JPH04291359A - Production of toner - Google Patents

Abstract

PURPOSE:To easily produce the toner forming images which are sharp regardless of a relatively small content of coloring agents and have good transparency particularly when the coloring agents exclusive of black are used for the coloring agents with a fewer production stages by forming resin film layers by using the coloring agents and resin fine particles on the surfaces of internal nucleus particles and further to allow the production of the toner by uniformly and easily controlling the resin film layers regardless of the compsn. and structure of the internal nucleus particles so that the toner having multilayered structures can be produced at a low cost. CONSTITUTION:Resin fine particles 6 contg. the coloring agents are produced by using raw materials consisting of a resin 2 and the coloring agents 3, etc. The internal nucleus particles 5 are then produced by using raw materials consisting of a binder resin 1, etc. The internal nucleus particles 5 are then subjected to an external addition treatment 7 to stick the resin fine particles 6 contg. the coloring agents, etc., to the surfaces thereof, by which the internal nucleus particles 8 externally added with the resin fine particles are produced. The internal nucleus particles 8 externally added with the resin fine particles are subjected to a film forming treatment 9 by bringing a solvent 4 dissolving the resin fine particles into contact therewith to form the resin film layers 10 by which the toner 11 formed with the resin films contg. the coloring agents is finally produced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a dry developing toner used in electrophotography, and more particularly to a method for producing a toner having a multilayer structure.

0002

2. Description of the Related Art Many conventional electrophotographic methods have been proposed based on the Carlson process shown in US Pat. No. 2,297,691. Generally, an electrostatic latent image is formed on a photoreceptor using a photoconductive substance, and then a fine powder called "toner" is selectively attached to the electrostatic latent image and development is performed. The image is visualized, transferred to a transfer material such as paper as necessary, and then fixed by heat and pressure, solvent vapor, etc. to obtain an image-formed product.

[0003] Development methods can be broadly classified into dry development methods and liquid development methods. Further, as dry development methods, two-component development methods using a carrier such as a magnetic brush development method and a cascade development method are known. Further, as one-component development methods, there are known jumping development methods, FEED development methods, magnetic brush development methods, and the like. The toners used in these development methods are further classified into insulating and conductive toners. Generally, the toner used in these development methods is made by dispersing colorants such as dyes and pigments and charge control agents in resin, and having various substances adhered to the surface of fine particles of approximately 10 μm. has been done.

[0004] Generally known methods for producing toner include a kneading and pulverizing method, a spray drying method, and a polymerization method. In addition, various methods for attaching various substances to the toner surface include methods such as applying heat using a fluidized drying oven, applying mechanical force using a mixer such as a ball mill, and polymerization methods. There are known methods to do this. Specifically, a color toner in which binder resin powder is electrostatically adhered to the surface of inner core particles containing a colorant and a charge control agent, and the binder resin powder is then thermally melted to cover the surface (Japanese Patent Application Laid-Open No. 1-227163). , a toner in which fine thermoplastic resin particles and a charge control agent are externally added to the surface of an inner core particle containing a colorant and magnetic powder by dry mixing, and then the surface is coated by fusing (Japanese Patent Laid-Open No. 63
-25663), a toner in which wax particles containing a colorant or magnetic powder are encapsulated by interfacial polymerization (JP-A-1-167850), a vinyl polymer and a colorant are dry mixed into the core particles obtained by a polymerization method. Toner (Japanese Unexamined Patent Application Publication No. 1983-1989) in which a vinyl polymer was added externally by dry mixing.
10263) etc.

[0005]

[Problems to be Solved by the Invention] However, as a prior art toner and toner manufacturing method,
The toner shown in No. 0263 has the disadvantage that the external additive easily peels off, resulting in poor image quality of the image formed and staining the inside of the image forming apparatus. Also, JP-A-1-
The toner manufacturing method shown in No. 167850 has the disadvantage that there are limitations on the raw materials used for interfacial polymerization. Also, JP-A-1-227163 and JP-A-63-256
The toner shown in No. 63 and other conventional toners contain a coloring agent in the inner core particles, but the colorant is hidden by the binder resin etc. and the color does not come out clearly. The quantity must be increased. In this case, light is blocked by the colorant, so when a colorant other than black is used, the transparency required as a color toner characteristic is poor, and the image becomes unclear. Furthermore, if the amount of colorant is large, when used as a two-component developing toner, the colorant is likely to elute onto the magnetic carrier surface during continuous image formation, so-called bleed-out, which may cause deterioration of toner properties and defects during transfer. It has the following drawbacks.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and to provide a clear and transparent image with a small amount of colorant, toner properties that do not deteriorate during toner transportation or storage, and to prevent the inside of the device from being damaged. Toner that has the property of not staining
This provides an easy manufacturing method with fewer steps.

[0007]

[Means for Solving the Problems] The toner manufacturing method of the present invention provides a toner that is used in a dry development method and has a resin coating layer formed on the surface of core particles made of at least a binder resin using at least a colorant and fine resin particles. in which fine resin particles containing at least a coloring agent are attached to the surface of the inner core particle;
Next, by treating with a solvent that dissolves the resin fine particles, a resin coating layer containing at least a coloring agent is formed.

[0008]

[Operation] In the toner manufacturing method of the present invention, adhesion of mixed particles such as fine resin particles to the surface of the inner core particles is carried out in a dry or wet manner. The principle of this method is that in the dry method, mutual collision motion is repeated between each particle, and the energy given at the time of collision forms a local active region, and the inner core particles are This involves attaching mixed particles such as fine resin particles to the surface. In the wet method, the adhesive is attached using electrical adsorption, chemical adsorption, physical adsorption, or the like. When the adhesion is carried out using the above method, mixed particles such as fine resin particles are uniformly dispersed on the surface of the inner core particles, and the particles are attached to the inner core particles without any local bias. At this time, raw materials,
By appropriately selecting conditions, methods, etc., it is possible to control the amount of resin particles, etc. attached to the surface of the inner core particles. Next, by dissolving the resin fine particles with a solvent, a resin coating layer containing various fine particles is formed on the surface of the inner core particle. Therefore, the adhesion and uniformity of the resin coating layer to the inner core particles are improved, and furthermore, additives such as colorants are fixed and prevented from peeling off. At this time, by controlling the dissolution time of the resin fine particles by selecting the type of solvent and the contact time between the particles and the solvent, it is possible to prevent the solvent from penetrating into the inner core particles. Therefore, even if, for example, the inner core particles have a lower softening point and are softer than the fine resin particles, a resin coating layer can be reliably formed, and aggregation and granulation phenomena of toner particles can be suppressed.

Further, in the toner obtained by the toner manufacturing method of the present invention, a resin coating layer is formed using at least a colorant and resin fine particles on the surface of the inner core particles made of at least a binder resin. That is, since the colorant is present near the surface of the toner, the colorant is also present near the surface of the image when an image is formed. Therefore, since the colorant is hardly hidden by the binder resin or the like, a clear image is formed despite the small amount of colorant. Furthermore, in a color toner using something other than black as a colorant, the less the colorant, the less the transmitted light will be blocked, so an image with good transparency, which is an important characteristic of color toners, can be obtained.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1(a) is a flowchart of the toner manufacturing method of the present invention, and FIG. 1(b) is a schematic diagram of the toner of the present invention. In the toner production method, colorant-containing resin fine particles 6 are produced by a kneading and pulverization method, a spray drying method, a polymerization method, etc. using raw materials consisting of a resin 2, a colorant 3, and the like. Next, the inner core particles 5 are produced by a kneading and pulverization method, a spray drying method, a polymerization method, etc. using raw materials including the binder resin 1 and the like. Next, an external addition process 7 is performed in which colorant-containing fine resin particles 6 and the like are attached to the surface of the inner core particles 5, thereby producing inner core particles 8 treated with external addition of resin fine particles. Next, a coating treatment 9 is performed by bringing the resin fine particle externally added inner core particles 8 into contact with a solvent 4 that dissolves the resin fine particles, thereby forming a resin coating layer 10 on the surface of the inner core particles 5, and finally coloring the inner core particles 8. agent-containing resin-coated toner 11
The purpose is to manufacture.

The inner core particles 5 used in the present invention are composed of at least a binder resin 1, and toner components can be added thereto as required. As the toner component, one or more types can be selected from inorganic agents, charge control agents, magnetic powders, conductive agents, mold release agents, dispersants, etc., as required. Further, if necessary, these can be mixed together with the resin 2 and the colorant 3 and put into the colorant-containing resin fine particles 6, and then put into the resin coating layer 10. Methods for producing the inner core particles 5 include commonly used kneading and pulverization methods, spray drying methods, polymerization methods, and the like. The shape may be either spherical or irregular, and the particle size is generally 1 to 40 μm.

Methods for producing the colorant-containing resin particles 6 using the resin 2 and the colorant 3 include commonly used kneading and pulverization methods, spray drying methods, emulsion polymerization methods, emulsion polymerization methods without adding emulsifiers, These include polymerization methods such as seed polymerization, dispersion polymerization, and suspension polymerization. The shape may be either spherical or irregular, and the particle size is generally 1 μm or less.

[0013] As a method for attaching the colorant-containing resin fine particles 6 to the surface of the inner core particles 5, either a dry method or a wet method can be used. As a dry type, a conventional mixer such as a ball mill or a V-type mixer can be used, but it is preferable to use a so-called high-speed fluidized mixer. As the high-speed fluidized stirrer, a so-called Henschel mixer, Mechano Fusion System (Hosokawa Micron), Nara Hybridization System (Nara Kikai Seisakusho), Mechano Mill (Okada Seiko), etc. are used. However, the apparatus for attaching the colorant-containing resin fine particles 6 to the surface of the inner core particles 5 is not limited to these. The wet method includes a heteroaggregation method that utilizes electrostatic adhesion due to the zeta potential difference between the surface of the inner core particles 5 and the surface of the colorant-containing resin particles 6, etc., and the inner core is placed in a solvent that does not dissolve the inner core particles 5 and the colorant-containing resin particles 6. A wet milling method in which a mixed dispersion in which particles 5 and colorant-containing resin fine particles 6 are dispersed is milled using a ball mill, sand mill, etc. Inner core particles 5 are treated with a coupling agent and then colorant-containing resin fine particles 6 are formed. A coupling agent method or the like in which the external addition treatment 7 is performed after mixing can be used. In detail, the solvent used at this time is hexane, heptane,
Petroleum-based solvents such as Isopar and kerosene, water, and the like are used. Furthermore, anionic, cationic, nonionic surfactants, etc. may be added to improve dispersibility.

The method described above can be used.

Methods for carrying out the coating treatment 9 with the solvent 4 include a spray drying method and a liquid immersion method, but any method may be used as long as the contact time can be controlled. Preferably, a powder coating device such as Dispercoat (Nissin Seifun) or Coatmizer (Freund Sangyo) is used.

The raw material for the binder resin 1 is not particularly limited, and commonly used materials can be used. In detail, polystyrene and its copolymers include hydrogenated styrene resin, ABS resin, ASA resin,
AS resin, AAS resin, ACS resin, AES resin, styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene crosslinked polymer, styrene-butadiene-chlorinated paraffin copolymer, styrene-allyl Alcohol copolymers, styrene-butadiene rubber emulsions, styrene-maleic acid ester copolymers, styrene-isobutylene copolymers, styrene-maleic anhydride copolymers, etc., acrylate resins or methacrylate resins, and their copolymers. In addition, styrene-acrylic resins and their copolymers include styrene-acrylic copolymers, styrene-diethylaminoethyl methacrylate copolymers, styrene-butadiene-acrylic acid ester copolymers, and styrene-methyl methacrylate copolymers. Coalescence, styrene-n-butyl methacrylate copolymer, styrene-methyl methacrylate-n-butyl acrylate copolymer, styrene-methyl methacrylate-butyl arylate-N-(ethoxymethyl)acrylamide copolymer, styrene-glycidyl Methacrylate copolymer, styrene-butadiene-
Dimethylaminoethyl methacrylate copolymer, styrene-acrylic acid ester-maleic ester copolymer, styrene-methyl methacrylate-acrylic acid-2
- ethylhexyl copolymer, styrene-n-butyl arylate-ethyl glycol methacrylate copolymer,
Styrene-n-butyl methacrylate-acrylic acid copolymer, styrene-n-butyl methacrylate-maleic anhydride copolymer, styrene-butyl acrylate-
Isobutyl maleic acid half ester-divinylbenzene copolymer, etc., polyester and its copolymers, polyethylene and its copolymers, epoxy resins, silicone resins, polypropylene and its copolymers, fluororesins, polyamide resins, polyvinyl alcohol resins , polyurethane resin, polyvinyl butyral resin, etc., and if necessary, one type or a mixture of two or more types of these can be used. Moreover, wax etc. can also be used as a substance other than resin. For more information, please see plant-based natural waxes such as candelilla wax, carnauba wax, and rice wax, animal-based natural waxes such as beeswax and lanolin, mineral-based natural waxes such as montan wax and ozokerite, and natural natural waxes such as paraffin wax, microcrystalline wax, and petrolatum. Petroleum waxes, polyethylene waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch waxes, modified waxes such as montan wax derivatives and paraffin wax derivatives, hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives, waxes such as synthetic waxes, and stearin. acids, higher fatty acids such as palmitic acid, polyolefins such as low molecular weight polyethylene, polyethylene oxide, and polypropylene, olefin copolymers such as ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, and ethylene-vinyl acetate copolymers. There are polymers, etc., and one type or two or more types of these can be used as necessary.

[0017] In detail, the colorant 3 includes carbon black, spirit black, copper oxide, manganese dioxide, aniline black, activated carbon, nigrosine, yellow lead, zinc yellow,
Cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, banzer yellow G, banzer yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, tartrazine lake, permanent yellow NCG , red yellow lead, molybdenum orange, pyrazolone orange, permanent orange GTR, Vulcan orange, industhrene brilliant orange RK, industhrene brilliant orange GK, benzidine orange G, red iron, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R , Lysol Red, Pyrazolone Red, Lake Red D, Brilliant Carmine 6B, Brilliant Carmine 3B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Manganese Purple, Fast Violet B
, Methyl Violet Lake, Cobalt Blue, Alkali Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Fast Sky Blue, Industhrene Blue BC, Pigment Green B, Malachite Green Lake, Final Yellow Green G, Zinc White, Titanium Oxide, Zinc Sulfide , phthalocyanine, rhodamine B lake, Solar Pure Yellow 8G, quinacridone, polytungstophosphoric acid, methylene blue, rose bengal, sulfonamide derivative, C.I. I. Direct black 19,
22, 28, 154, 168, C. I. Direct Yellow 12, 26, 86, 87, 130, 142, C. I
．． Direct Red 9, 13, 17, 23, C. I. Direct Blue 78, 86, 199, C. I. Assid Black 52, 172, 208, C. I. Ashido Yellow 23, 25, C. I. Ashido Red 52, 254
, 289, C. I. Ashido Blue 9, 254, C. I
．． Food Black 2, C. I. Solvent yellow 2,
6, 14, 15, 16, 19, 21, 33, 56, 61
, 80, C. I. Solvent Orange 1, 2, 5, 6,
14, 37, 40, 44, 45, C. I. Solvent red 1, 3, 8, 23, 24, 25, 27, 30, 49
, 81, 82, 83, 84, 100, 109, 121,
C. I. Disperse Red 9, C. I. Solvent Violet 8, 13, 14, 21, 27, C. I. Disperse Violet 1, C. I. Solvent Blue 2
, 11, 12, 25, 35, 36, 55, 73, C. I
．． Solvent Green 3, C. I. Solvent Brown 3, 5, 20, 37, C. I. Solvent black 3,
5, 22, 23, etc., and these can be used singly or in a mixture of two or more, if necessary.

Further, as a dispersing agent, metal soap, polyethylene glycol, etc. are added, and as a charge control agent, an electron-accepting organic complex, chlorinated polyester, nitrofnic acid, quaternary ammonium salt, pyridinyl salt, etc. are added as necessary. can do.

In addition, magnetic powders such as Fe3O4, Fe2O3, Fe, Cr, Ni, etc. can be used as the magnetic toner.

[0020] As the inorganic fine particles, Si02, TiO
2 (rutile, anatase), Zn0, Al2O3 (α type, β type), TiON, TiBaO3, MgO, ZrO2
, CaCO3, NiO, SnO, clay, talc, silica sand, mica, SiN, SiC, Ba2SO4, carbon black, and other fine particles can be used.

As the resin 2, polymethyl methacrylate (PMMA), polyethyl methacrylate (PE
MA), poly-n-butyl methacrylate (PBMA)
), polyester, styrene-butadiene copolymer, polyvinyl chloride (PVC), polyvinyl alcohol (PV
A), polyvinyl acetate (PVAc), poly-γ-methylglutamate, fluororesin, vinylidene fluoride resin, benzoquanamine resin, silicone resin, epoxy resin,
Nylon 66/6, nylon 11, nylon 12, polystyrene resin, crosslinked polystyrene resin, phenol resin, melamine resin, polyolefin resin, polyethylene resin, cellulose resin, etc. can be used.

The solvent 4 used when coating the surface of the inner core particle 5 with a coating 9 is not particularly limited as long as it dissolves the colorant-containing resin fine particles 6 attached to the surface of the inner core particle 5 by the method described above. In detail, n-hexane, heptane, cyclohexane, benzene, toluene, xylene,
dichloromethane, chloroform, tetrachloromethane,
Dichloroethane, chlorobenzene, nitromethane, acetonitrile, acrylonitrile, tetrahydrofuran,
Dioxane, methyl cellosolve, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methanol, ethanol, propanol, benzyl alcohol, pyridine, diethyl formamide, dimethyl formamide, etc., and these can be used singly or in combination as needed. It can be used as

By using the raw materials described above and forming the resin coating layer 10 containing the colorant 3 by the method described above, there is no need for operations such as classification after treatment, and the storage stability is excellent. 3 is located near the surface of the toner, it is possible to produce a colorant-containing resin-coated toner 11 with a clear image and good transparency despite the small amount of colorant.

This embodiment will be explained in more detail below. The numbers in the following Examples and Comparative Examples indicate parts by weight unless otherwise specified.

[Example 1] <Preparation of inner core particles> A styrene-isobutylene copolymer was used as the binder resin. This was melt-kneaded using a screw extruder, cooled, and then coarsely ground. Next, it is finely pulverized with a jet pulverizer and classified to have an average particle size of 10 μm and a particle size distribution of 5.
Inner core particles of ~15 μm were produced. <Preparation of colorant-containing resin fine particles> Resin...PBMA/95.0 Colorant...Benzidine Yellow G/5.0 Solvent...
Xylene/1,000.0 After the above composition was stirred and mixed, it was spray-dried using a spray drying method at a drying temperature of 60°C to obtain an average particle size of 0.
Particles of 5 μm were obtained. When the obtained particles were observed with an electron microscope, it was found that benzidine yellow G was present in the PBMA fine particles.
It was confirmed that the particles were uniformly dispersed.

<Attachment of colorant-containing resin particles to inner core particles> Colorant-containing resin particles...15.0 Inner core particles...85.0 A mixture of the above composition was subjected to a Mechanofusion System (manufactured by Hosokawa Micron). The colorant-containing PBMA microparticles were attached to the surface of the inner core particles using the following method. Attachment speed is 1500 rpm
The treatment was carried out under the following conditions: m, treatment time 30 minutes. When the obtained particles were observed using an electron microscope, it was confirmed that the colorant-containing PBMA fine particles adhered to the surface of the inner core particles without peeling off. In addition, when cross-sectional observation was performed using an electron microscope, it was found that PB containing a colorant was present on the surface of the inner core particle.
It was confirmed that the MA fine particles remained embedded in a spherical shape.

<Coating treatment> The outer core particles of the resin fine particles prepared by the above method were subjected to a coating treatment. Xylene was used as the solvent. The xylene dispersion air stream and the particle dispersion air stream were brought into contact for 1.0 seconds, and then spray-dried at a drying temperature of 60°C to evaporate the xylene. The particles obtained by this coating treatment had no binding between particles, and each particle was an aggregate in an independent state. Furthermore, when the cross section of the particles produced in this example was observed using an electron microscope, a resin coating layer with a thickness of 0.2 to 0.3 μm was formed on the surface of the inner core particle, and benzidine yellow G was uniformly distributed in the resin coating layer. It was confirmed that they were dispersed. When the toner produced by the above method was loaded into a laser printer equipped with a one-component non-contact developing machine and an OPC photoreceptor, and an image was formed using paper as the toner transfer material, a clear image was formed. was completed. Furthermore, when a similar test was conducted using an OHP transparent sheet as a toner transfer material, clear images with good transparency were formed. Furthermore, when we conducted a durability test of 30,000 sheets, we were able to obtain clear images just like the initial one. In addition, the toner produced in this example was sealed in a container and stored for three months in an environment with a temperature of 30°C and a humidity of 80%, and then a similar test was conducted, but there was no aggregation, and a clear image similar to the initial image was obtained. I was able to do that.

[Comparative Example 1] <Preparation of colorant-containing inner core particles> Binder resin...Styrene-isobutylene copolymer/98
．． 0 Colorant: Benzidine Yellow G/2.0 The above composition was treated in the same manner as in Example 1 to obtain particles. When the obtained particles were observed under an electron microscope, it was observed that benzidine yellow G was uniformly dispersed in the binder resin.

<Attachment of Resin Fine Particles> PBMA fine particles containing no colorant were used as the resin fine particles externally added to the surface of the colorant-containing inner core particles.

[0030] Resin fine particles...PBMA (average particle size 0.4 μm)/1
5.0 Colorant-containing inner core particles...85.0 A mixture having the above composition was deposited in the same manner as in Example 1. The obtained particles were in the same state as in Example 1.

<Coating Treatment> The outer core particles of the resin fine particles prepared by the above method were subjected to a coating treatment. The treatment method was the same as in Example 1. When the obtained particles were observed with an electron microscope, a film thickness of 0.2 μm was observed on the surface of the inner core particle.
It was confirmed that the resin coating layer was formed uniformly.

When the toner produced by the above method was loaded into the laser printer used in Example 1 and an image was formed using paper as a toner transfer material, there was no aggregation of the toner, but the amount of colorant was Even though the amount was larger than that in Example 1, a pale and unclear image was formed. Furthermore, when a similar test was conducted using an OHP transparent sheet as a toner transfer material, the transparency was poor, and a blurred image with pale colors was formed. [Example 2] <Preparation of inner core particles> Using montan wax as a binder resin, the mixture was kneaded in a batch type kneader, cooled, and coarsely pulverized, then finely pulverized in a jet pulverizer, classified, and averaged. Particle size 1
Inner core particles with a diameter of 0 μm and a particle size distribution of 5 to 25 μm were prepared.

<Preparation of colorant-containing resin particles> Example 1
The same composition and method were used. However, C.I. I
．． Solvent Red 100 was used. The average particle size of the obtained particles was 0.3 μm. Furthermore, when the obtained particles were observed using an electron microscope, they were found to be in the same state as in Example 1.

<Attachment of colorant-containing resin fine particles to inner core particles> Inner core particles...85.0 Colorant-containing PBMA fine particles...15.0 Solvent...Water/1,000.0 The above composition After stirring and mixing using a ball mill at room temperature for 10 hours and adhering by a heteroaggregation method, particles were obtained by drying by a spray drying method at a drying temperature of 70°C. The obtained particles were in the same state as in Example 1.

<Film forming treatment> Xylene was used as a solvent. The conditions for coating and spray drying were the same as in Example 1. As in Example 1, the obtained particles had no binding between the particles and were an aggregate of independent particles. Furthermore, when the obtained particles were cross-sectionally observed using an electron microscope, a resin coating layer with a thickness of 0.2 to 0.3 μm was formed on the surface of the inner core particle, and C. I. It was confirmed that Solvent Red 100 was uniformly dispersed.

When the toner produced by the above method was loaded into the laser printer used in Example 1 and an image was formed using paper as the toner transfer material, a clear image was formed at a low fixing temperature of 120°C. I was able to do that. Furthermore, when a similar test was conducted using an OHP transparent sheet as a toner transfer material, clear images with good transparency were formed at a fixing temperature of 120°C. Furthermore, when we conducted a durability test of 30,000 sheets, we were able to obtain clear images just like the initial one. Furthermore, the toner produced in this example was sealed in a container and stored for three months in an environment with a temperature of 30°C and a humidity of 80%, and a similar test was conducted, but there was no aggregation, and the image was as clear as the initial one. I was able to get it.

[Example 3] <Preparation of inner core particles> Binder resin 1...Beeswax/50.0 Binder resin 2...Rice wax/50.0 Using the above compositions, Example 1 and Inner core particles were obtained in a similar manner. The inner core particles after classification have an average particle size of 9 μm and a particle size distribution of 5 to 20
It was μm.

<Preparation of colorant-containing resin particles> Monomer 1
... Styrene / 80.0 Monomer 2 ... Methyl methacrylate / 20.0 Polymerization initiator ... Benzoyl peroxide 50% xylene solution / 5
．． 0 Colorant: Alkali Blue Lake/10.0 Dispersant/
...Nonionic surfactant/50.0 Dispersion medium...Water/
1,000.0 Using a homomixer, the above composition was reacted for 24 hours while stirring and mixing at a temperature of 80° C. and a stirring speed of 20,000 rpm. After cooling, xylene and residual monomers were removed, followed by washing with water, and the resulting cloudy liquid was spray-dried using a spray drying method to obtain colorant-containing resin fine particles with an average particle size of 0.2 μm. . When the obtained colorant-containing resin particles were observed under an electron microscope, it was confirmed that alkali blue lake was uniformly dispersed in the resin particles.

<Attachment of colorant-containing resin particles to inner core particles> Inner core particles...8.0 Colorant-containing resin particles...2.0 Solvent...Water/500.0 The above composition was milled in a ball mill. The mixture was mixed and stirred at room temperature for 10 hours, and then spray-dried using a spray drying method at a drying temperature of 70° C. to obtain particles. The obtained particles were in the same state as in Example 1.

<Film forming treatment> Tetrahydrofuran was used as a solvent. The conditions for coating treatment and spray drying are as in Example 1.
I did the same thing. As in Example 1, the obtained particles had no binding between the particles and were an aggregate of independent particles. Furthermore, when the obtained particles were cross-sectionally observed using an electron microscope, it was confirmed that a resin coating layer with a thickness of 0.1 μm was formed on the surface of the inner core particle, and that the alkali blue lake was uniformly dispersed in the resin coating layer. .

When the toner produced by the above method was loaded into the laser printer used in Example 1 and an image was formed using paper as the toner transfer material, a clear image was formed at a low fixing temperature of 110°C. I was able to do that. Furthermore, when a similar test was conducted using an OHP transparent sheet as a toner transfer material, clear images with good transparency were formed at a fixing temperature of 110°C. Furthermore, when we conducted a durability test of 30,000 sheets, we were able to obtain clear images just like the initial one. Furthermore, the toner produced in this example was sealed in a container and stored for three months in an environment with a temperature of 30°C and a humidity of 80%, and a similar test was conducted, but there was no aggregation, and the image was as clear as the initial one. I was able to get it.

[Example 4] <Preparation of inner core particles> Inner core particles were prepared using the same composition and method as in Example 1.

<Preparation of colorant-containing resin particles> Resin...
・PMMA/99.0 Colorant...Carbon black/1.0 Toner component...
- Inorganic agent (SiO2: particle size 0.05 μm) / 50.0 Solvent... Toluene / 1,000.0 After mixing and stirring the above composition, drying by spray drying at a drying temperature of 70 ° C. , average particle size 0.6 μm
particles were obtained. When the obtained particles were observed with an electron microscope, they were found to be in the same state as in Example 1.

<Adhesion to inner core particles> Inner core particles...Styrene-isobutylene copolymer/50
．． 0 Colorant-containing resin fine particles...10.0 Toner component...Magnetic powder (Fe3O4)/40.0 Using the above composition, attachment was carried out in the same manner as in Example 1. When the obtained particles were observed with an electron microscope, it was confirmed that the colorant-containing PMMA fine particles and Fe3O4 were uniformly attached to the surface of the inner core particle.

<Coating treatment> Toluene was used as a solvent. The coating treatment and spray drying conditions were the same as in Example 1. When we observed the cross section of the obtained particles using an electron microscope, we found that
It was confirmed that a resin coating layer with a thickness of 0.2 μm was formed on the surface of the inner core particles, and that the colorant and toner components were uniformly dispersed in the resin coating layer.

When the toner produced by the above method was loaded into a laser printer having a one-component magnetic brush developer and an OPC photoreceptor and an image was formed using paper as a toner transfer material, a clear image was formed. was completed. Furthermore, when we conducted a durability test of 30,000 sheets, we were able to obtain clear images just like the initial one. Furthermore, the toner produced in this example was sealed in a container and stored for three months in an environment with a temperature of 30°C and a humidity of 80%, and a similar test was conducted, but there was no aggregation, and the image was as clear as the initial one. I was able to get it.

[Comparative Example 2] Aniline black and PMMA with an average particle size of 0.3 μm were added to the inner core particles prepared in Example 4.
A sample was prepared in which fine particles were attached to the surface of an inner core particle using the same composition and method as in Example 1. When the obtained particles were observed under an electron microscope, it was observed that the resin fine particles and the colorant were uniformly adhered to the surface of the inner core particle.

When the toner produced by the above method was directly loaded into the laser printer used in Example 1 and an image was formed using paper as the toner transfer material, the toner had poor fluidity and the image was formed inside the developing machine. Aggregation occurred, and the externally added particles fell off, contaminating the inside of the device. Furthermore, the obtained image had background fog and was unclear.

[Example 5] <Preparation of inner core particles> Inner core particles were prepared using the same composition and method as in Example 1. The average particle size and particle size distribution after classification were the same as in Example 1.

<Preparation of colorant-containing resin particles> Alkali blue lake, benzidine yellow G, C as colorants.
．． I. Three types of particles were each produced using Solvent Red 100. Its composition is shown below. The manufacturing conditions were the same as in Example 1.

Resin...PBMA/95.0 Colorant...
-5.0 Solvent...Water/1,000.0 All of the obtained particles had an average particle size of 0.5 μm.

<Attachment of colorant-containing resin fine particles to inner core particles> Colorant-containing PBMA fine particles...20.0 Inner core particles...80.
0 The above composition was deposited using the same method and conditions as in Example 1. All three types of obtained particles were in the same state as in Example 1.

<Coating treatment> A resin coating treatment was carried out in the same manner as in Example 1. The three types of particles obtained were aggregates in which each particle was independent, with no binding between particles. Furthermore, cross-sectional observation of the particles produced in this example using an electron microscope revealed that a resin coating layer with a thickness of 0.3 μm was formed on the surface of the three types of inner core particles, and the colorant was uniformly dispersed in the resin coating layer. It was confirmed that

[0054] The three color toners prepared in the above manner were mixed with carriers, and then developed and transferred three times using a two-component magnetic brush developing machine and a laser printer equipped with an OPC photoreceptor, thereby producing a full-color image. was formed. The mixing ratio of toner and carrier was 10.0 parts by weight of toner and 90.0 parts by weight of carrier. When a full color image was formed using paper as a toner transfer material, 3
A clear image with good color reproducibility in the color and the two-color mixed portion was formed. Further, when a full-color image was formed using an OHP transparent sheet as a toner transfer material, a clear image with good color reproducibility and transparency in the mixed color portion was formed, just like when using paper. Furthermore, when we conducted a durability test of 30,000 sheets, no bleed-out occurred and we were able to obtain clear images just like the initial one.

Although the embodiments have been described above, the present invention is not limited to these embodiments, and it is also possible to add other toner components into the resin coating layer.

[0056]

Effects of the Invention As described above, according to the toner manufacturing method of the present invention, by forming a colorant-containing resin coating layer using resin fine particles containing a colorant etc. on the surface of the inner core particles, toner storage can be improved. Furthermore, since the colorant adhered to the toner surface does not come off, there is no contamination inside the device, and even though the amount of colorant is relatively small, the color is clear, especially if the colorant is anything other than black. When used, it has the outstanding effect of being able to form a highly transparent image and easily producing a toner with the property of not causing bleed-out with a small number of steps. Furthermore, regardless of the composition and structure of the inner core particles, the resin coating layer can be manufactured uniformly and easily by controlling the thickness, so a multilayer structure toner with the above-mentioned excellent functions can be compared with conventional technology. This has the great effect of being able to be manufactured at low cost.

Furthermore, the toner manufacturing method of the present invention and the toner obtained by the toner manufacturing method of the present invention can be used in image forming apparatuses using electrophotography, electrostatic recording, electrostatic printing, magnetic recording, etc.
In other words, it can be widely applied to copying machines, printers, facsimile machines, etc.

[Brief explanation of the drawing]

FIG. 1(a) is a diagram showing a flowchart of the toner manufacturing method of the present invention, and FIG. 1(b) is a schematic diagram of the toner obtained by the toner manufacturing method of the present invention.

[Explanation of symbols]

1 Binder resin 2 Resin 3 Coloring agent 4 Solvent 5 Inner core particle 6 Colorant-containing resin particles 7 External addition treatment 8　Resin fine particles externally added inner core particles 9 Filming treatment 10 Resin coating layer 11 Colorant-containing resin coated toner

Claims (1)

[Claims] 1. A method for producing a toner used in a dry development method, in which a resin coating layer is formed on the surface of an inner core particle made of at least a binder resin using at least a colorant and fine resin particles. A method for producing a toner, characterized in that a resin coating layer containing at least a colorant is formed by attaching the resin fine particles to the surface of the inner core particles and then treating with a solvent that dissolves the resin fine particles.