WO1998025186A1 - Process for producing polymeric toner - Google Patents

Abstract

A process for producing a polymeric toner having a core/shell structure, which comprises: passing a core-forming polymerizable monomer composition comprising at least a core-forming polymerizable monomer and a colorant through a space between a rotor rotating at a high speed and a stator surrounding the rotor and having small openings or comb teeth in an aqueous dispersion medium containing a dispersion stabilizer to thereby form droplets of the composition; polymerizing the droplets to obtain core particles; and then polymerizing in the presence of the core particles a shell-forming polymerizable monomer capable of forming a polymer having a higher glass transition temperature than the polymer constituting the core particles to thereby form shells which are polymer layers with which the core particles are covered; a polymeric toner obtained by the process; a method of image forming using the toner; and an image-forming apparatus containing the toner.

Description

 W

1

 Description Method for producing polymerized toner

Technology field>

 The present invention relates to a method for producing a polymerized toner, and more particularly, to a method for producing a polymerized toner suitable as an electrostatic image developing toner formed by electrophotography, electrostatic recording, or the like. The present invention relates to a production method, a polymerization toner obtained by the production method, an image forming method using the polymerization toner, and an image forming apparatus containing the polymerization toner.

<Background technology>

 In electrophotography and electrostatic recording, as a developer for visualizing an electrostatic charge image (electrostatic latent image), a two-component developer composed of toner and carrier particles is used. There is a one-component developer that consists only of toner and does not use carrier particles. The one-component developer includes a magnetic one-component developer containing magnetic powder and a non-magnetic one-component developer containing no magnetic powder. In non-magnetic one-component developers, a fluidizing agent such as colloidal force is often added independently to enhance the fluidity of the toner. As the toner, generally, colored particles formed by dispersing a colorant such as carbon black or other additives in a binder resin and granulating the toner are used.

Toner production methods are roughly classified into a pulverization method and a polymerization method. In the pulverization method, a synthetic resin, a colorant and, if necessary, other additives are melt-mixed, pulverized, and then classified to obtain particles having a desired particle size, thereby obtaining a toner. . In the polymerization method, various additives such as a coloring agent, a polymerization initiator, and, if necessary, a crosslinking agent and a charge controlling agent are added to the polymerizable monomer. A polymerizable monomer composition in which an additive is uniformly dissolved or dispersed is prepared, and then dispersed in an aqueous dispersion medium containing a dispersion stabilizer using a stirrer to obtain a polymerizable monomer composition. Fine droplet particles are formed and then heated to carry out suspension polymerization to obtain toner having a desired particle size (polymerized toner).

 In any of the developers, an electrostatic latent image is substantially formed by toner. Generally, in an image forming apparatus such as an electrophotographic apparatus and an electrostatic recording apparatus, an image is formed on a uniformly charged photoconductor by forming an electrostatic latent image, and toner is attached to the electrostatic latent image. The toner image is transferred to a transfer material such as transfer paper, and the unfixed toner image is then transferred to the toner image by various methods such as heating, pressing, and solvent vapor. , Fixed on the transfer material. In the fixing process, in many cases, a transfer material on which a toner image has been transferred is passed between a heating roll (fixing roll) and a pressure roll, and the toner is heated and pressed to be fused on the transfer material.

The image formed by an image forming apparatus such as an electrophotographic copying machine is required to have higher definition year by year. Conventionally, toner obtained by a pulverizing method has been the mainstream toner used in an image forming apparatus. According to the pulverization method, colored particles having a wide particle size distribution are easily formed. Therefore, in order to obtain satisfactory developing characteristics, it is necessary to classify the pulverized product to adjust the particle size distribution to a somewhat narrower range. However, the classification itself is complicated and the yield is poor, and the toner yield is greatly reduced. Thus, in recent years, attention has been paid to polymerization toners that can easily control the particle size and do not require complicated production processes such as classification. According to the suspension polymerization method, a polymerized toner having a desired particle size and particle size distribution can be obtained without performing pulverization or classification. However, conventional polymerized toners have been used in recent years to speed up copying, to achieve full color, and to save energy. There was a problem that it was not possible to sufficiently respond to demands such as energy consumption.

 In recent years, in electrophotographic copying machines, printers, and the like, high-speed copying and high-speed printing have been demanded while reducing power consumption. Among the electronic photo systems, the process that consumes energy is the fixing process after transferring the toner from the photoreceptor onto a transfer material such as transfer paper. In the fixing process, a heating roll heated to a temperature of 150 ° C. or higher is generally used to heat and melt the toner and fix the toner on the transfer material. Power is being used. It is required to lower the heating roll temperature from the viewpoint of energy saving. To lower the heating roll temperature, the toner must be able to fix at a lower temperature than before. That is, it is necessary to lower the fixing temperature of the toner itself. Using a toner that can fix at a lower temperature than before can reduce the heating roll temperature, but if the heating roll temperature is not so lowered, the fixing time will be shortened It can handle high-speed copying and high-speed printing.

 In the design of the toner, the glass transition temperature of the binder resin constituting the toner may be reduced to meet the demands of the image forming apparatus such as energy saving and high-speed copying. However, if the toner is made of a binder resin having a low glass transition temperature, the toners may be connected during storage, transportation, or in the toner box of the image forming apparatus. Blocking occurs, making it easy to form aggregates, which is what is called poor storage stability.

2. Description of the Related Art In recent years, it has been demanded that electrophotography be used to make color copying and color printing clear. For example, in full color copying, it is not sufficient to simply melt and soften the toner in the fixing step and fuse it on the transfer material.The toner of each color is uniformly melted and mixed. Mixed color It is necessary to. In particular, there are many cases where a single image is used for a 0 HP (one head project evening) sheet for presentations at various meetings. It is required that a toner image fixed on a sheet has excellent OHP transparency. To satisfy the 0 HP permeability, the toner must be uniformly melted on a 0 HP sheet made of a transparent synthetic resin. For that purpose, it is necessary to design the melt viscosity near the fixing temperature of the toner lower than that of the conventional one. Methods for lowering the melt viscosity of the toner include methods such as lowering the molecular weight of the binder resin and lowering the glass transition temperature compared to conventional binder resins for toner. However, no matter which method is used, the toner is prone to blocking and becomes a poorly preserved toner.

Conventionally, as a method for obtaining a polymerization toner having an excellent fixing property, for example, Japanese Patent Application Laid-Open No. 3-136665 discloses a polymerizable monomer containing a colorant and a charge control agent. A method of suspension polymerization in the presence of a macromonomer has been proposed. A macromonomer is a relatively long linear molecule having a polymerizable functional group at an end of a molecular chain, for example, an unsaturated group such as a carbon-carbon double bond. According to this method, the macromonomer is incorporated as a monomer unit into the molecular chain of the produced polymer, so that a large number of macromonomers due to long linear molecules in the molecular chain are present. Branches occur. The resulting polymer apparently becomes a high molecular weight polymer due to the entanglement of its branches, so-called physical crosslinking, so that the offset resistance of the polymerized toner is improved. On the other hand, physical cross-linking by the macromonomer component differs from chemical cross-linking using a cross-linking monomer such as divinylbenzene, and has a loose cross-linking structure. The bridging structure is easily broken. Therefore, this polymerization toner is used when fixing using a heating roll. Is excellent in fixing property because it is easily melted. However, in the case of this polymerized toner, aggregation of the toner easily occurs during storage, and the storage stability is not satisfactory.

 In this way, the conventional methods for lowering the fixing temperature of toner and improving the uniform melting property improve the fixing property of the obtained toner, but decrease the storage stability. Will occur. As a method to solve this inverse correlation, a toner composed of a binder resin with a low glass transition temperature is coated with a polymer with a high glass transition temperature to prevent A so-called capsule-type toner, which solves the problem of preservation by improving the storage property, has been proposed.

 As a method for producing a capsule-type toner, for example, Japanese Patent Application Laid-Open No. 60-173552 discloses a method of manufacturing a toner by using a jitter mill device on a surface of a spherical core particle having a fine particle diameter. There has been proposed a method of forming a coating layer composed of a colorant or magnetic particles or a conductive agent and a binder resin. As the core particles, a thermoplastic plastic transparent resin such as an acrylate resin or a styrene resin is used. The gazette reports that this method provides a multilayer toner having excellent fluidity and improved functionality. However, in this method, when nuclear particles having a low glass transition temperature are used, the nuclear particles themselves tend to aggregate. In addition, in this method, the thickness of the binder resin to be attached to the core particles tends to be large. Therefore, in this method, it is difficult to obtain a toner having improved fixability and uniform melting property while maintaining storage stability.

Japanese Unexamined Patent Application Publication No. 2-2595967 discloses a cross-linking prepared by suspension polymerization in a solution in which a polymer for forcepsing, a charge controlling agent and a release agent are dissolved in an organic solvent. After the toner particles are added, a poor solvent is added, and the surface of the bridge toner particles is charged with a capsule containing a charge controlling agent and a release agent. A method for producing an electrophotographic toner forming a coalescing coating has been proposed. However, in this method, since the solubility of the encapsulating polymer is reduced by dropping the poor solvent and the polymer is precipitated on the surface of the crosslinked toner particles, it is difficult to obtain spherical particles. According to this method, the capsule wall formed on the surface of the crosslinked toner particles is not uniform in thickness and relatively thick. As a result, the effect of improving the developing property and the fixing property is not sufficient.

 Japanese Patent Application Laid-Open No. 57-45558 discloses that the core particles formed by polymerization are mixed and dispersed in a 1 to 40% by weight aqueous solution of a latex, and then the aqueous solution is dissolved. There has been proposed a method for producing a toner for electrostatic image development, in which an inorganic salt is added and a coating layer of fine particles obtained by emulsion polymerization is formed on the surface of nucleus particles. However, according to this method, the charging characteristics of the toner are largely dependent on the environment due to the effect of a surfactant or an inorganic salt remaining on the fine particles, and the charging is reduced particularly under conditions of high temperature and high humidity. Had the disadvantage of doing so.

Japanese Patent Application Laid-Open No. 61-118578 discloses a suspension particle of a composition containing a vinyl monomer, a polymerization initiator and a colorant to obtain core particles. In the presence of the particles, a vinyl monomer which gives a polymer having hydrophilicity equal to or higher than that of the resin contained in the core particles and having a glass transition temperature higher than the glass transition temperature of the resin There is disclosed a method for producing a polymer in which a body is polymerized to form a shell. In this method, a vinyl monomer for forming a shell is adsorbed and grown on the core particles, so that the vinyl monomer absorbed into the core particles is polymerized to form a clear core. · In many cases, it is difficult to produce a seal structure. Therefore, it is difficult to obtain a toner having sufficiently improved preservation by this method. Also, in this method, in order to clarify the core-shell structure and to improve the storage stability, The shell had to be thicker.

 Japanese Patent Application Laid-Open No. 7-128908 discloses that a monomer composition containing a polymerizable monomer, a colorant, and a releasing agent is directly subjected to suspension polymerization in an aqueous dispersion medium. In the method for producing a polymerized toner obtained in the above, the mold release agent is contained in an amount of 10 to 40 parts by weight based on 100 parts by weight of the polymerizable monomer, and the surface of the toner is released after the polymerization process is completed. A toner production method including a step of removing an agent is disclosed. In this method, in order to remove the release agent on the toner surface, contamination due to the adhesion of the release agent (wax) to the developing sleeve, photosensitive drum, transfer drum, etc., is removed. It can be reduced. With this method, toner preservability, fixing temperature, etc., cannot be sufficiently improved, and the occurrence of capping, a decrease in print density, etc., are likely to occur.

<Disclosure of the Invention>

 An object of the present invention is to have a low fixing temperature and a uniform melting property, excellent storage stability (blocking resistance), a narrow particle size distribution, and an environmental dependence of the charge amount. An object of the present invention is to provide a method for producing a polymerized toner, which is small in size and hard to cause fogging and decrease in print density.

 Another object of the present invention is to provide a method for producing a polymer toner capable of coping with high-speed copying and printing, achieving full color, and saving energy.

 Further, an object of the present invention is to provide a polymer capable of forming a toner image having excellent transparency (0 HP transmittance) when printed on a 0 HP sheet and fixed. An object of the present invention is to provide a toner manufacturing method.

It is another object of the present invention to provide an image forming method using a polymer toner having such excellent characteristics, and an image forming apparatus containing the toner. The present inventors have conducted intensive studies to overcome the problems of the known capsule toner, and as a result, granulated a polymerizable monomer composition for a core by a specific granulation method. The droplets are polymerized to obtain core particles, and a shell capable of forming a polymer having a glass transition temperature higher than the glass transition temperature of the polymer component constituting the core particles in the presence of the core particles. It has been found that the above object can be achieved by a polymerized toner obtained by polymerizing a polymerizable monomer for use, and the present invention has been completed based on this finding.

 Thus, according to the present invention, (1) a core polymerizable monomer containing at least a core polymerizable monomer and a colorant in an aqueous dispersion medium containing a dispersion stabilizer; The body composition is passed through a gap between a rotor that rotates at a high speed and a stator that surrounds the rotor and has small holes or comb teeth, and is granulated. (2) The polymerizable unit for a granulated core is The droplets of the monomer composition are polymerized to obtain core particles. (3) In the presence of the core particles, a glass transition temperature higher than the glass transition temperature of the polymer component constituting the core particles is reduced. A polymer having a core-shell type structure in which a polymer comprising a polymer layer covering a core particle is polymerized by polymerizing a polymerizable monomer for a seal capable of forming a polymer having the same Is provided.

 In the step (1), the polymerizable monomer composition for a core is prepared such that the volume average particle size (dv) is 0.5 to 20 ^ ιη, the volume average particle size (d ν) and the number average particle size. The present invention provides a manufacturing method for forming droplets having a ratio (dV / dp) to (dp) of 1 to 1.5.

 Further, according to the present invention, there is provided a polymerized toner obtained by the above method.

Further, according to the present invention, a toner is attached to the surface of the photoreceptor on which the electrostatic latent image is formed to form a visible image, and then the visible image is transferred to a transfer material. An image forming method comprising the steps of: (a) using the core-shell type polymerized toner as a toner as a toner;

 Further, according to the present invention, a photoreceptor, a unit for charging the surface of the photoreceptor, a unit for forming an electrostatic latent image on the surface of the photoreceptor, a unit for containing toner, and a photoreceptor for supplying the toner In an image forming apparatus including means for developing an electrostatic latent image on the surface to form a toner image, and means for transferring the toner image from the photoreceptor surface to a transfer material, the means for accommodating the toner includes: An image forming apparatus characterized by containing the above-described core-shell type polymerized toner is provided.

<Brief description of drawings>

 FIG. 1 is a diagram showing an example of a granulating apparatus used in the present invention.

 FIG. 2 is a diagram showing an example of another granulating apparatus used in the present invention. FIG. 3 is an enlarged view of a rotor and a stator of the granulating apparatus of FIG. BEST MODE FOR CARRYING OUT THE INVENTION>

 (Outline of granulation process)

 The polymerized toner obtained by the production method of the present invention is a core-shell (capsule-type) colored polymer obtained by polymerizing a polymerizable monomer for sealing in the presence of core particles. Particles.

 In the present invention, a polymerizable monomer composition for a core containing a polymerizable monomer for a core and a colorant is granulated in an aqueous dispersion medium containing a dispersion stabilizer to form fine droplets. Then, the droplets are polymerized to prepare core particles.

The droplets of the polymerizable monomer composition for a core in an aqueous dispersion medium have a volume flatness. The average particle size (dv) is between 0.1 and 20 μm, preferably between 0.5 and 10 μm. If the droplets are too large, the particle size of the polymerized toner will be too large and the resolution of the image will be reduced.

 The ratio (particle size distribution) of the volume average particle diameter (dv) and the Z number average particle diameter (dp) of the droplets of the polymerizable monomer composition for the core is usually from 1 to 3, preferably from 1 to 2. , More preferably from 1 to 1.5. If the particle size distribution of the droplets is wide, the fixing temperature varies, and defects such as fogging and filming occur. The droplet preferably has a particle size distribution in the range of (volume average particle size ± 1 m), preferably at least 50% by volume, more preferably at least 60% by volume. New

 A rotor that rotates at a high speed a polymerizable monomer composition for a core containing at least a polymerizable monomer for a core and a colorant in an aqueous dispersion medium containing a dispersion stabilizer; When granulation is carried out by flowing through the gap between the stator and the stator having small holes or comb teeth, droplets of the polymerizable monomer composition for the core are converted to a volume average particle diameter (dV). Is 0.5 to 20 m, and the ratio (dVZdp) of the volume average particle diameter (dV) to the number average particle diameter (dp) is in the range of 1 to 1.5, quickly and stably. Can be granulated. (Colorant)

Examples of the coloring agent used in the present invention include: carbon black, titanium white, nig mouth thin base, aniline bull, canoleco oil blue, cromuy ero, ultra rama limbo no. , Orient oil red, phthalocyanine blue, malachite green oxalate, etc .; cobalt, nickel, iron sesquioxide, ferric oxide And magnetic particles such as iron oxide manganese, iron oxide zinc, iron oxide nickel, and the like. In addition to these, the following various coloring agents can be used. Examples of colorants for magnetic toners include C.I.Direct Red 1C.I.Direct Red 4C.I. 1 C. I. Basic red 1 C. I. Modern red 30 C. I. Direct blue 1 C. I. Direct blue 1 C. I. I. Acid Bull 1 C. I. Acid Bull 15 C. I. Basic Busole 3 C. I. Basic Bull 5 C. I. Modern Bullet 7 C.I.Direct Green 6 C.I.Basic Green 4 C.I.Basic Green 6. Examples of pigments include, for example, graphite, cadmium yellow, mineral fast yellow—, nepray yellow, nefton yellow S N-Zero Yellow G, Permanent Yellow NCG, Tar-Zin Lake, Red-Eyed Lead, Molybdenum Orange, ° —Mont-Orange Orange GTR Pyrazolone Range, Benzene Orange G, Cadmium Red, One Managed Red 4R, Watching Red Canoe Recipes, Salt Rake, Brilliant Carmine 3B, Mangan Purple, Fast Bayolet B, Methyl Bio Retray, Navy Blue, Black Bull , Alkali Blue Lake, Victorious Lake, Phthalion Anneal, Fast Scooter 1, Ind. Rem. BC, Chrom Green, Chromium Oxide, Vigment Green B, Malakite Green Rake, Finaleello Green G and the like.

Examples of magenta coloring pigments for full color toners include C.I. pigment red 12 3 4 5 6, 7, 8 9 and 10 1 1 1 2 1 3 1 4 1 5 , 16, 17 18, 19, 21 22, 23 30, 31 32, 37 38, 39, 40, 41 48, 49, 50 51 , 5 2 5 3 5 4, 5 5 5 7, 5 8 6 0, 6 3 6 4, 6 8, 8 1, 8 3 8 7 8 8 8 9 9 0 1 1 2 1 1 4, 1 2 2, 1 2 3, 1 6 3, 2 0 2, 2 0 6, 2 7, and

, ヽ ,,

20 9; C.I. Pigment No. 1 19; C.I. Lettlets 1, 2, 10, 13, 13, 15, 23, 29, and 3 5; and the like.

 Examples of magenta dyes include CI Solvent Red 1,

3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83,

84, 100, 109, and 121; C.I.

9; C.I. sonorevent violets 8, 13, 13, 14, 21 and 27; C.I. sparse violet violet 1; and other oil-soluble dyes. . Other magenta dyes include, for example, C.I. basic red 1,2,9,12,13,14,15,17,18,22,2 3, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40; C.I. , 3, 7, 10, 14, 14, 15, 21, 25, 26, 27, and 28; and other basic dyes.

 Examples of cyan color pigments for full color toners include CI Pigment Blue 1, 2, 3, 15, 16, and 17; CI Butt Bull C.I.A.I.D.B.I.45; and a copper phthalocyanine pigment in which 1 to 5 phthaloimidmethyl groups are substituted on a phthalocyanine skeleton.

 Examples of yellow color pigments for full color toners include C.I. pigmentation yellow 1, 2, 3, 4, 5, 6, 7, 10, 10, 11, and 12 , 13, 14, 15, 16, 17, 23, 65, 73, 83, 138, and 180; C.I. , And 20; and the like.

Of these colorants, dyes and pigments are the core polymerizable monomers 100 It is usually used in a proportion of 0.1 to 20 parts by weight, preferably 0.5 to 10 parts by weight, relative to parts by weight. The magnetic particles are generally used in an amount of 1 to 100 parts by weight, preferably 5 to 50 parts by weight, based on 100 parts by weight of the polymerizable monomer for core.

 (Polymerizable monomer for core)

 The polymerizable monomer for a core used in the present invention has a glass transition temperature of 80 ° C or less, preferably 10 to 70 ° C, more preferably 20 to 60 ° C. It can form a polymer. The core polymerizable monomers can be used alone or in combination of two or more. If the polymerizable monomer for the core is capable of forming a glass transition temperature exceeding 80 ° C., the fixing temperature of the polymer toner will increase, the 0 HP permeability will decrease, and copying and copying will fail. It is not suitable for high-speed printing.

 The glass transition temperature (T g) of a polymer is a calculated value (referred to as calculated T g) that is calculated according to the type of monomer used and the proportion used. When one type of monomer is used, the Tg of a homopolymer formed from the monomer is defined as the Tg of the polymer in the present invention. For example, since polystyrene has a Tg of 1 oo ° C, when styrene is used alone as a monomer, the monomer has a Tg of 100 It is said to form a polymer of ° c. When two or more types of monomers are used and the polymer to be produced is a copolymer, the Tg of the copolymer is determined according to the type of the monomer used and the usage ratio. calculate. For example, when 78% by weight of styrene and 22% by weight of n-butyl acrylate are used as monomers, styrene-n-butyl acrylate formed at this monomer ratio is used. Since the Tg of the monocopolymer is 50 ° C, this monomer is said to form a polymer having a Tg of 50 ° C.

In addition, “a core capable of forming a polymer having a glass transition temperature of 80 ° C. or lower” `` Polymerizable monomer for use '' means that when multiple monomers are used, each of the monomers must form a polymer with a Tg of 80 ° C or less. It does not mean When one type of monomer is used, the homopolymer formed from the monomer must have a Tg of 80 ° C or less. However, when two or more types of monomers are used, it is sufficient that the Tg of the copolymer formed from the monomer mixture is 80 ° C or lower, and the monomer alone may be used. Polymers having a Tg of more than 80 ° C may be included. For example, the homopolymer of styrene has a Tg of 100 ° C., but the styrene is converted to a monomer that forms a low Tg polymer (eg, n-butyl acrylate). In the case where a polymer having a Tg of 80 ° C or less can be formed by mixing and using styrene, styrene is used as the polymerizable monomer for the core. It can be used as a kind of

 In the present invention, a vinyl monomer is usually used as the polymerizable monomer for the core. The Tg of the polymer is adjusted to a desired range by using various vinyl monomers alone or in combination of two or more.

Examples of the vinyl monomer used in the present invention include styrene monomers such as styrene, vinylintoluene, and methinorestyrene; and acrylic acid. Methacrylic acid; methyl acrylate, ethyl acrylate, propyl methacrylate, butyl acrylate, 2-ethyl acrylate, Dimethylinoleaminoethyl acrylate, methyl methacrylate, methyl ethyl oleate, methacrylate propylate, butyl methacrylate, butyl methacrylate Norreic acid 2—ethylhexyl oleate, dimethyl oleate dimethylaminoethyl, acrylonitrile, methacrylonitrile, acrylamide, acrylamide, Derivatives of (meta) acrylinoleic acid such as methyl acrylamide; ethylene, Ethylenically unsaturated monoolefins such as propylene and butylene; vinyl halides such as vinyl chloride, vinylidene chloride and vinyl fluoride; vinyl acetate, propylene Vinyl esters such as vinyl acid; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone and methyl isopropenyl ketone; 2-vinyl pyridine; 4-vinyl pyridine And nitrogen-containing vinyl compounds such as N-vinylpyrrolidone. These vinyl monomers may be used alone, or a plurality of monomers may be used in combination.

 Among these, a combination of a styrene monomer and a derivative of (meth) acrylic acid is preferably used as the polymerizable monomer for the core. Preferred examples include styrene and butyl acrylate (ie, n-butyl acrylate), and styrene and 2-ethylethyl acrylate (ie, 2— Ethyl hexyl acrylate).

 (Crosslinkable monomer)

As the polymerizable monomer for the core, it is preferable to use a crosslinkable monomer together with these vinyl monomers from the viewpoint of improving the storage stability of the polymerized toner. Examples of the crosslinkable monomer include aromatic vinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof; ethylene glycol dimethyl acrylate, and ethylene glycol. Diethylenically unsaturated carboxylic acid esters such as recall dimethacrylate; N, N — divinylaniline, divinyl ethers such as divinyl ether; compounds having three or more vinyl groups And the like. These crosslinkable monomers can be used alone or in combination of two or more. In the present invention, the crosslinkable The monomer may be used in an amount of usually 0.01 to 5 parts by weight, preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the core polymerizable monomer. Desirable.

 (Macro Monomer)

 In the present invention, in order to improve the balance between storability and fixability, it is preferable to include a mouth monomer in the polymerizable monomer composition for the core. Macromonomers (also known as macromonomers) are relatively long molecules that have a polymerizable functional group at the end of the molecular chain (for example, an unsaturated group such as a carbon-carbon double bond). It is a linear molecule. Since the macromonomer has a vinyl polymerizable functional group at the terminal of the molecular chain, the number average molecular weight is usually from 1,000 to 300,000. Or a polymer is preferred. When a macromonomer having a small number average molecular weight is used, the surface portion of the polymerized toner becomes soft, and the effect of improving storage stability becomes insufficient. Conversely, when a macromonomer having a large number average molecular weight is used, the melting property of the macromonomer becomes poor and the fixing property is lowered.

 Examples of the vinyl polymerizable functional group at the terminal of the molecular chain of the macromolecule include an acryloyl group and a methacryloyl group. A methacryloyl group is preferred from the viewpoint of stiffness.

It is preferable that the macular monomer used in the present invention has a glass transition temperature higher than the glass transition temperature of the polymer obtained by polymerizing the core polymerizable monomer. The level of T g between the polymer obtained by polymerizing the polymerizable monomer for core and the macromonomer is relative. For example, when the polymerizable monomer for the core forms a polymer having a Tg of 70 ° C, the macromonomer has a Tg of more than 70 ° C. Should be fine. If the core polymerizable monomer forms a polymer having a T g of 20 ° C., the macromonomer is, for example, T g = 6 0. It may be that of C. The T g of a macromonomer is a value measured with a measuring instrument such as a normal DSC.

 Examples of the macromonomer used in the present invention include styrene, styrene derivatives, methacrylate ester, acrylate ester, and acrylonitrile. Polymer obtained by polymerizing trinole, methacrylonitrile, etc., alone or in combination of two or more kinds; a macromonomer having a polysiloxane skeleton; Examples thereof include those disclosed on pages 4 to 7 of JP-A-203374. Of these macromonomers, those obtained by polymerizing hydrophilic ones, especially methacrylates or acrylates, alone or in combination of these. The resulting polymer is suitable for the present invention.

 The amount of the macromonomer used is usually 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, per 100 parts by weight of the polymerizable monomer for the core. And more preferably 0.05 to 1 part by weight. If the amount of the macromonomer used is small, it is difficult to improve the storability and the fixing property in a good balance. As the amount of macromonomer used increases, the fixability tends to decrease.

 (Various additives)

 In the present invention, the core particles are preferably obtained by suspension polymerization of a vinyl monomer, a macromonomer, and a crosslinkable monomer as polymerizable components. Also, a polymerization initiator such as a polymerization initiator and a molecular weight regulator for polymerizing droplets of the core polymerizable monomer composition, and various additives such as a release agent and a pigment dispersant are used as cores. It can be mixed with polymerizable monomers for use.

 (Radical polymerization initiator)

Examples of the radical polymerization initiator include potassium persulfate and ammonium persulfate. Persulfates such as gum; 4,4-azobis (41-cyanovaleric acid), dimethyl-22'-azobis (2—methylpropironate), 22—azobis ( 2 — Amidinopropane) dihydrochloride, 22 2 — Azobis — 2 — Methinole N—1, 1 — Bis (hydroxylmethyl) 1 2 — Hydroxyshetylpro Pioamide, 2 2 '-azobis (24-dimethylbenzoylonitrile), 2 2'-azobisuisobutyronitrile, 1,1 'azobis (1-cyclo) Kisa down mosquitoes Norepo two Application Benefits Honoré) of which § zo compound; main Chiruechiruba one Okishi de, di one t one Puchirupaoki shea de, cetyl ⁰ - O key sheet de, di click Mi Honoré ⁰ - O key sheet de, la c b A Le Paoki shea de, base down along Norepa one O key shea de, t one-butyl ⁰ - O Peroxides such as silicon-2-ethyl ether, diisopropylpropyl carbonate, di-butyl carbonate, etc. Things; etc. can be exemplified. Further, a redox initiator obtained by combining a polymerization initiator and a reducing agent can be exemplified.

 Among these radical polymerization initiators, oil-soluble radical initiators are preferred, and in particular, the 10-hour half-life temperature is 680 ° C., preferably 658 ° C. An oil-soluble radical initiator selected from organic peroxides having a molecular weight of 250 or less is preferred. Among the oil-soluble radical initiators, t-butylbutyloxy-2-ethylhexanoet has low odor during printing of polymerized toner and low environmental destruction due to odors and other volatile components. Are particularly preferred.

 The amount of the polymerization initiator to be used is usually 0.0013% by weight based on the aqueous dispersion medium. If the amount of the polymerization initiator used is less than 0.001% by weight, the polymerization rate is low, and if it exceeds 3% by weight, it is not economical.

 (Molecular weight regulator)

Examples of the molecular weight modifier include t-decyl mercaptan, n Menolenic butanes such as dodecinolemenolecaptan, n-octylmenolecaptan; halogenated hydrocarbons such as carbon tetrachloride and carbon tetrabromide; and the like. These molecular weight regulators can be added before or during the polymerization. The molecular weight modifier is generally used in a proportion of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the core polymerizable monomer. .

 (Release agent)

 Examples of the release agent include polyfunctional ester compounds such as pen-ester erythritol tetra-stearate; low-molecular-weight polyethylene, low-molecular-weight polypropylene, and low-molecular-weight. Low molecular weight polyolefins such as polybutylene; paraffin waxes; and the like. As the release agent used in the present invention, a polyfunctional ester compound is preferable, and a polyfunctional ester compound comprising an alcohol having three or more functional groups and a carboxylic acid is particularly preferable.

 Examples of the trifunctional or higher polyhydric alcohol include aliphatic alcohols such as glycerin, phenol erythritol, pentaglycerol, etc .; Alicyclic alcohols such as sodium, quesole and inositol; aromatic alcohols such as tris (hydroxymethyl) benzene; D —Erylose, L—Arabinose, D—Mannose, D—Galactose, D—Funorectose, L—Ramnose, Sacca Sugars such as rose, maltose, lactose, etc .; sugars such as elitrite, D-traits, Larabit, adonite, xylite, etc. Alcohol; etc. can be mentioned. Of these, pentaerythritol is preferred.

Carboxylic acids include, for example, acetic acid, butyric acid, cabronic acid, phenanoic acid, hydropruric acid, perargonic acid, hydroprurinic acid, undecanoic acid, ゥ, myristic, stearic, margaric, arachidic, cerotic, melicic, eric, brassic Aliphatic carboxylic acids such as acid, sorbic acid, linoleic acid, linolenic acid, behenylic acid, tetratolic acid, xymenic acid; Alicyclics such as hexane carboxylate, hexahydrous sulfonic acid, hexahydroterephthalate, 3,4,5,6-tetrahydro phthalate Carboxylic acid; benzoic acid, toluic acid, cumic acid, phthalic acid, isophthalic acid, terephthalic acid, trimesic acid, trimellitic acid, Aromatic carboxylic acids such as hemi-melitic acid; and the like. Among these, a carboxylic acid having preferably 10 to 30 carbon atoms, more preferably 13 to 25 carbon atoms, is preferable, and a fatty acid having the carbon atom number is preferred. Aromatic carboxylic acids are more preferred. Of the aliphatic carboxylic acids, stearic acid and myristic acid are particularly preferred.

 In the polyfunctional ester compound used as the release agent in the present invention, the plurality of carboxylic acids bonded to the trifunctional or higher functional alcohol may be different or the same. Preferably, the difference between the maximum value and the minimum value of the number of carbon atoms in a plurality of carboxylic acids is 9 or less, preferably 5 or less.

Specific examples of polyfunctional ester compounds include pentaerythritol tetrastearate, pentaerythritol torelate, mirristate, and glycerol.ル Trial arachinic acid, etc. can be mentioned. The polyfunctional ester compound is preferably one that easily dissolves in the polymerizable monomer. Among the polyfunctional ester compounds, particularly, penstrate and pentose erythritol tetrastrate, and pentose erythritol torelate teramistate are preferred. Pentate elimination is particularly preferred. Ordinary resins are ground when mixed with polymerizable monomers. However, among the polyfunctional ester compounds, pentaerythritol tolamide, etc., can easily be added to the polymerizable monomer even at room temperature. Since it dissolves, the preparation of the polymerizable monomer composition is simple, and a polymer toner excellent in various properties can be provided.

 The release agent is used in an amount of usually 0.1 to 40 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the polymerizable monomer. If the amount of the release agent is too small, the effect of improving the low-temperature fixing property is small, and if it is too large, the blocking resistance is reduced.

 (Other additives)

 Lubricants such as oleic acid and stearic acid; and dispersion aids such as silane-based or titanium-based cutting agents for the purpose of uniform dispersion of the colorant in the core particles. May be used. Such a lubricant or dispersant is generally used in a proportion of about 1100 to 1Z1, based on the weight of the colorant.

 (Dispersion stabilizer)

 The polymerization of the droplets of the polymerizable monomer composition for the core is performed in an aqueous medium containing a dispersion stabilizer (also referred to as a dispersant). Specifically, a vinyl monomer, a macromolecule, a crosslinkable monomer, a radical polymerization initiator, a coloring agent, and other additives selected as needed are mixed to form a Paul Miller or the like. A mixed solution (hereinafter, referred to as a raw material liquid) is prepared by dispersing the raw material more uniformly, and then the raw material liquid is poured into an aqueous medium containing a dispersion stabilizer, and a high shear force mixing device is used. After dispersing and granulating into fine droplets, polymerization is usually carried out at a temperature of 30 to 200 ° C.

The dispersion stabilizer preferably used in the present invention contains a hardly water-soluble metal compound. Examples of poorly water-soluble metal compounds include sulfuric acid Sulfates such as lithium and calcium sulfates; carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; phosphates such as calcium phosphate; aluminum oxide And metal oxides such as titanium oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and ferric hydroxide. Of these, dispersants containing colloids of poorly water-soluble metal hydroxides are preferred because they can narrow the particle size distribution of the polymer particles and improve the sharpness of images. is there. Particularly when a crosslinkable monomer is not copolymerized, a dispersion stabilizer containing a colloid of a sparingly water-soluble metal hydroxide is suitable for improving the fixing property and the storage stability of the toner. It is.

 The dispersion stabilizer containing a colloid of a poorly water-soluble metal hydroxide is not limited by its manufacturing method, but can be adjusted by adjusting the pH of an aqueous solution of a water-soluble polyvalent metal compound to 7 or more. Colloids of the resulting poorly water-soluble metal hydroxides, especially colloids of poorly water-soluble metal hydroxides formed by the reaction of a water-soluble polyvalent metal compound with an alkali metal hydroxide in the aqueous phase It is preferable to use a password.

The colloid of the poorly water-soluble metal compound used in the present invention has a particle size distribution D _{5 ()} (cumulative value of 50% of the particle size distribution ₎ of 0.5 // m or less, and D _{9 ()} (90% cumulative value of the number particle size distribution) is preferably 1 m or less. When the particle size of the colloid is large, the stability of polymerization is lost, and the storage stability of the toner is reduced.

The dispersion stabilizer is generally used in a proportion of 0.1 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer for core. If this ratio is too small, it is difficult to obtain sufficient polymerization stability, and a polymer aggregate is easily generated. Conversely, if this ratio is too large, the viscosity in the aqueous dispersion medium increases, and the distribution of the polymerized toner particles is unfavorably widened. In the present invention, if necessary, a dispersion stabilizer containing a water-soluble polymer can be used. Examples of the water-soluble polymer include, for example, polyvinyl alcohol, methyl cellulose, gelatin, and the like. In the present invention, it is not necessary to use a surfactant, but it can be used in order to stably carry out polymerization within a range where the environmental dependence of the charging characteristics does not become large.

 (Granulation of droplets of polymerizable monomer composition for core)

 The polymerizable monomer composition for a core has a fine particle size by flowing through a gap between a high-speed rotating rotor and a stator surrounding the rotor and having small holes or comb teeth. Into droplets. That is, in the present invention, a granulating apparatus including a rotor and a stator is used for granulating the polymerizable monomer composition for a core.

 Examples of the rotor include a stirring blade attached to an ordinary stirrer and a comb-shaped ring as shown in FIG. The rotor rotates at high speed. The rotation speed is usually between 4,000 and 25,000 rpm, preferably between 10,000 and 25,000. The rotation speed is the measured value displayed by the rotation sensor.

 A stator having small holes or comb teeth is used as the stator. The small hole may be a round hole or a slit. Examples of the comb teeth include those having the shape of the stator 102 shown in FIG. The size of the round hole, the width of the slit, or the length (width) in the rotational direction of the comb teeth is usually 0.2 to 10 mm, preferably 0.5 to 5 mm. If the size or width is too wide, it becomes difficult to granulate the liquid particles finely and uniformly, and if it is too narrow, the throughput cannot be increased.

The stator is provided so as to surround the outside of the rotor. The size of the gap between the rotor and the stator is usually 0.1 to 1.3 mm, preferably It is 0.2 to 1.0 mm.

 A specific example of a device having a high-speed rotating rotor and a stator surrounding the rotor and having small holes or comb teeth is CLEAR MIX (c1earmix) manufactured by Aemtechnic Co., Ltd. And Ebara Milda-1 manufactured by EBARA CORPORATION.

 Figure 1 is an explanatory diagram showing the structure of the Ebara Milder. In FIG. 1, the rotor 101 is a ring having comb teeth. This ring rotates at high speed. A stator 102 composed of a ring having comb teeth concentric with the rotor and surrounding the rotor is provided outside the annular rotor 101. The rotor 101 and the stator 102 are combined with a slight gap therebetween due to the difference between the inner and outer diameters.

 The polymerizable monomer composition for the core dispersed in the aqueous dispersion medium containing the dispersion stabilizer enters the inside of the rotor 101 arranged in the casing from the liquid inlet 103, When flowing from the high-speed rotating rotor 101 to the outer stator 102, the rotor and the stator cause shearing force, collision, pressure fluctuation, and cavitating force. Or, it is ejected into the casing from the gap between the rotor and stator comb teeth under the action of the pottery core. By repeating these actions, droplets having a small particle size and a narrow particle size distribution are formed. The dispersion containing the droplets is discharged from the liquid outlet 104.

FIG. 2 and FIG. 3 are diagrams showing the structure of the clear mix. In FIG. 3, the rotor 201 is a stirring blade that can be rotated at a rotation speed of usually 4,500 to 21,500 rpm. Reference numeral 2 denotes an annular member provided with a number of slit-like small holes. The gap between the rotor and the stator is usually between 0.1 and 1.3 mm. Polymerizable monomer group for core dispersed in aqueous dispersion medium containing dispersion stabilizer The product is supplied to the gap between the rotor 201 and the stator 202 from the liquid inlet 204 shown in FIG. The rotor and stator are surrounded by, for example, a pot of about 500 cc (pressurized vacuum attachment; casing) and a temperature sensor. 06, a cooling jacket 207, and a cooling coil 208 are arranged around it. The supplied mixture is subjected to the action of the shear force, the collision property, the pressure fluctuation, the cavity or the potential core by the rotor and the stator, and from the small hole of the stator into the pot. Spouts. By these actions, droplets having a small particle size and a narrow particle size distribution are formed. The dispersion containing the droplets is discharged from the liquid outlet 205. The dispersion discharged from the liquid outlet is supplied into the polymerization tank. The amount of the aqueous dispersion medium containing the polymerizable monomer composition for the core to be passed through these granulators is usually 10 to 300 seconds, preferably 30 to 25 seconds, as indicated by the residence time. 0 seconds, more preferably 50 to 240 seconds.

Therefore, using a granulating device incorporating such a stator and a rotor in a casing, the polymerizable monomer composition for core is contained at the liquid inlet of the granulating device. An aqueous dispersion medium is continuously supplied, and after a certain residence time, discharged from a liquid outlet and charged into a polymerization reaction tank, droplets of a polymerizable monomer composition for a core having a certain particle diameter are obtained. It is possible to rapidly and stably prepare an aqueous dispersion medium in which is dispersed. On the other hand, the aqueous dispersion medium containing the polymerizable monomer composition is supplied to a granulation container equipped with a stirrer having a high shearing force, and the mixture is stirred and granulated. When the method of transfer to the polymerization tank is adopted, there is a time difference between the stirring step in the granulation vessel and the transfer step to the polymerization tank, and the desired particle size and particle size distribution are obtained due to excessive or insufficient stirring. It becomes difficult to stably prepare droplets. According to the method of the present invention, a dispersion containing droplets of the polymerizable monomer composition for a core having a desired particle size and particle size distribution is stably supplied in a short time to the polymerization tank. Thus, in combination with the subsequent step of forming a seal, it is possible to obtain a superposed toner having a core-shell type structure having excellent various properties.

 (Polymer polymerization process)

 In the present invention, in the polymerization step for obtaining the core particles, the polymerization conversion is usually at least 80%, preferably at least 85%, more preferably at least 90%. If the polymerization conversion rate in this step is less than 80%, a large amount of the core polymerizable monomer remains, so even if the sealing polymerizable monomer is added and polymerized, Since the copolymer of the polymerizable monomer for the shell and the polymerizable monomer for the core covers the surface of the core particles, the Tg difference between the core and the shell is small. The storage stability of the resulting polymerized toner is reduced.

 In the polymerized toner of the present invention, the volume average particle size (dv) of the core particles is usually 0.5 to 20 2111, preferably 1 to 10〃111. If the core particles are too large, the resolution of the image will decrease. The ratio (particle size distribution) of the volume average particle size (dv) and the Z number average particle size (dp) of the core particles is usually 1.7 or less, preferably 1.5 or less, more preferably 1.5% or less. 1.4 or less. When the droplets of the polymerizable monomer composition for a core are granulated using the granulating apparatus, the particle size distribution (dv / cip) of the generated core particles is 1.5 or less, and in many cases, 1.4 or less.

 (Seal formation process)

 In the present invention, a polymerizable monomer for a shell is polymerized in the presence of the core particle to form a polymer layer (sill) on the surface of the core particle.

The polymerizable monomer for a seal used in the present invention comprises core particles. It forms a polymer having a glass transition temperature higher than the glass transition temperature of the polymer component. The Tg of the polymer obtained from the polymerizable monomer for core and the Tg of the polymer component constituting the core particles (typically, the Tg of the polymer obtained from the polymerizable monomer for core ) Is relative.

 As the polymerizable monomer for sealing, a monomer that forms a polymer having a glass transition temperature exceeding 80 ° C, such as styrene or methyl methacrylate, is usually used. Use each alone or in combination of two or more. However, when the glass transition temperature of the polymer component of the core particle is much lower than 80 ° C, the polymerizable monomer for sealing forms a polymer at 80 ° C or lower. It may be something. It is necessary to set the glass transition temperature of the polymer composed of the polymerizable monomer for sealing so as to be at least higher than the glass transition temperature of the polymer component of the core particles. is there. The glass transition temperature of the polymer obtained from the polymerizable monomer for sealing is usually from 50 to 120 ° C, preferably from 50 to 120 ° C, in order to improve the storage stability of the polymer. It is between 60 and 110 ° C, more preferably between 80 and 105 ° C. If the glass transition temperature of the polymer composed of the polymerizable monomer for sealing is too low, the glass transition temperature is lower than the glass transition temperature of the polymer component constituting the core particles. Even if it is high, storage stability may decrease. The glass transition temperature of the polymer component of the core particles can be expressed by the calculated T g of the polymer formed from the polymerizable monomer for the core in many cases.

 The difference in glass transition temperature between the polymer composed of the polymerizable monomer for core and the polymer composed of the polymerizable monomer for shell is usually 10 ° C. or more, and is preferably. It is preferably at least 20 ° C, more preferably at least 30 ° C.

When polymerizing in the presence of core particles, the polymerizable monomer for shell In the system dispersion medium, it is preferable to carry out suspension polymerization after forming the droplets having the smaller number average particle diameter of the core particles. When the particle size of the droplets of the polymerizable monomer for the shell increases, the storage stability tends to decrease. In order to make the polymerizable monomer for shell into small droplets, a mixture of the polymerizable monomer for shell and an aqueous dispersion medium is finely dispersed using, for example, an ultrasonic emulsifier. Perform processing. It is preferable to add the aqueous dispersion thus obtained to an aqueous dispersion medium in which core particles are present.

 The polymerizable monomer for shell is not particularly limited by the solubility in water of 20. However, when the polymerizable monomer for shell having a solubility in water at 20 ° C of 0.1% by weight or more is used, Since the monomer having high solubility in water easily migrates to the surface of the core particle quickly, it is easy to obtain a polymerized toner having good storability.

 On the other hand, when a polymerizable monomer for sealing having a solubility in water at 20 ° C. of less than 0.1% by weight is used, the transfer to the core particles is delayed, and the monomer is formed into fine droplets. It is preferable to polymerize by adding to the reaction system. When a polymerizable monomer for a shell having a solubility in water at 20 ° C of less than 0.1% by weight is used, an organic solvent having a solubility in water at 20 ° C of 5% by weight or more is used in the reaction system. When added, the polymerizable monomer for shells is transferred to the core particles quickly, and it becomes easier to obtain a polymerized toner with good storage stability o

Monomers for shells having a solubility in water at 20 ° C of less than 0.1% by weight include styrene, butinorea acrylate, and 2-ethylhexyl acrylate. , Ethylene and propylene. Examples of the sealing monomer having a solubility in water at 20 ° C of 0.1% by weight or more include methyl methacrylate and methyl crelate (meta). Acrylic acid esters; amides such as acrylonitrile and metal acrylate; Vinyl cyanide compounds such as acrylonitrile and methyl chloronitrile; nitrogen-containing vinyl compounds such as 4-vinylpyridin; vinyl acetate, acrolein, etc. Can be

 2 0. Organic solvents that are preferably used when a shell monomer having a solubility in water of less than 0.1% by weight are selected from the group consisting of methanol, ethanol and Isopropyl alcohol, n-propyl alcohol, butyl alcohol, etc. ^; grade alcohol; acetone, methylethyl ketone, etc .; tetrahydrofuran Cyclic ethers such as lan and dioxane; ethenoles such as dimethinolle and tenenoles; aldehydes such as methylethylformaldehyde; and aldehydes such as methylthioformaldehyde.

 The organic solvent is added in such an amount ratio that the solubility of the polymerizable monomer for shell in a dispersion medium (total amount of water and the organic solvent) becomes 0.1% by weight or more. The amount of the organic solvent used depends on the type of the organic solvent and the type and amount of the polymerizable monomer for the shell, but is usually 0.1 to 50 parts by weight based on 100 parts by weight of the aqueous dispersion medium. Parts, preferably 0.1 to 40 parts by weight, more preferably 0.1 to 30 parts by weight. The order in which the organic solvent and the polymerizable monomer for the shell are added to the reaction system is not particularly limited, but the transfer of the polymerizable monomer for the shell to the core particles is promoted, and the polymerization having good storage stability is performed. In order to make it easier to obtain a toner, it is preferable to add an organic solvent to the reaction system first, and then add a polymerizable monomer for shell.

When a monomer having a solubility of less than 0.1% by weight in water at 20 ° C is used in combination with a monomer having a solubility of 0.1% by weight or more, the solubility in water at 20 ° C is firstly determined. 0.1% by weight or more of a monomer is added for polymerization, then an organic solvent is added, and then a monomer having a solubility in water at 20 ° C of less than 0.1% by weight is added. I prefer to do it. This addition method According to this, in order to adjust the fixing temperature of the polymerization toner, the Tg of the polymer obtained from the polymerizable monomer for shell polymerized in the presence of the core particles and the amount of the monomer added were adjusted. It can be controlled appropriately.

 The polymerizable monomer for a seal is preferably used by mixing a charge control agent. The charge control agent is used to improve the chargeability of the polymerization toner. As the charge control agent, various positively or negatively chargeable charge control agents can be used. Specific examples of the charge control agent include Nigrosin N 01 (manufactured by Orient Chemical Company), Niguchi Shin EX (manufactured by Orient Chemical Co.), and Spirobra TRH (manufactured by Hodogaya Chemical Co., Ltd.), T-77 (manufactured by Hodogaya Chemical Co., Ltd.), Bottron S-34 (manufactured by Orient Kagaku), Bottron E--8 4 (manufactured by Orient Chemical Co., Ltd.). The charge control agent is used in an amount of usually from 0.01 to 10 parts by weight, preferably from 0.1 to 5 parts by weight, based on 100 parts by weight of the polymerizable monomer for the shell. Can be

 As a specific method of suspension-polymerizing the polymerizable monomer for shell in the presence of core particles, a polymerization system for shell is used in a reaction system of the polymerization reaction performed to obtain the core particles. A method in which a polymerizable monomer is added to continuously polymerize, or core particles obtained in another reaction system are charged, and a polymerizable monomer for a shell is added thereto, and intermittently added. O Polymerization method can be listed o

 The polymerizable monomer for the shell may be added to the reaction system all at once or continuously or intermittently by using a pump such as a bumper pump. Can be added.

When adding the polymerizable monomer for shell, it is preferable to add a water-soluble radical initiator in order to easily obtain a polymer toner having a core-shell type structure. New When adding the polymerizable monomer for the shell, When the polymer initiator is added, the water-soluble radial initiator enters near the outer surface of the core particles to which the polymerizable monomer for shell has migrated, and the polymer layer ( Is likely to be formed.

 Examples of the water-soluble radical initiator include persulfates such as lithium persulfate and ammonium persulfate; 4,4-azobis (4-cyanovaleric acid); 2,2 — Azobis (2 — amidinopropane) dihydrochloride, 2, 2 — azobis 1 2 — methyl N — 1, 1 — bis (hydroxymethyl) 1 2 Examples thereof include azo-based initiators such as droxyshetyl propioamide; combinations of oil-soluble initiators such as cumoxide and redox catalysts; and the like. The amount of the water-soluble radical initiator used is usually 0.001-1% by weight based on the aqueous medium.

 (Polymerized toner)

 In the polymerization toner of the present invention, the weight ratio of the polymerizable monomer for core to the polymerizable monomer for shell is usually 40 Z 60 to 99. 9 / 0.1, preferably. Is 60 Z 40-99. 5 / 0.5, more preferably 80 / 20-99 Z 1. If the proportion of the polymerizable monomer for the shell is too small, the effect of improving the storage stability is small, and if it is too large, the effect of reducing the fixing temperature and improving the 0 HP permeability is small. You.

 The polymerized toner of the present invention has a volume average particle size of usually l to 20 ^ m, preferably 3 to 15 / m, and a particle size distribution (volume average particle size Z number average particle size). The particle size is usually 1.6 or less, preferably 1.5 or less, and is a spherical particle having a sharp particle size distribution.

 The polymer toner of the present invention is a polymer particle having a core-shell type structure comprising a core particle and a sealant covering the core particle.

In the core-to-shell type polymerized toner of the present invention, the average thickness of the shell is usually from 0.001 to 1.0 / m, preferably from 0.05 to 0.05 / m. ~ 0.5 m. If the thickness of the seal is too large, the fixability is reduced, and if it is too thin, the storage stability is reduced. When the core particle diameter and shell thickness of the polymerized toner can be observed with an electron microscope, the particle size and shell thickness selected at random from the observation photograph are directly measured. It can be obtained by measuring. If it is difficult to observe the core particles and the shell with an electron microscope, at the stage of forming the core particles, measure the particle size of the core particles in the same manner as described above using an electron microscope. Alternatively, the particle size of the polymer particles is measured by an electron microscope or a coater counter after the core particles are coated with the sealant. The average thickness of the shell can be determined from the measured and the change in particle size before and after coating the shell. In addition, when these methods are difficult, the thickness of the shell can be calculated from the particle size of the core particles and the amount of the monomer used to form the shell.

 In the polymerized toner of the present invention, the toluene insoluble content is usually 50% by weight or less, preferably 20% by weight or less, and more preferably 10% by weight or less. . When the content of insolubles in toluene increases, the fixability tends to decrease. The toluene-insoluble matter is defined as the polymer obtained by pressing and solidifying the polymerization toner, placing the polymer in a wire mesh basket of 80 mesh, and heating for 24 hours at room temperature in toluene. After immersion in a basket, the dry weight of the solid matter remaining in the basket was measured and expressed as a percentage by weight relative to the polymer.

The ratio of the major axis r1 to the minor axis rs (r1 / rs) of the polymerized toner of the present invention is usually from 1 to 1.25, preferably from 1 to 1.20, more preferably from 1 to 1.20. It is 1 to 1.15. If this ratio is increased, the resolution of the image is reduced, and the friction between the toners is increased when the toners are stored in the toner storage section of the image forming apparatus. However, durability tends to decrease due to peeling of the external additive. (Developer)

 The polymerized toner of the present invention may be used as it is as a developer, but is usually used as a developer in combination with an external additive such as a fluidizing agent or an abrasive. When the external additive is added to and mixed with the polymerized toner, the external additive adheres to the surface of the polymerized toner. The external additive has a function of increasing the fluidity of the polymerized toner or suppressing the formation of a toner film on a photoreceptor by a polishing action.

 As the external additive, inorganic particles and organic resin particles are typical. Examples of the inorganic particles include silica, aluminum oxide, titanium oxide, zinc oxide, tin oxide, barium titanate, and sodium titanate. And other particles. Organic resin particles include methacrylate polymer particles, acrylate polymer particles, styrene-methacrylate copolymer particles, and styrene-a Core particles in which the core is formed of a styrene polymer and the core is a methacrylate ester polymer and the core is a styrene-type particle. You.

 Among these, inorganic oxide particles are preferable, silica particles are more preferable, and hydrophobically treated silica particles are particularly preferable. In order to attach the external additive to the polymerized toner, usually, the external additive and the polymerized toner are charged into a mixer such as a hen-shell mixer and stirred. The usage amount of the external additive is not particularly limited, but is usually about 0.1 to 6 parts by weight based on 100 parts by weight of the polymerization toner.

When the polymerization toner of the present invention is used, the fixing temperature is usually from 80 to 180 ° C., preferably from 100 to 150 ° C., and more preferably from 100 to 13 ° C. It can be reduced to a temperature as low as 0 ° C, does not aggregate during storage, and has excellent storage properties. (Image forming device)

 An image forming apparatus to which the polymerized toner of the present invention is applied includes: a photoconductor, a unit for charging the surface of the photoconductor, a unit for forming an electrostatic latent image on the surface of the photoconductor, a unit for containing toner (developer), It has means for supplying toner and developing the electrostatic latent image on the surface of the photoreceptor to form a toner image, and means for transferring the toner image from the surface of the photoreceptor to a transfer material. FIG. 4 shows a specific example of such an image forming apparatus.

 As shown in FIG. 4, a photosensitive drum 1 as a photosensitive member is mounted on the image forming apparatus so as to be rotatable in the direction of arrow A. The photosensitive drum 1 has a photoconductive layer provided on the outer peripheral surface of a conductive support drum. The photoconductive layer is composed of, for example, an organic photoreceptor, a selenium photoreceptor, a zinc oxide photoreceptor, and an amorphous silicon photoreceptor.

 Around the photosensitive drum 1, along a circumferential direction thereof, a charging port 2 as a charging unit, a laser-light irradiating device 3 as a latent image forming unit, and a developing unit as a developing unit A roll 4, a transfer roll 10 as a transfer means, and a cleaning device (not shown) are arranged as required.

 The charging roll 2 is for uniformly and uniformly charging the surface of the photosensitive drum 1 positively or negatively. The surface of the photosensitive drum 1 is charged by applying a voltage to the charging roll 2 and bringing the charging roll 2 into contact with the surface of the photosensitive drum 1. The charging roll 2 can be replaced by charging means using corona discharge.

The laser beam irradiator 3 irradiates the surface of the photosensitive drum 1 with light corresponding to the image signal, and irradiates the uniformly charged surface of the photosensitive drum 1 with a predetermined pattern. Forms an electrostatic latent image on the part irradiated with (in the case of reversal development) or an electrostatic latent image on the part not irradiated with light (In the case of regular development). As another latent image forming means, there is a means composed of an LED array and an optical system.

 The developing roll 4 is for attaching toner to the electrostatic latent image of the photosensitive drum 1, and in the case of reversal development, the toner is attached only to the light irradiation portion, and in the case of regular development, the toner is attached. Then, a bias voltage is applied between the developing roll 4 and the photosensitive drum 1 so that the toner adheres only to the non-irradiated portion.

 A developing roll 4 and a supply roll 6 are provided in a casing 9 in which the toner 7 is accommodated. The developing roll 4 is disposed so as to be in close contact with the photosensitive drum 1 so as to be partially in contact therewith, and rotates in the direction B opposite to the photosensitive drum 1. The supply roll 6 comes into contact with the developing roller 4 and rotates in the same direction C as the developing port to supply toner to the outer periphery of the developing port 4. A stirring means (stirring blade) 8 for stirring the toner is installed in the casing 9.

 Around the developing roll 4, between the contact point with the supply roll 6 and the contact point with the photosensitive drum 1, a developing roll blade 5 as a layer thickness regulating means is provided. Is arranged. This blade 5 is made of conductive rubber stainless steel and injects electric charge into the toner, so that the voltage of | 200 V | to | 600 V | Has been applied. Therefore, the electrical resistivity of blade 5 is preferably 10 6 Ω cm or less.

The case 9 of the image forming apparatus accommodates the polymerization toner 7 of the present invention. The polymerization toner 7 may contain an additive such as a fluidizing agent. The polymerized toner of the present invention has a core-shell structure, and the shell of the surface layer is a polymer having a relatively high glass transition temperature. Since it is formed of, the surface has low adhesiveness, and aggregation in the casing 9 during storage is suppressed. Further, since the polymer toner of the present invention has a relatively short particle size distribution, when a toner layer is formed on the developing roll 4, the toner thickness is controlled by the layer thickness regulating means 5. Substantially a single layer can be obtained, thereby improving image reproducibility.

 The transfer roll 10 is for transferring the toner image formed on the surface of the photosensitive drum 1 by the developing roll 4 onto the transfer material 11. Examples of the transfer material 11 include paper and resin sheets such as 0HP sheets. As the transfer means, in addition to the transfer roll 10, a corona discharge device or a transfer belt can be used.

 The toner image transferred onto the transfer material 11 is fixed on the transfer material by fixing means. The fixing means usually comprises a heating means and a pressure bonding means. More specifically, the fixing means is usually composed of a combination of a heating roll (fixing roll) 12 and a pressure roll 13. The transfer material 11 onto which the toner image has been transferred is passed between the heating roll 12 and the pressure roll 13 to melt the toner, and at the same time, is pressed onto the transfer material 11 To fix.

 In the image forming apparatus of the present invention, since the polymerized toner of the present invention is used as the toner, even if the heating temperature by the heating means is low, the toner is easily melted and lightly pressed by the pressure bonding means. Then, the toner becomes smooth and fixed to the surface of the transfer material, enabling high-speed printing or copying. Further, the toner image fixed on the OHP sheet has excellent OHP transparency.

The cleaning device is for cleaning the transfer residual toner remaining on the surface of the photosensitive drum 1, and includes, for example, a cleaning blade. Be composed. This cleaning device does not necessarily need to be installed in the case where a method of performing cleaning at the same time as development by the development roll 4 is employed.

 The image forming apparatus illustrated in FIG. 4 includes, for one photoreceptor, a unit for charging the surface of the photoreceptor, a unit for forming an electrostatic latent image on the surface of the photoreceptor, a unit for containing a superposed toner, It has a means for supplying a polymerization toner and developing an electrostatic latent image on the surface of the photoreceptor to form a toner image, and a means for transferring the toner image from the surface of the photoreceptor to a transfer material. However, in order to form a full-color image, the image forming apparatus of the present invention surrounds one photoreceptor, and the surface of the photoreceptor corresponds to magenta, yellow, blue, and black. At least four means for forming an electrostatic latent image, and at least four means for accommodating the superimposed toner corresponding to magenta, yellow, blue and black, and the polymerized toner Supplying and developing each electrostatic latent image on the photoreceptor surface to form a toner image Includes a least for the even image forming apparatus for Furka La one that Yusuke four.

 (Image forming method)

 In the image forming method using the polymerized toner of the present invention, a step of attaching a toner to the surface of the photoreceptor on which the electrostatic latent image is formed to form a visible image, and then transferring the visible image to a transfer material , The polymerized toner of the present invention is used as a toner.

<Example>

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. Parts and percentages are by weight unless otherwise specified. The methods for measuring physical properties in Examples and Comparative Examples are as follows. (1) Toner particle size

 The volume average particle diameter (dV) and the particle size distribution of the polymer particles, that is, the ratio (dv / dp) between the volume average particle diameter and the number average particle diameter (dp), are determined by using a multi-sizer (manufactured by Kor Yuichi Co., Ltd.). ). The measurement by the multisizer was performed under the conditions of an aperture diameter: 50 m, a medium: Isoton II, a concentration: 10%, and the number of particles to be measured: 50, 000.

 (2) Seal thickness

 If the shell is thick, it can be measured with a multisizer or an electron microscope, but in the case of the thin shell, the calculation was made using the following formula.

^{π (r + x) 3 /} 7r r 3 = l + s / 1 0 0 p (i) r: core particle size prior to the addition of Shiweru polymerizable monomer for (Multisizer one volume diameter: m) Radius of

X: Thickness シ m)

s: the number of parts of the polymerizable monomer for the core added (ratio to 100 parts by weight of the polymerizable monomer for the core)

P: density of shell polymer (g / cm ³⁾

 Transforming equation (i) yields equation (ii).

 (+ r) / r = (1 + s / 100 p) 1/3

 (ii) Substituting p = 1 into equation (ii) gives equation (iii)

 (X + r) / r = (l + s / 1 0 0) 1 '3

 (iii) Equation (iv) is obtained from equation (iii).

x = r (1 + s / l0 0) ^lo -r (iv) The thickness of the shell was calculated using equation (iv).

 (3) Toner volume resistivity

The volume resistivity of the toner is measured using a dielectric loss meter (trade name: TRS-10 And Ando Electric Co., Ltd.) at a temperature of 30 ° C and a frequency of 1 kHz.

 (4) Toner fixing temperature

 Toner image evaluation was performed on a printer that was modified so that the temperature of the fixing roll part of a commercially available non-magnetic one-component developing printer could be changed. The temperature at which the fixing rate was 80% was evaluated as the fixing temperature. The fixing test was performed by changing the temperature of the fixing roll of the printer, measuring the fixing rate at each temperature, and determining the relationship between the constant temperature fixing rates. The fixation rate was calculated from the ratio of the image density before and after the tape peeling operation in the solid black area on the test paper printed with the remodeled printer. That is, assuming that the image density before tape removal is before ID and the image density after tape removal is after ID, the fixing rate can be calculated by the following equation.

 Fixing rate (%) = (after ID and before ID) X I 0 0

 The tape peeling operation is to apply an adhesive tape (Scout Mending Tape 810-3-18) manufactured by Sumitomo SLIM Co., Ltd. to the measurement area of the test paper, and extrude it at a constant pressure to adhere it. Then, a series of operations to peel off the adhesive tape in the direction along the paper at a constant speed. The image density was measured using a reflection image densitometer manufactured by McBeth, Inc.

 (5) Toner preservation

To evaluate the shelf life, place the toner sample in a closed container, seal it, submerge it in a thermostatic water bath whose temperature is controlled at 55 ° C, remove it after a certain period of time, and aggregate it. This was done by weighing the toner. The sample removed from the container was transferred onto a 42-mesh sieve so as not to destroy the structure as much as possible, and the sample was measured using RE 0 STAT of a powder measuring machine (manufactured by Hosokawa Mikuguchi). After setting the vibration intensity to 4.5 and vibrating for 30 seconds, the weight of the toner remaining on the sieve was measured, and the weight of the aggregated toner was measured. And the amount. The aggregation rate (% by weight) of the toner was calculated from the weight of the aggregated toner and the weight of the sample. The storage stability of the toner was evaluated on the following four levels.

 ◎: aggregation rate is less than 5% by weight,

〇: The aggregation rate is 5% by weight or more and less than 10% by weight,

Δ: The aggregation rate is 10% by weight or more and less than 50% by weight,

X: The aggregation rate is 50% by weight or more.

 (6) 0 H P permeability

 The temperature of the fixing roll of the modified printer was set to 170 ° C, and printing was performed using a commercially available 0 HP (Transparency Lance 1) sheet by Uchida Yoko Co., Ltd. Was evaluated for 0 HP permeability. The printed 0 HP sheet was placed on an O HP apparatus, and the appearance of the color was visually observed and evaluated according to the following criteria.

〇: Good permeability,

Δ: insufficient permeability,

X: Impervious.

 (7) Toner charge amount

 The electrification in each environment of L / L (temperature 10 and humidity 20%) and HZH (temperature 35 ° C and humidity 80%) was measured, and the state of the environmental fluctuation was evaluated.

 In each of the above environments, put the toner in a commercial printer (four-sheet machine), leave it for one day and night, print five halftone print patterns, and then use the toner on the developer port. Was sucked into a suction-type charge amount measuring device, and the charge amount per unit weight was measured from the charge amount and the suction amount.

 (8) Evaluation of image quality

Continuous printing is performed from the initial stage using the printer described above. The number of continuous prints that can maintain an image quality of 1.3 or more with a densitometer (manufactured by Macbeth) and less than 10% with a whiteness meter (manufactured by Nippon Denshoku Co.) evaluated.

 〇: The number of continuous prints that can maintain the above image quality is 10,000 or more,

Δ: The number of continuous prints that can maintain the above image quality is 5,000 or more and less than 10,000, and the continuous print number that can maintain the above image quality is less than 5,000.

[Example 1]

 Core monomer consisting of 78 parts of styrene and n-butyl acrylate 22 (calculated copolymer T g = 50 ° C) 7 parts (degussa, trade name: PRINTEX 150 T), 1 part of antistatic agent (Hodogaya Chemical Co., Ltd., trade name: Spiro black black TRH), 1 part, divinylbenzene 0. 3 parts, Polymethacrylic acid ester macromonomer (Toa Gosei Chemical Industry Co., Ltd., AA6, Tg = 94 ° C) 0.5 part, and pentaerythritol 10 parts of tetrastearate were dispersed with a ball mill at room temperature to obtain a uniform mixed solution (raw material solution).

On the other hand, 10 parts of methyl methacrylate (calculated T g = 105 ° C), 100 parts of water, and a charge control agent (Bontron E-84 manufactured by Orient Chemical Co., Ltd.) ) 0.01 part was finely dispersed by an ultrasonic emulsifier to obtain an aqueous dispersion of a polymerizable monomer for a shell. The particle size of the polymerizable monomer droplets for the seal was determined by adding the resulting droplets to a 1% aqueous solution of sodium phosphate phosphate at a concentration of 3%, and adding The volume particle diameter D _{9 ()} was 1 as determined by a particle size distribution analyzer.

On the other hand, in an aqueous solution in which 9.8 parts of magnesium chloride (water-soluble polyvalent metal salt) is dissolved in 250 parts of ion-exchanged water, and 50 parts of ion-exchanged water is added with sodium hydroxide (alkaline). Metal hydroxide) 6. Dissolve 9 parts of aqueous solution The dispersion was gradually added under stirring to prepare a dispersion of magnesium hydroxide colloid (a poorly water-soluble metal hydroxide colloid). The particle size distribution of the generated colloid was measured with a microtrack particle size distribution analyzer (manufactured by Nikkiso Co., Ltd.), and the particle size was D ₍₎ (50% cumulative value of the number particle size distribution _). ) Was 0.38 ^ m, and D _{9 ()} (90% cumulative value of the number particle size distribution) was 0.82 / m. In the measurement using this microtrack particle size distribution analyzer, the measurement range = 0.12 to 704 m, the measurement time = 30 seconds, and the medium ion-exchange water conditions. went.

 The raw material liquid is added to the magnesium hydroxide colloid dispersion obtained above, and the mixture is stirred and mixed using a propeller-type stirrer. Further, while stirring and mixing, t-butyl vinyl oxide is added. —4 parts of ethyl hexanoate was added to obtain a mixture of the polymerizable monomer composition for the core. Next, a 500 cc pressurized vacuum attachment, a rotor (rotor R-2), and a stator (screen S-1.0-224) are attached ( The gap between the rotor and the stator is 0.2 mm), and a granulator (CLEARMIX CLM-0.8S: Emtech) operating at a rotor speed of 21,100 rpm The mixture was supplied at a flow rate of 30 kg Zhr using a pump to granulate droplets of the monomer composition for core. The residence time was 60 seconds. The volume average particle diameter of droplets is about 5.0 m, the volume average particle diameter The ratio of Z number average particle diameter is about 1.18, and the number of droplets in the range of volume average particle diameter ± 1 m is about 70 m % By volume.

The aqueous dispersion of the granulated core polymerizable monomer composition was placed in a reactor equipped with a stirring blade, and the polymerization reaction was started at 90 ° C., and the polymerization conversion reached 98%. Occasionally, 1 part was sampled, and the rest was added with the above-mentioned polymerizable monomer for shell and 1 part of a 1% aqueous solution of potassium persulfate, and the reaction was continued for 3 hours. · Polymer particles with a shell structure Was obtained.

 The sampled core particles had a volume average particle size of 6.3 m, a volume average particle size (dV) and a Z number average particle size (dp) of 1.18. The volume average particle diameter of the core-shell type polymer particles is 6.9 m, and the volume average particle diameter (dV) / number average particle diameter (dp) is 1.20, 1 to 1/3. Was 1.1 and the toluene-insoluble content was 3%.

 While the aqueous dispersion of the polymer particles having the core-shell structure obtained above was stirred, the pH of the system was adjusted to 4 or less with sulfuric acid, followed by acid washing (25 ° C, 10 minutes). After water was separated by filtration, 500 parts of ion-exchanged water was added, and the slurry was re-slurried and washed with water. After that, dehydration and washing with water were repeated several times again, and the solid content was separated by filtration, followed by drying in a drier at 45 ° C for two days and nights to obtain polymer particles (polymerized toner). To 100 parts of the polymerized toner obtained as described above, 0.3 part of a hydrophobized colloid darica (trade name: R—202, manufactured by Nippon Aerosil Co., Ltd.) was added. To prepare a developer (hereinafter simply referred to as toner). When the volume resistivity of the toner thus obtained was measured, it was 11.4 (1 ogΩ ocm).

 Table 1 shows the evaluation results of the polymerized toner obtained as described above. In other image evaluations, an image having a high image density, no fog, no unevenness, and an extremely good resolution was obtained.

 [Example 2]

A polymerized toner was obtained in the same manner as in Example 1 except that the number of rotations of the rotor was changed to 15 and OOO rpm. The results are shown in Table 1. In the image evaluation, an image having a high image density, no fog, no unevenness, and an extremely good resolution was obtained. [Example 3]

 Polymerized toner was obtained in the same manner as in Example 1 except that the supply flow rate of the mixed solution was changed to 20 kg / hr. The results are shown in Table 1.

 [Comparative Example 1]

 In the same manner as in Example 1, except that granulation was performed with a TK homomixer operating at a rotational speed of 1200 rpm instead of granulating with clear mix in Example 1, As a result, a polymerized toner was obtained. The results are shown in Table 1. In the granulation using this TK homomixer, the volume average particle size of the droplets was 7.1 m, and the volume average particle size Z number average particle size was 1.52. table 1

 Example Example Comparative Example

1 2 3 1 Core particle

 dv [μm] 6.3 6.6 6.2 7.5 dv / dp 1.18 1.17 1.19 1.42 Polymer particles

 Chenore thickness [, ιη] 0.31 0.33 0.31 0.37 Insoluble in toluene [ο] 3 4 3 3 Toner evaluation

 dv [〃 m] 6.9 7.3 6.8 8.2 dv / dp 1.20 1.18 1.20 1.45 Volume resistivity [log Ω cm] 11.4 11.4 11.3 11.0 Fixing temperature rc] 120 130 120 140 Storage ◎ ◎ ◎ Δ L 'charge amount [C / g] -27 -25-28 -23

H / H charge amount [C / g] -24 -21-24 -16 Image evaluation 〇 〇 〇 X As is evident from the results in Table 1, the polymerization temperature obtained by the production method of the present invention (Examples 1 to 3) was set to a fixing temperature of 120 to 130 ° C. It is possible to reduce it, and it is also excellent in preservability. In addition, the dependence of the charge amount on the environment is small, and it is difficult to cause fogging and decrease in print density. On the other hand, the polymerized toner obtained in Comparative Example 1 does not have a sufficient balance between the effect of lowering the fixing temperature and the storage stability, has a large environmental dependence of the charge amount, and has a low image evaluation. It is.

 [Example 4]

 In Example 1, instead of granulating with clear mix, a rotor having comb teeth and a stator having comb teeth similar to the rotor having comb teeth were used. A polymerized toner was obtained in the same manner as in Example 1 except that granulation was performed using a working ebaramyelda. In addition,. The residence time in the granulation step was 70 seconds. The results are shown in Table 2.

 [Example 5]

 A polymerization toner was prepared in the same manner as in Example 1 except that the butyl acrylate used in the core polymerizable monomer composition was changed to 2-ethylhexyl acrylate. Obtained. The results are shown in Table 2.

 [Comparative Example 2]

 To 7 parts of ion exchange water, add 7—Amino Probuilt Remedies, Inc. 0.188 parts, and add aerogel # 200 (Nippon Ae After adding 8 parts, the mixture was heated to 70 ° C and dispersed at 3,000 rpm for 15 minutes using a TK homomixer. Further, 0.1 N hydrochloric acid was added to obtain an aqueous dispersion medium.

85 parts of styrene, 15 parts of butyl acrylate, 1 part of cyclized rubber (Albex CK450: manufactured by Hexstar), 1 part of j-tert-butylamyl aluminum butylate 1.5 parts, copper phthalocyanine Part, paraffin wax (T550: manufactured by Taisei Kosan Co., Ltd.) 16 Heat the part at 70 ° C in a container, disperse it for 5 minutes with a TK homomixer, and further disperse. While maintaining 70 ° C., 5 parts of initiator V601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved to prepare a polymerizable monomer composition.

 The polymerizable monomer composition is added to the dispersion medium, and the mixture is dispersed with a TK homomixer at 70 ° C., and a granulation apparatus (Ebara Milder) operating at a rotation speed of 5,000 rpm is used. —: Ebara Corporation) with a pump at 180 kg / hr to granulate the dispersion, polymerize it at 70 ° C, polymerize, wash and dry to obtain polymerized toner. Using this polymerized toner, a developer (toner) was obtained in the same manner as in Example 1. The results are shown in Table 2.

 [Comparative Example 3]

A polymerized toner was obtained in the same manner as in Example 1 except that the shell monomer was not added. The results are shown in Table 2.

Table 2

表 2 の結果から明らかなよう に、 本発明の製造方法によ り得られ た重合 卜ナ一 （実施例 4 〜 5 ) は、 定着温度を 1 2 0 〜 1 3 0 °Cに 低減するこ とが可能で、 しかも保存性に優れており、 さ らには、 帯 電量の環境依存性が小さ く 、 かぶりの発生、 印字濃度の低下などが 生じに く い。 これに対して、 比較例 2で得られた重合 ト ナーは、 定 着温度の低減効果と保存性とのバラ ン スが充分ではな く 、 帯電量の 環境依存性が大き く 、 画像評価も低いも のであ る。 比較例 3 で得ら れた重合 トナーは、 定着温度が低いものの、 シヱルがないため、 保 存性が劣悪なものであり、 画像評価も低かった。 [実施例 6 ]

As is evident from the results in Table 2, in the polymerized toner obtained by the production method of the present invention (Examples 4 to 5), the fixing temperature was reduced to 120 to 130 ° C. In addition, the storage capacity is excellent and the storage capacity is less dependent on the environment, and the occurrence of fogging and lowering of the print density are unlikely to occur. On the other hand, the polymerization toner obtained in Comparative Example 2 does not have a sufficient balance between the effect of lowering the fixing temperature and the storage stability, has a large environmental dependence of the charge amount, and has a poor image evaluation. It is low. The polymerized toner obtained in Comparative Example 3 had a low fixing temperature, but had no seal, and therefore had poor storage stability and low image evaluation. [Example 6]

 Example 1 was repeated in the same manner as in Example 1 except that instead of 7 parts of black rubber, 5 parts of a magenta pigment (a pigment 122) were used. Got a ner. The results are shown in Table 3.

 [Example 7]

 Example 1 was repeated in the same manner as in Example 1 except that 5 parts of yellow quinophthalone pigment (Vigment Yellow 1338) was used in place of 7 parts of black pigment. Polymerized toner was obtained. Table 3 shows the results.

 [Example 8]

Example 1 was repeated in the same manner as in Example 1 except that 5 parts of cyan paint (Vigment Blue 15: 3) were used instead of 7 parts of carbon black. A polymer toner was obtained. The results are shown in Table 3.

Example

 6 7 8

 Core particles

 dv [μ.m] 6.4 6.6 6.4

 dv 1 dp 1.18 1.19 1.18

 Polymer particles

 Chenore thickness ί ΐίΐ 0.32 0.33 0.32

 Toluene insoluble content [%] 5 4 3

 Tona-Evaluation

 dv [^ mj 7.0 7.3 7.0

 dv / dp 1.20 1.20 1.19

 Volume resistivity [log Ω cm] 11.8 11.9 11.6

 Fixing temperature [° C] 120 130 120

 Storage stability ◎ ◎ ◎

 L / L charge amount [C / g] -31 -32 -26

 H / H charge [C / g] -28 -29 -24

 OHP permeability 〇 〇 〇

 Image evaluation 〇 〇 〇

As is evident from the results in Table 3, the polymerization toners obtained by the production method of the present invention (Examples 6 to 8) can reduce the fixing temperature to 120 to 130. It is possible and has excellent storage properties. In addition, the amount of charge is less dependent on the environment, and is less likely to cause fogging and decrease in print density.

<Industrial applicability>

According to the present invention, it has a low fixing temperature, a uniform melting property, and Provided is a method for producing a polymerized toner having excellent properties. Use of the polymerized toner according to the production method of the present invention enables high-speed copying and printing, full colorization, and energy saving. Further, the polymerized toner of the present invention shows excellent transparency when printed on an HP sheet and fixed. The polymerized toner of the present invention can form a high-quality image without fogging or a decrease in print density. According to the present invention, there is provided an image forming method using a polymerized toner having such excellent characteristics, and an image forming apparatus containing the polymerized toner.

Claims

The scope of the claims 1. (1) A high-speed rotation of a polymerizable monomer composition for core containing at least a polymerizable monomer for core and a colorant in an aqueous dispersion medium containing a dispersion stabilizer. (2) granulating by passing through a gap between a stator and a stator surrounding the rotor and having small holes or comb teeth; (2) Dropping the granulated polymerizable monomer composition for a core; Polymerizing to obtain core particles, and then (3) forming a polymer having a glass transition temperature higher than the glass transition temperature of the polymer component constituting the core particles in the presence of the core particles. A method for producing a core-to-core type polymerized toner in which a polymerizable monomer for a shell is polymerized to form a seal comprising a polymer layer covering core particles. 2. In the step (1), the polymerizable monomer composition for a core is prepared such that the volume average particle size (dV) is 0.5 to 20 m, the volume average particle size (dv) and the number average particle size 2. The production method according to claim 1, wherein the droplets are formed into droplets having a ratio (dV / dp) to (dp) of (1 to 1.5). 3. In the step (1), a rotor, a stator surrounding the rotor and having small holes or comb teeth, and a granulating device built in the casing are used to form a liquid at a liquid inlet of the granulating device. A rotor that continuously supplies an aqueous dispersion medium containing the polymerizable monomer composition for the core and rotates the polymerizable monomer composition for the core at a high speed in the casing; 2.The method according to claim 1, wherein the mixture is passed through a gap with a stator having small holes or comb teeth and granulated, and after a certain residence time, discharged from a liquid outlet and charged into a polymerization reaction tank. . 4. The production method according to claim 1, wherein the dispersion stabilizer is a colloid of a poorly water-soluble metal hydroxide. 5. The colloid of the poorly water-soluble metal hydroxide has a 50% cumulative value of its number average particle size distribution (D is less than 0.5 μm and 90% of its number particle size distribution). 5. The method according to claim 4, wherein the cumulative value (D9 ₍₎ ) is 1 ^ m or less. 6. The method according to claim 4, wherein the colloid of the poorly water-soluble metal hydroxide is obtained by adjusting the pH of the aqueous solution of the water-soluble polyvalent metal compound to 7 or more. 7. The production method according to claim 1, wherein the polymerizable monomer for a core contains a styrene monomer and a derivative of (meth) acrylic acid. 8. The method according to claim 1, wherein the core polymerizable monomer is a combination of styrene and n-butyl acrylate or 2-ethylhexyl acrylate. 9. The production method according to claim 1, wherein in step (1), the polymerizable monomer composition for a core further contains a macromonomer. 10. The method according to claim 9, wherein the macromonomer is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the polymerizable monomer for the core. 11. The production method according to claim 1, wherein in step (1), the polymerizable monomer composition for a core further contains a crosslinkable monomer. 12. The production method according to claim 9, wherein the macromonomer has an acryloyl group or a methacryloyl group at a molecular chain terminal. 1 3. The production method according to claim 1, wherein in step (1), the polymerizable monomer composition for a core further contains a release agent. 14. The method according to claim 13, wherein the release agent is a polyfunctional ester compound. 1 5. In step (2), the granulated droplets of the polymerizable monomer composition for a core are suspended at a temperature of 30 to 200 ° C. in the presence of an oil-soluble radical initiator. The production method according to claim 1, wherein the core particles are formed by turbid polymerization. 1 6. In step (2), the volume average particle diameter (dV) is 0.5 to 20 2m, and the ratio (dV) between the volume average particle diameter (dV) and the number average particle diameter (dp) is 2. The production method according to claim 1, wherein core particles having a ratio of (dp) of 1.5 or less are formed. 17. The production method according to claim 1, wherein, in the step (3), the polymerizable monomer for sealing is formed into droplets having a number average particle diameter smaller than that of the core particles, and the suspension polymerization is performed. 1 8. In step (3), the solubility in water at 20 ° C is 0.1 2. The method according to claim 1, wherein the polymerizable monomer for shell is used in an amount of at least% by weight. 1 9. In step (3), a polymerizable monomer for a shell having a solubility in water at 20 ° C of less than 0.1% by weight and a polymerizable monomer having a solubility in water at 20 ° C of 5% by weight or more. The production method according to claim 1, wherein suspension polymerization is performed by adding an organic solvent. 20. The production method according to claim 1, wherein in step (3), a polymerizable monomer for shell and a charge controlling agent are added to carry out suspension polymerization. 21. The method according to claim 1, wherein in step (3), the polymerizable monomer for sealing is subjected to suspension polymerization in the presence of a water-soluble radical initiator. 22. The production method according to claim 1, wherein in step (3), a shell comprising a polymer layer having an average film thickness of 0.001-1. 2 3. In a water-based dispersion medium containing a dispersion stabilizer, a polymerizable monomer composition for a core containing at least a polymerizable monomer for a core and a colorant is prepared by volume average particle diameter (dV ) Is 0.5 to 20 m, and the ratio of the volume average particle diameter (dV) to the number average particle diameter (dp) (dVZdp) force, granulates into droplets of '1 to 1.5 The granules of the granulated polymerizable monomer composition for a core are polymerized to obtain core particles, and then, in the presence of the core particles, a glass of a polymer component constituting the core particles is formed. A core polymer which polymerizes a polymerizable monomer for a shell capable of forming a polymer having a glass transition temperature higher than the transition temperature to form a seal comprising a polymer layer covering the core particles. Pell type structure Production method of polymerization. 24. A core-type polymerized toner obtained by the production method according to any one of the above items. 25. A method for forming a visible image by attaching toner to the surface of the photoreceptor on which the electrostatic latent image is formed, and then transferring the visible image to a transfer material, the method comprising the steps of: 25. An image forming method, comprising using the polymerized toner having a core-shell type structure according to claim 24. 26. Photoreceptor, means for charging the surface of the photoreceptor, means for forming an electrostatic latent image on the surface of the photoreceptor, means for containing toner, supply of the toner to develop the electrostatic latent image on the surface of the photoreceptor 25. The core shell according to claim 24, wherein in the image forming apparatus including means for forming a toner image by means of a toner, and means for transferring the toner image from the surface of the photoreceptor to a transfer material, the means for accommodating toner is provided. An image forming apparatus characterized in that it accommodates a polymer type polymer toner.