JP4355645B2 - Non-magnetic one-component developer and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonmagnetic one-component developer not causing development streaks due to endurance deterioration, toner flying-off, dilution of a deep color at low temperature and low humidity, or fogging at high temperature and high humidity, and to provide an image forming method. <P>SOLUTION: The nonmagnetic one-component developer has toner particles including a binder resin, a colorant and a release agent, and inorganic fine particles, wherein the toner particles are formed by a polymerization method using a low-molecular-weight peroxy-ester compound represented by formula (1) (where R<SB>1</SB>-R<SB>4</SB>are each alkyl) as an initiator, and when a load of 4.9&times;10<SP>-4</SP>N is applied on one toner particle, both relational expressions: 1.5&le;X/Y&le;2.5 and 10.0&le;X+Y&le;20.0 are satisfied, wherein X represents (amount of plasticity displacement)/(particle diameter)&times;100; and Y represents (amount of elasticity displacement)/(particle diameter)&times;100. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a non-magnetic one-component developer and an image forming method used in a recording method using an electrophotographic method, an electrostatic recording method or the like. Specifically, a non-magnetic one-component developer used in an image forming apparatus such as a copying machine, a printer, or a fax machine that forms an image on a latent electrostatic image bearing member in advance and then transfers the image onto a transfer material to form an image. The present invention relates to an image forming method.

  In recent years, equipment using electrophotography has been applied to devices such as printers and fax machines, as well as multifunction peripherals, in addition to conventional copying machines.

  The developing methods used in these devices are roughly classified into a one-component developing method and a two-component developing method, but in recent years, there are an increasing number of one-component developing methods advantageous for downsizing. The one-component developing method uses a one-component developer (hereinafter also referred to as “toner”), friction between a layer thickness regulating member (hereinafter also referred to as “blade”) and toner particles, and a developer carrier (hereinafter referred to as “developing roller”). )) And the toner particles are charged by the friction of the toner particles, and at the same time, are applied thinly and uniformly on the developing roller, and the developing roller and the electrostatic latent image carrier (hereinafter also referred to as “drum”) are opposed to each other. The toner is conveyed to the area, and the electrostatic latent image on the drum is developed, and visualized as a toner image.

  Unlike the two-component development method that requires carrier particles such as glass beads, iron powder, and ferrite, this one-component development method does not require carrier particles, and thus the development apparatus itself can be reduced in size and weight. Furthermore, since the two-component development method needs to keep the toner concentration in the developer constant, a device that detects the toner concentration and replenishes the necessary amount of toner is required, which leads to an increase in the size and weight of the developing device. . In this respect as well, the one-component development method is advantageous for reduction in size and weight. In addition, the one-component development method can be divided into a magnetic one-component development method and a non-magnetic one-component development method. However, since it is difficult to use magnetic powder of a color developer in full color, a non-magnetic toner is used as a toner. Has come to be used.

  In addition, with regard to the one-component developing device, development is performed by electrostatically flying toner from the developing roller to the electrostatic latent image on the drum, with contact development in which the drum and the developing roller are brought into contact with each other, and at a predetermined interval. Although there is jumping development to be performed, jumping development is advantageous in preventing toner deterioration because there is no contact between the drum and the developing roller, and this prevents fogging and roughness due to image deterioration in the latter half of the durability test. It is very effective.

  However, this jumping development has a very narrow appropriate charging area in development, so various adverse effects may occur if the chargeability of the toner changes under high temperature and high humidity, low temperature and low humidity, in the initial stage of use or when the toner is almost gone. I know it.

  Specifically, there are image margin, toner scattering, low density under low temperature and low humidity, fogging under high temperature and high humidity, and development streak in the second half of the durability test.

  In addition, in recent years, image quality such as photographic images (hereinafter referred to as gloss) has become an important image quality in the improvement of image quality. In order to achieve this quality, methods of fixing images with a heat roller and methods of generating gloss by slowing down the printing speed by slowing down the fixing speed are considered, but using a heat roller consumes power. In addition to the increase in the image, there is a problem that the image cannot be output until the heat roller is warmed. The method of reducing the fixing speed takes time until the image is displayed and the fog is deteriorated. There is.

In order to improve this problem, it has been proposed that the toner is made to have a moderately soft composition (see, for example, Patent Document 1), but the toner is scattered, the concentration is low at low temperature and low humidity, and the temperature is high and high humidity. The fog was not improved. In addition, a toner having improved environmental stability by improving the external additive (see, for example, Patent Document 2) is disclosed, but a toner with a soft design such as a high gloss toner is durable only by improving the external additive. There is also a risk of poor stability. Although this is adjusted including the setting from the apparatus side to improve environmental stability and transferability (for example, refer to Patent Document 3), there is disclosed toner deterioration and toner scattering with high gloss toner. There was no improvement. Similarly, a toner that changes the colorant of the black toner to create a polymerized toner to balance the four colors and improve the environmental stability (for example, see Patent Document 4) is disclosed. There was no improvement in toner degradation and toner scattering.
JP 2000-172015 A JP-A-8-202079 JP-A-8-278673 JP 2000-169337 A

  The present invention relates to a non-magnetic one-component developer and an image forming method in a non-magnetic one-component jumping development method, and development streaks due to endurance deterioration of toner, toner scattering, image blur, dark color thinness under low temperature and low humidity, high temperature and high humidity It is an object of the present invention to provide a non-magnetic one-component developer and an image forming method with improved fog under.

The above object is achieved by the present invention described below.
That is, according to the present invention, the electrostatic latent image formed on the drum is applied with an AC voltage on which the DC voltage is superimposed on the developing roller spaced apart from the drum by applying a toner (non-magnetic) on the developing roller. A toner used in an image forming method developed with a one-component developer), the toner having at least toner particles containing a binder resin, a colorant, and a release agent, and inorganic fine particles; The toner particles are used as an initiator, represented by the following general formula (I) (R1 to R4 have 1 carbon
-6 alkyl groups, which may be the same or different from each other) and produced by a polymerization method using one or more of low molecular weight peroxyester compounds represented by When a load of 4.9 × 10 ⁻⁴ N is applied to one toner particle, the plastic displacement amount / particle size × 100 is X, and the elastic amount / particle size × 100 is Y = 1.5 ≦ X / Y ≦ 2.5 and 10.0 ≦ X + Y ≦ 20.0 A toner characterized by satisfying both relational expressions and at least one toner can be achieved by an image forming method using the above toner.

According to the present invention, in a jumping development system using a full-color non-magnetic one-component developer, development streaks, toner scattering, image blur, low temperature and low humidity due to endurance deterioration of the toner that is likely to occur when a high gloss image is produced. It is possible to improve image defects such as dark color thinning and fogging under high temperature and high humidity.

As a result of intensive studies by the present inventor, an electrostatic voltage superimposed on the electrostatic latent image formed on the drum is applied to the developing roller at a predetermined distance from the drum, thereby applying the developing roller to the developing roller. A non-magnetic one-component developer used in the image forming method for developing with the above non-magnetic one-component developer, and the non-magnetic one-component developer contains at least a binder resin, a colorant, and a release agent. The toner particles have at least toner particles and inorganic fine particles, and the toner particles are represented by the following general formula (I) (R1 to R4 are alkyl groups having 1 to 6 carbon atoms, and may be the same or different from each other) Is produced by a polymerization method using one or more of low molecular weight peroxyester compounds represented by the formula (1), and a load of 4.9 × 10 ⁻⁴ N is applied to one toner particle. Plastic displacement / particle size x 100 when X is The amount / particle size × 100 when a Y 1.5 ≦ X / Y ≦ 2.5
A non-magnetic one-component developer satisfying both the relational expressions 10.0 ≦ X + Y ≦ 20.0 and an image forming method using at least one non-magnetic one-component developer By using the present invention, it has been found that image defects such as development streaks due to endurance deterioration of toner, toner scattering, image blur, dark color thinness under low temperature and low humidity, and fogging under high temperature and high humidity can be improved. It came to.

Details will be described below.
<Non-magnetic one-component developer of the present invention (hereinafter also referred to as toner of the present invention)>
The toner of the present invention has at least toner particles containing at least a binder resin, a colorant, and a release agent, and inorganic fine particles. The toner particles are compounds represented by the following general formula (I) as initiators ( R1 to R4 are alkyl groups having 1 to 6 carbon atoms, which may be the same or different from each other, and are produced by polymerization using one or more of the toner particles. 1.5 ≦ X / Y ≦ 2.5, 10.0 when X is plastic displacement / particle size × 100 and Y is elastic displacement / particle size × 100 when a load of 4.9 × 10 ⁻⁴ N is applied to one It is characterized by satisfying both relational expressions ≦ X + Y ≦ 20.0.

The toner of the present invention can contain inorganic fine particles on the toner surface as an external additive of toner particles containing at least a binder resin, a colorant, and a release agent. Inorganic fine particles include oxide powders such as silicon, magnesium, zinc, aluminum, titanium, cobalt, zirconium, manganese, cerium, and strontium, and composite metal oxides such as calcium titanate, magnesium titanate, strontium titanate, and barium titanate. Examples thereof include powders of substances, carbides such as boron, silicon, titanium, vanadium, zirconium, molybdenum and tungsten, carbonates such as magnesium, calcium, strontium and barium, sulfates and phosphates. Among these, silica powder is preferable (particularly silica fine particles are preferable) for improving fluidity, and it is preferable to contain this on the toner surface.

Of the silica fine particles, particularly preferred are both so-called dry process produced by vapor phase oxidation of silicon halogen compounds or dry silica called fumed silica, and so-called wet silica produced from water glass or the like. Dry silica that can be used but has few silanol groups on the surface and inside of the silica fine particles, and has no production residue such as Na ₂ O, SO ₃ ²⁻ is more preferable.

In dry silica, composite fine particles of silica and other metal oxides can be obtained by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds in the production process. Is also included.
The silica fine particles used in the present invention may be surface-treated with a treatment agent such as a silane coupling agent or an organosilicon compound for the purpose of hydrophobization and triboelectric charge control, if necessary. As the method, a known method is used, and the surface is treated with a treating agent that reacts or physically adsorbs with silica particles.

  Examples of such treatment agents include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyldimethylchlorosilane. , Bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyl Dimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane 1,3-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having 2 to 12 siloxane units per molecule and containing hydroxyl groups bonded to one Si at each terminal unit . These are used alone or in a mixture of two or more.

The inorganic fine particles used in the toner of the present invention may be those that have been surface-treated with silicone oil. As the surface treatment method for silicone oil, known methods are used. For example, inorganic fine powder and silicone oil may be directly mixed using a mixer such as a Henschel mixer, or silicone oil may be added to the base fine powder. A spraying method may be used.
Alternatively, after dissolving or dispersing silicone oil in a suitable solvent, an inorganic fine powder may be added and mixed to remove the solvent. Further, known silicone oils used in the present invention are used, for example, dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chrome phenyl silicone oil, fluorine modified silicone oil, etc. .

Organic particles or composite particles can be added to the toner of the present invention for the same purpose. Examples of such organic particles and composite particles include polyamide resin particles, silicone resin particles, silicone rubber particles, urethane particles, melamine-formaldehyde particles, acrylic particles, and the like; rubbers, waxes, fatty acid compounds, resins, and the like. Composite particles composed of inorganic particles such as metals, metal oxides, metal salts, and carbon black; fluororesins such as polyfluorinated ethylene and polyvinylidene fluoride; fluorine compounds such as carbon fluoride; fatty acid metal salts such as zinc stearate; Examples include fatty acid derivatives such as fatty acids and fatty acid esters; molybdenum sulfide, amino acids and amino acid derivatives.

The inorganic fine particles can be used as an external additive, and can be externally added at any time after the production of the toner particles. For example, it can be externally added to the toner particles in a step of classifying or spheroidizing the toner particles.
The amount of these external additives used is 0.1 to 5.0 parts by mass, preferably 0.5 to 3.0 parts by mass with respect to 100 parts by mass of toner particles.

  The method for producing the toner of the present invention is not particularly limited, but a toner produced by a so-called suspension polymerization method, in which the particle size distribution is easily controlled and a spherical toner can be easily obtained, is preferably used.

The method for producing the toner of the present invention will be described below by taking the suspension polymerization method as an example.
First, wax as a mold release agent, polar resin, colorant, charge control agent, polymerization initiator, and other additives are added to the polymerizable monomer and uniformly dissolved or dispersed by a homogenizer, ultrasonic disperser, etc. The caulked monomer system is dispersed in an aqueous phase containing a dispersion stabilizer by an ordinary stirrer, homogenizer, homomixer or the like. At this time, granulation is preferably performed while adjusting the stirring speed and time so that the monomer droplets have a desired developer particle size. Thereafter, stirring may be performed to such an extent that the particle state is maintained and the settling of the particles is prevented by the action of the dispersion stabilizer. The polymerization temperature is preferably set to 40 ° C. or higher, generally 50 ° C. to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers and by-products that cause odors when fixing the developer, the latter half of the reaction or at the end of the reaction. A part of the aqueous medium may be distilled off. After completion of the reaction, the produced developer particles are washed, collected by filtration and dried. In the suspension polymerization method, it is usually preferable to use 300 parts by mass to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer system.

  Toner particle size distribution control and particle size control can be done by adjusting the pH of the system during granulation, changing the type and addition amount of a sparingly water-soluble inorganic salt and protective colloid, mechanical equipment conditions, For example, it can be achieved by controlling the stirring conditions such as the peripheral speed of the rotor, the number of passes, the shape of the stirring blade, the shape of the container or the solid content in the aqueous solution, and the like.

  Examples of the polymerizable monomer that forms the binder resin used in the present invention include styrene monomers such as styrene, o- (m-, p-) methylstyrene, m- (p-) ethylenestyrene; Methyl) methacrylate, Propyl (meth) acrylate, Butyl (meth) acrylate, Octyl (meth) acrylate, Dodecyl (meth) acrylate, Stearyl (meth) acrylate, Behenyl (meth) acrylate, (Meta ) (Meth) acrylic acid ester monomers such as 2-ethylhexyl acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexane, (meth) acrylonitrile, acrylamide Monomers such as are preferably used.

Moreover, as a polar resin added at the time of superposition | polymerization, the copolymer of a styrene (meth) acrylic acid, a maleic acid copolymer, a polyester resin, and an epoxy resin are used preferably.
The polar resin may not be used, but when used, the polar resin is 0.1 to 30 parts by mass, preferably 1 to 20 parts by mass with respect to 100 parts by mass of the binder resin component. preferable.

  Further, the toner of the present invention preferably contains sulfur atoms, and as a production method, it is preferable to add a resin having a sulfur atom or a single substance thereof from the viewpoint of performance such as ease of toner production and charging stability.

In the toner of the present invention, it is possible to define a suitable range of the amount of sulfur atoms present on the toner particle surface by X-ray photoelectron spectroscopic analysis described later. Specifically, the ratio (E) of the content (E) of sulfur element having a peak top at a binding energy of 166 to 172 eV with respect to the content (A) of carbon element present on the toner surface as measured by X-ray photoelectron spectroscopy analysis / A) is preferably in the range of 0.0003 to 0.0050, and is more suitable for the average particle size of the iron oxide used, the amount of sulfur atoms contained in the binder resin, and the amount of polymer having sulfur atoms used. It is possible to control. If it is less than 0.0003, the tendency that a sufficient charge amount cannot be obtained increases, and if it exceeds 0.0050, it becomes difficult to obtain the humidity dependency of the charge amount.

  The ratio (E / A) of the sulfur element content (E) to the carbon element content (A) present on the toner particle surface is subjected to surface composition analysis by ESCA (X-ray photoelectron spectroscopy) as follows. Can be measured.

The ESCA apparatus and measurement conditions in the present invention are as follows.
Equipment used: 1600S type X-ray photoelectron spectrometer manufactured by PHI Measurement conditions: X-ray source MgKα (400 W)
Spectral region 800μmφ
In the present invention, the surface atomic concentration was calculated from the measured peak intensity of each element using a relative sensitivity factor provided by PHI.
This measurement is preferably performed by ultrasonically washing the toner, removing the external additive adhering to the surface of the toner particles, separating by magnetic force, and drying.

  Examples of the sulfur-containing monomer for producing a resin having a sulfur atom used in the toner of the present invention include styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, and 2-methacrylamide-2-methylpropanesulfone. Examples thereof include acids, vinyl sulfonic acid, methacryl sulfonic acid, and the like, or maleic acid amide derivatives, maleimide derivatives, and styrene derivatives having the following structures.

  The sulfur atom-containing resin used in the toner of the present invention may be a homopolymer of the above monomer, or may be a copolymer of the above monomer and another monomer. Absent. As a monomer that forms a copolymer with the above monomer, there is a vinyl polymerizable monomer, and a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

  In order to obtain the circularity of the toner of the present invention, a copolymer having a sulfonic acid among the above monomers is preferable, and a sulfonic acid group-containing (meth) acrylamide is more preferable.

  In the toner of the present invention, it is possible to add wax as a release agent in order to prevent fixing offset. As the wax to be used, paraffin wax, polyolefin wax, Fischer-Tropsch wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof are preferably used. These waxes are generally 1 to 30 parts by mass, more preferably 5 to 20 parts by mass with respect to 100 parts by mass of the binder resin component in the toner particles in order to achieve an improvement in releasability at the time of fixing. Part is used.

  As the polymerization initiator used in the production of the toner of the present invention, a peroxyester peroxide polymerization initiator is used. Specifically, an initiator represented by the following general formula (I) is used (R1 to R4 are alkyl groups having 1 to 6 carbon atoms, which may be the same as or different from each other).

上記重合開始剤としては、例えばｔ−ヘキシルパーオキシピバレート、ｔ-ブチルパー
オキシピバレート、ｔ-ブチルパーオキシイソブチレート、ｔ-ブチルパーオキシアセテート、ｔ-ブチルパーオキシベンゾエート等が挙げられる。

Examples of the polymerization initiator include t-hexyl peroxypivalate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-butyl peroxyacetate, t-butyl peroxybenzoate, and the like. .

  When the polymerization initiator is not as described above, the dispersion state of the colorant or release agent dispersed inside, the molecular weight distribution of the resin, the chargeability due to the polymerization terminal and the initiator residue are different, so fog and toner scattering, There is a possibility that the effect of improving the development streak may not appear, and there is also a possibility that the image margin and density thinning will deteriorate.

  Although the addition amount of this polymerization initiator changes with the target degree of polymerization, generally it is used by the addition amount of 0.5 to 20.0 mass parts with respect to a polymerizable monomer. The kind of the polymerization initiator is slightly different depending on the polymerization method, but may be used alone or in combination with reference to the 10-hour half-life temperature. Further, it is desirable that the polymerization reaction temperature at that time is appropriately adjusted according to the initiator used and the target degree of polymerization.

Examples of the dispersant used when the suspension polymerization is used in the production of the toner of the present invention include, for example, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, carbonic acid as an inorganic oxide. Examples thereof include magnesium, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, magnetic substance, and ferrite. As the organic compound, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like are used dispersed in an aqueous phase.
These dispersants are preferably used in an amount of 0.2 to 2.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer.

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

  In order to make these dispersants finer, 0.001 to 0.1 parts by mass of a surfactant may be used in combination with the dispersion medium. Specifically, commercially available nonionic, anionic and cationic surfactants can be used, such as sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, Calcium oleate is preferably used.

In the toner of the present invention, in addition to black colorants such as carbon black and magnetite, all pigments and / or dyes such as yellow / magenta / cyan colorants shown below can be used as colorants. For example, when the toner according to the present invention is used as a full-color toner, the following may be mentioned.

  Examples of the magenta color pigment used in the toner of the present invention include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90, 112, 114, 122, 123, 163, 202, 206, 207, 209; I. Pigment violet 19; C.I. I. Buttred 1, 2, 10, 13, 15, 23, 29, 35 may be mentioned. Although the pigment alone may be used, it is more preferable from the viewpoint of the image quality of the full-color image that the combination of the dye and the pigment improves the sharpness.

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

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

Examples of the color pigment for yellow used in the toner of the present invention include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 65, 73, 83; I. Vat yellow 1, 3, 20 etc. are mentioned.
These colorants can be used singly or in combination, and usually from 0.1 to 30 parts by weight with respect to 100 parts by mass of the binder resin component from the viewpoint of electrophotographic characteristics and transparency.
Used in parts by weight, preferably 1.0 to 20 parts by weight.

  In the toner of the present invention, a charge control agent can be used to control the charge amount of the toner. As the charge control agent, for example, when the toner is controlled to be positively charged, a modified product such as a fatty acid metal salt; tributylbenzidylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, etc. Quaternary ammonium salts and onium salts such as phosphonium salts that are analogs thereof; amines and polyamine compounds; metal salts of higher fatty acids; acetylacetone metal complexes; diorganotins such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide Oxide; Diorganotin borate such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate and the like are added. Also, when controlling to negative charge, organometallic complexes and chelate compounds are effective, salicylic acid, naphthoic acid, dicarboxylic acid, metal compounds of their derivatives, polymer compounds having sulfonic acid in the side chain, boron compounds , Urea compounds, silicon compounds, calixarene, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes can be used.

  The usage-amount of the said charge control agent is 0.1-15.0 mass parts with respect to 100 mass parts of binder resin components, Preferably it is 0.1-10.0 mass parts.

A rubber component or a thermoplastic elastomer can be added to the toner of the present invention in order to adjust the elastic displacement amount and the plastic displacement amount. These include, for example, diene rubbers such as styrene / butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), nitrile / butadiene rubber (NBR), nitrile / isoprene rubber (NIR), chloroprene rubber (CR); Olefin rubber such as butyl rubber (IRR), ethylene / propylene rubber (EPM, EPDM), chlorosulfonated polyethylene (CSM); Ether rubber such as epichlorohydrin rubber (CHR, CHC); Other silicone rubber, fluorine rubber, acrylic rubber There are elastomeric materials such as urethane elastomers and thermoplastic elastomers such as styrene, olefin, polyvinyl chloride, urethane, polyester, polyamide, fluorine, chlorinated polyethylene, etc. Add It is possible. However, since it varies depending on the substance to be added, its dispersion state, the addition method, etc., it cannot be generally stated, but since a large amount of addition leads to an increase in elasticity, it is advantageous for toner deterioration, but the gloss of the fixed image does not appear. It is not preferable.
The amount of the rubber component or thermoplastic elastomer used is 0.01 to 50 parts by mass, preferably 0.05 to 30 parts by mass with respect to 100 parts by mass of the binder resin component.

  For the same reason as described above, a crosslinking agent can be added to the toner of the present invention. As a cross-linking agent, bifunctional cross-linking agents include divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1 , 5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 Each diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (MANDA Nippon Kayaku), and the above Include those which instead of methacrylate Relate.

Pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, polyethoxyphenyl) Examples include propane, diallyl phthalate, triallyl cyanurate, triallyl asocyanurate, triallyl isocyanurate, triallyl trimellitate, and diaryl chlorendate. Also in these cases, addition of a large amount leads to a decrease in the amount of plastic displacement, which is advantageous for toner deterioration, but is not preferable because gloss of a fixed image is not generated. The crosslinking agent may not be used, but when used, it is 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the binder resin component.

The toner of the present invention is 1.5 when the plastic displacement / particle size × 100 is X and the elastic displacement / particle size × 100 is Y when a load of 4.9 × 10 ⁻⁴ N is applied to one toner particle. ≦ X / Y ≦ 2.5 and 10.0 ≦ X + Y ≦ 20.0 are satisfied.
In the toner of the present invention, the value of X / Y represents the elasticity of the toner, and the smaller the value, the more elastic. If the X / Y value is less than 1.5, the elasticity is so strong that toner deterioration due to continuous printing is very strong. However, when fixed on a recording material, gloss does not easily occur. It becomes impossible to fix on the material. When the X / Y value is greater than 2.5, gloss on the recording material is likely to occur, and there is an advantage that fixing can be performed at a lower temperature. However, toner deterioration due to continuous printing is likely to occur, and development streaks, fog, and offset occur. It becomes easy to do. A more preferable range of the value of X / Y is 1.7 or more and 2.3 or less.

Further, in the toner of the present invention, the value of X + Y represents the softness of the toner, and the larger the value, the softer the value. When the value of X + Y is less than 10.0, toner deterioration is suppressed because the toner particles are hard, but gloss on the recording material is difficult to occur, and toner scattering and fogging due to toner cracking are likely to deteriorate. If the value is too small, fixing on the recording material cannot be performed. On the other hand, if the value of X + Y is greater than 20, there is a merit that gloss on the recording material is easily generated and fixing at a lower temperature, but toner deterioration due to continuous printing is likely to occur, and development streaks, fog, Offset is likely to occur. A more preferable range of the value of X + Y is 11 or more and less than 16. These X / Y and X + Y both need to satisfy the above conditions. If these conditions are not satisfied, it becomes difficult to suppress toner deterioration while ensuring high gloss.

  The X / Y and X + Y values are adjusted within the above ranges by appropriately adjusting the molecular weight of the resin constituting the toner, the added amount of the rubber component and thermoplastic elastomer, the added amount of the crosslinking agent, and the like. Is possible.

The plastic displacement amount and the elastic displacement amount can be measured with an ultra micro hardness tester manufactured by Elionix Co., Ltd. or a micro compression tester manufactured by Shimadzu Corporation.
In the present invention, the amount of plastic displacement and elastic displacement of the toner was measured using an ultra micro hardness meter ENT1100 manufactured by Elionix Corporation. The working indenter was a 100 μm × 100 μm square flat indenter, and the measurement environment was 27 ° C. and humidity 60%. A maximum load of 4.9 × 10 ⁻⁴ N is applied at a speed of 0.98 × 10 ⁻⁵ N / sec. After reaching the maximum load, leave it at that load for 0.1 sec. The amount displaced at that time is defined as the maximum displacement amount, the load is further unloaded at a speed of 0.98 × 10 ⁻⁵ N / sec through the maximum load, and the displacement amount when the load becomes zero is defined as the plastic displacement amount. did. The elastic displacement was a value obtained by subtracting the plastic displacement from the maximum displacement.

In actual measurement, a toner is applied on a ceramic cell, and minute air is blown so that the toner is dispersed on the cell. The cell is set in the apparatus and measured.
For the measurement, while looking through the microscope attached to the apparatus, a measurement photograph screen (horizontal width: 160 μm, vertical width: 120 μm) with a single toner particle is selected. In order to eliminate the displacement error as much as possible, a toner having a toner particle size of around 7 μm is selected and measured. In the measurement, an arbitrary toner is selected from the measurement photographic screen, and the toner particle size is measured by using a software attached to the microhardness meter ENT1100. With respect to the measurement data, 100 arbitrary particles were selected and measured, and the remaining 80 pieces were used as data except for the maximum and minimum values of the measurement results, and the plastic displacement amount from the average of the 80 pieces, The amount of elastic displacement was determined.

The toner of the present invention has an average circularity of 0.960 to 0.995.
In the toner of the present invention, the average circularity of the toner is preferably in the range of 0.960 to 0.995. If the average circularity of the toner is less than 0.960, fog, toner scattering and image density thinness are inferior. Conversely, if the average circularity of the toner is greater than 0.995, the charging member contamination, poor cleaning, and toner scattering are worsened, which is not preferable. With respect to the average circularity of the toner, 0.970 or more and 0.990 or less is more preferably used for the above-mentioned adverse effects.

  The average circularity of the toner can be adjusted by a toner production method, a toner mechanical or thermal spheroidization treatment, and the like.

In the present invention, the average circularity is measured in a toner-based number equivalent circle diameter-circularity scattergram measured by a flow particle image measuring apparatus. In the present invention, “FPIA-1000 type” is used. Measurement was performed using Toa Medical Electronics.
The average circularity is calculated from the following formula (II), where the circularity (center value) at the dividing point i of the toner particle size distribution is ci and the frequency is fci.

The circularity in the above formula was calculated using the following (Formula III).
(Formula III) Circularity = circumferential length having the same projection area as the particle image / perimeter of the particle projection image Here, “particle projection area” is the area of the binarized toner image, and “particle projection” The “peripheral length of the image” is defined as the length of the contour line obtained by connecting the edge points of the toner image. The circularity is an index indicating the degree of unevenness of the toner, and is 1.00 when the toner is a perfect sphere. The more complicated the surface shape, the smaller the circularity.

The equivalent circle diameter of the toner is calculated from the following (formula IV).
(Formula IV) equivalent circle diameter = (particle projected area / π) ^1/2 × 2

  As a specific method for measuring the average circularity, 10 ml of ion-exchanged water from which impure solids and the like were previously removed was prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, was added as a dispersant therein. Thereafter, 0.02 g of a measurement sample is further added and dispersed uniformly. As a means for dispersion, an ultrasonic disperser “UH-50 type” (manufactured by SMT Co., Ltd.) equipped with a 5Φ titanium alloy chip as a vibrator is subjected to a dispersion treatment for 5 minutes, and a measurement dispersion liquid and To do. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more.

To measure the shape of the toner, the flow type particle image measuring device is used, the concentration of the dispersion is readjusted so that the toner particle concentration at the time of measurement is 3000 to 10,000 / μl, and 1000 or more toner particles are obtained. measure. After measurement, the average circularity of the toner is obtained using data excluding particles of 3 μm or less in order to eliminate the influence of the liberated external additive.

<Full-color image forming method of the present invention (hereinafter also referred to as the method of the present invention)>
The method of the present invention applies an AC voltage obtained by superimposing a DC voltage on an electrostatic latent image formed on an electrostatic latent image carrier to a developer carrier that is spaced apart from the electrostatic latent image carrier. Thus, there is provided an image forming method for developing with a non-magnetic one-component developer on the developer carrying member, wherein at least one toner of the present invention is used.
Further, the method of the present invention is characterized in that the nonmagnetic one-component developer contains a binder resin having a sulfur atom in at least one color developer.

  In the method of the present invention, a jumping development method can be used. The jumping development method is a development region between the developing roller and the drum, and the toner reciprocates between the developing roller and the drum by an AC bias voltage in which a DC bias applied between the developing roller and the drum is superimposed. Thus, the toner selectively moves and adheres to the drum surface in accordance with the latent image pattern, and is visualized. This jumping development method is a development method in which toner is allowed to fly between the developing roller and the drum. Therefore, compared with the contact development method, the toner particle size and chargeability distribution are wide, and the toner chargeability is low under low humidity. Fluctuations after continuous paper feeding under high humidity tend to cause problems such as image blur, toner scattering, fogging, and low density.

The jumping development has a gap (hereinafter referred to as “SD gap”) between the developing roller and the drum at the development position. The SD gap is preferably set to 100 to 500 μm, more preferably 300 μm or less, by a drum abutting roller rotatably supported on the developing roller shaft. If the SD gap is less than 100 μm, the electric field tends to leak from the developer carrying member to the latent image holding member, and it becomes difficult to develop the latent image. On the other hand, if it is 500 μm or more, it is difficult for the toner to fly to the drum, and there is a tendency that the image density is thin, the toner scatters, and the sweeping tends to deteriorate.

  In the method of the present invention, as the developing roller used in the image forming unit, a roller having an appropriate form may be used according to the type of toner used, but for example, a high hardness resin coated on aluminum, The developing roller is preferably formed by coating the surface of a metal roller with a polymer elastic body or by integrally molding a polymer elastic body on a metal core, and among them, the one using a polymer elastic body is a toner. It is preferable to prevent deterioration of the resin, and aluminum coated with a resin is also preferably used because of its excellent quality stability and cost.

  As the polymer elastic body in the developing roller, various polymer compositions having elasticity are used, for example, EPDM (ethylene-propylene-diene terpolymer), urethane, silicone rubber, nitrile butadiene rubber, chloroprene rubber. Resin selected from styrene butadiene rubber, butadiene rubber, etc., and those obtained by dispersing and mixing conductive fine particles such as carbon and titanium oxide as electrical resistance adjusting materials in these resins, and ionic conductive materials such as those mentioned above, such as An electrical resistance adjusting resin using an inorganic ionic conductive material such as sodium perchlorate, calcium perchlorate, or sodium chloride is used.

In addition, the resin-coated aluminum is one in which carbon and graphite are dispersed in a phenol resin to increase the hardness while maintaining the necessary conductivity of the sleeve. It is created by applying about ~ 20 μm. The surface roughness (JIS B0601-1994) of these developing rollers is preferably Rz (μm) = 1 to 8, or Ra (μm) = 0.1 to 1.2. The surface roughness of the developing roller can be adjusted, for example, by putting coarse particles in the resin to be coated or by blasting the aluminum tube.

  An image forming unit used in the method of the present invention includes the developing roller and a blade that directly or indirectly contacts the developing roller and regulates the thickness of the toner layer on the developing roller. The shape of the blade is not particularly limited, but it is preferably a blade that controls the toner coat amount on the developing roller by regulating the toner that is provided in contact with the developing roller and carried on the developing roller. As such a blade, a known blade such as a flexible plate member or a metal plate such as SUS or phosphor bronze is used.

  In the method of the present invention, the drum used in the image forming unit can be either Se-based or amorphous silicon-based. However, an organic photoreceptor is used from the viewpoint of high image quality such as filming and drum scraping and safety. Is preferred.

  As resins forming the organic photoreceptor, various polycarbonate resins, polystyrene resins, polyarylate resins, polyphenylene ether acrylic resins, phenol resins, alkyd resins, diaryl phthalate resins, epoxy resins, vinyl chloride resins, methacrylate ester resins, polyamide resins, A polyphenylene oxide resin, a polysulfone resin, or the like can be used, but a polycarbonate resin or a polyarylate resin is more preferable as the main component of the binder resin used for the drum surface layer. The reason is that the polycarbonate resin and the polyarylate resin are structurally higher in mechanical strength than general resins used for the surface layer of other electrophotographic photosensitive members. In addition, the affinity with the toner and the discharge product is kept low, which is also effective for preventing fusion.

The image forming unit used in the method of the present invention has these configurations. Specifically, the drum and the developing roller are arranged as shown in FIG. 1, and the toner of the present invention is supplied to the developing roller. This means that the drum and the developing roller are detachable or integrated, as long as they are arranged as described above during development.

  The toner and the image forming method of the present invention can be used in various forms as long as the image forming unit (apparatus) satisfies the above requirements, and is developed in a copying machine, a printer, a FAX, or the like. Satisfying the present invention, such as an apparatus, a process cartridge in which a drum and a cleaner, a developing roller, and a toner storage container are integrated, or a developing apparatus in which a process cartridge and a drum unit in which a developing roller and a toner storage container are integrated are separated Any developing device can be used.

An example of an image forming unit used in the toner and image forming method of the present invention is shown in FIG. A charging means for charging the surface of the drum 25 to a constant potential by applying a DC voltage to the roller-like member; and a charging process. The exposure means (not shown) for recording an electrostatic latent image on the drum, and the electrostatic latent image on the drum 25 are DC-directed to the developing roller 24 maintaining a constant distance α (SD gap) from the drum 25. Developing means for developing the toner on the developing roller 24 by applying an alternating voltage (bias) 26 including a voltage. The toner container 21 is filled with a non-magnetic one-component toner T, and the toner is supplied to the developing roller by the toner supply roller 22, is uniformly charged by the blade 23, and is thinly and uniformly coated on the developing roller 24 for development. It is a configuration to be provided. The developing residual toner on the developing roller is peeled off by the toner supply roller 22 so that the toner is newly supplied to the developing roller.

Such an image forming unit can be used for an image forming apparatus having only a single black color, but it may be a non-magnetic toner and can be suitably used for a full-color machine. At this time, the image forming apparatus is a tandem type in which image forming units are arranged in series, a rotary type using only one drum, a type using an intermediate transfer, or the non-magnetic single component in the present invention. Any configuration that can realize jumping development can be used preferably.

  The image forming unit used in the method of the present invention includes a non-contact charging type in which the drum surface is charged in a non-contact manner, such as corona discharge, and a roller-like member or the like is brought into contact with the drum and a voltage is applied thereto. The method of the present invention preferably includes a charging member that contacts and charges the drum surface. According to such a configuration, generation of ozone when the drum surface is charged by discharge can be prevented, and the drum surface can be charged at a lower voltage. And from the viewpoint of preventing deterioration of the drum.

  Examples of such a charging member include a charging roller having a cored bar and a conductive elastic layer formed on the peripheral surface of the cored bar, a conductive sleeve, and a magnetic force generated on the peripheral surface of the conductive sleeve. A known contact charging member such as a magnetic brush charging member having magnetic force generating means such as a magnet roll and conductive magnetic particles carried on a conductive sleeve is used.

  Further, the image forming unit used in the method of the present invention can have various elements such as various means and members in addition to the drum and the developing device described later. For example, the image forming apparatus used in the method of the present invention can be suitably used in a cleaner-less system, but has a cleaning member that is provided in contact with the drum and removes transfer residual toner on the drum. Is also possible. According to such a configuration, the drum surface can be cleaned before one image forming process is completed and the next image forming process is started, and image defects due to charging failure or inhibition of latent image formation are prevented. It is preferable in preventing.

  As such a cleaning member, for example, a known cleaning member such as an elastic blade such as rubber, a rotatable roll-shaped brush member, or a roll member whose surface is formed by an elastic layer is used. The cleaning member is generally provided in an opening portion of a waste toner container that opens toward the drum, and accommodates the removed transfer residual toner in the waste toner container.

The toner supply member of the image forming unit used in the method of the present invention is in contact with the contact portion of the blade with the developing roller surface on the upstream side in the rotation direction of the developing roller and is rotatably supported. As this structure, a foamed skeleton-like sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a core metal is preferable from the viewpoint of supplying toner to the developing roller and stripping off undeveloped toner, Among them, as a material, a rubber member such as silicone rubber, urethane rubber, SBR rubber, or a toner supply roller using a foamed elastic body made by foaming a base material made of plastic such as polypropylene or polyvinyl chloride is preferable. Used. The contact width of the toner supply roller with respect to the developing roller is preferably 1 to 8 mm, and more preferably a relative speed at the contact portion with respect to the developing roller.

  Regarding the container for storing the toner of the image forming unit used in the method of the present invention, even if it is equipped with a stirrer and a toner supply roller, it can be replenished with toner later, A well-known thing can be used.

Next, the relationship between the configuration of the present invention and the problem to be solved will be described in detail.
The present inventor considers “development streaks” in the latter half of the durability as follows. This is a development streak that occurs because the toner deteriorates when a large amount of images are printed literally. Toner deterioration is mainly caused by external additives adhering to the toner surface being embedded in the toner particles. This causes the toner particles to lose chargeability and fluidity, and the toner is fused to the blade. It is thought to be generated by becoming easier.

  With regard to “toner scattering”, toner scattering occurs even in normal contact development, but especially in jumping development, the toner is originally developed by flying toner, and since the AC electric field works during development, toner scattering Is very likely to occur. In addition, since jumping development causes the toner to fly, it is necessary that the toner charge distribution and particle size distribution be uniform, and that the change in environment and the charge amount of the toner at the beginning and end of development must be small. is there.

  With regard to “Image Bose”, this means that the image appears blurry because the toner is not evenly placed on the image. If it is a solid image, the gloss of the image surface is reduced, or if it is a halftone image It is a state where the toner is removed in some places and the background can be seen. As the cause, there are a case where the image on the drum is lost when it is transferred to the recording material, and a case where the toner is scattered after the transfer until the fixing.

  As for “thin density” at low temperature and low humidity, the toner charge amount increases as the image is produced, so even if development is performed with the same charge amount, the amount of toner used for it is reduced. This is a so-called charge-up phenomenon. This becomes significant when the environmental humidity is low.

  The “fogging” at high temperature and high humidity is a fog that deteriorates when the amount of toner that is not sufficiently charged increases due to the low toner charge amount due to humidity at high humidity.

In contrast to these adverse effects, the present invention provides a low molecular weight peroxyester compound represented by the following general formula (I) as an initiator (R1 to R4 are alkyl groups having 1 to 6 carbon atoms and are the same as each other). (Which may be different from or different from each other) and produced by a polymerization method using one or more of them, and a plastic displacement when a load of 4.9 × 10 ^-4 N is applied to one toner particle It was improved by satisfying both of the relational expressions 1.5 ≦ X / Y ≦ 2.5 and 10.0 ≦ X + Y ≦ 20.0, where X is X in the amount / particle size × 100 and Y is the elastic displacement / particle size × 100.

  The reason why the above-described configuration has prevented the harmful effect is not clear, but by using a relatively low molecular weight peroxyester-based initiator, the plasticizing effect and the polarity of the initiator cause the wax and colorant in the toner particles Dispersibility is improved, toner can be produced in a more uniform dispersion state, and if the above initiator is used, the reaction proceeds at a relatively low temperature, so re-aggregation of coloring materials and localization of wax, etc. Therefore, it is considered that a suitable dispersed state is maintained and the charging of the individual toner particles becomes uniform. As the toner, a toner by suspension polymerization is preferably used because the above-described good dispersibility is maintained. In addition, things such as charge control resins are also suitably dispersed and appear to work more effectively than would normally be used to maintain them.

  Further, these uniform dispersion and uniform charging of the toner particles are very effective in preventing image blurring, toner scattering, fogging, and low density in jumping development, and further improvement with toner base particles. Therefore, it is effective because it maintains a uniform charge even with respect to toner charging and changes in charging properties due to environmental fluctuations. However, for the contact development method, since the tolerance range of the toner charge amount fluctuation in the original contact development method is wide, the developer design of the present invention may not exhibit the above-described adverse effect of uniform charging.

In the toner of the present invention, when a load of 4.9 × 10 ⁻⁴ N is applied to one toner particle, X is plastic displacement / particle size × 100, and elastic displacement / particle size × 100 is Y. By satisfying both of the relational expressions of 1.5 ≦ X / Y ≦ 2.5 and 10.0 ≦ X + Y ≦ 20.0, it is possible to suppress durability deterioration while maintaining high gloss. Since this value is greatly affected by the dispersion state inside the toner particles, even if the initiator is changed, the dispersion and plasticizing effect on the inside of the toner may change, and the reaction temperature and reaction conditions may vary. But sometimes this value is out of balance.

  Hereinafter, the present invention will be specifically described with reference to production examples and examples, but this does not limit the present invention in any way. In addition, all the parts in the following mixing | blending are a mass part.

(Production example of polar polymer)
In a pressurizable reaction vessel equipped with a reflux tube, a stirrer, a thermometer, a nitrogen introduction tube, a dropping device and a decompression device, 250 parts by mass of methanol as a solvent, 150 parts by mass of 2-butanone and 100 parts by mass of 2-propanol, As a monomer, 82 parts by mass of styrene, 10 parts by mass of 2-ethylhexyl acrylate, and 8 parts by mass of 2-acrylamido-2-methylpropanesulfonic acid were added and heated to reflux temperature while stirring. A solution obtained by diluting 1 part by mass of t-butylperoxy-2-ethylhexanoate as a polymerization initiator with 20 parts by mass of 2-butanone was added dropwise over 30 minutes, and stirring was continued for 5 hours. Further, t-butylperoxy was further added. A solution prepared by diluting 1 part by mass of 2-ethylhexanoate with 20 parts by mass of 2-butanone was added dropwise over 30 minutes, and the mixture was further stirred for 5 hours to complete the polymerization. Furthermore, 500 parts by mass of deionized water was added while maintaining the temperature, and the mixture was stirred for 2 hours at 80 to 100 revolutions per minute so as not to disturb the interface between the organic layer and the aqueous layer, and then allowed to stand for 30 minutes for separation. Later, the aqueous layer was discarded, and anhydrous sodium sulfate was added to the organic layer for dehydration.

  Next, the polymer obtained after the polymerization solvent was distilled off under reduced pressure was coarsely pulverized to 100 μm or less using a cutter mill (manufactured by Nara Machinery Co., Ltd.) equipped with a 150 mesh screen. The obtained polar polymer had a glass transition point (Tg) of about 75 ° C. The glass transition point can be measured by a known differential scanning calorimeter (DSC). More specifically, it can be measured according to the temperature setting pattern of ASTM (D3418-82) at a temperature rate of 10 ° C./min using a differential scanning calorimeter DSC-7 (manufactured by PerkinElmer).

(Toner A production example)
After adding 450 parts by mass of 0.1M Na ₃ PO ₄ aqueous solution to 400 parts by mass of ion-exchanged water and heating to 50 ° C., 10,000 rpm using a TK type homomixer (manufactured by Special Machine Industries). Was stirred at. To this, 68 parts by mass of 1.0 M CaCl ₂ aqueous solution was added to obtain an aqueous medium containing calcium phosphate.
on the other hand,
80 parts by mass of styrene 19 parts by mass of n-butyl acrylate C.I. I. Pigment Blue 15: 3 5 parts by weight Polar polymer 1 part by weight Saturated polyester 10 parts by weight (acid value 10 mg KOH / g, peak molecular weight (Mp) 11,000 measured by GPC)
Ester wax (DSC main peak = 66 ° C.) 12 parts by mass Aluminum salicylate compound 1 part by mass (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
Divinylbenzene (hereinafter also referred to as DVB) 0.05 part by mass Polystyrene-poly (ethylene / propylene) block copolymer (hereinafter also referred to as SEP) (Septon 2003: manufactured by Kuraray Co., Ltd.)
0.05 parts by mass

The above formulation was heated to 60 ° C., and uniformly dissolved and dispersed at 5000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). Into this, 5.5 parts by mass of a polymerization initiator t-butyl peroxypivalate was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition is charged into the aqueous medium, and stirred at 10000 rpm in a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 60 ° C. (reaction temperature 1) and N ₂ atmosphere. The reactive monomer composition was granulated.
Then, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C. at a temperature rising rate of 40 ° C./Hr after 5 hours, and the reaction was allowed to proceed for 5 hours (reaction temperature 2). After completion of the polymerization reaction, the residual monomer was distilled off under reduced pressure. After cooling, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt.
Thereafter, filtration, washing with ion exchange water, and drying were performed to obtain toner particles a. To 100 parts by mass of the toner particles, 1.5 parts by mass of hydrophobic silica fine powder (R972 manufactured by Aerosil) and 0.1 part by mass of titanium oxide (average primary particle size 0.27 μm, rutile type) were added to a Henschel mixer (Mitsui The toner A of the present invention was obtained by dry mixing for 5 minutes. Table 1 shows the physical properties of the toner.

(Toner P production example)
Styrene-butyl acrylate copolymer (initiator: t-butyl peroxypivalate)
(Weight average molecular weight (Mw): 100,000 Number average molecular weight (Mn): 6000
St / BA: 80/20 Melting point (Tm): 125 ° C.)
100 parts by mass C.I. I. Pigment Blue 15: 3 5 parts by mass Stearyl stearate wax (DSC main peak = 60 ° C.) 10 parts by mass Aluminum salicylate compound 2 parts by mass (Bontron E-88: manufactured by Orient Chemical Co., Ltd.)
Polar polymer 1 part by weight Polystyrene-poly (ethylene / propylene) block copolymer (SEP)
(Septon 2003: manufactured by Kuraray Co., Ltd.) 0.05 parts by mass

  After the above materials were premixed, melt kneading was performed with a twin-screw kneading extruder (manufactured by Toyo Seiki Seisakusho) set at 130 ° C. The kneaded product is cooled, coarsely pulverized, finely pulverized by a pulverizer using a jet stream (Hosokawa Micron), further classified using a DS classifier (Nihon Pneumatic), and finally hybridization. The system (made by Nara Machinery Co., Ltd.) was used to spheroidize for 8 minutes to make a toner base. To 100 parts by mass of the toner base, 1.5 parts by mass of hydrophobic silica fine powder (Aerosil R972) and 0.1 parts by mass of titanium oxide (average primary particle size 0.27 μm, rutile type) were added to a Henschel mixer (Mitsui Toner P was obtained by dry mixing for 5 minutes. Table 1 shows the physical properties of Toner P.

<Example 1>
As an evaluation machine, LBP-2510 (manufactured by Canon Inc.) modified as follows was used. As for the developing device configuration of the evaluation machine, as shown in FIG. 1, the auxiliary charging roller (not shown) mounted on the developing roller 24 was removed from the original cartridge, and 200 g of toner A was charged. In addition, the diameter of the roller on the left and right of the developing roller was changed to a larger one, and the SD gap between the developing roller and the drum was set to 270 μm. Further, a jumping development was performed by applying a DC and AC superimposed voltage to the developing roller. The alternating electric field at that time was a peak-to-peak voltage of 1800 V and a frequency of 3000 Hz. Further, the developing roller is a resin-coated aluminum base tube having a ten-point average surface roughness Rz (μm) = 7.5 and a center line surface roughness Ra (μm) = 0.5 (JIS B0601-1994). used.
The yellow toner at the time of the test evaluation is the colorant C.I. I. Pigment Yellow 17 is used, and magenta toner is the colorant C.I. I. Pigment Red 122, black toner was prepared in the same manner as Cyan Toner A in Toner A Production Example, except that the colorant in the Production Example of Toner A was replaced with Carbon Black (Degussa: Printex L6). evaluated. Thereafter, the toner B and the subsequent toners were similarly changed to produce four colors and subjected to simultaneous evaluation.

Regarding the test environment, 2% in three environments: a high temperature and high humidity environment (30 ° C., 80% RH), a low temperature and low humidity environment (15 ° C., 10% RH), and a normal temperature and normal humidity environment (23 ° C., 60% RH). Images with a print ratio of up to 10,000 are printed out. At that time, solid white, solid black, halftone images and their composite images are output every 1000 sheets, and the image density on the images in a low-temperature and low-humidity environment is reduced. Evaluation of the image boss was performed. Further, development streaks, gloss, and toner scattering were evaluated in a normal temperature and humidity environment, and fog was evaluated in an image in a high temperature and high humidity environment.
The results are shown in Table 2.

The image evaluation was determined as follows.
(1) Image boss A: Very good No occurrence at all B: Good Discomfort is recognized but visually uncomfortable C: Somewhat difficult to see D: Unusable Image is mottled

(2) Development streak A: Very good Not generated at all B: Good Slightly streaky unevenness C: Slightly difficult Visually one or two slight streaks D: Unusable There are dark streaks in the book, or there are many streaks even if they are minor

(3) Toner scattering A: Very good No scattering at all B: Good A little scattering (difficult to see)
C: Somewhat difficult Level immediately confirming that toner is scattered D: Unusable Toner is scattered around the developing cartridge

(4) Whiteness (reflectance Ds (%)) of the white portion of the printout image measured by image fog “REFLECTMETER MODEL TC-6DS” (manufactured by Tokyo Denshoku Co., Ltd.) and whiteness (average reflectance Dr) of the transfer paper The fog density (%) (= Dr (%) − Ds (%)) was calculated from the difference in (%)), and the image fog at the end of the durability evaluation was evaluated. The filter used was amber light for cyan, blue for yellow, and green for magenta and black.
A: Very good Less than 0.5% B: Good 0.5% or more, less than 1.5% C: Somewhat difficult 1.5% or more, less than 3.0% D: There is a problem 3.0% or more

(5) Thin image density Using a normal copying machine plain paper (75 g / m ² ) transfer material, a solid image was output in an image output test, and the density was evaluated by measuring the average of 5 points. . The image density was measured by using a “Macbeth reflection densitometer RD918” (manufactured by Macbeth Co., Ltd.) to measure the relative density with respect to an image of a white background portion having a document density of 0.00.
A: Very good 1.40 or more B: Good 1.30 or more, less than 1.40 C: Somewhat difficult 1.10 or more, less than 1.30 D: Unusable 1. Less than 1.10

(6) Gloss Using a normal copy machine plain paper (75 g / m ² ) transfer material, a solid image was output in an image output test, and the density was evaluated by measuring the average of 5 points. In the present invention, the glossiness indicating the degree of gloss is determined based on the specifications described in JIS Z 8741 (mirror gloss measurement method) and JIS K 7105 (plastic optical property test method). This is a value measured using a gloss meter PG-3D (manufactured by Nippon Denshoku Industries Co., Ltd.) under the condition of a light incident angle of 75 degrees.
A: Very good 40 or more, less than 55 B: Good 25 or more, less than 40 C: Somewhat difficult 10 or less, less than 25 D: Problem Less than 10

  In the present invention, the rank B or higher is set as the allowable range.

<Example 2>
Toner B was prepared in the same manner as in Example 1 except that 0.1 part by weight of divinylbenzene (DVB) was added and no SEP was added, and evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

<Example 3>
Toner C was prepared in the same manner as in Example 1 except that the reaction temperature of reaction temperature 1 was 63 ° C., and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 4>
Toner D was prepared in the same manner as in Example 1 except that SEP was changed to 0.1 part by mass, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 5>
Toner E was prepared in the same manner as in Example 4 except that the reaction temperature of reaction temperature 1 was 63 ° C., and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 6>
Toner F was prepared in the same manner as in Example 1 except that the shape was adjusted by dispersing toner particles a in a gas phase at 200 ° C. with a spray dryer, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 7>
Toner G was prepared in the same manner as in Example 2 except that no binder resin containing sulfur atoms was used, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 8>
Toner H was prepared in the same manner as in Example 2 except that t-hexyl peroxide was used as a polymerization initiator, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Example 9>
Evaluation was performed in the same manner as in Example 1 except that evaluation was performed using four colors of toner G, black toner, and toner A yellow toner, magenta toner, and cyan toner. The results are shown in Table 2.

<Example 10>
The evaluation was performed in the same manner as in Example 1 except that the evaluation was performed using four colors of black toner of toner H, yellow toner of toner G, magenta toner, and cyan toner. The results are shown in Table 2.

<Comparative Example 1>
Toner I was prepared in the same manner as in Example 1 except that t-butylperoxyneodecanate was used as the polymerization initiator and the reaction temperature of reaction temperature 1 was changed to 55 ° C., and evaluated in the same manner as in Example 1. did. The results are shown in Table 2.

<Comparative example 2>
T-Butylperoxy-2-ethylhexanoate is used as a polymerization initiator and the reaction temperature is 1
Toner J was prepared in the same manner as in Example 1 except that the reaction temperature was 81 ° C. and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Comparative Example 3>
Toner K was prepared in the same manner as in Example 1 except that 2,2′-azobis (2,4-dimethylvaleronitrile) was used as the polymerization initiator, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Comparative example 4>
Toner L was prepared in the same manner as in Example 1 except that 1 part by weight of SEP was used.
And evaluated in the same manner. The results are shown in Table 2.

<Comparative Example 5>
Toner M was prepared in the same manner as in Example 1 except that 0.5 parts by mass of divinylbenzene was used, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

<Comparative Example 6>
Toner N was prepared in the same manner as in Example 1 except that SEP and divinylbenzene were not used and the reaction temperature of reaction temperature 1 was 65 ° C., and evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

<Comparative Example 7>
Evaluation was performed in the same manner as in Example 1 except that the toner P was used. The results are shown in Table 2.

1 shows an example of a developing unit used in the present invention.

Explanation of symbols

T: Toner
21: Toner container
22: Toner supply roller
23: Blade
24: Developing roller
25: Drum
26: AC voltage (bias) including DC voltage
α: SD gap

Claims (4)

The electrostatic latent image formed on the electrostatic latent image carrier is developed by applying an alternating voltage on which a DC voltage is superimposed on a developer carrier that is spaced apart from the electrostatic latent image carrier. A non-magnetic one-component developer used in an image forming method for developing with a non-magnetic one-component developer on an agent carrier, the non-magnetic one-component developer comprising at least a binder resin, a colorant, and a release agent Toner particles containing at least inorganic particles, and the toner particles are compounds represented by the following general formula (I) as initiators (R1 to R4 are alkyl groups having 1 to 6 carbon atoms; (It may be the same or different) and is produced by polymerization using one or more of them, and the plasticity when a load of 4.9 × 10 ^-4 N is applied to one toner particle When the displacement / particle size × 100 is X and the elastic displacement / particle size × 100 is Y, the following relationship A non-magnetic one-component developing agent characterized in that meet.

  The nonmagnetic one-component developer according to claim 1, wherein the average circularity of the developer is 0.960 to 0.995. The electrostatic latent image formed on the electrostatic latent image carrier is developed by applying an alternating voltage on which a DC voltage is superimposed on a developer carrier that is spaced apart from the electrostatic latent image carrier. agent an image forming method for developing a non-magnetic one-component developer on the carrier, the nonmagnetic one-component developer, using at least one of the non-magnetic one-component developer according to claim 1 or 2 To be characterized by
A full-color image forming method.   4. The full-color image forming method according to claim 3, wherein the non-magnetic one-component developer contains a binder resin having a sulfur atom in at least one color developer.

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