JP2003228193A - Toner for developing electrostatic images - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic image development having excellent color reproducibility of the obtained image including transmission characteristics for an OHP and excellent electrification property, free from scattering of the toner in a machine or free from problems about fluidity and blocking, and capable of stably forming a high-quality developed image for a long time. <P>SOLUTION: In the toner for electrostatic image development containing at least a binder resin and a coloring agent, the coloring agent comprises color particles having 10 to 100 nm average particle size prepared by physically coupling a pigment to the surface of titanium oxide particles by a mechanochemical method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic copying machine in which an image is formed by utilizing an electrophotographic method, an electrostatic recording method, etc.
The present invention relates to toner used for developing an electrostatic latent image in a laser beam printer or the like. More specifically, the present invention relates to a full-color electrophotographic toner having excellent copy quality, durability, and stability.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic copying machine, a laser beam printer, a facsimile machine or the like, in order to obtain a desired copy or a recorded image such as a transmitted image, an electrostatic charge of an electrophotographic photoreceptor or an electrostatic recording medium is obtained. An electrostatic charge image is formed on the image carrier by various means, the electrostatic charge image formed on the electrostatic charge image carrier is developed, and the obtained toner image is transferred to a transfer material such as transfer paper. Then, a method of fixing the transferred toner image by heating, pressurizing or heating / pressurizing is widely adopted. The electrostatic image development method includes a wet development method in which a liquid developer including fine toner dispersed in an electrically insulating liquid is used for development, and a powder containing a colorant dispersed in a binder resin. A dry development method is known in which a two-component developer using a body toner and carrier particles, or a one-component magnetic toner in which magnetic powder or the like is dispersed and contained in a binder resin is used. The latter dry development method is generally used. It is used for.

By the way, in copying in an electrophotographic copying machine, printing of an image or data by a laser beam printer, and printing of a transmission image by a facsimile, etc., in recent years, downsizing of the apparatus, cost reduction, personalization, While higher output speed and lower energy are required, the demand for color is also increasing, and it is necessary to meet these demands.

There are two colors for colorization, multi-color, full-color, and the like, and as a method for forming a color image, there are an analog method and a digital method. For example, in order to form a full-color image by electrophotography using a digital method, the following steps are usually taken. That is, first, a color document is color-separated and read using R (red), G (green), and B (blue) color filters, and an electrostatic latent image corresponding to one color of the color-separated image is exposed. In order to form on the body, the charged photoreceptor is exposed to the laser beam corresponding to the color separation image, and the formed electrostatic latent image is transferred to C (cyan), M (magenta), Y
After development with (yellow) and, if necessary, one color toner of B (black) toner and a color toner corresponding to the color separation image, the toner image is once transferred to the intermediate transfer member. The photoconductor to which the magenta toner has been transferred is cleaned, discharged, and then charged again, and the above steps are sequentially repeated to form a full-color toner image on the intermediate transfer member. Finally, the full-color toner image formed on the intermediate transfer member is transferred to a transfer material and heated or heated and pressure-fixed to obtain a copy. As a transfer material for forming a color image, a synthetic resin film for an overhead projector (OHP) is used in addition to paper.

In forming an image using such a color toner, the toner has good chargeability, fluidity, durability, transferability and the like as in the formation of a black and white image, and under any environment. In addition, in addition to the property that a high-quality toner image can always be formed even when a large number of sheets are continuously copied, the color reproducibility of a color image is further desired. The color reproducibility of the toner is affected not only by the hue, saturation, color separation reflection characteristics of the colorant used, but also by the dispersibility of the colorant in the binder resin. In the case where the colorant is unevenly distributed in the toner, the charging characteristics are also affected, and sufficient color reproducibility cannot be obtained. Further, in the OHP, since color display is performed by transmitted light, it is also required that the light transmittance of the toner is good. Furthermore, for example, when forming a full-color image with a full-color laser printer, it is necessary to reduce the dot diameter for high-definition image reproducibility. Although it is reproduced by changing it, there is a problem that diffused reflection due to scattered dots occurs in the light-colored image portion, and the light-transmitting property and the color reproducibility are easily deteriorated. This problem becomes more prominent when wax is added to the toner, resulting in a problem that the color reproducibility of light colors when an image is formed on an OHP film is deteriorated. From these various viewpoints, various improvements have been attempted in conventional color toners such as a binder resin, a charge control agent, a colorant, and a wax in order to satisfy various properties required.

Further, a charge control agent is generally used in order to improve the charging characteristics of the toner, but many of the conventionally known charge control agents are colored, and such colored charge is used. When the control agent is used as a charge control agent for color toner, there is a problem that color stains occur and color reproducibility deteriorates. Among the charge control agents, many are salicylic acid metal compounds, quaternary ammonium salts, etc. that are white or light-colored, and the charge control agents for color toners are white or light-colored in consideration of color reproducibility. Is selected and used. However, even when such a white or light-colored charge control agent is used, the obtained image has a whitish color, or some color stain occurs, and the color reproducibility is sufficiently satisfied. is not. There is also a problem that the OHP transparency is lowered or the transmitted color becomes whitish.
The transmission characteristics are also not completely satisfactory. As described above, by using the charge control agent, it is possible to obtain a toner having good charging characteristics, but on the other hand, the obtained image has a whitish color and the saturation and hue are lowered, resulting in color reproduction. There is a problem in terms of sex. Further, when a transparent toner image for OHP is formed, there is a problem that the projected image becomes whitish. Therefore, it is preferable from the viewpoint of color reproducibility that a color toner having good charging characteristics can be obtained without using a charge control agent, but if a charge control agent is not used, a toner having good charging characteristics is formed. The problem arises that it is difficult to do.

[0007]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a toner for forming a full-color image, which solves the above-mentioned problems. Specifically, the color reproducibility of the obtained image including the OHP color reproducibility is excellent, the chargeability is excellent, the toner does not scatter in the machine, and there are no problems such as fluidity, offset resistance, and blocking.
Moreover, it is an object of the present invention to provide a full-color toner capable of stably obtaining a high-quality developed image for a long period of time.

As a result of intensive studies, the present inventors have made it possible to use particles obtained by physically binding a pigment to the surface of titanium oxide particles by a mechanochemical method as a colorant from the viewpoint of color reproducibility and good chargeability. The present invention has been accomplished by finding that the above objects can be achieved by using the same.

[0009]

The present invention provides a toner for developing an electrostatic charge image containing at least a binder resin and a colorant, wherein the colorant physically binds the pigment to the surface of titanium oxide particles by a mechanochemical method. Average particle size 10-100n
m colored particles.

The toner for developing an electrostatic image of the present invention is characterized in that the crystal form of titanium oxide is anatase type.

The toner for developing an electrostatic charge image of the present invention is characterized in that it does not contain a charge control agent.

Further, the electrostatic image developing toner of the present invention is characterized in that the mechanochemical method is a compaction pulverization process.

The toner for developing an electrostatic charge image of the present invention is characterized in that the compaction and pulverization treatment is a line load of 10 to 70 kg / cm.

In the toner for developing an electrostatic image of the present invention, the mechanochemical method uses titanium oxide particles treated with a silane coupling agent or a silylating agent, or the presence of a silane coupling agent or a silylating agent is used. It is characterized in that it is carried out below.

The electrostatic image developing toner of the present invention is characterized in that the mechanochemical method is carried out in the presence of a pigment derivative.

In the toner for developing an electrostatic image of the present invention, the pigment is quinacridone, phthalocyanine, insoluble azo pigment,
It is characterized by being one of carbon black.

[0017]

The present invention will be described in more detail below. The colored particles of the present invention have a particle structure in which the surface of titanium oxide particles is coated with a pigment, and the pigment is physically bound to the titanium oxide particles by a known mechanochemical method. The titanium oxide used here has an average particle size of 5 to 1
It is a powder of 00 nm, and can be either hydrophobic or hydrophilic. The colored particles have an average particle size measured by SEM of 10 to 100 nm. The crystal structure of titanium oxide is preferably anatase type.

As the pigment, one selected from carbon black and organic pigments can be appropriately used according to the purpose, but a finely divided pigment is preferable from the viewpoint of efficiency of mechanochemical treatment. Such finely divided pigments include SEM
The average particle size measured in 1. is 10 to 80 nm.

The ratio of the titanium oxide particles to the pigment is 10 to 200 parts by weight of pigment with respect to 100 parts by weight of titanium oxide particles. It is preferably 70 to 130 parts by weight with respect to 100 parts by weight of titanium oxide.

The mechanochemical method is a compaction crushing treatment, and is preferably carried out under the condition that the line weight is 10 to 70 kg / cm. More preferably 40-60 Kg / cm
Is. If the line weight is less than 10 kg / cm, the pigment cannot be fixed to the titanium oxide particles. On the other hand, if the line weight is more than 70 kg / cm, the weight is too large and the colored particles are fixed and agglomerated, which makes it difficult to disperse them in the binder resin. The treatment time is 10 to 300 minutes, and is adjusted according to the characteristics of the pigment to be treated. If the treatment time is 10 minutes or less, the pigment cannot be sufficiently fixed on the titanium oxide particles. Further, if the processing time exceeds 300 minutes, the colored particles are fixed and aggregate.

The colored particles of the present invention have a titanium oxide surface of 1
A pigment layer having a thickness of about 10 nm is formed, which has a feeling of density and is excellent in color development as compared with the pigment used. According to the mechanochemical method of the present invention, the colored particles have a nearly spherical structure having an aspect ratio of about 1 to 1.5 or less when viewed as a plane shape, depending on the shape of the titanium oxide particles. .

In the mechanochemical treatment of the titanium oxide particles and the pigment, if the pigment derivative is used in an amount of 5 to 50 parts by weight per 100 parts by weight of the pigment, the mechanochemical treatment time is shortened and the particles are made finer and toner is formed. Results in improved dispersibility.

The organic pigments include toluidine red, toluidine maroon, Hansa yellow, benzidine yellow,
Insoluble azo pigments such as pyrazolone red, soluble azo pigments such as litol red, heliobordeaux, pigment scarlet, permanent red 2B, derivatives from vat dyes such as alizarin, indanthrone and thioindigo maroon, phthalocyanine blue, phthalocyanine green, etc. Phthalocyanine, quinacridone red,
Quinacridones such as quinacridone magenta, perylenes such as perylene red and perylene scarlet, isoindolinone such as isoindolinone yellow and isoindolinone orange, pyranthrone such as pyranthrone red and pyranthrone orange, thioindigo, condensed azo , Benzimidazolone series, quinophthalone series such as quinophthalone yellow, isoindoline series such as isoindoline yellow, and other pigments such as diketopyrrolopyrrole, flavanthron yellow, acylamide yellow,
Examples thereof include nickel azo yellow, copper azomethine yellow, perinone orange, anthron orange, dianthraquinonyl red, dioxazine violet and the like.

The organic pigment is shown by the color index (CI) number, CI pigment yellow 12,
13, 14, 17, 20, 24, 74, 83, 869
3, 109, 110, 117, 125, 137, 13
8, 147, 148, 153, 154, 166, 16
8, C.I. I. Pigment Orange 16, 36, 43,
51, 55, 59, 61, C.I. I. Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 1
23, 149, 168, 177, 180, 192, 21
5, 216, 217, 220, 223, 224, 22
6, 227, 228, 238, 240, C.I. I. Pigment Violet 19, 23, 29, 30, 37, 4
0, 50, C.I. I. Pigment Blue 15, 15: 1,
15: 3, 15: 4, 15: 6, 22, 60, 64,
C. I. Pigment Green 7, 36, C.I. I. Pigment Brown 23, 25, 26 and the like.

It is preferable that these pigments have a particle size of several tens of nm to 300 nm in terms of efficiency of mechanochemical treatment.
Alternatively, it is preferable to perform various fine particle treatments (for example, acid pasting) to adjust the particle size to be suitable for use.

In the mechanochemical method of the present invention, a pigment derivative may be used together with the pigment to coat the titanium oxide particles. The pigment derivative is one in which a basic group or an acidic group is introduced into the pigment or its skeleton,
For example, there is one represented by the following general formula (1).

P- [XYZN (R ¹ ) R ² ] n (1) (wherein P is an organic dye or a residue of a compound having a similar structure, X is —SO ₂ —, — _{CO -, - CH 2 -,} - CH
_{2 S -, - CH 2 O} -, - O -, - COO -, - NH-,
-CH ₂ NHCOCH- or a divalent linking group selected from a combination thereof, Y is a direct bond, -NR- (wherein R is H or an alkyl group having 1 to 18 carbon atoms), -O.
A divalent linking group selected from-, Z is an alkylene group having 1 to 6 carbon atoms, R ^{1 and} R ² are each independently an optionally substituted alkyl group having 1 to 18 carbon atoms (R ¹ and A heterocycle may be formed with R ² and the heterocycle may have a substituent.), And n is an integer of 1 to 3. )

The organic dye residues represented by P in the formula (1) include the residues of the organic pigments exemplified above, and the pigment-similar structure compounds include, for example, anthraquinone and acridone.

Specific examples of the pigment derivative represented by the formula (1) include the following a to g. Pigment derivative a organic pigment residue substituent C.I. Pigment Blue _{15 -SO 2 NH (CH 2)} 2 N (C 2 H 5) 2 pigment derivative b organic pigment residue substituent C.I. Pigment Yellow 24 - SO ₂ NH (CH ₂ ) ₂ N (C ₃ H ₇ ) ₂ Pigment Derivative c Organic Dye Residue Substituent CI Pigment Violet 19-SO ₂ NH (CH ₂ ) ₃ N (C ₄ H ₉ ) ₂ Pigment derivative d organic pigment residue substituent C.I. pigment Blue _{15 -CH 2 S-CH 2 N} (C 3 H 7) 2 pigment derivative e organic pigment residue substituent C.I. pigment yellow 0.99 -SO ₂ NH _{(CH 2) 3 N (C} 2 H 5) 2 pigment derivative f organic pigment residue substituent CI pigment yellow _{108 -CH 2 O-CH 2 N} (C 2 H 5) 2 pigment derivative g organic pigment residue substituent CI Pigment violet _{19 -CH 2 S-CH 2 N} (C 4 H 9) 2

In the mechanochemical method, the use of an additive is also an important factor in the above-mentioned compaction pulverization treatment, and a silane coupling agent or a silylating agent is used as such an additive. These are titanium oxide particles 1
It is preferable to use 0.1 to 30 parts by weight relative to 00 parts by weight, and it may be used for the surface treatment of the titanium oxide particles before the mechanochemical treatment of the titanium oxide particles and the pigment.

As the silane coupling agent, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-
Aminoethyl) aminopropylmethyldimethoxysilane, aminosilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane Etc.

As the silylating agent, dimethyldichlorosilane, dimethyldimethoxysilane, dimethyldiethoxysilane, n-butyltrimethoxysilane, octadecyltrichlorosilane, trimethylchlorosilane, t-butyldimethylchlorosilane, hexamethyldisilazane,
N-trimethylsilylacetamide, N, O-bis (trimethylsilyl) acetamide, N-trimethylsilylimidazole, N, N'-bis (trimethylsilyl) urea, N-trimethylsilylN, N'diphenylurea, N, O-bis (trimethylsilyl) tri Examples thereof include fluoroacetamide, N, O-bis (trimethylsilyl) carbamate, N, O-bis (trimethylsilyl) sulfamate, and trimethylsilyltrifluoromethanesulfonic acid.

The amount of the colored particles added is usually 100 for the binder resin.
0.1 to 20 parts by weight, preferably 0.3
The addition amount of 10 to 10 parts by weight is preferable.

Specific examples of the binder resin used in the toner of the present invention include styrene polymers such as polystyrene, poly-p-chlorostyrene, and homopolymers of styrene and its substitution products such as polyvinyltoluene. Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic copolymer, styrene-α-chloromethacrylic acid methyl ester Copolymer, styrene-vinyl methyl ether copolymer,
Styrene-vinyl ethyl ether copolymer, styrene-
Vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene diethylaminoethyl acrylate copolymer, styrene- Styrene-based copolymers such as butyl acrylate-diethylaminoethyl methacrylate copolymer, cross-linked styrene-based copolymers, etc .; polyester resins such as aliphatic dicarboxylic acids, aromatic dicarboxylic acids, aromatic dialcohols, diphenols Polyester resin having a monomer selected from the structural units as a structural unit, cross-linked polyester resin, etc .; other polyvinyl chloride, phenol resin, modified phenol resin, malein resin, rosin modified maleic resin, polyvinyl acetate Silicone resins, polyurethane resins, polyamide resins, epoxy resins, polyvinyl butyral, rosin, modified rosin, terpene resin, xylene resin, aliphatic or aliphatic hydrocarbon resins, and petroleum resins.

Examples of the acrylic monomer used in the styrene-acrylic copolymer include acrylic acid and methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate. , 2-ethylhexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate,
Examples thereof include (meth) acrylic acid esters such as butyl methacrylate and octyl methacrylate, and examples of monomers that can be used with these include acrylonitrile, methacrylonitrile, acrylamide, maleic acid, and maleic acid such as butyl maleate. Acid half ester or diester, vinyl acetate, vinyl chloride,
Examples thereof include vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone.

As the cross-linking agent used for producing the above-mentioned cross-linked styrenic polymer, a compound mainly having two or more unsaturated bonds can be mentioned, and specific examples thereof include divinylbenzene and divinyl. Aromatic divinyl compounds such as naphthalene; Carboxylic esters having two or more unsaturated bonds such as ethylene glycol diacrylate and ethylene glycol dimethacrylate; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and unsaturated The compounds having three or more bonds can be used alone or in combination. The cross-linking agent is used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on 100 parts by weight of the binder resin.

These resins can be used alone or in combination of two or more kinds. Of these resins, styrene polymers and polyester resins are preferable because they exhibit particularly excellent charging characteristics. The molecular weight distribution measured by GPC (gel permeation chromatography) has at least one peak in the region of 1x10 ³ to 5x10 ⁴ and at least one peak or shoulder in the region of 10 ⁵ or more. Such a molecular weight can be obtained by using a styrene-based copolymer that has the above-mentioned styrene-based copolymer, further two or more kinds of resins, for example, a combination of the styrene resin and a styrene-acrylic copolymer or a combination of two or more kinds of styrene-acrylic copolymers. A resin composition having a distribution is preferable from the viewpoint of toner pulverizability and fixing property.

Further, when the pressure fixing method is used, a binder resin for pressure toner can be used. Examples of such resins include polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene-ethyl acrylate copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin and other waxes.

To the toner of the present invention, an additive such as a release agent which has been conventionally used in the production of toner can be added as long as it does not have a substantial adverse effect. As the releasing agent, for example, an aliphatic hydrocarbon that improves the releasing property (offset prevention property) at the time of heat roll fixing,
Examples thereof include fatty acid metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, and various waxes. Among these, the weight average molecular weight is 1
000 to 10,000, low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax,
Waxes such as carnauba wax, sazol wax and paraffin wax are preferred. These are usually 0.5-
It is added to the toner in an amount of about 5% by weight.

As the external additive used in the toner of the present invention, a fluidizing agent, an abrasive, a conductivity-imparting agent, a lubricant and the like can be used. As the base material of the fluidizing agent used in the present invention, for example, fine powder of silica, alumina, titania, magnesia, amorphous silicon-aluminum co-oxide, amorphous silicon-titanium co-oxide, etc. is used. You can Further, the fluidizing agent as an external additive has not only the purpose of imparting fluidity to the toner, but also the role of imparting and controlling the charging property of the toner. That is, the external additive adheres to the outermost surface of the toner, and thus has a great influence on the charging property of the toner.

The particles used as the fluidizing agent can be used as they are without surface treatment.
In some cases, environmental stability may be impaired due to hygroscopicity, and the fluidizing agent may adhere to the surface of the photoconductor drum to cause filming, resulting in image defects. Regarding the problem that the environmental stability due to hygroscopicity is impaired, in a high humidity environment, the fluidizing agent is affected by water, causing charge decay of the toner, causing fog on the image, and causing the toner to fly inside the machine. Will be. Therefore, the surface treatment of the particles used for the fluidizing agent is performed,
It is preferably hydrophobic. Further, by selecting a treating agent used for the surface treatment, it is possible to adjust and control the chargeability of the toner by making it have desired polarities of positive polarity and negative polarity, and stabilize the toner. It is necessary to select the surface treatment agent to be used. Examples of the surface treatment agent for the fluidizing agent used in the present invention include organoalkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane, dimethyldichlorosilane, trimethylchlorosilane, octadecyltrichlorosilane, and organochlorosilanes such as t-butyldimethylchlorosilane. , Silazanes such as hexamethyldisilazane, organoaminosilanes such as bis (dimethylamino) dimethylsilane, and silicone oil compounds can be used.

As the silicone oil type compound, straight silicone oil such as dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, or modified silicone oil can be used. The modifying group used in the modified silicone oil includes a methylstyrene group, a long-chain alkyl group, a polyether group, a carbinol group, an amino group, an epoxy group,
Examples thereof include a carboxyl group, a higher fatty acid group, a mercapto group and a methacryl group. Silicone oil has excellent releasability and slidability, and thus has the effect of preventing toner components from adhering to the surface of the photosensitive drum and filming.

As the external additives other than the fluidizing agent used in the present invention, the following publicly known lubricants, abrasives, conductivity-imparting agents and the like can be used. Examples of lubricants include polytetrafluoroethylene and zinc stearate,
Examples of the abrasive include fine powders of strontium titanate, calcium titanate, barium titanate, calcium carbonate, chromium oxide, silicon carbide, tungsten carbide, silicon nitride and the like. These abrasives have the effect of removing the toner component deposits and filming substances on the surface of the photoconductor drum by polishing and shaving them, and are used together with the fluidizing agent surface-treated with the silicone oil. Therefore, a great effect can be found. A metal oxide such as tin oxide may be added as the conductivity-imparting agent. However, these examples are merely examples, and what is added and mixed in the electrophotographic developer of the present invention is not limited to those specifically exemplified above.

The toner for developing an electrostatic image of the present invention can be used as a two-component developer together with a carrier. The carrier used with the toner of the present invention may be any conventionally used carrier, for example, ferromagnetic metal such as iron powder or alloy powder of ferromagnetic metal, nickel, copper, zinc, magnesium, barium, etc. Ferrite powder, magnetite powder and the like composed of elements are preferred. These carriers are styrene / acrylic copolymer, styrene / methacrylate copolymer,
It may be coated with a resin such as a styrene polymer, a silicone resin, a fluorine-containing resin or a mixture thereof. As a method of coating the carrier with a resin, a resin for coating is dissolved in a solvent, and this is coated on the core particles by a dipping method, a spray method, a fluidized bed method, etc., dried and then heated if necessary. Any known method such as a method of curing the film can be used. The average particle size of carrier particles is usually 1
Those having a thickness of 5 to 500 μm, preferably 20 to 300 μm can be used.

The toner according to the present invention can be manufactured by a conventionally known toner manufacturing method. Generally, the toner constituent materials as described above are premixed by a dry blender, a Henschel mixer, a ball mill, etc., and then the mixture is melt-kneaded by a heat kneader such as a heat roll, a kneader, a uniaxial or biaxial extruder. After cooling and solidifying, a method of mechanically coarsely pulverizing using a pulverizer such as a hammer mill, then finely pulverizing with a jet mill, turbo mill or the like, and then classifying is preferable. After further classification, it is preferable to use the external additive after thoroughly mixing it with a mixer such as a Henschel mixer. However, the method for producing the toner used in the present invention is
The method is not limited to the pulverization method.For example, the toner constituent materials are dispersed in a binder resin solution and then spray-dried, or a predetermined material is mixed with a monomer that constitutes the binder resin and the emulsion suspension is used. Needless to say, any of the conventionally known methods such as a method of obtaining a toner by polymerizing the suspension may be used. The toner used in the present invention preferably has a volume average particle diameter of 3 to 35 μm,
25 μm is more preferable. 4 for small particle size toner
It is used with a particle size of about 15 μm.

The present invention will be described below based on examples.
In the examples, "parts" means "parts by weight".

Production Example of Colored Particles Production Example 1 100 parts of titanium oxide particles (STT-30 manufactured by Titanium Industry Co., Ltd.) not surface-treated, copper phthalocyanine pigment (Pigment Blue 15: 3, Toyo Ink Manufacturing Rionol Blue) 90 parts of FG-7330) was subjected to consolidation crushing treatment for 20 minutes at a line load of 50 kg / cm.
The colored particles obtained were blue particles in which copper phthalocyanine was bound to the surface of titanium oxide particles by mechanochemical treatment, the specific surface area was 70 m ² / g, and the average particle diameter measured by SEM was 35 nm. This is designated as P1.

Production Example 2 100 parts of titanium oxide particles (STT-30 manufactured by Titanium Industry Co., Ltd.) not surface-treated, silane coupling agent
(γ-methacryloxypropyltrimethoxysilane) 2
Part, copper phthalocyanine pigment (Pigment Blue)
15: 3 Toyo Ink Mfg. Co., Ltd. Lionol Blue F
G-7330) 90 parts was subjected to a consolidation crushing treatment for 20 minutes with a line load of 50 kg / cm. The obtained colored particles are blue particles in which copper phthalocyanine is bound to the surface of titanium oxide particles by mechanochemical, and have a specific surface area of 75 m ² /
g, the average particle diameter measured by SEM was 33 nm. This is designated as P2.

Production Example 3 P- [CH ₂ NH (CH ₂ ) ₄ N (C
H ₃ ) ₂ ] ₃ (P is a copper phthalocyanine residue) (25 parts) was added, and mechanochemical treatment was performed under the same conditions as for the colored particles 1. The colored particles obtained had a specific surface area of 77 m ² / g, SE
The average particle size according to M was 36 nm. This is designated as P3.

Production Example 4 100 parts of titanium oxide particles (STT-30 manufactured by Titanium Industry Co., Ltd.) not surface-treated, silane coupling agent
(γ-methacryloxypropyltrimethoxysilane) 2
Part, copper phthalocyanine pigment (Pigment Blue)
15: 3 Toyo Ink Mfg. Co., Ltd. Lionol Blue F
G-7330) 90 parts, P- _{[CH 2 NH (CH 2) 4} N
25 parts of (CH ₃ ) ₂ ] ₃ (P is a copper phthalocyanine residue) was added, and mechanochemical treatment was performed under the same conditions as P1.
The obtained colored particles had a specific surface area of 72 m ² / g and an average particle diameter by SEM of 34 nm. This is designated as P4.
Hereinafter, colored particles were produced by the same method.

[0051]

[Table 1]

[0052]

EXAMPLES The present invention will be described in more detail with reference to production examples, examples and comparative examples, but the embodiments of the present invention are not limited to these examples. In the following, all parts are parts by weight.

[Example 1] (Component) (Blending amount) Saturated copolyester resin 92 parts Colored particles P1 5 parts Low molecular weight polypropylene 3 parts After uniformly mixing the above materials with a Henschel mixer, add them to a biaxial heating kneader. What was charged, kneaded, and extruded was cooled at room temperature and coarsely crushed with a hammer mill to obtain chips.
Next, this was finely pulverized with a turbo mill pulverizer, introduced into a classifier, and a portion having an average particle size of 11.5 μm was taken out to obtain a fine powder for cyan toner. Next, with respect to 100 parts by weight of this toner fine powder, a hydrophobic silica fine powder of 0.
3 parts by weight were added and mixed to obtain a negatively chargeable cyan toner. 5 parts of the obtained toner and 95 parts of a carrier coated with a silicone resin having an average particle size of 50 μm were mixed using a ball mill to prepare a developer. Next, using this toner and developer, a commercial full-color copying machine CLC-5 made by Canon Inc.
No. 50, an actual copying test was performed in an environment of 23 ° C. and 50% RH. When the obtained toner and developer were used, fogging was small even after actual copying of 50,000 sheets, the image density was stable, and neither toner scattering in the machine nor image stain was observed. Image densities of 1.40 in the initial and 50,000 copies respectively
And 1.38, and the fog at the initial stage and at the time of copying 50,000 sheets were 0.7 and 0.7, respectively.

The image density is measured by using a Macbeth photometer and may be 1.35 or more. The fogging was performed by measuring the reflectance with a photo bolt. A value of 1.2% or less is a good value. The toner scattering inside the machine was performed by confirming whether the scattered toner was present on the transfer charger of the copying machine. When the toner scattering is seen on the transfer charger, the image stain is generated accordingly.

Examples 2 to 22 Instead of using the colored particles P1 used in Example 1, Table 1
The same evaluation as in Example 1 was carried out except that the colored particles described in 1. were used. The results are shown in Table 2.

Comparative Example 1 Pigment Blue 1 instead of the colored particles P1
5: 3 (specific surface area 75 m ²/ G) Actual except that 5 parts are used
A cyan toner was obtained in the same manner as in Example 1. The results are shown in Table 2.
Show.

Comparative Example 2 Pigment Blue 1 was used in place of the colored particles P1.
A cyan toner was obtained in the same manner as in Example 1 except that 3 parts of 5: 3 (specific surface area 75 m ² / g) and 2 parts of titanium oxide particles STT-30 were used. The results are shown in Table 2.

Comparative Example 3 Pigment Red 122 was used in place of the colored particles P1.
Example 1 except that 5 parts (specific surface area 77 m ² / g) were used.
A magenta toner was obtained in the same manner as in. The results are shown in Table 2.

Comparative Example 4 Pigment Red 122 instead of the colored particles P1
(Specific surface area 77 m ² / g) 3 parts, titanium oxide particles STT
A magenta toner was obtained in the same manner as in Example 1 except that -30 2 parts was used. The results are shown in Table 2.

Reference Example 1 Cyan was carried out in the same manner as in Example 1 except that 1 part of 3,5-di-tert-butylsalicylic acid zinc compound and 91 parts of saturated copolymerized polyester resin were used in place of 92 parts of saturated copolymerized polyester resin. Toner was obtained. The results are shown in Table 2.

[0061]

[Table 2]

[0062]

As described in detail above, the toner of the present invention has a particular effect that a high-quality image having remarkably improved color reproducibility can be stably formed for a long period from the beginning of development. I have. In addition, it is possible to reduce the amount of the dye component used, and it becomes possible to formulate the ratio of high-priced materials.

Claims (8)

[Claims] 1. An electrostatic charge image developing toner containing at least a binder resin and a colorant, wherein the colorant has an average particle size of 10 to 100 nm in which a pigment is physically bound to the surface of titanium oxide particles by a mechanochemical method. A toner for developing an electrostatic charge image, which is colored particles. 2. The toner according to claim 1, wherein the crystal form of titanium oxide is anatase type. 3. The toner according to claim 1, wherein the toner does not contain a charge control agent. 4. The toner for developing an electrostatic charge image according to claim 1, wherein the mechanochemical method is a compaction pulverization process. 5. Consolidation crushing treatment, wire load 10-70Kg /
The toner for developing an electrostatic charge image according to claim 4, which has a size of cm. 6. The mechanochemical method is carried out by using titanium oxide particles treated with a silane coupling agent or a silylating agent, or in the presence of a silane coupling agent or a silylating agent. The toner for developing an electrostatic charge image according to any one of claims 1. 7. The toner for developing an electrostatic charge image according to claim 1, wherein the mechanochemical method is carried out in the presence of a pigment derivative. 8. The toner for developing an electrostatic charge image according to claim 1, wherein the pigment is any one of quinacridone, phthalocyanine, insoluble azo pigment and carbon black.