak at 32.50 deg and the intensity level (I _b ) of the peak at 40.00 deg of the Bragg angle (2θ ± 0.20 deg), the titanic acid in the strontium titanate particles. The abundance of calcium or magnesium titanate can be expressed.

That is, when (I _b ) / (I _a ) is less than 0.15, the amount of calcium titanate and magnesium titanate increases so that it is difficult to maintain the solid solution state, the particle strength is weakened, and mechanical deterioration in durability is caused. It is easy to cause etc.

On the other hand, when (I _b ) / (I _a ) is 0.50 or more, the amounts of calcium titanate and magnesium titanate are extremely reduced, and the charge relaxation effect tends to be reduced. Therefore, it is easy to cause developability deterioration and electrostatic offset property deterioration.

[Preparation of external additive sample]
1) 3 g of toner is put in a 500 ml beaker, and 200 ml of THF (tetrahydroxyfuran) is added to 3 g of the toner.
2) The solution obtained in 1) is irradiated with ultrasonic waves for 3 minutes to disperse the toner and release the external additive.
3) The THF supernatant solution containing the liberated external additive obtained in 2) is separated by decantation to obtain a sample solution.
4) Add 200 ml of THF again to the toner particles remaining in the operation of 3), and repeat the operations of 2) and 3) (about 3 times).
5) Repeat steps 1) to 4) until the required amount of sample solution is obtained.
6) The obtained sample solution (THF supernatant solution containing the liberated external additive) is vacuum filtered using a 2 μm membrane filter, and the solid content is recovered to obtain an external additive sample.

  The obtained external additive sample is subjected to X-ray diffraction measurement using CuKα rays. The X-ray diffraction measurement is performed under the following conditions using, for example, a Rigaku / sample horizontal strong X-ray diffractometer (RINT TTRII).

[Measurement conditions for X-ray diffraction]
Tube: Cu
Parallel beam optical system voltage: 50 kV
Current: 300mA
Starting angle: 30 °
End angle: 50 °
Sampling width: 0.02 °
Scan speed: 4.00 ° / min
Divergent slit: Open divergence longitudinal slit: 10 mm
Scattering slit: Open light receiving slit: 1.0 mm

  The attribution of the obtained X-ray diffraction peak and the calculation of the half-value width are performed using analysis software “Jade 6” manufactured by Rigaku. Similarly, the peak intensity is calculated from the peak area after peak separation by the same software.

  The number average particle diameter of the composite inorganic fine powder contained in the toner of the present invention is preferably 50 nm or more and less than 1000 nm. When the number average particle size of the composite inorganic fine powder is less than 50 nm, the specific surface area of the composite inorganic fine powder is increased, the moisture absorption property is deteriorated, and the charge of the developer is easily lowered. In addition, an embedding phenomenon in the toner base during the development and transfer processes is likely to occur, and the effect of suppressing excessive charging on the surface of the fixing member is reduced, and the effect of suppressing the destruction of the fixing member such as leak spots is likely to be reduced. When the number average particle diameter is 1000 nm or more, the composite inorganic fine powder is easily released from the toner particles and separated in the development and transfer processes, and transferred to the cleaner as transfer residual toner, so that the supply amount to the fixing device is increased. And the effect of preventing destruction of the fixing device is reduced.

  About the number average particle diameter of the inorganic fine powder in the present invention, 100 average particle diameters were measured from photographs taken at a magnification of 50,000 times with an electron microscope, and the average was determined.

  The content of the inorganic fine powder contained in the toner of the present invention is preferably 0.01 to 5.0 parts by mass, more preferably 0.05 to 3.0 parts by mass with respect to 100 parts by mass of the toner particles.

  When the content of the composite inorganic fine powder is larger than 5.0 parts by mass, the balance of charging of the developer is lost, and problems such as a decrease in density and occurrence of fogging easily occur in the development process. When the content of the composite inorganic fine powder is smaller than 0.01 parts by mass, the effect of the inorganic fine powder is difficult to be exhibited, and image defects due to the occurrence of electrostatic offset are liable to occur.

  The composite inorganic fine powder contained in the developer of the present invention is not particularly limited as long as it satisfies the above requirements, but is produced, for example, by the following method.

As a general method for producing titanate particles, there is a method in which a solid phase reaction between titanium oxide and carbonate is performed. For example, in the case of strontium titanate, a known reaction employed in this production method can be represented by the following formula.
TiO ₂ + SrCO ₃ → SrTiO ₃ + CO ₂

  That is, a mixture containing titanium oxide and carbonate is washed, dried, sintered, mechanically pulverized and classified. At this time, by adjusting the raw materials and firing conditions, a composite inorganic fine powder containing a metal titanate such as strontium titanate, calcium titanate or magnesium titanate, or titanium oxide can be obtained.

The strontium carbonate as a raw material in this case is not particularly limited as long as it has a SrCO ₃ composition, and any commercially available one can be used. The preferred particle size of strontium carbonate is 30 or more and less than 300 nm, and more preferably 50 or more and less than 150 nm.

In addition, the titanium oxide as a raw material in this case is not particularly limited as long as it has a TiO ₂ composition. Examples of the titanium oxide include metatitanic acid slurry (undried hydrous titanium oxide) obtained by a sulfuric acid method, titanium oxide powder, and the like. A preferred titanium oxide is a metatitanic acid slurry obtained by the sulfuric acid method. This is because it is excellent in uniform dispersibility in an aqueous wet process. The preferred particle size of titanium oxide is 20 to 50 nm.

  In the sintering, as long as the composite inorganic fine powder satisfies the above requirements, the firing conditions are not limited, but a preferable firing temperature is 500 to 1300 ° C, and more preferably 650 to 1100 ° C. When the firing temperature is higher than 1300 ° C., secondary agglomeration due to sintering between particles is likely to occur, and the load in the pulverization process increases. Moreover, when the calcination temperature is lower than 600 ° C., many unreacted components remain and it is difficult to produce stable titanate particles.

  Moreover, a preferable baking time is 0.5 to 16 hours, and more preferably 1 to 5 hours. Similarly, when calcination time is longer than 16 hours, strontium carbonate and titanium oxide all react, and the resulting composite inorganic fine powder may not contain them. When the calcination time is shorter than 0.5 hour, there are many unreacted components. It is difficult to produce stable titanate particles.

  In addition to the composite inorganic fine powder contained in the toner of the present invention, as other external additives, inorganic oxides such as silica, alumina, titanium oxide, etc., fine particles of inorganic particles such as carbon black, carbon fluoride, etc. are used as the toner. It may be externally added to the particles. These impart fluidity and chargeability to the developer.

  If the silica fine powder, alumina fine powder or titanium oxide fine powder dispersed on the surface of the toner particles are fine particles, these fine powders have a high fluidity-imparting effect, so these fine powders are fine particles. It is preferable. The preferred number average particle diameter of these fine powders is 5 to 100 nm, more preferably 5 to 50 nm.

  A preferable addition amount of these inorganic fine powders is 0.03 or more and less than 5 parts by mass with respect to 100 parts by mass of the toner particles. When the added amount of the inorganic fine powder is less than 0.03 parts by mass, sufficient fluidity imparting effect cannot often be obtained. On the other hand, when the amount is 5 parts by mass or more, the compression index of the toner becomes high, the toner is easily tightened, and an excessive external additive is liberated, which tends to have an adverse effect.

  A fluidity improver may be added to the toner of the present invention. The fluidity improver can improve the fluidity by externally adding to the toner particles. Examples of the fluidity improver include fluorine resin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder; wet powder silica, fine powder silica such as dry process silica; fine powder titanium oxide; fine powder alumina. They include silane coupling agents, titanium coupling agents, and treated silica surface-treated with silicone oil.

Further, a preferred fluidity improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, and is called so-called dry silica or fumed silica. For example, it utilizes a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is represented by the following formula.
SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl

  In this production process, it is also possible to obtain a metal composite silica of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds. To do.

  The particle size of the fluidity improver is preferably within a range of 0.001 or more and less than 2 μm as an average primary particle size, and particularly preferably a silica fine powder within a range of 0.002 or more and less than 0.2 μm. Good to use.

  Examples of commercially available silica fine powders produced by vapor phase oxidation of the silicon halogen compounds include those having the following trade names.

  AEROSIL (Nippon Aerosil Co., Ltd.) 130, 200, 300, 380, TT600, MOX170, MOX80, COK84; Ca-O-SiL (CABOT Co.) M-5, MS-7, MS-75, HS-5, EH -5; (WACKER-CHEMIE GMBH) HDK, N20, N15, N20E, T30, T40; D-C Fine Silica (Dow Corning Co.); Fransol (Fransil) and the like.

  Hydrophobization of the fluidity improver is carried out by chemical treatment with an organosilicon compound that reacts with or physically adsorbs silica fine powder. A preferred hydrophobizing fluidity improver is a silica fine powder produced by vapor phase oxidation of a silicon halide compound and treated with an organosilicon compound.

  Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane, Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxy Silane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1 , 3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and having one hydroxyl group in each of the terminal units of Si. In addition, silicone oils such as dimethyl silicone oil are included. These may be used alone or as a mixture of two or more.

The specific surface area of the fluidity improver is preferably 30 m ² / g or more, more preferably 50 m ² / g or more. This specific surface area is measured by the BET method by nitrogen adsorption. A preferable amount of the fluidity improver added is 0.01 to 8 parts by mass, more preferably 0.1 to 4 parts by mass with respect to 100 parts by mass of the toner.

  The preferred degree of hydrophobicity of the fluidity improver used in the toner of the present invention is 30% or more, preferably 50% or more in methanol wettability. As the hydrophobizing agent, a silane compound and silicone oil which are silicon-containing surface treating agents are preferable.

  Examples of the silicon-containing surface treatment agent include dimethyldimethoxysilane, trimethylethoxysilane, butyltrimethoxysilane and other alkylalkoxysilanes; dimethyldichlorosilane, trimethylchlorosilane, allyldimethylchlorosilane, hexamethylenedimethylchlorosilane, allyl Silane coupling agents such as phenyldimethylchlorosilane, benzyldimethylchlorosilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, divinylchlorosilane, dimethylvinylchlorosilane and the like are included.

  In the toner of the present invention, a binder resin, a colorant, other additives and the like are sufficiently mixed by a mixer such as a Henschel mixer or a ball mill, and then a heat kneader such as a heating roll, a kneader, or an extruder is used. It is melt-kneaded, cooled and solidified, pulverized and classified, and further mixed with a composite inorganic fine powder and, if necessary, a desired additive by a mixer such as a Henschel mixer.

  Examples of the mixer include a Henschel mixer (manufactured by Mitsui Mining); a super mixer (manufactured by Kawata); a ribocorn (manufactured by Okawara Seisakusho); Pin mixer 1 (manufactured by Taiheiyo Kiko Co., Ltd.); Ladige mixer (manufactured by Matsubo Co., Ltd.) is included, examples of kneaders are KRC kneader (manufactured by Kurimoto Iron Works Co., Ltd.); bus co kneader (manufactured by Buss Co., Ltd.) TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by Nippon Steel Works); PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.); ; Needex (Mitsui Mining Co., Ltd.); MS pressure kneader, Nider Ruder (Moriyama Seisakusho); Banbury mixer (Kobe Steel Co., Ltd.) included Examples of the pulverizer include counter jet mill, micron jet, inomizer (manufactured by Hosokawa Micron); IDS type mill, PJM jet pulverizer (manufactured by Nippon Pneumatic Industry Co., Ltd.); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet Oh Mill (manufactured by Seishin Enterprise Co., Ltd.); Cryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turboue Industries Co., Ltd.), and examples of classifiers include: Classifier, Micron Classifier, Spedick Classifier (manufactured by Seishin Enterprise); Turbo Classifier (manufactured by Nissin Engineering); Micron Separator, Turboplex (ATP), TSP Separator (manufactured by Hosokawa Micron); Elbow Jet (Japan) Iron Mining Co., Ltd.), Dispersion Center An example of a sieving device used for sieving coarse particles is included in the slater (manufactured by Nippon Pneumatic Engineering Co., Ltd.); YM Microcut (manufactured by Yaskawa Shoji Co., Ltd.). Resona sieve, gyro shifter (Tokuju Kosakusha); Vibrasonic system (Dalton); Soniclean (Shinto Kogyo); Turbo screener (Turboe); A circular vibrating sieve is included.

  In particular, it is preferable to use a mechanical pulverizer as the pulverizing means used in the method for producing toner in which the shape of coarse particles, which is a preferred embodiment of the present invention, is controlled. Examples of the mechanical pulverizer include a pulverizer inomizer manufactured by Hosokawa Micron Corporation, a pulverizer KTM manufactured by Kawasaki Heavy Industries, Ltd., and a turbo mill manufactured by Turbo Industry Co., Ltd. It is preferable to use these apparatuses as they are or after being appropriately modified.

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

[Inorganic fine powder production example 1]
Dissolve titanyl sulfate powder in distilled water, and add sulfuric acid and distilled water so that the Ti concentration in the solution is 1.5 (mol / l) and the acid concentration at the end of the reaction is 2.0 (mol / l). The added solution was prepared, and this solution was subjected to a hydrolysis reaction at 110 ° C. for 36 hours in a sealed container to carry out a hydrolysis reaction. Thereafter, washing with water was performed to sufficiently remove sulfuric acid and impurities to obtain a metatitanic acid slurry. To this slurry, strontium carbonate (average particle diameter of 80 nm) and calcium carbonate (average particle diameter of 70 nm) are added at a ratio of 82/16 so as to be equimolar with respect to titanium oxide. After thoroughly mixing in an aqueous wet, washing and drying, sintering was performed at 800 ° C. for 6 hours, and mechanical fine grinding and classification were performed to obtain an inorganic fine powder 1 having a number average particle diameter of 100 nm. The physical properties of the obtained composite inorganic fine powder 1 are shown in Table 1.

[Inorganic Fine Powder Production Examples 2 to 13]
Using the above-mentioned metatitanic acid slurry, the ratio of strontium carbonate, calcium carbonate, and magnesium carbonate, the particle diameter, and the firing conditions were changed as shown in Table 1, and the pulverization and classification conditions were adjusted as appropriate. In the same manner as in Example 1, inorganic fine powders 2 to 14 were obtained. Table 1 shows the physical properties of the obtained inorganic fine powder.

[Inorganic Fine Powder Production Example 14]
Using the metatitanic acid slurry, strontium carbonate (average particle diameter 800 nm) is added so as to have an equimolar amount with respect to titanium oxide. The mixture was thoroughly mixed in an aqueous wet, washed, dried, fired at 1200 ° C. for 6 hours, and subjected to mechanical grinding and classification to obtain an inorganic fine powder 14 having a number average particle diameter of 860 nm. Table 1 shows the physical properties of the obtained inorganic fine powder.

[Inorganic fine powder production example 15]
Using the metatitanic acid slurry, calcium carbonate (average particle diameter 600 nm) is added so as to be equimolar with respect to titanium oxide. The mixture was thoroughly mixed in an aqueous wet, washed, dried, fired at 1200 ° C. for 6 hours, and subjected to mechanical pulverization and classification to obtain inorganic fine powder 15 having a number average particle diameter of 850 nm. Table 1 shows the physical properties of the obtained inorganic fine powder.

[Resin Production Example 1]
(Hybrid resin)
(1) Manufacture of polyester resin, terephthalic acid: 6.1 mol
・ Dodecenyl succinic anhydride: 3.6 mol
-Trimellitic anhydride: 3.3 mol
PO-BPA: 7.2 mol
-EO-BPA: 2.8 mol
The above polyester monomer is charged into an autoclave together with an esterification catalyst, and a polycondensation reaction is performed while heating to 215 ° C. in a nitrogen gas atmosphere with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device. A polyester resin was obtained.

(2) Production of Hybrid Resin Component 80 parts by mass of the polyester resin was dissolved and swollen in 100 parts by mass of xylene. Next, 15 parts by mass of styrene, 5 parts by mass of 2-ethylhexyl acrylate, and 0.15 parts by mass of dibutyltin oxide as an esterification catalyst were added and heated to the reflux temperature of xylene. The transesterification reaction with ethylhexyl was started. Further, a xylene solution prepared by dissolving 1 part by mass of t-butyl hydroperoxide in 30 parts by mass of xylene as a radical polymerization initiator was dropped over about 1 hour. The radical polymerization reaction was completed by holding at that temperature for 6 hours. By heating to 200 ° C. under reduced pressure to remove the solvent, a transesterification reaction between the hydroxyl group of the polyester resin and 2-ethylhexyl acrylate, which is a copolymer monomer of the vinyl polymer unit, is carried out. The hybrid resin 1 produced by ester-bonding the polymer, the polyester unit and the vinyl polymer unit was obtained.

  The obtained hybrid resin 1 has an acid value of 28.7 mgKOH / g, a Tg of 58 ° C., a peak molecular weight (Mn) of 7600, a weight average molecular weight (Mw) of 45000, and a THF insoluble content of about 12 mass. % Content.

[Resin Production Example 2]
(Polyester resin)
・ Terephthalic acid 8mol%
・ Fumaric acid 25mol%
-Trimellitic anhydride 7 mol%
・ PO-BPO 32mol%
・ EO-BPA 28mol%
The above polyester monomer is charged into an autoclave together with an esterification catalyst, and a polycondensation reaction is performed while heating to 210 ° C. in a nitrogen gas atmosphere with a decompression device, a water separation device, a nitrogen gas introduction device, a temperature measurement device, and a stirring device. First polyester resin A was obtained.

  The obtained first polyester resin A has an acid value of 28 mgKOH / g, a hydroxyl value of 42 mgKOH / g, Tg of 58 ° C., Mn of 3,200, and Mw of 11,500. Yes, the THF-insoluble content was 0%.

next,
・ Fumaric acid 30mol%
・ Trimellitic anhydride 8mol%
・ PO-BPO 35mol%
・ EO-BPA 25mol%
These were similarly subjected to a condensation polymerization reaction, and 2 mol% of trimellitic anhydride was further added during the polymerization to obtain a second polyester resin B.

  The obtained second polyester resin B has an acid value of 25 mgKOH / g, a hydroxyl value of 32 mgKOH / g, Tg of 62 ° C., Mn of 3,000, and Mw of 155,000. Yes, and contained 27 mass% of THF-insoluble matter.

  The obtained polyester resins A and B were mixed by 50 parts by weight with a Henschel mixer to obtain polyester resin 2.

  The obtained polyester resin 2 has an acid value of 25 mgKOH / g, a hydroxyl value of 35 mgKOH / g, a Tg of 59 ° C., an Mn of 2,700, an Mw of 83,000, It contained 15 wt% of insoluble matter.

[Resin Production Example 3]
(Styrene-acrylic resin)
-70 parts by mass of styrene-30 parts by mass of n-butyl acrylate-6 parts by mass of monobutyl maleate-1 part by mass of di-t-butyl peroxide 1 part by mass of xylene in a four-necked flask and stirring the inside of the container After sufficiently replacing with nitrogen and raising the temperature to 130 ° C., the above components were added dropwise over 3.5 hours. Furthermore, the polymerization was completed under reflux of xylene, and the solvent was distilled off under reduced pressure to obtain styrene-acrylic resin 3.

  The obtained styrene-acrylic resin 3 had an acid value of 27 mgKOH / g, Tg of 59 ° C., a peak molecular weight of 14,000, a weight average molecular weight (Mw) of 78000, and Mw / Mn of 12.0. .

[Toner Production Example 1]
Hybrid resin 1 100 parts by mass Low molecular weight ethylene-propylene copolymer (melting point 102 ° C.) 6 parts by mass • Charge control agent (azo-based iron complex compound) 2 parts by mass • Magnetic iron oxide 90 parts by mass (average particle size 0. 19 μm, coercive force 11.2 KA / m, remanent magnetization 10.8 Am ² / kg, saturation magnetization 82.3 Am ² / kg)
The above mixture was melt-kneaded with a twin-screw kneader heated to 130 ° C., and the cooled mixture was coarsely pulverized with a hammer mill. Further, the mixture is finely pulverized by a collision type pulverizer, and the obtained finely pulverized product is classified by an air classifier to obtain toner particles in which particles having a weight average diameter of 7.6 μm, 10.1 μm or more are 6.8% by volume. It was.

The inorganic fine powder 1 is 1.0 part by mass with respect to 100 parts by mass of the toner particles, the hydrophobic dry silica (BET specific surface area: 300 m ² / g) is 1.0 part by mass, and the stirring blade rotational speed is 1100 rpm. The toner (1) of the present invention was obtained by rotating for 4 minutes using a Henschel mixer FM500 (manufactured by Mitsui Miike Co., Ltd.) and externally adding it.

[Toner Production Examples 2 to 13 and Comparative Toner Production Examples 1 to 3]
As shown in Table 1, the toners (2) to (13) and the comparative toner (1) were prepared in the same manner as in the toner production example 1 except that the inorganic fine powders 1 to 14 were changed to the inorganic fine powders 1 to 14 instead of the inorganic fine powder 1. Thru (3) were obtained.

[Comparative Toner Production Example 4]
A comparative toner (4) was obtained in the same manner as in Developer Production Example 13 except that the inorganic fine powder 14 was changed to 0.5 mass% and the inorganic fine powder 15 was changed to 0.5 mass% instead of the inorganic fine powder 10. It was.

[Example 1]
The following evaluation was performed using the toner (1). The evaluation results are shown in Table 5.

<Image evaluation test>
A test chart with a print ratio of 6% in a high-temperature, high-humidity environment (40 ° C / 90% RH) with a modification of a commercially available copier imageRUNNER1023 (manufactured by Canon Inc.) so that the printing speed is 23 cpm → 50 cpm. Was used, and the image density, in-plane uniformity, fog, and dot reproducibility were evaluated as shown below.

1) Image Density With a “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.), an SPI filter was used to measure the reflection density of an image having a 5 mm diameter circle, and the average value was evaluated.
Rank 5: Reflection density 1.45 or higher Rank 4: Reflection density 1.40 to 1.44
Rank 3: reflection density 1.35 to 1.39
Rank 2: Reflection density 1.30 to 1.34
Rank 1: Reflection density less than 1.29

2) In-plane density uniformity “Macbeth reflection densitometer” (manufactured by Macbeth Co., Ltd.) uses an SPI filter to measure the reflection density of a solid black image, the maximum value (Dmax) of the reflection density and the lowest In-plane density uniformity was evaluated based on the difference (Dmax−Dmin) of the value (Dmin).
Rank 5: In-plane density uniformity Less than 0.02 Rank 4: In-plane density uniformity 0.03 to 0.05
Rank 3: In-plane density uniformity 0.06 to 0.10
Rank 2: In-plane density uniformity 0.11 to 0.20
Rank 1: In-plane density uniformity 0.21 or more

3) Fog Using a “reflection densitometer” (reflectometer model TC-6DS manufactured by Tokyo Denshoku Co., Ltd.), the reflection density (Dr) of the transfer paper before image formation and the reflection density after copying the solid white image The worst value was measured as (Ds), and the difference (Ds−Dr) was evaluated as the fog value.
Rank 5: Fog less than 0.1 Rank 4: Fog 0.1 to 0.5
Rank 3: fog 0.5 to 1.5
Rank 2: fog 1.5 to 2.0
Rank 1: fog 2.0 or higher

4) Evaluation of dot reproducibility A checkered electrostatic latent image composed of 1 dot, 2 dots, 3 dots, and 4 dots shown in FIG. 1 is formed on the photoreceptor, and a developer is supplied to the surface of the photoreceptor. The obtained visible image was used as a sample. This sample was observed with an optical microscope to evaluate dot reproducibility.
Rank 5: An image faithful to the latent image.
Rank 4: When enlarged with an optical microscope, some scattering is observed.
Rank 3: When enlarged with an optical microscope, scattering and disturbance are observed.
Rank 2: Scattering and image distortion are observed by visual inspection.
Rank 1: The original is not reproduced.

5) Evaluation of electrostatic offset property A commercially available electrophotographic copying machine imageRUNNER1023 (manufactured by Canon Inc.) was modified so that the printing speed was changed from 23 cpm to 50 cpm, and the room temperature was low humidity (15 ° C., 10% RH). In the first half of the image, a line with a width of 1 cm and 0.2 mm is drawn perpendicular to the moving direction of the transfer material, and the second half of the image is 1000 sheets continuously using a white electrostatic offset test chart. Then, the electrostatic offset property was visually evaluated. At this time, dry paper (water content of less than 4%) was used as the transfer paper.
Rank 5: An image faithful to a latent image that is not seen at all.
Rank 4: When enlarged with an optical microscope, some scattering is observed.
Rank 3: A slight portion of the white background portion is observed. Rank 2: Appears widely in the white background portion.
Rank 1: The white background is very dirty

6) Pinhole leak evaluation Using a commercially available electrophotographic copying machine imageRUNNER1023 (manufactured by Canon Inc.), a copying test was conducted for 100,000 sheets while applying a DC power of −1000 V between the film of the fixing member and the pressure roller. A minute pinhole was confirmed by visual observation of the surface and microscopic observation. Further, visual observation of the electrostatic offset property on the image was performed.
Rank 5: Pinholes are not seen at all Rank 4: Minute pinholes can be confirmed by microscopic observation. Rank 3 that cannot be visually confirmed: Pinholes can be confirmed with a microscope. Some pinholes can be confirmed visually.
Rank 2: Pinholes can be confirmed visually, but can be confirmed by electrostatic offset images.
Rank 1: Pinhole leak traces can be confirmed on the image in the form of rain.

[Examples 2 to 13, Comparative Examples 1 to 4]
Evaluation was performed in the same manner as in Example 1 using the toners (2) to (13) and the comparative toners (1) to (4). The evaluation results are shown in Table 2.

It is explanatory drawing of the checker pattern for testing the development characteristic of the toner of this invention.

Claims (2)

A toner having at least toner particles and inorganic fine powder;
The inorganic fine powder has at least an average particle diameter of 50 nm to 1000 nm, and has a maximum peak at 32.80 deg of at least a Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction,
The following formula [SrO] _1-X [MO] _X [TiO ₂ ]
[Wherein M represents a metal element selected from the group consisting of Mg and Ca. X is 0.01 to 0.20. ]
A toner comprising a complex oxide represented by the formula: The inorganic fine powder has a peak at 40.00 deg of the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction and 32.32 of the Bragg angle (2θ ± 0.20 deg) in CuKα characteristic X-ray diffraction. The intensity level (I _a ) of the maximum peak at 50 deg and the intensity level (I _b ) of the peak at 40.00 deg of the Bragg angle (2θ ± 0.20 deg) are expressed by the following formula: 0.15 <(I _b ) / (I _a ) <0.50
The toner according to claim 1, wherein:

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