JP2008076464A - Developing roller and image forming method using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing roller which efficiently carries out leakage of counter charge generated on a roller surface, and has high durability. <P>SOLUTION: The developing roller has at least one resin layer formed around a conductive shaft, wherein the resin layer contains resin-silica hybrid body as a main component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a developing roller used in an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile receiver.

  In an electrophotographic image forming method, an image is usually formed on a transfer sheet through the following steps. In other words, the charged toner is supplied in contact or non-contact with the electrostatic latent image formed on the electrostatic latent image carrier represented by the electrophotographic photosensitive member to visualize the electrostatic latent image. The toner image on the electrostatic latent image carrier is transferred to a sheet or the like, and then fixed to form a final image.

  Development methods for forming a toner image on an electrostatic latent image carrier include a two-component development method using a two-component developer composed of a carrier and a toner, and a one-component developer composed only of a toner. There is a one-component development system used. In the developing method of the one-component developing method, charging is performed by rubbing and pressing the toner against the charging member and the developing roller surface without using a carrier, and there is an advantage that the structure of the developing device can be simplified and made compact. . In particular, the full-color image forming apparatus in which a plurality of developing devices such as yellow, magenta, cyan, black, etc. are arranged in a limited space with respect to the trend of colorization of toner images is prominent in non-magnetic one-component image formation is there. In addition, full-color pictorial images can be formed by using so-called polymerized toner that can be produced while controlling the particle size and shape of the toner in the manufacturing process (see, for example, Patent Document 1).

  The developing roller used for non-magnetic single-component image formation has, for example, a form in which a resin layer is provided on a rubber layer provided on the outer periphery of the shaft. A layer is formed. The toner thin layer formed on the developing roller is charged by the action of friction from the above-described metal plate or roller.

The resin layer formed on the surface of the developing roller imparts stable chargeability to the toner, and good toner transportability is required, and the technology for preventing the adhesion and fusion of the toner to the surface of the developing roller has been heretofore. Has been studied. For example, attempts have been made to use fluororesins or improve their performance. In addition, since the formation of a thin toner layer on the surface of the developing roller imposes a load not only on the toner but also on the developing roller, studies have been made on techniques for improving the durability of the developing roller. For example, there is also a technology that improves the durability of the roller by providing an intermediate layer formed using a silane coupling agent on the base rubber and further providing a resin layer containing a fluororesin on the intermediate layer. Yes (see, for example, Patent Document 2).
JP 2000-214629 A JP-A-8-190263

  By the way, in non-magnetic one-component development, since charge is transferred between the toner and the developing roller, the counter charge of the toner tends to accumulate on the surface of the developing roller. Therefore, it is necessary to leak the counter charge on the surface of the developing roller to electrically neutralize the developing roller surface. However, most of the developing rollers produced by the prior art have difficulty in leaking counter charges generated on the roller surface, and residual charges are likely to accumulate on the developing roller surface with image formation. In the above-mentioned patent document, there is no description or suggestion about improving the leakage property of residual charges accumulated on the surface of the developing roller.

  In recent years, in the field of small-scale print orders, where it has been difficult to make profits with conventional printing technology, the so-called on-demand method can be used to create the required number of prints without hassle with an electrophotographic full-color printer. The production of prints has been expanded. In such an image forming apparatus, there is no need to increase the residual potential even when image formation is repeated, and it is required that a high-quality full-color print can be stably produced. At the same time, a developing roller is used to stabilize print production. It was necessary to improve the durability of itself.

  The present invention relates to a developing roller used in a non-magnetic one-component image forming apparatus, and an object thereof is to provide a developing roller that can efficiently leak counter charges generated on the roller surface and has high durability. To do.

  The present inventor has found that the problems of the present invention are solved by the configuration described below.

  According to the first aspect of the present invention, “in the developing roller having at least one resin layer around the conductive shaft, the resin layer contains a resin-silica hybrid as a main component. A developing roller characterized by that. ].

  According to a second aspect of the present invention, “the developing roller according to the first aspect, wherein the content of the silica skeleton constituting the resin-silica hybrid body is 1% by mass or more and 30% by mass or less. ].

  According to a third aspect of the invention, the developing roller according to the first or second aspect, wherein the resin part constituting the resin-silica hybrid body contains a compound having a urethane bond. ].

  According to a fourth aspect of the present invention, in the first or second aspect, the resin portion constituting the resin-silica hybrid includes a vinyl polymer having an acid group in a side chain. The developing roller as described. ].

  According to a fifth aspect of the present invention, “a developer composed of at least toner is conveyed to a developing region by a developing roller, and an electrostatic latent image formed on an electrostatic latent image carrier is visualized by the developer. In the image forming method, the developing roller has at least one resin layer around the conductive shaft, and the resin layer contains a resin-silica hybrid as a main component. An image forming method. ].

  According to the present invention, even if image formation is repeated, accumulation of counter charges on the surface of the developing roller does not occur, and it becomes possible to stably produce a high-quality printed matter.

  As a method for suppressing the accumulation of the counter charge, it has been conventionally considered to give the developing roller performance that promotes charge leakage. For example, there is a method in which carbon black or the like is added to the resin layer so that polar ion groups are present in the resin itself, thereby reducing the resistance of the resin and promoting charge leakage. However, with this method, the overall resistance is lowered, and the influence of resistance fluctuation is given to image formation. As described above, it has been difficult to suppress the accumulation of the counter charge.

  In the present invention, the development roller does not have the influence of the resistance fluctuation due to the structure of the roller provided with the resin layer around the conductive shaft and the presence of the resin-silica hybrid contained in the resin layer. It is presumed that leaks can be made.

  Further, according to the present invention, it is possible to provide a developing roller having high durability without causing the resin layer provided on the shaft to be peeled off or damaged even when image formation is repeated.

  In particular, according to the present invention, it is possible to stably produce high-quality full-color prints in an on-demand full-color printer that is required to stably produce the required number of prints. It was.

  The present invention relates to a developing roller having a resin layer around a conductive shaft, and in particular, the resin layer contains as a main component a substance composed of a region having a silica structure called a resin-silica hybrid and a region made of resin. To do. In this structure, since the silica unit is present in the molecule, the leak point composed of the inorganic component is finely dispersed in the molecule. For this reason, it is presumed that an appropriate balance between the leak and the insulating property of the resin itself is achieved, and the effects of the present invention can be achieved.

  The developing roller according to the present invention is provided with at least one resin layer around a conductive shaft, and the resin layer is mainly composed of a resin-silica hybrid formed by molecularly bonding resin and silica. contains. According to the present invention, residual charges on the roller surface can be easily removed, and deterioration in image quality due to increase in residual potential due to repeated use can be prevented. This is presumably due to the structure in which the counter charge generated on the roller surface is easily moved to the shaft surface by directly providing the resin layer on the conductive shaft. However, with a developing roller having the same structure but no resin-silica hybrid in the resin layer, as will be described later, the effects of the present invention are not exhibited, so the resin-silica hybrid in the resin layer leaks residual charges. It is presumed that it has some action in making it.

  In addition, the developing roller according to the present invention is provided with durability. This is because the affinity between the resin layer containing the resin-silica hybrid body as a main component and the shaft surface acts on the shaft and the resin layer. It is presumed that the adhesiveness of the resin improved and the durability improved. That is, it is presumed that the adhesion is improved as a result of the formation of molecular bonds between the silica component constituting the resin-silica hybrid and the polar group including the hydroxyl group present on the shaft surface.

  Hereinafter, the present invention will be described in detail.

  In the developing roller according to the present invention, the resin layer contains a resin-silica hybrid as a main component. The main component here means that the content of the resin-silica hybrid in the resin layer is 50. It shows that it is at least mass%. The resin layer containing the resin-silica hybrid as a main component is obtained, for example, by applying a resin layer forming solution containing an alkoxysilane condensate such as a tetramethoxysilane condensate or a tetraethoxysilane condensate on the shaft. It is formed by performing a condensation reaction by heating.

  The developing roller according to the present invention has at least one resin layer around a conductive shaft. FIG. 1 shows a typical sectional configuration of a developing roller according to the present invention. The developing roller according to the present invention is not limited to the cross-sectional configuration shown in FIG.

  The developing roller 10 includes a conductive shaft 11 and a resin layer 12 provided on the shaft 11, and the resin layer 12 contains a resin-silica hybrid as a main component.

  The shaft 11 is composed of a conductive member, and specifically, a metal material such as stainless steel such as SUS304, iron, aluminum, nickel, an aluminum alloy, or a nickel alloy is preferable. Also, a conductive resin in which a conductive material such as the above-described metal powder or carbon black is filled in the resin can be used.

  The resin layer 12 contains a resin-silica hybrid as a main component. Here, the resin-silica hybrid is a compound having a structure in which a resin component and a silica component are integrated by molecular bonding. That is, from a region having a silica structure (also referred to as a silica skeleton in the present invention) formed in a network by alternately bonding silicon and oxygen, and a region of an organic polymer resin such as a polyurethane resin or a vinyl polymer resin. It is composed.

  Specifically, an alkoxy group-containing silane-modified resin formed by reacting a resin having a functional group reactive with an epoxy group and an epoxy group-containing alkoxysilane partial condensate to form an alkoxy group-containing silane-modified resin Is cured by a condensation reaction to form a silica structure. Thus, the resin layer 12 constituting the developing roller 10 according to the present invention contains, as a main component, a resin-silica hybrid having a structure in which a resin component and a silica component are molecularly bonded. The specific description of the resin-silica hybrid will be described in detail later.

  The thickness of the resin layer 12 is preferably set in the range of 1 to 30 μm, and particularly preferably 5 to 20 μm. The thickness of the resin layer can be measured from a cross-sectional sample including the resin layer taken from the developing roller and the micrograph. Further, as shown in FIG. 1B, the developing roller according to the present invention may have a multilayer structure in which the resin layer is composed of a plurality of layers.

  Further, the ratio of the silica component in the resin-silica hybrid contained in the resin layer 12 is preferably 1% by mass or more and 30% by mass or less, and when the ratio of the silica component is within this range, the resin layer 12 and the shaft 11 A strong adhesive force is expressed between the two.

  The developing roller according to the present invention can also contain carbon black in the resin layer 12. Thus, by including carbon black in the resin layer 12, a certain degree of conductivity is imparted in the resin layer, and the residual charge generated on the roller surface is easily leaked to the conductive shaft. Guessed.

  In addition, the developing roller according to the present invention does not reduce the adhesive strength between the resin layer and the shaft due to the influence of carbon black contained in the resin layer 12, and exhibits high durability. This is presumed to be because an adhesive surface between the resin layer and the shaft is secured by the presence of the resin-silica hybrid in the resin layer.

  The resin layer adjacent to the conductive shaft of the developing roller according to the present invention contains a resin-silica hybrid, and strong adhesiveness is expressed between the resin layer and the shaft. Specifically, it has been confirmed that it has a peel strength of 4.0 N or more, and the durability of the developing roller is improved. The peel strength of the resin layer 12 is obtained, for example, by measuring the interlayer adhesion shown in FIG. 2, and this is performed by the following procedure.

  As shown in FIG. 2A, the produced developing roller is cut with a width of 2.5 cm indicated by a broken line X along the outer periphery of the resin layer 12 at the center of the roller. Further, a cut (broken line Y) is made in the direction of the shaft body with respect to the resin layer 12, and the resin layer 12 is slightly peeled therefrom, and as shown in FIG. 2 (b), the end of the peeled resin layer 12 is obtained. The part is pulled up vertically by Autograph AGS (manufactured by Shimadzu Corporation) (in the direction of the arrow Z), and it is measured how much the resin layer 12 starts to peel from the layer below it, and the layer indirect at that time The adhesion is evaluated as peel strength.

  In addition, the pulling speed of the resin layer 12 was 100 mm / min, and a load value capable of pulling up the resin layer without increasing the load in the process of increasing the load capacity to 20 N was obtained.

  Next, the developing roller manufacturing method according to the present invention will be described. In the developing roller according to the present invention, a coating solution containing a resin-silica hybrid forming material such as an epoxy group-containing alkoxysilane partial condensate is applied around a conductive shaft, and after application, a condensation reaction is performed by heating. It is possible to form a region containing the resin-silica hybrid as a main component. Further, another coating liquid is further applied on the resin layer thus formed, followed by drying and heat treatment, thereby producing a developing roller having a multilayer structure as shown in FIG. It is also possible. The procedure for producing the developing roller according to the present invention will be further described.

  First, a resin layer forming coating solution is prepared by mixing and dissolving a material for forming a resin layer formed around a conductive shaft in an organic solvent. That is, a coating solution containing a resin-silica hybrid forming material such as an epoxy group-containing alkoxysilane partial condensate is prepared. If necessary, inorganic / organic fine particles can be contained in the resin layer forming solution. In this case, the fine particles are prepared so as to form a dispersed state in the coating solution. In this way, a coating solution for forming a resin layer containing a resin-silica hybrid as a main component is prepared.

  Next, the aforementioned coating solution for forming a resin layer is applied on the conductive shaft. As the coating method, various methods can be selected according to the viscosity of the coating solution for forming the resin layer. Specific examples of the application method include conventional methods such as a dipping method, a spray method, a roll coating method, and a brush coating method. In the present invention, these application methods are not limited.

  And after apply | coating the coating liquid for resin layer formation on a conductive shaft, drying and heat processing (temperature; 120-200 degreeC, processing time; 20-90 minutes) are performed, and the solvent in the coating solution for resin layer formation And a condensation reaction such as an epoxy group-containing alkoxysilane partial condensate is performed to form a resin layer containing the resin-silica hybrid as a main component.

  In the present invention, after forming the resin layer containing the resin-silica hybrid as a main component in the above-described procedure, for example, a coating solution containing a silicone copolymer resin is separated on the formed resin layer. It is also possible to produce a developing roller having a multilayer structure shown in FIG.

  Next, the resin-silica hybrid body contained as a main component in the resin layer 12 will be described. The resin-silica hybrid has a structure in which a polymer chain constituting the resin component and an inorganic silica skeleton chain are bonded by molecular bonding. This structure is formed by a condensation reaction between a resin having a functional group reactive to an epoxy group and an epoxy group-containing alkoxysilane partial condensate that is a precursor of a silica skeleton. Examples of the resin having a functional group reactive with an epoxy group include a resin having a urethane bond (polyurethane resin) and a resin made of a vinyl polymer.

  Moreover, it is preferable that content of the silica component in a resin-silica hybrid body shall be 1 mass% or more and 30 mass or less, and the resin layer 12 and the shaft surface 11 are made into the content of a silica component in this range. A strong adhesive force is expressed between the two. Hereinafter, the resin having a functional group having reactivity with the epoxy group forming the resin-silica hybrid will be described.

  One example of a resin having a functional group having reactivity with an epoxy group is a polyurethane resin. The polyurethane resin is obtained by reacting a polyhydric alcohol compound and a polyvalent isocyanate compound, and has a functional group having reactivity with an epoxy group in the molecule.

  The polyhydric alcohol compound has a plurality of hydroxyl groups in the molecule, and preferably has a hydroxyl group at the end of the molecular chain. Also, from the viewpoint of imparting appropriate elasticity to the produced resin, it is called a polyol having a number average molecular weight (calculated as a styrene equivalent number average molecular weight by GPC (gel permeation chromatography)) of about 1000 to 6000. Polyhydric alcohol compounds are preferred. Specific examples of the polyol include a polyester polyol having an ester bond in the molecule, a polycarbonate polyol having a carbonate bond in the molecule, a polyether polyol having an ether bond in the molecule, and a polyolefin polyol. These polyols preferably have the above-described molecular weight in order to impart a certain degree of mechanical properties and elasticity to the resulting resin-silica hybrid. Among these polyols, polyester polyols and polycarbonate polyols are preferable, and a hybrid of a polyurethane resin and silica produced using these polyols exhibits high durability.

  The polyester polyol is obtained by dehydration condensation of the following glycols or ethers with a divalent carboxylic acid or carboxylic anhydride. Here, the specific compound used for preparation of the polyester polyol which can be used for this invention is mentioned. First, saturated or unsaturated glycols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neo Various glycols such as pentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, 1,4-butynediol, dipropylene glycol and the like can be mentioned. Examples of ethers include alkyl glycidyl ethers such as n-butyl glycidyl ether and 2-ethylhexyl glycidyl ether, and monocarboxylic acid glycidyl ethers such as versatic acid glycidyl ether. Divalent carboxylic acids and acid anhydrides include adipic acid, maleic acid, fumaric acid, phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, and azelaic acid. And dibasic acids such as sebacic acid and suberic acid, or acid anhydrides, dimer acids, castor oil and fatty acids thereof corresponding to these. In addition to polyester polyols obtained by dehydration condensation using these, polyester polyols obtained by ring-opening polymerization of a cyclic ester compound are also included.

  Polycarbonate polyol generally undergoes a reaction such as a demethanol condensation reaction between a polyhydric alcohol and dimethyl carbonate, a dephenol condensation reaction between a polyhydric alcohol and diphenyl carbonate, or a deethylene glycol condensation reaction between a polyhydric alcohol and ethylene carbonate. It is generated after. Examples of the polyhydric alcohol used in these reactions include 1,6-hexanediol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl- Various saturated or unsaturated glycols such as 1,5-pentanediol, octanediol, 1,4-butynediol and dipropylene glycol, and alicyclic rings such as 1,4-cyclohexanediglycol and 1,4-cyclohexanedimethanol Group glycol and the like.

  Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol and the like obtained by ring-opening polymerization of ethylene oxide, propylene oxide, tetrahydrofuran and the like.

  Examples of the polyvalent isocyanate compound constituting the polyurethane resin include aromatic, aliphatic or alicyclic polyvalent isocyanate compounds. In particular, in the present invention, a diisocyanate compound is preferable from the viewpoint of imparting elasticity to the resin.

  Specific examples of the polyvalent isocyanate compound include 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetra Alkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene Diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate , Xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diene Examples thereof include an isocyanate compound and a dimerized isocyanate compound obtained by converting a carboxyl group of dimer acid into an isocyanate group.

  It is also possible to use a compound called a chain extender in order to extend the molecular chain of the polyurethane resin. Specific examples of the chain extender include glycols listed in the above-mentioned polyester polyol, glycols having a carboxyl group such as dimethylolpropionic acid and dimethylolbutanoic acid, ethylenediamine, propylenediamine, hexamethylenediamine, and triethylene. Polyamines such as tetramine, diethylenetriamine, isophorone diamine, dicyclohexylmethane-4,4′-diamine, dimer acid obtained by converting the carboxyl group of dimer acid to an amino group, and polyamines containing carboxyl groups such as L-lysine and L-arginine And monovalent amines. In particular, when amines are used as the chain extender, urea bonds are formed in the molecule, and the urea bond and urethane bond coexist in the molecule, so that interactions due to hydrogen bonds are expressed between the molecules. The durability and adhesiveness of the resin layer can be further improved. The amount of the urea bond is preferably 1 to 10 mol% with respect to the urethane bond in a molar ratio. This is realized by adding 99 to 90 mol% of glycols and 1 to 10 mol% of amines during the reaction. By setting the amount of the urea bond within the above range, it is presumed that an appropriate intermolecular interaction is expressed without causing repulsion between the urea bonds and the adhesiveness is improved.

  In preparing the polyurethane resin, a polymerization terminator can be used to adjust the molecular weight. Specific polymerization stoppers include alkyl monoamines such as di-n-butylamine and n-butylamine, monoamines having a carboxyl group such as D-alanine and D-glutamic acid, alcohols such as ethanol and isopropyl alcohol, Examples thereof include alcohols having a carboxyl group in the molecule such as glycolic acid.

  The polyurethane used in the present invention has a functional group reactive with an epoxy group, and this functional group may be present at either the molecular chain end of the polyurethane or at the main chain. Specific examples of functional groups having reactivity with epoxy groups include acidic groups such as carboxyl groups, sulfonic acid groups, and phosphoric acid groups, amino groups, hydroxyl groups, mercapto groups, etc. Among them, reaction with epoxy groups From the viewpoint of properties and functional group-providing properties, acidic groups and amino groups are preferred.

  The method for imparting an acidic group to the polyurethane molecule is not particularly limited. For example, the functional group can be imparted by using a compound having the aforementioned functional group as a chain extender or a polymerization terminator. Moreover, as a method of providing an amino group in a polyurethane molecule, for example, a method of reacting a polyamine with an amino group in excess with respect to a terminal isocyanate group of a prepolymer can be mentioned.

  The amount of the epoxy group-reactive functional group in the polyurethane is not particularly limited, but usually 0.1 to 20 KOHmg / g is preferable. When it exists in this range, favorable softness | flexibility, heat resistance, and also water resistance are provided to a polyurethane resin-silica hybrid body. In addition, what has a urea bond in a polyurethane molecule improves adhesiveness more.

  Next, the manufacturing method of a polyurethane resin is demonstrated. As a typical method for producing a polyurethane resin usable in the present invention, a one-step method and a two-step method are exemplified. The one-stage method is a method for producing a polyurethane resin by reacting a polyol, a diisocyanate compound, and, if necessary, a chain extender or a polymerization terminator in a suitable solvent at a time. In the two-stage method, a prepolymer having an isocyanate group at the end of the polyol chain is prepared by reacting a polyol and a diisocyanate compound in an environment where the isocyanate group is excessive, and this is then subjected to chain extension in an appropriate solvent. The reaction is performed in an environment in which an agent and a polymerization terminator are present. Among these, the two-stage method has an advantage that a uniform polymer solution can be easily obtained.

  As a solvent used when producing a polyurethane resin, the following are usually mentioned. Aromatic solvents such as benzene, toluene, xylene; ester solvents such as ethyl acetate and butyl acetate; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, diacetone alcohol; acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Examples include ketone solvents, other dimethylformamide, dimethylacetamide, ethylene glycol dimethyl ether, tetrahydrofuran, and cyclohexanone. These organic solvents can be used alone or in combination.

  Next, a vinyl polymer having a functional group reactive with an epoxy group will be described.

  Examples of the vinyl polymer having a functional group having reactivity with an epoxy group in the side chain that can be used in the present invention include vinyl polymers having an acrylate group or a methacrylate group in the side chain. This vinyl polymer is produced by polymerizing a vinyl monomer having an acrylic ester group or a methacrylic ester group in the side chain, or a vinyl monomer mixed with these functional groups.

A monomer having a typical acrylic acid ester group or a methacrylic acid ester group as a monomer constituting the polymer usable in the present invention can react with an epoxy group. As a specific example, for example, 2-hydroxyethyl Examples include hydroxyalkyl (meth) acrylates such as (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate, carboxylic acids such as (meth) acrylic acid, and amides such as acrylamide. . Other constituent monomers are not particularly limited, and examples thereof include acrylic acid alkyl esters, methacrylic acid alkyl esters, acrylic acid alkoxyalkyl esters, methacrylic acid alkyl esters, and methacrylic acid alkoxyalkyl esters.
Examples of alkyl acrylate esters include 1 to 6 carbon atoms such as methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, pentyl acrylate, and hexyl acrylate. Examples of alkyl esters and alkyl methacrylates include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, etc. Examples of the alkyl ester having 1 to 6 carbon atoms and alkoxyalkyl acrylate ester include methoxymethyl acrylate, ethoxyethyl acrylate, and alkoxyalkyl methacrylate. Acrylic acid methoxymethyl, and the like methacrylic acid ethoxyethyl.
Among these, it is preferable to use an alkyl ester of methacrylic acid, and it is particularly preferable to use methyl methacrylate, ethyl methacrylate, isobutyl methacrylate or the like.

  Next, the epoxy group containing alkoxysilane partial condensate which can be used for this invention is demonstrated. The layer adjacent to the conductive shaft of the developing roller according to the present invention contains a resin-silica hybrid having a silica skeleton. The silica constituting this resin-silica hybrid is formed via an epoxy group-containing alkoxysilane partial condensate such as a tetramethoxysilane partial condensate. Specifically, it is formed by dealcoholization reaction of an epoxy group-containing alkoxysilane partial condensate.

  The epoxy group-containing alkoxysilane partial condensate that can be used in the present invention is produced by a dealcoholization reaction between the epoxy compound (A) and the alkoxysilane partial condensate (B).

  The number of epoxy groups is not particularly limited as long as the epoxy compound (A) used for producing the epoxy group-containing alkoxysilane partial condensate is an epoxy compound having one hydroxyl group in one molecule. In addition, the smaller the molecular weight of the epoxy compound (A), the better the compatibility with the alkoxysilane partial condensate (B), and also the effect of improving heat resistance and adhesion. Specifically, those having 15 or less carbon atoms are suitable. For example, monoglycidyl having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with water, dihydric alcohol or phenols. Ethers; polyglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with a trihydric or higher polyhydric alcohol such as glycerin or pentaerythritol; epichlorohydrin and amino monoalcohol And an alicyclic hydrocarbon monoepoxide having one hydroxyl group in the molecule (for example, epoxidized tetrahydrobenzyl alcohol) and the like. Among these epoxy compounds, glycidol is most excellent in terms of the effect of imparting heat resistance, and is optimal because of its high reactivity with the alkoxysilane partial condensate (2).

  Next, as the alkoxysilane partial condensate (B), a hydrolyzable alkoxysilane monomer represented by the following general formula (a) is hydrolyzed in the presence of acid or alkaline water and partially condensed. Is used.

Formula (a): R ¹ _p Si (OR ² ) _4-p
(In the formula, p represents 0 or 1. R ¹ represents a lower alkyl group, aryl group or unsaturated aliphatic residue which may have a functional group directly connected to a carbon atom. R ² represents a methyl group. Or an ethyl group, and R ² may be the same or different.
Specific hydrolyzable alkoxysilane monomers include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, Examples include trialkoxysilanes such as methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, and isopropyltriethoxysilane. These alkoxysilane partial condensates (B) can be used without any particular limitation on those exemplified above, but when two or more of these are used in combination, the ratio of tetramethoxysilane is reduced to the total alkoxysilane. The amount is preferably 70 mol% or more of the monomer amount.

  The silica skeleton constituting the resin-silica hybrid is formed by further dealcoholizing the epoxy group-containing alkoxysilane partial condensate formed from the epoxy compound and the alkoxysilane partial condensate. The ratio of the silane skeleton contained in the resin-silica hybrid is preferably 1.0% by mass or more and 30.0% by mass or less. When the ratio is within this range, stable adhesion to the shaft is long. It is possible to last for a period.

  The alkoxysilane partial condensate (B) has, for example, a structure represented by the following general formula (b) or (c).

(In the formula, R ^1, .R ² showing a lower alkyl group which may have a functional group directly bonded to a carbon atom, an aryl group or an unsaturated aliphatic residue represents a methyl group or an ethyl group, R ² Each may be the same or different.)

(In the general formula (c), R ² is Formula (b) the same as R ² in.)
Next, the image forming method according to the present invention will be described. The developing roller according to the present invention is preferably used in an image forming apparatus using a non-magnetic one-component developer that forms an image without using a carrier.

  The developing roller according to the present invention is mounted in a developing device that supplies toner onto an image carrier that forms an electrostatic latent image. The developing device has a toner layer regulating member and a toner replenishing auxiliary member in addition to the developing roller according to the present invention, and these members are arranged so as to contact each other. In the developing device, a thin toner layer is formed on the developing roller by the toner layer regulating member and the toner replenishing auxiliary member, and this is supplied onto the image carrier to visualize the latent image formed on the image carrier. .

  The toner layer regulating member supplies the toner in a uniform thin layer state on the developing roller and frictionally charges the supplied toner. The toner layer regulating member is a member having a certain degree of elasticity, such as urethane rubber or a metal plate, and forms a thin layer of toner on the developing roller by contacting the developing roller. The toner thin layer formed on the developing roller has a maximum thickness of 10 toner particles, preferably 5 or less.

  The contact force of the toner layer regulating member to the developing roller is preferably 100 mN / cm to 5 N / cm, and particularly preferably 200 mN / cm to 4 N / cm. By setting the contact force within this range, the toner can be conveyed without causing unevenness in conveyance, thereby preventing the occurrence of image defects such as white stripes. Further, by setting the contact force within the above range, the toner can be supplied to the developing roller without being deformed or crushed.

  The toner replenishment auxiliary member is for stably supplying toner to the developing roller. As the toner replenishing auxiliary member, for example, a water wheel-like roller with a stirring blade or a sponge-like roller is used. The size (diameter) of the toner replenishing auxiliary member is preferably 0.2 to 1.5 times the diameter of the developing roller. When the toner replenishing auxiliary member is within this range, the toner is supplied to the developing roller without excess or deficiency, and there is no image defect. Enables good image formation.

  Examples of the image carrier used in the image forming method according to the present invention include inorganic photoreceptors, amorphous silicon photoreceptors, and organic photoreceptors. Among these, organic photoreceptors are particularly preferable, and charge transport is further performed. A layered structure of a layer and a charge generation layer is preferred.

  Hereinafter, a developing device (developing device) that can be used in the image forming method according to the present invention will be described in detail.

  FIG. 3 is a schematic sectional view of a developing unit that can be used in the image forming method according to the present invention.

  In FIG. 3, the non-magnetic one-component toner 16 built in the toner tank 17 is conveyed and supplied onto the sponge roller 14 which is also a toner replenishment auxiliary member by the stirring blade 15 which is a toner replenishment auxiliary member. The toner fed onto the sponge roller is conveyed onto the developing roller 10 by the rotation of the sponge roller 14 in the direction of the arrow, and is electrostatically and physically attracted to the surface by friction with the developing roller 10.

  On the developing roller 10, the adsorbed toner is uniformly thinned and frictionally charged by the rotation of the developing roller 10 and the elastic blade 13 which is a toner layer thickness regulating member. The toner thin layer formed on the developing roller 10 is supplied onto the photosensitive drum 11 as an image carrier by a contact or non-contact method, and the latent image is developed.

  The configuration of the developing device on which the developing roller according to the present invention can be mounted is not limited to that shown in FIG.

  Next, examples of the fixing method that can be used in the image forming method according to the present invention include a so-called contact heating type fixing method, and the contact heating type fixing method includes a hot pressure fixing method, a hot roll fixing method, and a fixing method. Examples include a pressure heating fixing method in which fixing is performed by a pressure member that rotates in a state in which the arranged heating body is included.

  In many cases, a heat roll fixing type fixing device has a heat source inside a metal cylinder composed of iron, aluminum or the like whose surface is coated with tetrafluoroethylene or polytetrafluoroethylene-perfluoroalkoxy vinyl ether copolymers. It is comprised from the arrange | positioned upper roller and the lower roller formed with silicone rubber etc. A typical heat source is a linear heater, and the surface temperature of the upper roller is heated to about 120 to 200 ° C. In the fixing unit, pressure is applied between the upper roller and the lower roller, and the lower roller is deformed to form a nip. The nip width is 1 to 10 mm, preferably 1.5 to 7 mm. The fixing linear velocity is preferably 40 mm / sec to 600 mm / sec. When the nip width is in the above range, heat is uniformly applied to the toner, and fixing without unevenness can be performed. Further, by setting the nip width in the above range, the melting of the resin constituting the toner is controlled to prevent the occurrence of fixing offset.

  Further, there is a fixing method using a pressure member that rotates in a state in which a heating element fixedly disposed is included. This fixing system includes a fixedly arranged heating body and a pressure member that is in pressure-contact with the heating body and that closely contacts a recording sheet on which a toner image is formed via a film member. It is.

  In the pressure contact fixing method, the heating body has a smaller heat capacity than a conventional heating roller, and a linear heating unit is provided in a direction perpendicular to the recording sheet conveyance direction. The temperature of the heating body is 100 to 300 ° C.

  Next, a developer that can be used for image formation using the developing roller according to the present invention will be described. The toner that can be used for image formation using the developing roller according to the present invention is either a so-called pulverized toner manufactured through a pulverizing / classifying process, or a so-called polymerized toner manufactured directly from a polymerization process for preparing resin particles. Can be used. Among these, in particular, the polymerized toner can be produced while controlling the particle size and shape of the toner during the production process, which is convenient for producing a toner having a small particle size having a uniform shape.

  By using toner with a small particle size that has a uniform shape, it is easy to form a high-resolution and high-definition image as required in digital image formation, and is particularly preferable for, for example, high-gradation pictorial full-color image formation. It is. It is expected that high-definition full-color image formation can be stably produced by combining with the developing roller according to the present invention.

  On the other hand, the polymerized toner includes an emulsion-association type toner in which particles are aggregated to form toner particles in the production process, but a small amount of the coagulant used in the aggregation process remains on the surface of the produced toner particles. It is also possible to do. There has been a concern about the influence on the residual charge on the surface of the developing roller due to such residue remaining on the surface of the developing roller.

  However, in the developing roller according to the present invention, even if image formation is repeated using polymerized toner, the residual charge on the surface of the developing roller does not increase, and good image formation can be achieved from the results of Examples described later. confirmed.

  Hereinafter, elements constituting a polymerized toner which is an example that can be used for image formation using the developing roller according to the present invention will be described.

As the polymerizable monomer, a radically polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. Moreover, it is preferable to contain at least one radical polymerizable monomer having the following acidic group or radical polymerizable monomer having a basic group.
(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Moreover, it can be used combining 1 type (s) or 2 or more types so that the required characteristic may be satisfy | filled.

  Specifically, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers , Halogenated olefin monomers and the like can be used.

  Examples of the aromatic vinyl monomer include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-methoxy styrene, p-phenyl styrene, p-chloro styrene, p-ethyl styrene, p. -N-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2, Examples thereof include styrene monomers such as 4-dimethylstyrene and 3,4-dichlorostyrene and derivatives thereof.

  Examples of (meth) acrylic acid ester monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. Examples include butyl, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

  Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl benzoate.

  Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

  Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

  Examples of the diolefin monomer include butadiene, isoprene, chloroprene and the like.

(2) Crosslinking agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added to improve the properties of the toner. Examples of the radically polymerizable crosslinking agent include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having acidic group or basic group As the radical polymerizable monomer having acidic group or radical polymerizable monomer having basic group, for example, a carboxyl group-containing monomer Amine-based compounds such as sulfonic acid group-containing monomers, primary amines, secondary amines, tertiary amines, and quaternary ammonium salts can be used.

  Examples of the radical polymerizable monomer having an acidic group include carboxylic acid group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, and maleic acid monoester. An octyl ester etc. are mentioned.

  Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

  These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

  Examples of the radical polymerizable monomer having a basic group include amine compounds, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts of the above four compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide Vinyl pyridine, vinyl pyrrolidone; vinyl-N-methylpyridinium chloride, vinyl-N-ethylpyridinium chloride, N, N-di Lil ammonium chloride, N, may be mentioned N- diallyl-ethyl chloride or the like.

  As the radical polymerizable monomer, it is preferable to use a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group in an amount of 0.1 to 15% by mass of the whole monomer, The radical polymerizable cross-linking agent is preferably used in the range of 0.1 to 10% by mass with respect to the total radical polymerizable monomer, although it depends on its characteristics.

  Moreover, it is possible to use the chain transfer agent generally used for the purpose of adjusting molecular weight.

  The chain transfer agent is not particularly limited, and for example, octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, n-octyl-3-mercaptopropionic acid ester, carbon tetrabromide and styrene dimer are used.

  The radical polymerization initiator can be appropriately used as long as it is water-soluble. For example, persulfate (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salt, etc.), A peroxide compound etc. are mentioned.

  Furthermore, the radical polymerization initiator can be combined with a reducing agent as necessary to form a redox initiator. By using a redox initiator, the polymerization activity is increased, the polymerization temperature can be lowered, and the polymerization time can be further shortened.

  The polymerization temperature may be any temperature as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator. For example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to polymerize at room temperature or slightly higher temperature by using a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid or the like).

  In order to perform polymerization using the above-mentioned radical polymerizable monomer, it is necessary to perform oil droplet dispersion in an aqueous medium using a surfactant. Although it does not specifically limit as surfactant which can be used in this case, The following ionic surfactant can be mentioned as an example of a suitable thing.

  Examples of ionic surfactants include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6 Sodium sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-6-sodium sulfonate, etc.), sulfuric acid Ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate) Beam, calcium oleate and the like).

  Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester Etc. These are mainly used as an emulsifier at the time of emulsion polymerization, but may be used for other processes or purposes.

  Examples of the colorant include inorganic pigments, organic pigments, and dyes.

  A conventionally well-known thing can be used as an inorganic pigment. Specific inorganic pigments are exemplified below.

  Examples of the black pigment include carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black, and magnetic powder such as magnetite and ferrite.

  These inorganic pigments can be used alone or in combination as required. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  Conventionally known organic pigments and dyes can also be used. Specific organic pigments and dyes are exemplified below.

  Examples of pigments for magenta or red include C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of the orange or yellow pigment include C.I. I. Pigment orange 31, C.I. I. Pigment orange 43, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 155, C.I. I. Pigment yellow 156, and the like.

  Examples of pigments for green or cyan include C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. Pigment blue 60, C.I. I. And CI Pigment Green 7.

  As the dye, C.I. I. Solvent Red 1, C.I. I. Solvent Red 49, C.I. I. Solvent Red 52, C.I. I. Solvent Red 58, C.I. I. Solvent Red 63, C.I. I. Solvent Red 111, C.I. I. Solvent Red 122, C.I. I. Solvent Yellow 19, C.I. I. Solvent Yellow 44, C.I. I. Solvent Yellow 77, C.I. I. Solvent Yellow 79, C.I. I. Solvent Yellow 81, C.I. I. Solvent Yellow 82, C.I. I. Solvent Yellow 93, C.I. I. Solvent Yellow 98, C.I. I. Solvent Yellow 103, C.I. I. Solvent Yellow 104, C.I. I. Solvent Yellow 112, C.I. I. Solvent Yellow 162, C.I. I. Solvent Blue 25, C.I. I. Solvent Blue 36, C.I. I. Solvent Blue 60, C.I. I. Solvent Blue 70, C.I. I. Solvent Blue 93, C.I. I. Solvent blue 95 etc. can be used and these mixtures can also be used.

  These organic pigments and dyes can be used alone or in combination as desired. Moreover, the addition amount of a pigment is 2-20 mass% with respect to a polymer, Preferably 3-15 mass% is selected.

  In the polymerized toner, it is possible to include wax in the toner particles. There is no particular limitation on the structure and composition of the wax itself. Low molecular weight polyolefin waxes such as polypropylene and polyethylene, paraffin wax, Fischer-Tropsch wax, ester wax and the like can be used.

  The addition amount is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass with respect to the whole toner.

  As a toner that can be used for image formation using the developing roller according to the present invention, a toner in which wax is dissolved is dispersed in water and polymerized to form particles in which wax is encapsulated in resin particles. The toner is preferably salted out / fused with the colorant particles to form a toner.

  The toner usable in the present invention comprises a step of dispersing a monomer solution in which wax is dissolved in an aqueous medium, and then preparing resin particles containing a release agent by a polymerization method, and using the resin particle dispersion. The step of fusing resin particles in an aqueous medium, the step of filtering the obtained particles from the aqueous medium to remove the surfactant, the step of drying the obtained particles, and the particles obtained by further drying It is preferable to produce by a polymerization method comprising an external additive addition step of adding an external additive to the catalyst. Here, the resin particles may be colored particles. Further, non-colored particles can also be used as resin particles. In this case, colored particles are formed by adding a colorant particle dispersion or the like to a dispersion of resin particles and then fusing in an aqueous medium.

  In particular, the method of fusing is preferably a method of salting out / fusing using resin particles produced by the polymerization step. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out / fused in an aqueous medium.

  In addition to the colorant and the release agent, a charge control agent that is a component of the toner can be added as particles in this step.

  In addition, an aqueous medium here consists of water as a main component, and shows content whose water content is 50 mass% or more. Examples of those other than water include organic solvents that dissolve in water, and examples include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran.

  As a preferred polymerization method in the present invention, a monomer solution in which a release agent is dissolved in a monomer is dispersed in oil droplets by mechanical energy in an aqueous medium in which a surfactant having a critical micelle concentration or less is dissolved. A method may be mentioned in which a water-soluble polymerization initiator is added to the dispersion and radical polymerization is performed. In this case, an oil-soluble polymerization initiator may be added to the monomer.

  The disperser for performing the oil droplet dispersion is not particularly limited, and examples thereof include CLEARMIX, ultrasonic disperser, mechanical homogenizer, manton gourin, pressure homogenizer, and the like.

  As described above, the colorant itself may be used after surface modification. In the surface modification method of the colorant, the colorant is dispersed in a solvent, and after the surface modifier is added therein, the temperature is raised and the reaction is performed. After completion of the reaction, the mixture is filtered, washed with the same solvent, repeatedly filtered and dried to obtain a pigment treated with a surface modifier.

  There is a method in which the colorant particles are prepared by dispersing a colorant in an aqueous medium. This dispersion is performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).

  The disperser at the time of pigment dispersion is not particularly limited, but preferably a medium such as CLEARMIX, ultrasonic disperser, mechanical homogenizer, pressure disperser such as Manton Gorin or pressure homogenizer, sand grinder, Getzmann mill, diamond fine mill, etc. Type disperser.

  As the surfactant used here, the aforementioned surfactants can be used.

  In the step of salting out / fusion, a salting-out agent composed of an alkali metal salt or an alkaline earth metal salt is added as a flocculant having a critical coagulation concentration or more in water in which resin particles and colorant particles are present. Next, it is a step of performing fusion at the same time as salting-out proceeds by heating the resin particles to a temperature higher than the glass transition point.

  Here, the alkali metal salt and the alkaline earth metal salt which are salting-out agents include lithium, potassium, sodium and the like as the alkali metal, and examples of the alkaline earth metal include magnesium, calcium, strontium and barium. Preferably, potassium, sodium, magnesium, calcium, and barium are used. Examples of the salt include chlorine salt, bromine salt, iodine salt, carbonate salt, sulfate salt and the like.

  In addition to the resin, the colorant, and the release agent, the toner may be added with a material that can impart various functions as a toner material. Specific examples include charge control agents. These components can be added simultaneously with the resin particles and the colorant particles in the salting out / fusion step described above, and can be added by various methods such as a method included in the toner and a method of adding to the resin particles themselves.

  Similarly, various known charge control agents and those that can be dispersed in water can be used. Specific examples include nigrosine dyes, naphthenic acid or higher fatty acid metal salts, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof.

  To the toner usable in the present invention, so-called external additives can be added and used for the purpose of improving fluidity, chargeability and cleaning property. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used. Usually, the particles before adding these external additives are often called colored particles, and the particles after the addition are often called toner or toner particles. However, both may be toner or toner particles.

  A conventionally well-known thing can be used as an inorganic fine particle. Specifically, silica, titanium, alumina fine particles and the like having a number average primary particle diameter of 5 to 500 nm can be preferably used. These inorganic fine particles are preferably hydrophobic.

  Specifically, as silica fine particles, for example, commercially available products R-805, R-976, R-974, R-972, R-812, R-809 manufactured by Nippon Aerosil Co., Ltd., HVK-2150, H manufactured by Hoechst -200, commercially available products TS-720, TS-530, TS-610, H-5, MS-5 and the like manufactured by Cabot Corporation.

  Examples of the titanium fine particles include commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., commercial products MT-100S, MT-100B, MT-500BS, MT-600, MT-600SS, and JA- 1. Commercial products TA-300SI, TA-500, TAF-130, TAF-510, TAF-510T manufactured by Fuji Titanium Co., Ltd. Commercial products IT-S, IT-OA, IT-OB, IT- manufactured by Idemitsu Kosan Co., Ltd. OC etc. are mentioned.

  Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd. and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

  As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

  Examples of lubricants include, for example, zinc stearate, aluminum, copper, magnesium, calcium, etc., zinc oleate, manganese, iron, copper, magnesium, etc., zinc palmitate, copper, magnesium, calcium, etc. And salts of higher fatty acids such as zinc of linoleic acid, salts of calcium, etc., zinc of ricinoleic acid, salts of calcium, etc.

  The amount of these external additives added is preferably 0.1 to 5% by mass with respect to the toner.

  As a method for adding the external additive, various known mixing apparatuses such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

Examples of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto.
1. Production of developing roller (1) Production of resin-silica hybrid-containing layer forming material 1 (polyurethane resin)
A reactor equipped with a stirrer, a thermometer, and a nitrogen gas introduction tube was charged with 1000 g of polycarbonate diol (Placcel CD220 (manufactured by Daicel Chemical)) having a number average molecular weight of 2000 and 278 g of isophorone diisocyanate, and the temperature was 100 ° C. under a nitrogen stream. For 6 hours to form a prepolymer having a free isocyanate value of 3.44%. To this prepolymer, 548 g of methyl ethyl ketone was added to prepare a uniform solution of urethane prepolymer.

  Next, 1000 g of the urethane prepolymer solution was added to a mixture consisting of 71.8 g of isophoronediamine, 4.0 g of di-n-butylamine, 906 g of methyl ethyl ketone, and 603 g of isopropyl alcohol, and reacted at 50 ° C. for 3 hours. A resin solution was obtained (hereinafter referred to as “polyurethane resin solution (1A)”). The obtained “polyurethane resin solution (1A)” had a resin solid content concentration of 30% and an amine value of 1.2 KOH (mg / g).

  On the other hand, in a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen gas introduction pipe, 1400 g of glycidol (Epiol OH (manufactured by NOF Corporation)) and tetramethoxysilane having an average number of silicon atoms of 4 8957.9 g of a partial condensate (methyl silicate 51 (manufactured by Tama Chemical Co., Ltd.)) was added and the temperature was raised to 90 ° C. while stirring in a nitrogen stream, and then 2.0 g of dibutyltin dilaurate was added as a catalyst. The reaction was performed.

  During the reaction, methanol was distilled off using a water separator, and when the amount reached about 630 g, the reaction system was cooled. The time required for the cooling after the temperature was raised to 90 ° C. was 5 hours. After completion of the cooling, about 80 g of methanol remaining in the system was removed under reduced pressure by applying a pressure of 13 kPa to the reaction system for about 10 minutes. In this way, an epoxy group-containing alkoxysilane partial condensate (2A) was produced.

  Further, 500 g of “polyurethane resin solution (1A)” (in terms of solid content) was added to the same reaction apparatus, heated to 50 ° C., and 10.95 g of the epoxy group-containing alkoxysilane partial condensate (2A) described above was then added. It was added and reacted at 60 ° C. for 4 hours under a nitrogen stream to produce “alkoxy group-containing silane-modified polyurethane resin 1”.

  The produced “alkoxy group-containing silane-modified polyurethane resin 1” was mixed with a urethane resin “Nipporan 5199 (manufactured by Nippon Polyurethane Co., Ltd.)”, and further mixed with 30 parts by mass of ketjen black (carbon black). Then, “resin-silica hybrid-containing layer forming material 1” containing 63% by mass of “alkoxy group-containing silane-modified polyurethane resin 1” was produced.

The ratio of the equivalent of the epoxy group of the epoxy group-containing alkoxysilane partial condensate (2A) to the equivalent of the amino group of the polyurethane resin (1A) (equivalent ratio (2A / 1A)) is 2, and the alkoxy group-containing silane-modified polyurethane resin The Si content in the solid residue was 3.3% in terms of silica mass.
(2) Production of resin-silica hybrid-containing layer forming material 2 (polyurethane resin)
The polycarbonate diol (Placcel CD220) used in the production of the “resin-silica hybrid-containing layer forming material 1” was changed to a polyester polyol having a number average molecular weight of 2000 (Kuraray polyol P2010 (manufactured by Kuraray Co., Ltd.)). Obtained “polyurethane resin solution (1B)” by the same procedure. “Polyurethane resin solution (1B)” had a resin solid content of 30% and an amine value of 1.2 KOH mg / g.

  Similar to the reactor used for the production of “resin-silica hybrid-containing layer forming material 1”, a tetramethoxysilane partial condensate “methyl silicate 56 having 250.0 g of glycidol and an average number of silicon atoms of 10” is used. (Made by Tama Chemical Co., Ltd.) 2675.4 g was added, the temperature was raised to 90 ° C. while stirring in a nitrogen stream atmosphere, and 0.5 g of dibutyltin dilaurate was added as a catalyst for reaction. It was.

  During the reaction, methanol was distilled off using a water separator, and when the amount reached about 125 g, the reaction system was cooled. In addition, the time required from heating up to 90 ° C. until cooling was 6.5 hours. After completion of cooling, a pressure of 13 kPa was applied to the reaction system for about 10 minutes, and about 5 g of residual methanol in the system was removed under reduced pressure. In this way, “epoxy group-containing alkoxysilane partial condensate (2B)” was produced. In addition, the equivalent of the hydroxyl group of the epoxy compound (A) at the time of charging / the equivalent of the alkoxyl group of the alkoxysilane condensate (B) (equivalent ratio) = 0.05, and the epoxy equivalent was 830 g / eq.

  Further, 500 g of the above-mentioned “polyurethane resin solution (1B)” (in terms of solid content) was added to the same reaction apparatus, heated to 50 ° C., and then the above-mentioned “epoxy group-containing alkoxysilane partial condensate (2B)” 17 .75 g was added and reacted at 60 ° C. for 4 hours under a nitrogen stream atmosphere to obtain “alkoxy group-containing silane-modified polyurethane resin 2”.

  The produced “alkoxy group-containing silane-modified polyurethane resin 2” was mixed with urethane resin “Nippolan 5199 (manufactured by Nippon Polyurethane Co., Ltd.)”, and further mixed with 30 parts by mass of ketjen black (carbon black). Then, “resin-silica hybrid-containing layer forming material 2” containing 74% by mass of “alkoxy group-containing silane-modified polyurethane resin 2” was produced.

The ratio of the equivalent of the epoxy group of the “epoxy group-containing alkoxysilane partial condensate (2B)” to the equivalent of the amino group of the “polyurethane resin (1B)” (equivalent ratio (2B / 1B)) is 2, and the alkoxy group contains The Si content in the solid residue in the silane-modified polyurethane resin was 6.0% in terms of silica mass.
(3) Production of resin-silica hybrid-containing layer forming material 3 (polyurethane resin)
1000 g of polycarbonate diol “Placcel CD220” and 278 g of isophorone diisocyanate are put into a reaction apparatus similar to the reaction apparatus used in the production of “resin-silica hybrid-containing layer forming material 1”, and under a nitrogen stream at 100 ° C. The reaction was carried out for 6 hours to form a prepolymer having a free isocyanate value of 3.44%. 548 g of methyl ethyl ketone was added to this prepolymer to prepare a uniform solution of urethane prepolymer.

  Next, 1000 g of the urethane prepolymer solution was added to a mixture consisting of 77.6 g of isophoronediamine, 2.4 g of di-n-butylamine, 913 g of methyl ethyl ketone, and 607 g of isopropyl alcohol, and reacted at 50 ° C. for 3 hours. A “polyurethane resin solution (1C)” was produced. The “polyurethane resin solution (1C)” had a resin solid content concentration of 30% and an amine value of 2.4 KOH mg / g.

  Furthermore, using the same reaction apparatus, after heating 500 g (in terms of solid content) of the above “polyurethane resin solution (1C)” to 50 ° C., the “epoxy group” used in “resin-silica hybrid-containing layer forming material 1” 18.54 g of “containing alkoxysilane partial condensate (2A)” was added and reacted at 60 ° C. for 4 hours under a nitrogen stream to obtain “alkoxy group-containing silane-modified polyurethane resin 3”.

  Urethane resin “Nipporan 5199 (manufactured by Nippon Polyurethane Co., Ltd.)” was mixed with the produced “alkoxy group-containing silane-modified polyurethane resin 3”, and 30 parts by mass of ketjen black (carbon black) was further mixed. A “resin-silica hybrid-containing layer forming material 3” containing 52% by mass of “alkoxy group-containing silane-modified polyurethane resin 3” was produced.

The ratio of the equivalent of the epoxy group of the “epoxy group-containing alkoxysilane partial condensate (2A)” to the equivalent of the amino group of the “polyurethane resin (1C)” (equivalent ratio (2A / 1C)) is 2, The silicon content in the solid residue in the “containing silane-modified polyurethane resin 3” was 6.4% in terms of silica mass.
(4) Production of resin-silica hybrid-containing layer forming material 4 (polyurethane resin)
In a reactor similar to that used for the production of “resin-silica hybrid-containing layer forming material 1”, 1000 g of a polyester polyol “Kuraray polyol P2010” having a number average molecular weight of 2000, 40 g of dimethylolbutanoic acid, and 342 g of isophorone diisocyanate The prepolymer having a free isocyanate value of 3.28% was prepared by charging and reacting under a nitrogen stream at 100 ° C. for 6 hours. To this prepolymer, 593 g of methyl ethyl ketone was added to prepare a uniform solution of urethane prepolymer.

  Next, 1000 g of the urethane prepolymer solution was added to a mixture consisting of 59.7 g of isophoronediamine, 9.9 g of di-n-butylamine, 897 g of methyl ethyl ketone, and 599 g of isopropyl alcohol, and reacted at 50 ° C. for 3 hours. A “polyurethane resin solution (1D)” was prepared. The “polyurethane resin solution (1D)” had a resin solid content concentration of 30% and an amine value of 3.0 KOH mg / g.

  Further, using the same reaction apparatus, 500 g of the above-mentioned “polyurethane resin solution (1D)” (in terms of solid content) was heated to 50 ° C., and then used in the production of “resin-silica hybrid-containing layer forming material 1”. 18.54 g of “epoxy group-containing alkoxysilane partial condensate (2A)” was added and reacted at 60 ° C. for 4 hours under a nitrogen stream to obtain “alkoxy group-containing silane-modified urethane resin 4”.

  The urethane resin “Nipporan 5199 (manufactured by Nippon Polyurethane Co., Ltd.)” was mixed with the produced “alkoxy group-containing silane-modified polyurethane resin 4”, and 30 parts by mass of ketjen black (carbon black) was further mixed. Then, “resin-silica hybrid-containing layer forming material 4” containing 84% by mass of “alkoxy group-containing silane-modified polyurethane resin 4” was produced.

The ratio of the equivalent of the epoxy group of the “epoxy group-containing alkoxysilane partial condensate (2A)” to the equivalent of the carboxyl group of the “urethane resin (1D)” (equivalent ratio (2A / 1D)) is 2, The silicon content in the solid residue in the “containing silane-modified polyurethane resin 4” was 7.8% in terms of silica mass.
(5) Production of resin-silica hybrid-containing layer forming material 5 (vinyl polymer resin)
37.8 g of methyl methacrylate monomer and 16.2 g of methacrylic acid monomer were added to the same reaction apparatus as that used for the production of “resin-silica hybrid body-containing layer forming material 1” and stirred sufficiently. Thereafter, the system was purged with nitrogen. This was heated to 95 ° C., and a solution prepared by dissolving 1 g of azobisisobutyronitrile (AIBN) as a polymerization initiator in 10 ml of methyl isobutyl ketone was added over 2 hours. The reaction solution was further maintained at the same temperature for 3 hours to produce “vinyl polymer resin (1E)”.

  Furthermore, using the same reaction apparatus, after heating 500 g of the above “vinyl polymer resin (1E)” to 50 ° C., the “epoxy group-containing alkoxy” used in the production of “resin-silica hybrid-containing layer forming material 1”. “Silane partial condensate (2A)” (18.54 g) was added and reacted at 60 ° C. for 4 hours under a nitrogen stream to produce “alkoxy group-containing silane-modified vinyl polymer resin 1”.

  The produced “alkoxy group-containing silane-modified vinyl polymer resin 1” was mixed with an acrylic resin “Acrypet VH (manufactured by Sumitomo Chemical Co., Ltd.)”, and further mixed with 30 parts by mass of ketjen black (carbon black). Then, “resin-silica hybrid-containing layer forming material 5” containing 70% by mass of “alkoxy group-containing silane-modified vinyl polymer resin 1” was produced.

The ratio of the equivalent of the epoxy group of the “epoxy group-containing alkoxysilane partial condensate (2A)” to the equivalent of the carboxyl group of the “vinyl polymer resin (1E)” (equivalent ratio (2A / 1E)) is 2, The silicon content in the solid residue in the “alkoxy group-containing silane-modified vinyl polymer resin 5” was 7.8% in terms of silica mass.
(6) Preparation of Comparative Resin Layer Forming Material 1 100 parts by mass of urethane resin “Nipporan 5199 (manufactured by Nippon Polyurethane)” and 30 parts by mass of Ketjen Black are mixed and dispersed in 400 parts by mass of methyl ethyl ketone (MEK). Comparative resin layer forming material 1 ”was prepared.
(7) Production of Comparative Resin Layer Forming Material 2 100 parts by mass of acrylic resin “Acrypet VH (manufactured by Sumitomo Chemical Co.)” and 30 parts by mass of ketjen black are mixed and dispersed in 400 parts by mass of methyl ethyl ketone (MEK). “Comparative resin layer forming material 2” was produced.
(8) Production of development roller (a) Production of development roller 1 The above-mentioned “resin-silica hybrid-containing layer forming material 1” is applied to the peripheral surface of a shaft made of SUS303 having a diameter of 10 mm to a thickness of 15 μm. A “developing roller 1” having a layer containing 63% by mass of a polyurethane resin-silica hybrid was produced by heat treatment at a temperature of 1 ° C. for 1 hour.
(B) Preparation of developing roller 2 Instead of “resin-silica hybrid-containing layer forming material 1” used in the preparation of “developing roller 1”, “resin-silica hybrid-containing layer forming material 2” has a thickness of 10 μm. A “developing roller 2” having a layer containing 74% by mass of a polyurethane resin-silica hybrid was produced in the same manner except that the coating was applied.
(C) Production of developing roller 3 Instead of “resin-silica hybrid-containing layer forming material 1” used in the production of “developing roller 1”, a “resin-silica hybrid-containing layer forming material 3” having a thickness of 12 μm is used. A “developing roller 3” having a layer containing 52% by mass of a polyurethane resin-silica hybrid was prepared in the same manner except that the coating was applied.
(D) Production of developing roller 4 In place of “resin-silica hybrid-containing layer forming material 1” used in the production of “developing roller 1”, “resin-silica hybrid-containing layer forming material 4” was used. In the same manner, “Developing roller 4” having a layer containing 84% by mass of a polyurethane resin-silica hybrid was prepared.
(E) Production of developing roller 5 Other than using “resin-silica hybrid-containing layer forming material 5” instead of “resin-silica hybrid-containing layer forming material 1” used in the production of “developing roller 1”. In the same manner, “Developing roller 5” having a layer containing 70% by mass of a vinyl polymer resin-silica hybrid was produced.
(F) Production of comparative developing roller 1 In the production of the “developing roller 1”, bis-1,2-triethoxysilylethane was placed on the shaft instead of the “resin-silica hybrid-containing layer forming material 1”. The film was uniformly coated and heat-treated at 100 ° C. for 1 hour to prepare “Comparative developing roller 1”.
(G) Production of comparative developing roller 2 In the production of “developing roller 1”, the above-mentioned “comparative resin layer forming material 1” was used instead of “resin-silica hybrid-containing layer forming material 1”. In the same manner, “Comparative developing roller 2” was produced.
(H) Production of Comparative Developing Roller 3 In the production of “Developing Roller 1”, the above-mentioned “Comparative Resin Layer Forming Material 2” was used instead of “Resin-Silica Hybrid Containing Layer Forming Material 1”. In the same manner, “Comparative developing roller 3” was produced.
2. Preparation of Toner (1) Preparation of “Resin Particle Dispersion 1” A flask equipped with a stirrer was charged with 72.0 g of pentaerythritol tetrastearate, 115.1 g of styrene, 42.0 g of n-butyl acrylate, and methacrylic acid. It added to the monomer liquid mixture which consists of 10.9g of acids, and it heated and dissolved at 80 degreeC.

  On the other hand, a surface activity in which 7.08 g of an anionic surfactant (sodium dodecylbenzenesulfonate: SDS) was dissolved in 2760 g of ion-exchanged water in a separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. The agent solution was added, and the temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm under a nitrogen stream. Next, the monomer solution (80 ° C.) is mixed and dispersed in the surfactant solution (80 ° C.) by a mechanical disperser “CLEARMIX (M Technique Co., Ltd.)” having a circulation path, An emulsified liquid in which emulsified particles (oil droplets) having a uniform dispersed particle diameter were dispersed was prepared.

To this dispersion was added an initiator solution prepared by dissolving 0.84 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water, and this system was heated and stirred at 80 ° C. for 3 hours for polymerization. Reaction was performed. A solution obtained by dissolving 7.73 g of a polymerization initiator (KPS) in 240 g of ion-exchanged water was added to the obtained reaction solution. After 15 minutes, the temperature was adjusted to 80 ° C., followed by 383.6 g of styrene and n-butyl acrylate. A mixture of 140.0 g, 36.4 g of methacrylic acid, and 12 g of n-octyl mercaptan was added dropwise over 100 minutes, and the system was heated and stirred at 80 ° C. for 60 minutes. Was then cooled to prepare “resin particle dispersion 1” (hereinafter referred to as “latex (1)”) containing wax.
(2) Preparation of “Colorant Dispersion Liquid K” On the other hand, 9.2 g of sodium n-dodecyl sulfate was stirred and dissolved in 160 g of ion-exchanged water. While stirring this solution, 20 g of carbon black “MOGAL L” (Cabot Corporation) is gradually added as a colorant, and then using a mechanical disperser “CLEAMIX” (M Technique Co., Ltd.). By performing the dispersion treatment, “colorant dispersion liquid K” was prepared. When the particle diameter of the colorant particles in “Colorant Dispersion Liquid K” was measured with an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm.
(3) Preparation of “colored particle 1K” In a reaction vessel (four-necked flask) equipped with a temperature sensor, a cooling pipe, a stirring device (having two stirring blades, an intersection angle of 20 °), and a shape monitoring device, 1250 g of “resin particle dispersion 1” (in terms of solid content), 2000 g of ion-exchanged water, and “colorant dispersion 1” were all added, and the internal temperature was adjusted to 25 ° C., and then 5 mol / liter of this dispersion mixture was added. A sodium hydroxide aqueous solution was added to adjust the pH to 10.0. Next, an aqueous solution obtained by dissolving 52.6 g of magnesium chloride hexahydrate in 72 g of ion-exchanged water was added at 25 ° C. for 10 minutes with stirring. Thereafter, the temperature increase was started immediately, and this system was heated to 95 ° C. over 5 minutes (temperature increase rate: 14 ° C./min).

  In this state, the particle size of the aggregated particles was measured with “Multisizer 3 (manufactured by Beckman Coulter)”. When the volume-based median diameter (D50) reached 6.5 μm, 115 g of sodium chloride was exchanged with ion-exchanged water. An aqueous solution dissolved in 700 g was added to stop particle growth. Furthermore, after heating and stirring for 8 hours at a liquid temperature of 90 ° C. (stirring rotation speed: 120 rpm) and continuing aging, the system was cooled to 30 ° C. at 10 ° C./min. The pH was adjusted to 3.0 by addition and stirring was stopped.

The produced particles are filtered, washed repeatedly with ion-exchanged water, classified in liquid using a centrifugal separator, and then dried using a flash jet dryer to give “colored particles 1K” having a water content of 1.0 mass%. Was generated.
(4) Preparation of “Colorant Dispersion Y” In the preparation of “Colorant Dispersion K”, the same procedure was followed except that 20 g of the pigment “CI Pigment Yellow 74” was used instead of 20 g of carbon black. “Colorant dispersion Y” was prepared. When the particle diameter of the colorant particles in “Colorant Dispersion Liquid Y” was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm.
(5) Preparation of “Colorant Dispersion Liquid M” In the preparation of “Colorant Dispersion Liquid K”, except that 20 g of quinacridone-based magenta pigment “CI Pigment Red 122” was used instead of 20 g of carbon black, According to the procedure, “Colorant Dispersion Liquid M” was prepared. When the particle diameter of the colorant particles in “Colorant Dispersion Liquid M” was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm.
(6) Preparation of “Colorant Dispersion C” In the preparation of “Colorant Dispersion K”, 20 g of phthalocyanine cyan pigment “CI Pigment Blue 15: 3” was used instead of 20 g of carbon black. Prepared “Colorant Dispersion C” by the same procedure. When the particle diameter of the colorant particles in “Colorant Dispersion C” was measured using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.), the mass average particle diameter was 120 nm.
(7) Preparation of “Colored Particles 1Y” In the preparation of “Colored Particles 1K”, “Colored Particles 1K” was prepared in the same manner as in “Colored Particles 1K”, except that “Colorant Dispersion Liquid Y” was used instead of “Colorant Dispersion Liquid K”. 1Y "was produced.
(8) Preparation of “Colored Particles 1M” In the preparation of “Colored Particles 1K”, “Colored Particles 1K” was prepared in the same manner as in “Colored Particles 1K”, except that “Colorant Dispersion Liquid M” was used instead of “Colorant Dispersion Liquid K”. 1M "was produced.
(9) Preparation of “Colored Particles 1C” In the preparation of “Colored Particles 1K”, “Colored Particles 1K” was prepared in the same manner as in “Colored Particles 1K”, except that “Colorant Dispersion Liquid C” was used instead of “Colorant Dispersion Liquid K”. 1C "was produced.
(10) Preparation of Toner In the “colored particles”, 0.8 part by mass of hydrophobic silica having a number average primary particle size of 12 nm and a hydrophobicity of 65, a number average primary particle size of 30 nm, and a hydrophobicity of 55 0.5 part by mass of hydrophobic titania was added and mixed with a Henschel mixer to prepare a toner. These were designated as “toner 1K, toner 1Y, toner 1M, and toner 1C”.
3. Evaluation Experiment (1) Evaluation of Adhesive Strength (Durability) of Developing Roller As shown in FIG. 2 (a), the developed developing roller is shown by a broken line X along the outer periphery of the resin layer at the center of the roller. A cut with a width of 2.5 cm is made, and further, a cut is made in the axial direction with respect to the resin layer (broken line Y), and the resin layer is peeled off a little from there, as shown in FIG. The end of the peeled resin layer was pulled up vertically by Autograph AGS (manufactured by Shimadzu Corp.) (in the direction of arrow Z), and it was evaluated by measuring how much the resin layer began to peel off when pulled up. . The pulling rate of the resin layer was 100 mm / min. A load with a load of 4.0 N or more when starting to be peeled off was considered acceptable.
(2) Image Evaluation A commercially available color laser printer “Magicor 2300DL (manufactured by Konica Minolta Business Technology Co., Ltd.)” was used as an evaluation device, and the developing roller was loaded into the developing device for evaluation. Evaluation was performed by continuous printing of 3000 sheets in A4 size with a pixel rate of 20% (full color mode of 5% for each color of yellow, magenta, cyan, and black) in a normal temperature and low humidity environment (20 ° C., 10% RH). went. For initial evaluation and after printing 3000 sheets, print an original image with a pixel rate of 10% (A4 size original image with a fine line image, a human face photo, a solid white image, and a solid black image divided into quarters). Samples were evaluated as follows.
<Reproducibility of thin lines>
The fine line part was enlarged using a 10-times loupe, and the resolution was evaluated by visually evaluating the presence or absence of blurring (the number of fine lines present in 1 mm was evaluated).
<Fog density>
The solid white image portion was measured with a Macbeth reflection densitometer “RD-918”, and the reflection density of the transfer paper was set to 0, and the relative reflection density was evaluated.

  The results are shown in Table 1.

  As shown in Table 1, in Examples 1 to 5 corresponding to the present invention, it was confirmed that good adhesiveness was expressed between the resin layer and the shaft. Further, when 3000 sheets were continuously printed, fine line reproducibility was maintained and no fogging was observed. As described above, in Examples 1 to 5, it was confirmed that even if image formation was repeatedly performed, there was no influence due to an increase in residual charge. On the other hand, in Comparative Examples 1 to 3 outside the present invention, sufficient adhesive strength could not be obtained, and when continuous printing was performed, thin line reproduction defects and fogging due to creaking occurred before reaching 3000 sheets, and stable. It was confirmed that image formation could not be performed.

  Thus, from the results of the examples, by using a developing roller in which a resin layer containing a resin-silica hybrid as a main component is provided around the conductive shaft, good image quality can be obtained even when image formation is repeated. It was found that printed materials can be created stably.

It is a figure which shows the cross-sectional structure of the developing roller which concerns on this invention. It is a schematic diagram of a measuring device for measuring the strength of the developing roller according to the present invention. It is sectional drawing of the developing device which can mount the developing roller which concerns on this invention.

Explanation of symbols

10 Developing roller 11 Conductive shaft 12 Resin layer

Claims (5)

In the developing roller having at least one resin layer around the conductive shaft,
The developing roller, wherein the resin layer contains a resin-silica hybrid as a main component. The developing roller according to claim 1, wherein the content of the silica skeleton constituting the resin-silica hybrid is 1% by mass or more and 30% by mass or less. The developing roller according to claim 1, wherein the resin portion constituting the resin-silica hybrid body contains a compound having a urethane bond. The developing roller according to claim 1, wherein the resin part constituting the resin-silica hybrid contains a vinyl polymer having an acid group in a side chain. In an image forming method comprising a step of transporting at least a developer composed only of toner to a developing region by a developing roller, and forming an electrostatic latent image formed on the electrostatic latent image bearing member into a visible image with the developer.
The image forming method, wherein the developing roller has at least one resin layer around a conductive shaft, and the resin layer contains a resin-silica hybrid as a main component.

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