JPH04291357A - 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 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:The internal nucleus particles 5 are 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 6 to stick the coloring agents 2 and the resin fine particles 3, etc., thereto by which the internal nucleus particles 7 externally added with the coloring agents and the resin fine particles are produced. The internal nucleus particles 7 externally added with the coloring agents and the resin fine particles are subjected to a film forming treatment 8 by bringing a solvent 4 dissolving the resin fine particles into contact therewith to form the resin film layers 9, by which the toner 10 formed with the resin films contg. the coloring agents is 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 a binder resin powder is electrostatically adhered around inner core particles containing a colorant and a charge control agent and then thermally melted to coat the surface (Japanese Patent Laid-Open No. 1-227163)
, a toner in which wax particles containing a colorant or magnetic powder are encapsulated by interfacial polymerization (Japanese Patent Application Laid-Open No. 1-167)
850), a toner in which the inner core particles are microencapsulated with a pigment and then microencapsulated with a charge control resin (JP-A-64-62666), a dry process in which a vinyl polymer and a colorant are added to the inner core particles obtained by a polymerization method. Toner that is externally added by mixing and then externally added vinyl polymer by dry mixing (Japanese Patent Laid-Open No. 6
4-10263) etc.

[0005]

[Problems to be Solved by the Invention] However, as for the above-mentioned toner, the toner disclosed in JP-A No. 64-10263 has external additives that easily peel off, resulting in poor image quality of the image formed and problems with image forming devices. In addition, the toner manufacturing method shown in JP-A-1-167850 has limitations on the raw materials used for interfacial polymerization;
The toner manufacturing method shown in JP-A-1-227163 has many steps and leads to an increase in cost.
The toner shown in Figure 1 and conventional toners contain a coloring agent in the inner core particles, but the colorant is hidden by the binder resin and the color does not come out clearly, so the amount of colorant is must be increased. In this case, since light is blocked by the colorant, transparency, which is necessary 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.

Therefore, an 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, and to prevent the characteristics from deteriorating during toner transportation and 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 uses at least a coloring agent and fine resin particles to form a resin coating layer on the surface of core particles made of at least a binder resin, which are used in a dry development method. The toner is characterized in that a resin coating layer containing at least a colorant is formed by attaching at least fine resin particles to the surface of the inner core particles and then treating with a solvent that contains a colorant and dissolves the fine resin particles. shall be.

[0008]

[Operation] In the toner manufacturing method of the present invention, mixed particles such as fine resin particles are first attached to the surface of the inner core particles using a dry method or a wet method. 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 The method involves adhering mixed particles such as fine resin particles to the surface of the resin. In the wet method, the particles are attached by utilizing the electrical adsorption force, chemical adsorption force, physical adsorption force, etc. that act between each particle. When the adhesion is carried out by the above method, mixed particles such as fine resin particles are uniformly dispersed on the surface of the inner core particle, and the particles are attached to the surface of the inner core particle in a state where the particles are not locally biased. Next, the resin fine particles attached to the surface of the inner core particle are dissolved in a solvent containing a colorant, thereby forming a resin coating layer containing various fine particles 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 manufacturing method, inner core particles 5 are produced by a kneading and pulverizing method, a spray drying method, a polymerization method, etc. using a raw material consisting of a binder resin 1, etc., and then resin fine particles 2, etc. are attached to the surface of the inner core particles 5. External addition treatment 6 is performed to prepare resin fine particle external addition treated inner core particles 7, and then resin fine particle external addition treated inner core particles 7 are brought into contact with a solvent 4 that contains a coloring agent 3 and dissolves the resin fine particles to be colored and coated. Processing 8 is performed to form a resin coating layer 9 on the surface of the inner core particles 5, thereby producing a colorant-containing resin coating toner 10.

The inner core particles used in the present invention are made of at least a binder resin, and can contain toner components 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 particles can be attached to the surface of the inner core particle together with the resin fine particles and incorporated into the resin coating layer. Furthermore, colorants can also be deposited in the same manner as toner components. Methods for producing the inner core particles include commonly used kneading and pulverization methods, spray drying methods, polymerization methods, and the like. The shape may be either spherical or amorphous, and the particle size is generally 1 to 40μ.
Use m.

[0012] As a dry method for adhering mixed powder such as fine resin particles to the surface of the inner core particles, ordinary mixers 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 stirrer. preferable. Examples of high-speed fluidized stirrers include the so-called Henschel mixer, Mechano Fusion System (Hosokawa Micron), Nara Hybridization System (Nara Kikai Seisakusho), and Mechano Mill (
Okada Seiko) etc. are used. However, the device for adhering fine particles to the surface of the inner core particles is by no means limited to these. In addition, wet methods include a heteroaggregation method that utilizes electrostatic adhesion due to the zeta potential difference between the surface of the inner core particles and the surface of the resin microparticles, and a method in which the resin microparticles and inner core particles are dispersed in a solvent that does not dissolve the resin microparticles and the inner core particles. A wet milling method in which a mixed dispersion liquid is milled with a ball mill or sand mill, etc., a coupling agent method in which inner core particles are treated with a coupling agent and then mixed with resin fine particles, etc. for external addition treatment, etc. can be used. . Specifically, the solvent used at this time includes petroleum solvents such as hexane, heptane, Isopar, and kerosene, and water. Furthermore, anionic, cationic, nonionic surfactants, etc. may be added to improve dispersibility.

Methods for forming a resin coating layer by treatment with a solvent include spray drying and immersion, 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 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, A
S 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-copolymers, etc.
Acrylic acid ester copolymer, styrene-methyl methacrylate copolymer, 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 acid 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,
There are polyamide resins, polyvinyl alcohol resins, polyurethane resins, polyvinyl butyral resins, etc., and one type or a mixture of two or more of these can be used as required. 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, montan wax derivatives,
Modified waxes such as paraffin wax derivatives, hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives, waxes such as synthetic waxes, higher fatty acids such as stearic acid and palmitic acid, polyolefins such as low molecular weight polyethylene, oxidized polyethylene, and polypropylene; Ethylene-
There are olefin copolymers such as acrylic acid copolymers, ethylene-acrylic acid ester copolymers, and ethylene-vinyl acetate copolymers, and one type or two or more types of these can be used as required.

The colorant is not particularly limited as long as it can be dispersed or dissolved in a solvent that dissolves the resin particles. For details, see 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, First 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 8
G, quinacridone, polytungstophosphoric acid, methylene blue, rose bengal, sulfonamide derivative, C. I
．． Direct black 19, 22, 28, 154, 16
8.C. I. Direct yellow 12, 26, 86, 8
7, 130, 142, C. I. Direct Red 9,1
3, 17, 23, C. I. Direct Blue 78, 86
, 199, C. I. Ashido Black 52, 172, 2
08,C. I. Ashido Yellow 23, 25, C. I.
Assid Red 52, 254, 289, C. I. Ashido Blue 9, 254, C. I. Food Black 2, C.
I. Solvent Yellow 2, 6, 14, 15, 16, 1
9, 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, 2
4, 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. These are dyes or pigments such as Solvent Black 3, 5, 22, 23, etc., and these can be used alone or in combination of two or more types as required.

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, specifically Fe3O4, Fe2O3, Fe, Cr, Ni, etc., can be used as the magnetic toner.

[0018] As the inorganic fine particles, Si02, TiO2
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 fine particles, polymethyl methacrylate (PMMA) and polyethyl methacrylate (PMMA) are used.
EMA), poly-n-butyl methacrylate (PBM
A), polyester, styrene-butadiene copolymer,
Polyvinyl chloride (PVC), polyvinyl alcohol (P
VA), 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, etc. can be used. The solvent used when coating the surface of the inner core particle is not particularly limited as long as it dissolves the fine resin particles attached to the surface of the inner core particle by the method described above. For details, see n-hexane, heptane, cyclohexane, benzene, toluene, xylene, dichloromethane, chloroform, tetrachloromethane, dichloroethane, chlorobenzene, nitromethane, acetonitrile, acrylonitrile, tetrahydrofuran, dioxane, methylcellosolve, ethyl acetate, butyl acetate, acetone. , methyl ethyl ketone, methanol, ethanol, propanol, benzyl alcohol, pyridine, diethyl formamide, dimethyl formamide, etc., and these can be used alone or in combination of two or more types as required.

[0020] By using the above-mentioned raw materials and forming a resin coating layer containing a colorant by the above-mentioned method, there is no need for operations such as classification after treatment, and excellent storage stability is achieved.
Furthermore, since the colorant is located near the surface of the toner, a toner with a clear image and good transparency can be produced 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-acrylic copolymer was used as a raw material. 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 9 μm and a particle size distribution of 5 to 20 μm.
The inner core particles were prepared.

<Adhesion of fine resin particles> P as fine resin particles
BMA was used. PBMA with a particle size of 0.4 μm was used. The resin fine particles and the inner core particles were mixed to have the composition shown below, and the mixture was attached to the surface of the inner core particles using a mechanofusion system (manufactured by Hosokawa Micron). Its composition and conditions are shown below.

PBMA fine particles...15.0 inner core particles.
...85.0 The deposition was carried out at a rotation speed of 1500 rpm and a processing time of 30 minutes. It was confirmed by electron microscopy that the PBMA fine particles of the obtained particles adhered to the surface of the inner core particles without peeling off. Further, when cross-sectional observation was performed using an electron microscope, it was confirmed that the PBMA fine particles remained spherical and were embedded in the surface of the inner core particles.

<Coloring and film-forming treatment> Coloring and film-forming treatments were performed on the resin fine particle externally added inner core particles prepared by the above method. Xylene was used as a solvent and phthalocyanine blue was used as a coloring agent. Its composition and method are shown below.

Xylene: 98.5 Phthalocyanine Blue: 1.5 The dispersion airflow of the above composition and the dispersion airflow of particles are brought into contact for a contact time of 1.0 seconds, and then the drying temperature is 60°C.
The xylene was evaporated by spray drying. 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, it was 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 particle, and phthalocyanine blue was uniformly dispersed therein.

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 obtained. was able to form. 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, after conducting a durability test of 30,000 sheets,
I was able to obtain clear images just like in the beginning. 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> A styrene-acrylic copolymer was used as a raw material, and phthalocyanine blue was used as a colorant. Its composition is shown below. Further, the manufacturing method was the same as in Example 1.

Styrene-acrylic copolymer...97.
5 Phthalocyanine Blue...2.5 When the obtained particles were observed in cross section using an electron microscope, it was observed that phthalocyanine blue was uniformly dispersed in the resin.

<Attachment of fine resin particles> PBMA having the same particle size as in Example 1 was used as the inner core particles and fine resin particles. The PBMA fine particles and the inner core particles were mixed to have the composition shown below, and the mixture was attached to the surface of the inner core particles. The method of attachment was the same as in Example 1.

PBMA fine particles...15.0 inner core particles.
...85.0 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> Wax was used as the inner core particles. Its composition and method are shown below.

Paraffin wax: 50.0 Polyethylene wax: 50.0 These were kneaded in a batch type kneader, cooled, and coarsely ground. Next, the mixture was finely pulverized using a jet pulverizer, and then classified to produce inner core particles having an average particle size of 10 μm and a particle size distribution of 5 to 25 μm.

<Adhesion of fine resin particles> P with a particle size of 0.4 μm
Deposition was carried out using BMA with a composition similar to Example 1. Wet milling method was used as the method, and the rotation speed was 500 r.
The treatment was carried out under the following conditions: pm, and treatment time was 30 minutes. The obtained particles were in the same state as in Example 1.

<Coloring and coating treatment> Xylene was used as a solvent and C.I. I. Solvent Yellow 6 was used. The composition, coloring and coating treatment, and spray drying conditions 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 toner was cross-sectionally observed using an electron microscope, it was found that the film thickness was 0.3 on the surface of the inner core particles.
A resin coating layer of .mu.m is formed, and C. I. It was confirmed that Solvent Yellow 6 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> Wax was used as the inner core particles. Its composition is shown below. The manufacturing method was the same as in Example 2.

Candelilla wax...60.0 Polyethylene wax...40.0 The inner core particles after classification have an average particle size of 9 μm and a particle size distribution of 5 to 2
It was 0 μm.

<Attachment of fine resin particles> A polyester resin having a particle size of 0.5 μm was attached using the same method and conditions as in Example 2 using SiO2 as an external additive. Its composition is shown below.

Inner core particles...75.0 Polyester resin...15.0 SiO2...10.0 When the obtained particles were observed with an electron microscope, polyester resin fine particles and SiO2 were uniformly distributed on the surface of the inner core particles. It was confirmed that it was attached.

<Coloring and coating treatment> Tetrahydrofuran was used as a solvent and C.I. I. Direct Red 13 was used. The composition, coloring and coating treatment, and spray drying conditions were the same as in Example 1. The obtained particles had good fluidity, and as in Example 1, there was no binding between particles.
Each particle was a collection of independent particles. Furthermore, when the obtained toner was cross-sectionally observed using an electron microscope, a resin coating layer with a thickness of 0.2 μm was formed on the surface of the inner core particles, and C. I. Direct Red 13 and SiO
It was confirmed that 2 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 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.

<Attachment of fine resin particles and toner components> PMMA having a particle size of 0.5 μm was used as the fine resin particles, and magnetic powder Fe3O4 was used as the external additive. Its composition is shown below. However, the manufacturing method was the same as in Example 1. Inner core particles...50.0 PMMA fine particles...10.0 Fe3O4...40.0 When the obtained particles were observed under an electron microscope, it was found that the PMMA fine particles and magnetic powder were uniformly attached to the surface of the inner core particles. It was confirmed that

<Coloring and coating treatment> Toluene was used as a solvent and aniline black was used as a coloring agent. composition,
The conditions for coloring, coating, and spray drying were the same as in Example 1. When the obtained particles were cross-sectionally observed using an electron microscope, it was found that a resin coating layer with a thickness of 0.3 μm was formed on the surface of the inner core particle, and that aniline black and Fe were further contained in the resin coating layer.
It was confirmed that 3O4 was uniformly dispersed.

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 as a coloring agent and PMMA particles with a particle size of 0.5 μm as resin particles were attached to the surface of the inner core particle prepared in Example 4 in the same manner as in Example 1. I made something like this. When the obtained particles were observed with an electron microscope, it was observed that the PMMA fine particles and aniline black were uniformly attached to the surface of the inner core particles.

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 inside of the developing machine was damaged due to the poor fluidity of the toner. This caused aggregation, 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 raw materials and method as in Example 1. The average particle size and particle size distribution after classification were the same as in Example 1.

<Adhesion of colorant and resin fine particles> PMMA with a particle size of 0.5 μm was used as the resin fine particles, and C was used as the colorant.
．． I. Solvent Violet 14 was used. These particles were mixed in the composition shown below and adhered to the surface of the inner core particles in the same manner as in Example 1. Its composition and conditions are shown below.

Inner core particles...85.0 PMMA fine particles...14.5 C. I. Solvent Violet 14...0.5 deposition was carried out at a rotation speed of 1500 rpm and a processing time of 30 minutes. When the obtained particles were observed with an electron microscope, PM
MA fine particles and C. I. It was confirmed that Solvent Violet 14 adhered to the surface of the inner core particles without peeling off. Further, when the cross section was observed using an electron microscope, it was observed that the PBMA fine particles remained spherical and were embedded in the surface of the inner core particle.

<Coloring and film-forming treatment> A film-forming process was performed on the inner core particles added to the outside of the fine particles produced by the above method. Toluene as a solvent and C.I. as a colorant. I. Solvent Violet 14 was used. Its composition and method are shown below.

Toluene...99.0C. I. Solvent Violet 14...1.0 The contact time between the dispersion airflow of the above composition and the dispersion airflow of particles is 1.
．． They were brought into contact for 2 seconds, and then spray-dried at a drying temperature of 70°C to evaporate toluene. The particles obtained by this coating treatment had no binding between particles, and each particle was an aggregate in an independent state. Further, 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 0.3 μm was formed on the surface of the inner core particle, and C. I. It was confirmed that Solvent Violet 14 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 a toner transfer material, a clear image could be formed. In addition, OHP can be used as a toner transfer material.
When a similar test was conducted using a transparent sheet, 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.

[Example 6] <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.

<Attachment of fine resin particles> Using the same composition and method as in Example 1, fine resin particles were attached to the surface of the inner core particles. The obtained particles were in the same state as in Example 1.

<Coloring and film-forming treatment> The fine particle externally added inner core particles prepared by the above method were subjected to coloring and film-forming treatments. Xylene was used as a solvent, and phthalocyanine blue and C.I. I. Solvent Yellow 6, C. I
．． Particles of three colors were produced using Direct Red 13. Its composition is shown below. The conditions for coloring, coating, and spray drying were the same as in Example 1.

[0059] Xylene: 98.5 Colorant: 1.5 The particles obtained by the above treatment had no binding between particles, and all three types were aggregates in which each particle was independent. . In addition, when the obtained particles were observed in cross section using an electron microscope, it was found that all three types had a film thickness of 0.2 μm on the surface of the inner core particle.
It was confirmed that a resin coating layer was formed and the colorant was uniformly dispersed therein.

The three color toners prepared in the above manner mixed with carriers were repeatedly developed and transferred three times using a two-component magnetic brush type developer and a laser printer equipped with an OPC photoreceptor to form 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.

[0062]

As described above, the toner obtained by the toner production method of the present invention has a resin coating layer formed on the surface of the inner core particles using resin fine particles. More specifically, mixed particles such as fine resin particles are attached to the surface of the inner core particles, and then treated with a solvent that contains a colorant and dissolves the fine resin particles, so that the toner does not agglomerate during storage and is fixed to the surface of the toner. Since the colorant etc. does not peel off, there is no contamination inside the device, and even though the amount of colorant is relatively small, images are clear and have good transparency, especially when a colorant other than black is used. It also has the property of not causing bleed-out. According to the toner manufacturing method of the present invention, a toner having the above characteristics can be easily manufactured in a small number of steps, which is an outstanding effect. 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.
This method has a great effect in that a multilayer structured toner having the above-mentioned excellent functions can be manufactured at a lower cost than conventional techniques.

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 fine particles 3 Coloring agent 4 Solvent 5 Inner core particle 6 External addition treatment 7. Inner core particles treated with external addition of resin fine particles 8 Coloring and coating treatment 9 Resin coating layer 10 Colorant-containing resin-coated toner

Claims (1)

[Claims] 1. A toner manufacturing method for forming a resin coating layer using at least a coloring agent and fine resin particles on the surface of an inner core particle made of at least a binder resin, which is used in a dry development method. 1. A method for producing toner, which comprises depositing fine resin particles and then treating with a solvent that contains a colorant and dissolves the fine resin particles, thereby forming a resin coating layer containing at least a colorant.