JPH03276162A - Magneta developer - Google Patents

Abstract

PURPOSE:To reproduce the low saturation black of a full-color image and to improve the transparency and fastness of magenta by blending two kinds of specified binding resins in a prescribed ratio and mixing two kinds of specified colorants. CONSTITUTION:This developer is a mixture of a carrier preferably coated with prescribed fluororesin or prescribed silicone resin with a toner contg. polyester-based resin (A) and styrene-acrylic resin (B) obtd. by copolymerizing a copolymerizable monomer contg. an amino group as binding resins in (55:45)-(95:5) weight ratio of A:B and further contg. C.I. Solvent Red 49 and C.I. Solvent Red 8 as colorants. The ring and ball softening point of both the resins A, B has been regulated to <=120 deg.C.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a developer for developing electrostatic images, and more specifically, for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a color developer, particularly a positively chargeable magenta developer.

[Prior art and problems to be solved by the invention] Conventional electrophotographic methods include U.S. Pat.
As described in specifications such as No. 97691 and No. 2357809, a photoconductive insulating layer is uniformly charged (charging step), and then the layer is exposed to light (exposure step), so that the charge of the exposed portion is increased. An electrostatic latent image is formed by dissipating the electrostatic latent image, and the electrostatic latent image is made visible by attaching a colored, charged fine powder called toner (development process). The method consists of a step of transferring the image onto a transfer material such as transfer paper (transfer step) and then permanently fixing it by heating, pressure, or other appropriate means (fixing step).

The developing methods applied to these electrophotographic methods are broadly divided into dry developing methods and wet developing methods. The former method further includes a method using a one-component developer and a method using a two-component developer, and the present invention relates to a two-component dry developer.

Two-component dry developers include a magnetic brush development method using a magnetic powder carrier, a cascade development method using a somewhat coarse bead carrier, etc., depending on the type of system for conveying the toner. Color developers are also basically produced using the electrophotographic method described above: [Charging] → [Exposure] → [Development] → [
A color image is formed by repeating the transfer process several times and fixing the image. However, in the exposure process, exposure is performed by exposing with a color separation filter or by writing an image read by a scanner with a laser or the like.

As toners applied to these developing methods, fine powders in which colorants such as dyes and pigments are dispersed in natural or synthetic thermoplastic resins have conventionally been used. Examples of synthetic resin systems include mixing and dispersing various additives such as colorants, charge control agents, and waxes in binder resins such as styrene-acrylic copolymer (polystyrene) resins, polyester resins, and epoxy resins. Particles obtained by pulverizing the particles to a particle size of about 1 to 30 ρ are used as toner. In the case of a system using a two-component dry developer, the toner is usually mixed with carrier particles such as glass beads or iron powder, and at that time, the toner is held on the carrier by electrostatic attraction generated by friction, resulting in an electrostatic latent image. transported to the surface. The charging property of the toner is determined by the charging polarity of the electrostatic latent image, and a clear positive or negative polarity and an appropriate amount of charge are required. To make the toner possess a desired charge, it is possible to utilize the triboelectric properties of the carrier, its surface material, and the resin that is a component of the toner.
Alternatively, it is unsatisfactory because it is difficult to quickly reach the desired amount of charge.

In such a case, the image obtained by development is likely to have background fog and become unclear. Therefore, in order to quickly impart the desired amount of charge to the toner,
Addition of a substance called a charge control agent to control chargeability has been carried out. For positive charging, compounds having an electron-donating group such as nigrosine dyes are effective, and for negative charging, electron-accepting organic complexes such as oil-soluble metal-containing dyes are widely used. Since nigrosine dyes generally have poor compatibility with resins, they are often used as modified products with oleic acid, stearic acid, etc.

Other charge control agents for positive charging include fatty acid amines, quaternary ammonium salts, Feschwaltz HBW,
Sudan Cheeksharz BBC.

Brilliant Spirit, etc., but many of these charge control agents are derived from dyes and pigments, have complicated structures, and many have strong coloring properties. In the case of chromatic toners, colored compounds cannot be used, so colorless or light-colored charge control agents are being considered;
There is nothing that surpasses the performance of pigments, and although it is unsatisfactory, dyes and pigments are currently being used.

These charge control agents are usually mixed with a thermoplastic resin, dispersed by hot melt kneading, finely pulverized, and adjusted to an appropriate particle size as necessary before use. These dyes and pigments used as charge control agents have no choice but to be used for charge control, but this gives rise to a number of complaints.

Firstly, its molecular structure is complex and its properties are not constant, making it susceptible to deterioration due to hot melt contamination and changes in performance due to temperature and humidity conditions.As the number of copies increases, the quality of electrophotographic images deteriorates. Characteristics are likely to deteriorate. The second problem is that it is extremely difficult to uniformly disperse these charge control agents in a thermoplastic resin, which causes a difference in the amount of frictional charge between the toner particles obtained by pulverization, resulting in a decrease in image quality. It is to invite.

Thirdly, many of the charge control agents are hydrophilic, and due to poor dispersion in these resins, they are easily exposed on the surface of the toner particles. Therefore, under high temperature conditions, the charge control agent absorbs moisture and reduces the amount of charge on the toner. The image quality deteriorates, making it impossible to obtain high-quality images. Fourth
However, there is a problem in that most of the dyes and pigments that are generally known as charge control agents are chromatic or dark colored, and cannot be incorporated into toners that have a vivid, desired color. . Fifth, when toner mixed with a charge control agent is used for a long period of time, the charge control agent may adhere to the surface of the photoreceptor or may promote adhesion of the toner to the photoreceptor, which is bad for electrostatic latent image formation. There are many things that have negative effects on the cleaning process of copying machines, such as damaging the photoconductor surface or cleaning blade due to filming, or accelerating wear of these parts. .

As described above, when a charge control agent is used in a toner, the amount of charge generated on the surface of the toner particles varies during the process of generating frictional charging between toner particles or between a toner and a carrier. As a result, development fog,
Problems such as toner scattering and carrier contamination are likely to occur. In addition, this problem becomes more noticeable when a large number of copies are made, and the product becomes virtually unusable.

Furthermore, under high temperature conditions, not only the quality of the toner image deteriorates, but also the transfer efficiency to the transfer paper decreases significantly, making the toner image unusable. Further, since charge control agents cause a number of undesirable problems in both black toner and color toner, efforts have been made to avoid these problems. For example, Japanese Patent Application Laid-Open No. 6.0-112051 discloses that a specific polyester resin and a copolymerizable monomer having a tertiary amino group and a hydrophobic By using a copolymer resin of copolymerizable monomers as a binder resin and combining it with a carrier coated with a vinyl chloride-vinyl acetate copolymer resin, uniform and sufficient positive polarity can be achieved without using conventional charge control agents. A developer toner is disclosed that is electrically charged. This toner has a composition ratio of a polyester resin, a copolymerizable monomer having a tertiary amine group, and a hydrophobic copolymerizable monomer of 10 to 50% by weight and 50 to 90% by weight, and The ring and ball softening point of each resin is limited to a range of 100 to 180°C. However, the softening point is 12
If the temperature is higher than 0°C, when used as a full-color developer, the transparency will be impaired and clear images will not be obtained. That is, the object of the invention in the above-mentioned publication is, as stated, related to an offset avoidance means, and cannot solve the above-mentioned problems related to color toner.

Characteristics required as a color developer include color performance and transparency. Regarding color performance, each of the three primary color toners must have good spectral reflection characteristics in order to faithfully reproduce the colors of the original. On the other hand, transparency requires that light passes through a plurality of toner layers in which a plurality of toners of different colors are superimposed, and that a composite color reproducibility can be obtained. In addition to simply color reproduction, it is also necessary that the transparency of the OIIP projected image of the toner image transferred and fixed to the overhead projector (OHP) transparent range be excellent, that is, it must have good spectral transmittance. . Although known organic pigments and dyes are used as colorants for color toners, each of them has many drawbacks. Organic pigments generally have higher fastness to heat and light than dyes, but even those with relatively good spectral reflection properties have strong hiding power because they exist in a dispersed state as pigment particles in the toner layer, and dispersed particles Due to light scattering caused by light scattering, the hue of the image in reflection and transmission changes, and the spectral transmittance is low.

On the other hand, dyes are dissolved in the toner layer or exist in a more finely dispersed state than pigments, so they have excellent color vividness, transparency, and coloring power, but they fade due to heat and light. It has the disadvantage that it is easy to occur.

The charging property of toner is determined by the charging polarity of the electrostatic latent image, and a clear positive or negative polarity and an appropriate amount of charge are required. However, the colorant, which is an essential component of color developers, has a normal charge. Dyes that are not used as control agents also have some functional groups, that is, electron-donating groups and electron-accepting groups, which can be a hindrance in designing the charge amount of toner, or when used repeatedly. This is an obstacle to obtaining a stable charge amount transition.

The colorant used in magenta toner is
Dyes and pigments such as those described in Japanese Patent Publication No. 3-26382 and Japanese Patent Publication No. 53-47175 have been proposed, but none of these dyes and pigments has been able to satisfy all of the above characteristics. However, there is a strong need in the art to improve these magenta toners.

The object of the present invention is to provide a color developer which overcomes the above-mentioned problems, and more particularly to provide a magenta developer which provides an improved full-color image that reproduces very desaturated blacks through image superimposition. There is a particular thing.

Another object of the present invention is to provide a magenta developer that reproduces colors faithful to originals and has excellent transparency. Still another object of the present invention is to provide a magenta developer that has high fastness to heat and light and is capable of providing full-color images with high chroma. Still another object of the present invention is to provide a developer that enables faithful development and transfer of electrostatic latent images, that is, no background fogging during development, no toner scattering around etched areas, and high image density. The purpose of the present invention is to provide a developer with excellent midtone reproducibility. Still another object of the present invention is to provide a developer which maintains its initial characteristics even when the developer is used for a long period of time, has no toner aggregation, and has excellent storage stability.

[Means to solve the problem]

The present inventors have made extensive studies in view of the current state of the prior art described above, and as a result have found a magenta developer that overcomes the above-described drawbacks and have arrived at the present invention.

That is, the present invention provides a dry developer formed by mixing a carrier and a toner, in which the binder resin, which is the main component of the toner, is
It consists of a polyester resin (A) and a styrene-acrylic resin (B) obtained by copolymerizing a copolymerizable monomer containing an amino group, and the weight ratio of resin (A) and resin (B) is A'):(B) is in the range of 55:45 to 95:5, the softening point (ring and ball method) of the resins (A) and (B) is 120°C or less, and the colorant is mixed with the binder resin. The agent is C
,1,5olvent Red 49 and C,1,5ol
The present invention provides a magenta developer characterized by comprising vent Red 8.

The binder resin, which is the main component of the magenta developer of the present invention, is a styrene-acrylic resin (A) made by copolymerizing a polyester resin (A) and a copolymerizable monomer containing an amine group.
B), and the weight ratio of resin (A) and resin (B) (
A):(B) is in the range of 55:45 to 95:5, and the softening point of the resins (A) and (B) (ring and ball method JIS K
-2207) is 120°C or less. For magenta developers, transparency is required as a resin property, and it is important that the resin has sharp melt properties. A binder resin that meets these requirements must have a glass transition temperature (Tg) of 55°C or higher for storage stability, and a binder resin used for magenta developers must have an affinity for organic pigments and dyes. It is preferable to have a chemical structure with high dispersibility or solubility.

Blending weight ratio of resin (A) and resin (B) (A): (B
) is 55:45 to 95:5, more preferably 65
: In the range of 35 to 90:10. If the ratio of the resin (B) is less than 5, the amount of charge on the toner will be insufficient or the toner will be negatively charged. Furthermore, if the ratio of resin (B) is more than 45, the polyester resin loses its ability to disperse or dissolve dyes and pigments, and when used in a magenta toner, the chroma becomes low and dull, and OHP The disadvantage is that the projected image becomes dark, which is undesirable. Further, the softening point (SP) of each resin (A) and (B) must be 120° C. or lower. If SP exceeds this range, the molecular weight of the binder resin becomes too large and the sharp dissolution property is impaired due to the entanglement of polymer chains, resulting in a lack of transparency and a dull-toned image with low chroma, which is undesirable.

On the other hand, regarding colorants, C0I, 5olvent R
ed49 is a metal complex dye C, 1.5olvent
By using Red 8 in combination, fading of color due to heat and light can be reduced and hue can be controlled, and an excellent magenta developer can be obtained.

In addition, by mixing dyes and pigments, or pigments and pigments of the same hue in the binder resin, clear and high-density images can be obtained, and images fixed on OHP transparent ranges have high spectral transmission characteristics. It can be made to have good projection properties.

Furthermore, according to the present invention, it is possible to obtain a magenta developer that is less affected by temperature and humidity environments and always has stable charging properties. In addition, it is possible to use no dye, or to use it in a very small amount, and as a result, dye bleeding, filming on the photoreceptor, spending on the carrier, etc. can be significantly improved. , it is possible to obtain a highly durable magenta developer that maintains its initial performance even when the developer is used for a long period of time.

A more preferred embodiment of the present invention is obtained by specifying the blending ratio of the colorant.

That is, C,1,5olvent Red 49 and C,1
, 5 in combination with Solvent Red 8, the total amount of colorant based on 100 parts by weight of binder resin is 4.0 to 0.5 parts by weight.
5 parts by weight, and C,1,5olvent Re
d49 is 3.0 to 0.5 parts by weight, more preferably 2.
5 to 1.0 parts by weight, C.I. I. SolventRed 8
is 2.0 to 0.1 parts by weight, more preferably 1.5 to 0.1 parts by weight.
3 parts by weight. C. I. SolventR
If the proportion of ed 49 is more than 3.0 parts by weight, it becomes difficult to control charging properties, and there is a tendency for light fastness to decrease. On the other hand, if the proportion is less than 0.5 parts by weight, the desired image density cannot be obtained. Also, C.I.SolventRed 8
If the proportion is more than 2.0 parts by weight, it becomes susceptible to changes in temperature and humidity environment. On the other hand, if it is less than 0.1 part by weight, the desired image density cannot be obtained.

The polyester resin (A) used as the binder resin of the present invention is synthesized by a condensation reaction between a polyhydric carboxylic acid and a polyhydric alcohol. Examples of polyhydric carboxylic acids include carboxylic acids such as fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, succinic acid, and adipic acid, their anhydrides, or lower alkyl esters thereof. can. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, neopentyl glycol, and polyoxyethylene (2,2)-2,2''-bis(4-hydroxyphenyl)propane. , polyoxypropylene (2,2
)2.2''-bis(4-hydroxyphenyl)propane, hydrogenated bisphenol A1 glycerin, etc. can be used.Moreover, monocarboxylic acids and monoalcohols can be added if necessary.

Furthermore, a styrene-acrylic copolymerizable monomer is used as a raw material for the styrene-acrylic resin (B) obtained by copolymerizing the amino group-containing copolymerizable monomer used as the binder resin of the present invention. As a body, styrene, 0-methylstyrene,
Styrenic monomers such as m-methylstyrene, p-methylstyrene, α-methylstyrene, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, n-butyl methacrylate, methacrylic acid 1so- Butyl, 2-ethylhexyl methacrylate,
Examples include esters of acrylic acid and methacrylic acid such as lauryl methacrylate, and other copolymerizable monomers may be used in combination if necessary.

Copolymerizable monomers containing amino groups include dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, p-dimethylaminostyrene. , N-vinylpyridine,
Monomers such as N-vinylpyrrolidone can be used.

As the carrier used in the present invention, well-known carriers can be used, and specifically, iron, ferrite, steel, magnetite,
Examples include magnetic materials such as nickel, and carrier materials whose surfaces are coated with various resins. Further, particularly suitable carrier coating materials for use in the magenta developer of the present invention include fluororesins and silicone resins.

As for the fluororesin, the proportion of fluorine atoms in the monovalent atoms bonded to the carbon main chain and side chains is 80 mol%.
Fluororesins having the above properties are preferred. Such fluororesins include poly(tetrafluoroethylene-vinylidene fluoride), poly(tetrafluoroethylene-fluoropropyl vinyl ether), copolymers of 2-perfluorooctylethyl methacrylate and n-butyl methacrylate, and poly(tetrafluoroethylene-vinylidene fluoride), Examples thereof include tetrafluoroethylene-hexafluoropropylene) alone and in mixtures.

Further, as the silicone resin, a silicone resin that cures at room temperature is preferable, and a silicone resin that cures at room temperature after coating the carrier with a silicone varnish that cures at room temperature is particularly preferable.

The room temperature curable silicone varnish is a silicone resin having the chemical structure shown in the following formula, such as KR414,
KR-220, KR-251, Kl? -255 (both manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

R2R30 →0-3i÷4 (However, in the formula, R1 to R4 are a hydrogen atom, a hydroxyl group, a lower alkoxyl group having 1 to 4 carbon atoms, a methyl group, or a phenyl group.) [Example] The present invention is described below. will be explained using a specific example. However, the present invention is not limited to the following examples. Further, the numbers in the composition ratios shown below are expressed in parts by weight unless otherwise specified.

Examples of manufacturing a carrier particularly suitable for the present invention and synthesis examples of a binder resin used in the present invention are also shown below.

<Carrier production example> Production example 1 100 parts of iron powder (TSV-300) manufactured by Nippon Tetsuko Co., Ltd. was fluidized in a fluidized bed, heated to 80°C, and mixed with 5% water.
Spray 10 parts (in terms of resin content) of a fluororesin (manufactured by Daicel Chemical Industries, Ltd., Guiflon ND-4) diluted to
A coated carrier (1) was obtained by heat treatment for 120 minutes.

Production example 2 Ferrite particles (F2O3) manufactured by Nippon Iron Powder Co., Ltd. 1000
While fluidizing the part in a fluidized bed, raise and maintain the temperature at 60°C,
Spray 10 parts (resin content equivalent) of silicone resin (manufactured by Shin-Etsu Silicone Co., Ltd., KR-251) dissolved to 5% in toluene, dry for another 20 minutes, and then heat-treat in an electric furnace at 200°C for 130 minutes to coat. Obtained carrier (2).

Synthesis Example of Binder Resin> Synthesis Example I 149.1 parts of propylene glycol, 52.1 parts of ethylene glycol, and 410.2 parts of dimethyl terephthalate were subjected to a condensation reaction, and further 55.3 parts of trimellitic anhydride was added and reacted. Polyester resin (1
) was obtained.

Synthesis example ■ Polyoxypropylene (2,2) -2,2'-bis(
350.0 parts of (4hydroxyphenyl)propane, 116.0 parts of maleic acid, and 0.2 parts of hydroquinone methyl ether were subjected to a condensation reaction, and sp was 98. A polyester resin (2) having an ε°C1Tg of 60.5°C was obtained.

Synthesis example ■ 5.0 parts of dodecyl mercaptan, 120.0 parts of styrene, 70 parts of n-butyl methacrylate in 60.0 parts of toluene.
．． 0 parts, diethylaminoethyl methacrylate 10.0
After adding 4.0 parts of α, α” azobisisobutyronitrile as a polymerization initiator and carrying out a ripening reaction, toluene was removed as a topping to obtain a styrene-acrylic resin (1). .

The resin had an sp of 104.5°C and a Tg of 62.3°C.

Synthesis example ■ 3.0 parts of dodecyl mercaptan in 60.0 parts of xylene
parts, 170.0 parts of styrene, 20.0 parts of 2-ethylhexyl acrylate, 1-dimethylaminoethyl acrylate
10.0 parts, and 6.0 parts of α,α゛-azobisdimethyl cracked nitrile was added as a polymerization initiator to polymerize.
After the aging reaction, xylene was removed to obtain styrene-acrylic resin (2).

The resin had an sp of 106.2°C and a Tg of 68.8°C.

Example-1 Polyester resin (2) 80.0 parts, styrene-acrylic resin (2) 20,0 parts, Aizen Rhodam
ine Red Ba5e (manufactured by Hodogaya Chemical Industry Co., Ltd. C, 1
, 5olvent Red 49) 2.5 parts, Zapo
n Fast Red BE (C.I.S. manufactured by BASF)
After mixing 1.0 part of OlventRed 8), melt-knead with a twin-screw extruder mixer, coarsely grind to 2 mm or less with a cutter mill, and then grind 5 to 2 Q pm with an air jet mill.
It was crushed and classified to an average of 10. A magenta toner was prepared by mixing 0.2 parts of hydrophobic silica R974 (manufactured by Nippon Aerosil Co., Ltd.) with 100 parts of the fine particles using a high-speed mixer. 50 parts of this magenta toner and 950 parts of coat carrier (1) were mixed in a ■ type blender to obtain a developer.

When the developability of this developer was evaluated using a commercially available general-purpose copying machine, the initial charge amount by blow-off method was 16.
A clear, fog-free image with a high image density (ID-1, 62 by Macbeth densitometer RD-914) was obtained. Also, even after 10,000 sheets were continuously copied, the amount of charge remained at 17.
．． An image of good quality comparable to the initial image of 6 pc/g and 10 of 1.54 was obtained. Also, copy onto the Kano P sheet and use the upper and lower silicone roll fixing machines (temperature 1
The image fixed at 60°C and a circumferential speed of 50 mm/5ec) is
It had good transparency, and the image projected by OHP had a good magenta color. In addition, the solid part of the copy image is divided into two parts, one part is stored in a cool and dark place, and the other part is stored in an S
un 5hine Weather Meter 4
Ultraviolet rays were irradiated with a carbon arc in an atmosphere of 5°C. After irradiating with ultraviolet rays for 5 hours, the color difference (ΔE) was determined using a colorimeter (model ND4001DP) manufactured by Nihon Heavy Industries Co., Ltd.

The result was ΔE=4.6, indicating that there was little fading.

Example-2 70.0 parts of polyester resin (1), 30.0 parts of styrene-acrylic resin (1), 0RIENT O4l Pi
nk 312 (C, 1,5ol manufactured by Orient Chemical Industry Co., Ltd.
vent'Red 49N, Part 5, Valifast
Red 3304 (manufactured by Orient Chemical Industry Co., Ltd., C, 1,
Example 1 using 1.5 parts of 5olvent Red 8)
A magenta toner was manufactured using the same process.

30 parts of this magenta toner and coat carrier (2) 97
0 parts were mixed in a ■-type blender to obtain a developer.

When this developer was evaluated in the same manner as in Example-1, the initial charge amount was 17.4 pc/g, it was clear and had no fog, and the I
An image with D of 1.46 was obtained, and after 10,000 sheets were continuously copied, the charge amount was 16.6 pc/g, and there was no fog with 10 of 1.50 (an image comparable to the initial image was obtained, and it was fixed on the OHP sheet. When the resulting image was projected, it exhibited a good magenta color and had good transparency.Furthermore, the color difference after irradiation with ultraviolet light for 5 hours was 8E=3.7, and no fading was observed.

Further, the amount of charge after the developer was left in an environment of 35° C./80% RH for 24 hours was 12.6 μc/g, and a clear image without fogging was obtained.

Example-3 75.0 parts of polyester resin (1), 25.0 parts of styrene-acrylic resin (2), Aizen Rhodam
ine Red Ba5e1.0 part, Valifast
A magenta toner was produced using 33042.0 parts of Red 33042.0 parts in the same process as in Example-1. 50 parts of this magenta toner and 950 parts of coat carrier (1) were mixed in a ■ type blender to obtain a developer. This developer was used in Example-1.
When evaluated in the same manner as above, the initial charge amount was 16.6pc.
/g, a clear and fog-free image with an ID of 1.54 was obtained, 1ooo.

After continuous copying, an image with a charge amount of 16.2 pc/g and a 10 of 1.60 without fog was obtained, comparable to the initial image.
When the fixed image was projected onto an OHP sheet, it exhibited a good magenta color and had good transparency. Further, the color difference after irradiation with ultraviolet rays for 5 hours was ΔE=2.9, and no fading was observed.

Example-4 65.0 parts of polyester resin (2), 35.0 parts of styrene-acrylic resin (1), 0RIENT Oil Pi
nk 3121.5 parts, Aizen 5pilon R
ed BEH (Hodogaya Chemical Industry Co., Ltd. C, I, 5olve)
A magenta toner was produced using 0.5 part of nt Red 8) in the same process as in Example-1. 50 parts of this magenta toner and an uncoated carrier (manufactured by Nippon Tetsuko Co., Ltd., TEFV-
200/300) were mixed with 950 parts in a ■ type blender to obtain a developer. When this developer was evaluated in the same manner as in Example-1, an image with an initial charge amount of 13.6 μc/g, clear and fog-free, and an ID of 1.62 was obtained.
After continuous copying of 00 sheets, the amount of charge was 14.1μc/g, I
A fog-free image with a D of 1.67 was obtained, comparable to the initial image, and when the fixed image was projected onto an OHP sheet, it exhibited a good magenta color and had good transparency. Further, the color difference after irradiation with ultraviolet rays for 5 hours was ΔE=5.2, and no fading was observed.

Comparative Example-1 Rhodamine B Ba5e (BA
SF company C, 1Solvent Red 49) 3.0
A magenta toner was produced in the same manner as in Example 1, except that the following procedure was used.

50 parts of this magenta toner and coat carrier (1) 95
0 parts were mixed in a V-type blender to obtain a developer. When this developer was evaluated in the same manner as in Example-1, the initial charge amount was 18.3 pc/g, clear and fog-free, and 10 was 1.
．． After continuous copying of 10,000 sheets, images with a charge amount of 12.1 pc/g and a TD of 1.74 were obtained, but some fogging occurred. Furthermore, when the fixed image was projected onto an OHP sheet, it exhibited a good magenta color and had good transparency. Further, the color difference after irradiation with ultraviolet rays for 5 hours was ΔE = 18.3, and clear discoloration was observed.

Comparative Example 2 A magenta toner was produced in the same manner as in Example 2, except that 40.0 parts of polyester resin (1) and 60.0 parts of styrene-acrylic resin (1) were used. 30 parts of this magenta toner and 970 parts of coat carrier (2) were mixed in a ■ type blender to obtain a developer. This developer was used in Example-1.
When evaluated in the same manner as above, the initial charge amount was 22.8pc.
/g, clear and fog-free images with an ID of 1.44 are obtained, and the amount of charge is 23.1 μ even after 10,000 continuous copies.
An image with c/g, 10 of 1.37 was obtained, and a clear image without fog was obtained. However, when the 0) IP receipt fixed image was projected, it exhibited a grayish magenta color and had poor transparency. Further, the color difference after irradiation with ultraviolet rays for 5 hours was ΔE=3.9, and no fading was observed.

Comparative Example-3 Polyester resin (2) 100 parts, Bontron P-5
2 (manufactured by Orient Chemical Co., Ltd., charge control agent) 3.0 parts, Ai
zen Rhodamine Red Ba5e 2.
A magenta toner was produced in the same manner as in Example-1 except that 5 parts of Zapon FastRed BE and 1.0 part of Zapon FastRed BE were used. 50 copies of this magenta toner and coat carrier (
1) were mixed with 950 parts using a ■ type blender to obtain a developer. When this developer was evaluated in the same manner as in Example-1,
The initial charge amount was 13.2 pc/g, and a clear, fog-free image with an ID of 1.51 was obtained, and after continuous copying of 10,000 sheets, the charge amount was 8.3 pc/g, and 10 was 1.03, which was remarkable. Fog occurred, resulting in poor images lacking clarity.

Comparative Example-4 Polyester resin (1) 75.0 parts, styrene-acrylic resin (]) 225.0 parts0RIENT Oil Pi
A magenta toner was produced using 3121.5 parts of NK in the same process as in Example-1. 30 parts of this magenta toner and 970 parts of coat carrier (2) were mixed in a ■ type blender to obtain a developer. When this developer was evaluated in the same manner as in Example-1, an image with an initial charge amount of 15.7 μC/g, a clear image with no fog, and a 10 of 1.52 was obtained.
Even after continuous copying of 0,000 sheets, the amount of charge is 16.1pc/g,
10 was 1.58, an image with no fog and comparable to the initial image was obtained. In addition, when the image fixed on the 01(P sheet was projected, it exhibited a good magenta color and had good transparency. However, the color difference after irradiation with ultraviolet rays for 5 hours was ΔE = 1
8.3, and the color was significantly faded.

〔Effect of the invention〕

As described above, by using the positively chargeable dry magenta developer of the present invention, it was possible to obtain a full-color image with unprecedented clarity.

Furthermore, the image developed into OHP I-Lance Spare Range had good transparency, and the light transmission image showed vivid color development.

Claims (1)

[Claims] 1. In a dry developer formed by mixing a carrier and a toner, the binder resin, which is the main component of the toner, is composed of a polyester resin (A) and a copolymerizable monomer containing an amino group. styrene-acrylic resin (B) formed by copolymerizing polymers, and the weight ratio of resin (A) and resin (B) (A): (B
) is in the range of 55:45 to 95:5, the softening points (ring and ball method) of the resins (A) and (B) are 120°C or less, and the colorant mixed with the binder resin is in the range of C.I. I. SolventR
ed49 and C. I. A magenta developer comprising Solvent Red 8. 2. The blending ratio of the colorant to 100 parts by weight of the binder resin is C. I. Solve
ntRed49 is 3.0 to 0.5 parts by weight and C.I. I. So
2. The magenta developer according to claim 1, wherein lventRed8 is in the range of 2.0 to 0.1 parts by weight, and the total amount of both colorants is 4.0 to 0.5 parts by weight. 3. The carrier according to claim 1 or 2, wherein the carrier is coated with a fluororesin in which the proportion of fluorine atoms among the monovalent atoms bonded to the carbon chain is 80 mol% or more. Magenta developer. 4. The carrier is coated with room temperature curing silicone resin,
The magenta developer according to claim 1 or 2, wherein the magenta developer is heat-treated at at least 180°C.