JPH05165257A - Nonmagnetic one-component color developer - Google Patents

Abstract

PURPOSE:To provide a nonmagnetic one-component color developer having enough electrification property, fluidity, and environmental stability to be used as a developer for contact or noncontact developing method, which gives high picture density, little fogging, and high picture quality level. CONSTITUTION:This developer is used for such a developing method that a developer blade to regulate thickness of the developer layer is disposed in contact with the surface of a developer roll under pressure, the developer is uniformly applied on the surface of the developer roll, and then the developer roll is directly brought into contact with an electrostatic latent image on a photosensitive body or is made to indirectly face to the latent image to develop the image. The developer consists of a mixture of 100 pts.wt. of coloring fine particles and 0.3-10 pts.wt, of an inorg. fine powder (2). The coloring fine particles contain at least a binder resin, coloring agent, and boron metal complex compd. expressed by formula as the charge controlling agent. The inorg. fine powder (2) is obtd. by treating an inorg. fine powder (1) having 0.1-10mum average particle diameter with <=1wt.% weight decrease by heating (under conditions of drying at 150 deg.C for one hour) with a silicone oil to render the powder hydrophobic. In formula, A is alkali metal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color developer,
More specifically, it relates to a non-magnetic one-component color developer that visualizes an electrostatic latent image formed on a photoconductor or a dielectric by an electrophotographic device or an electrostatic recording device.

[0002]

2. Description of the Related Art Toner is obtained by externally adding finer colloidal silica or the like as a fluidizing agent (adding independently to colored fine particles) to colored fine particles containing at least a binder resin and a colorant. The two-component developer composed of the toner and carrier is widely used because of its good image quality.

However, on the other hand, there are drawbacks common to two-component developers as described below. (1) Toner receives a triboelectric charge due to mutual friction between the toner and the carrier, but when used for a long period of time, the carrier surface is contaminated by the toner, and as a result, the toner cannot acquire the triboelectric charge sufficiently.

(2) The toner and the carrier must be adjusted to have a mixing ratio within a predetermined range, but if used for a long period of time, the mixing ratio fluctuates and deviates from the predetermined range.

(3) Iron powder or glass beads whose surface is oxidized is generally used as the carrier, but the surface of the photoreceptor is mechanically damaged by these carriers.

Therefore, in recent years, without using a carrier,
Various developing methods using a magnetic one-component developer containing magnetic powder in toner have been proposed (for example, US Pat. No. 3,909,258 and US Pat. No. 4,121,93).
No. 1). However, these known methods also have the following drawbacks.

(1) Since the magnetic one-component developer contains a large amount of magnetic powder having a low electric resistance, the developed image on the electrostatic latent image is electrostatically transferred onto a supporting member such as plain paper. Is difficult. In particular, sufficient transfer performance cannot be obtained in a humid atmosphere.

(2) Since a large amount of black magnetic powder is contained, it is difficult to change the hue of the developer, that is, it is difficult to color the developer.

(3) Since the magnetic one-component developer contains a large amount of magnetic powder, the fixing power is lower than that of the two-component developer. As a result, it is necessary to raise the temperature and pressure of the fixing device, which has the drawback of increasing the running cost.

By the way, recently, a developing method using a one-component developer containing no magnetic powder and having a large resistance has attracted attention. As the developing method thereof, for example, US Pat.
895,847, U.S. Pat. No. 3,152,012,
Examples thereof include those based on touchdown or impression development described in JP-B-41-9475, JP-B-45-2877, JP-B-54-3624 and the like. In these methods, of the developers conventionally used for two-component developers, the toner excluding the carrier is used as the non-magnetic one-component developer.

However, conventionally, there is a problem that it is difficult to obtain a non-magnetic one-component developer with less fog. In the two-component developer, a developer containing a large amount of carrier such as iron powder or glass beads is used in addition to the toner, and the toner is forcibly stirred with a magnetic roll or the like, so that a high charge amount can be easily given to the toner. it can. Further, in the magnetic one-component developing method, although there is no carrier, the toner on the developing sleeve can be magnetically moved by the magnetic roll and can be rubbed between the sleeve and the toner. Therefore, even in this method, a sufficient charge amount is given to the toner. be able to. On the other hand, in the non-magnetic one-component developing method, the toner is pressed against the developing roll by the developing blade to charge the toner, so that only the upper portion of the toner layer can be charged.

Further, as compared with the conventional charge control agent, the charge control agent of the color developer does not have a high chargeability, so that the image density is low and only an image with a large fog is obtained. ..

[0013]

SUMMARY OF THE INVENTION The object of the present invention is to overcome the problems of the above-mentioned prior art and to provide sufficient chargeability, fluidity and environmental stability as a developer used in a contact or non-contact development system. And a non-magnetic one-component color developer having high image density, low fog and high image quality.

The inventors of the present invention have conducted extensive studies in order to overcome the problems of the above-mentioned prior art, and as a result, used a specific compound containing a boron metal as a complex in the developer as a charge control agent, and By using an inorganic fine powder with a large particle size and specific chargeability, which has been modified by being hydrophobized with silicone oil, the fluidity of the developer can be increased and the chargeability, especially during development, can be improved. It has been found that the surface potential of the toner on the developing roll can be increased and the above object can be achieved. The present invention has been completed based on these findings.

[0015]

Thus, according to the present invention, the developing blade for controlling the layer thickness of the developer is arranged so as to be in pressure contact with the surface of the developing roll, and the developer is uniformly applied to the surface of the developing roll. A developer used in a method of developing by directly contacting a developing roll with an electrostatic latent image on a photoconductor, or facing it in a non-contact manner, at least a binder resin, a colorant,
And 100 parts by weight of colored fine particles containing a boron metal complex compound represented by the following formula as a charge control agent,
Inorganic fine powder (1) having an average particle size of 0.1 to 10 μm and a heat loss (drying condition at 150 ° C. for 1 hour) of 1% by weight or less
Inorganic fine powder with hydrophobic treatment of silicone oil (2)
There is provided a non-magnetic one-component color developer obtained by mixing 0.3 to 10 parts by weight.

[0016]

[Chemical 2] (However, A is an alkali metal.)

The blow-off charge amount of the hydrophobically treated inorganic fine powder (2) is preferably in the range of -50 to -200 μc / g. As the inorganic fine powder (1), various ones can be used, but among them, silicon dioxide, aluminum silicate, magnesium silicate or alumina is particularly preferable because of its electrostatic property.

The present invention will be described in detail below. (Charge Control Agent) The charge control agent used in the present invention is a boron metal complex compound represented by the following formula.

[0019]

[Chemical 3] However, A is an alkali metal and is cationized to form a salt with the boron metal complex.

The boron metal complex compound has good dispersibility with the binder resin component, has thermal stability up to a temperature at which melt kneading can be sufficiently performed, and is colorless, so that the developer is highly negatively charged. Can be given. Metal complexes other than boron have insufficient chargeability, and chromium and iron are not suitable for color because they are colored.

The boron metal complex compound is lithium,
Although it is a salt of an alkali metal such as sodium or potassium, potassium is preferable among the alkali metals because of its chargeability. Environmental stability is insufficient with salts other than alkali metals.

The ratio of the boron metal complex compound used is
The amount is usually 0.3 to 10 parts by weight, preferably 0.5 to 7 parts by weight, based on 100 parts by weight of the binder resin. If this usage ratio is less than 0.3 parts by weight, sufficient charging properties cannot be obtained at the beginning of the number of printed sheets. If this usage ratio is more than 10 parts by weight, the charge amount after continuous printing will decrease, and similarly fog and image density will decrease.

(Inorganic Fine Powder) The raw material inorganic fine powder (1) used in the present invention has a particle size of 0.1 to 10 μm, preferably 0.3 to 5 μm. If it is smaller than 0.1 μm, the charging property is low, and if it is larger than 10 μm, the photoconductor or the like is scratched or the fluidity is deteriorated, and the image quality is deteriorated.

The proportion of the hydrophobically treated inorganic fine powder (2) used is 0.3 to 100 parts by weight of colored fine particles containing at least a binder resin, a colorant, and the specific boron metal complex compound. 10 parts by weight, preferably 0.5-
It is in the range of 5.0 parts by weight. If this ratio is less than 0.3 parts by weight, the charging property will be low, and if it is more than 10 parts by weight, the fluidity will be deteriorated and the image quality will be deteriorated.

The material of the inorganic fine powder used in the present invention is preferably silicon dioxide, aluminum silicate, magnesium silicate, or alumina because of its electrostatic property.

The inorganic fine powder used in the present invention has a temperature of 150 ° C.
The loss on heating under dry conditions for 1 hour is 1% by weight or less, preferably 0.5% by weight or less. If the heating loss is more than 1% by weight, the subsequent hydrophobic treatment will not be successful,
Environmental resistance deteriorates.

Therefore, when the loss on heating of the inorganic fine powder before the hydrophobic treatment is high (drying condition at 150 ° C. for 1 hour), it is important to preliminarily perform heat treatment or the like to 1% by weight or less. From such a point, the fired inorganic fine powder is more preferable.

(Hydrophobic treatment) In the present invention, as the inorganic fine powder (2), one which has been hydrophobized with silicone oil is used. The silicone oil is used as it is or after diluted with an organic solvent. The amount of silicone oil used is usually 0.1 per 100 parts by weight of the inorganic fine powder.
It is about 10 parts by weight.

In the hydrophobic treatment, the silicone oil is added to the inorganic fine powder (1) as it is or in a liquid diluted with an organic solvent, and the mixture is mixed using a mixer such as a Henschel mixer, and then the solvent is used. If necessary, remove the solvent by air drying,
Then, from room temperature to 300 using heating or curing catalyst
It is carried out by curing or wetting the silicone oil for several minutes to several days under the temperature condition up to ° C.

Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone oil, silanol modified silicone oil, alkyl modified silicone oil, amino modified silicone oil, epoxy modified silicone oil, fluorosilicone oil and silicone. Various materials such as polyether copolymers can be mentioned, and among them, dimethyl silicone oil, methyl hydrogen silicone oil, and silanol-modified silicone oil are particularly preferable in view of ease of treatment and water repellency.

Dimethyl silicone oil has a viscosity of 10
In the range of ~ 2,000 cs, use as it is,
Alternatively, it is diluted with an organic solvent before use. Inorganic fine powder 100
Dimethyl silicone oil is added in an amount of 0.1 to 0.1 wt.
Add 10 parts by weight and mix with a Henschel mixer or the like. After that, when an organic solvent is used, it is air-dried to remove the organic solvent, and the temperature is 100 to 300 ° C. for 10 minutes to 1 minute.
It is cured or moistened for 0 hours, and then subjected to a hydrophobic treatment.

The methyl hydrogen silicone oil may be used as it is or may be diluted with an organic solvent before use. Methyl hydrogen silicone oil was added at a ratio of 0.1 to 10 parts by weight to 100 parts by weight of the inorganic fine powder (1), mixed with a Henschel mixer, and air dried when an organic solvent was used. Remove the solvent to 100
Harden or wet by heat treatment at ~ 200 ° C for 0.5-5 hours. Further, 0.1 to 5 parts by weight of a catalyst such as zinc octylate, tin octylate, and dibutyltin dilaurate is added to 100 parts by weight of methyl hydrogen silicone oil. When an organic solvent is used, it is air-dried to remove the solvent. At room temperature to 200 ° C. for 0.5 to 24 hours,
Hydrophobize.

The silanol-modified silicone oil is 2 to 10 parts by weight of a methyl hydrogen silicone oil or an alkoxy-modified silicone oil as a cross-linking agent, and zinc octylate, tin octylate, or dibutyltin dilaurate 0.5 to 5 as a catalyst. One part by weight is mixed with 100 parts by weight of silanol-modified silicone oil, and this is diluted with an organic solvent. This solution was added to 100 parts by weight of inorganic fine powder,
The silanol-modified silicone oil is mixed in an amount of 0.5 to 2 parts by weight. After air-drying this, room temperature to 200 ° C
Then, the composition is cured or moistened for 0.5 to 24 hours.

The blow-off charge amount of the hydrophobically treated inorganic fine powder (2) used in the present invention is -50 to -200 μc.
It is preferably within the range of / g. If the blow-off charge amount is greater than -50 μc / g, the charge amount is insufficient, the image density is low, and fog increases, and the amount is -200 μc.
When it is smaller than / g, the image density is similarly low and the fog is large.

(Binder Resin, Coloring Agent, etc.) As the binder resin (binder resin) of the developer used in the present invention, resins which have been widely used in the conventional developers for electrophotography or printers, for example, Polymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and their substitution products; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene. Copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene -Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, Tylene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene resin Polymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene copolymers such as styrene-maleic acid ester copolymers; polymethylmethacrylate, polyvinyl chloride, Polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic Petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.

Other charge control agents used in the developer include, for example, oxide starch, metal-containing dyes, salicylic acid metal complexes, nigrosine dyes, triphenylmethane dyes, rhodamine dyes and phthalocyanine dyes. If desired, a small amount may be used in combination with the boron metal complex compound.

As the colorant used in the developer, various coloring materials such as carbon black, dyes and pigments can be used.
Specifically, for example, carbon black, nigrosine dye, iron black naphthol yellow S, Hansa yellow (10
G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), Permanent Yellow (NCG), Balkan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Lead Tan, Lead Vermilion, Cadmium Red, Cadmium Mercury Red. , Antimon Zhu, Permanent Red 4R, Para Red, Faise Red,
Parachlor Ortho Nitroaniline Red, Resor Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Bengal Fast Rubin B,
Resor Red, Rake Red (C, D), Anthocin B, Brilliant Scarlet G, Resor Rubin G
K, Permanent Red F5R, Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y. , Alizarin Rake,
Thioindigo red B, thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome permillion, benzidine orange, perinone orange, oil orange, cobalt blue, cerulean blue, alkali blue lake, peacock blue lake, Buktoria blue rake, metal-free phthalocyanine blue, phthalocyanine blue, fast sky blue, indanthrene blue (RS, B
C), indigo, ultramarine, navy blue, anthraquinone blue,
Fast violet B, methyl violet rake,
Cobalt purple, manganese purple, dioxane violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment green B, naphthol green B, green goalgo, acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, oxidation Examples include titanium, zinc white, lithophone, and the like. These can be used alone or in combination of two or more.

If desired, a wax such as polypropylene or polyethylene may be added to the developer of the present invention as a release agent.

(Development Method) In the non-magnetic one-component color developer of the present invention, a developing blade for controlling the layer thickness of the developer is arranged so as to be in pressure contact with the surface of the developing roll, and the developer is uniformly applied to the surface of the developing roll. Then, the developer is used in a method of developing by directly contacting the electrostatic latent image on the photoconductor with a developing roll or facing it in a non-contact manner.

A developing device and a developing method in which the developer of the present invention is used will be described with reference to FIG. Figure 1
Shows a developing device of a type in which a developing roll is brought into direct contact with an electrostatic latent image on a photoconductor. As shown in Figure 1,
The developer (4) contained in the developer container (5) is moved between the developing roll (2) and the developing blade (3) by a stirring rod (6) to forcibly thin the developer, and , To charge.

The photoconductor (1) is previously charged with the charger wire (9).
Electrified with, and irradiate it with an optical signal or optical image (10),
An electrostatic latent image is formed, and the developer on the developing roll (2) is brought into contact with it to develop the latent image. Next, using the transfer charger wire (11), the developed developer on the photoconductor is transferred to a support such as paper, which is passed through a heating roll (12) and fixed. At this time, the untransferred developer on the photoconductor is
It is scraped off by the cleaning blade (7) and collected by the screw (8) in the waste developer container on the back side of the developing device.

[0042]

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

The physical properties were evaluated by the following methods. <Flowability> The flowability of the developer is Hosokawa Micron Co., Ltd.
It measured using the powder tester apparatus by the company, and evaluated. That is, a certain amount of the developer is weighed, placed on a 60-mesh sieve, vibrated with a certain amplitude for a certain period of time, and the amount of toner passing through is converted into the weight per minute and displayed.

<Blow-off charge amount> Carrier TEFV150 / 250 manufactured by Powder Tech Co., Ltd. 59.
Weigh 7 g and 0.3 g of hydrophobized inorganic fine powder,
Put it in a SUS pot, rotate it for 30 minutes, and use a blow-off meter made by Toshiba Chemicals Co., Ltd., nitrogen gas 1 kg / cm ²
It was blown off at the pressure of and the charge amount was measured.

<Surface potential> The developer is put in the developing device shown in FIG. 1, stopped during printing, and the surface potential of the developer on the developing roll is measured by a surface potential meter. At this time, the measurement position of the surface electrometer is adjusted to a constant value using a micro laser outer diameter measuring device.

<Image characteristics> As a durability test, 20,000 copies were made with the developing device shown in FIG.
(2) Presence or absence of fog, (3) Presence or absence of a film adhered to the photoconductor by the developer were visually observed and evaluated. The image density (ID) was evaluated by using a Macbeth reflection densitometer to measure the black solid part. (4) Environmental test is 30 ℃ × 80% R
Copying was performed in an environment of high temperature and high humidity of H and low temperature and low humidity of 10 ° C. × 20% RH, and images were similarly evaluated.

Each image characteristic was evaluated in the following three stages. ◯: Stable and good image, Δ: When image density is slightly low or fogging is slightly observed, x: Image density is low, fogging occurs, image is uneven, or film is attached. And so on.

[Example 1] 100 parts by weight of a styrene-butyl acrylate copolymer as a binder resin, 5 parts by weight of a red pigment as a colorant, 4 parts by weight of low molecular weight polypropylene, and the boron metal complex compound (potassium) as a charge control agent. After mixing 2 parts by weight of salt) with a Henschel mixer, 1
Knead uniformly with a kneading roll at 50 ° C., then cool,
After crushing with a crusher, 5 to 20 with an air jet crusher
The particles were pulverized to a particle size of 12 μm with a classifier to prepare colored fine particles.

Hydrophobized inorganic fine powder is silicon dioxide 1
It was prepared by adding 1 part by weight of dimethyl silicone oil to 00 parts by weight, mixing the mixture with a Henschel mixer, curing or wetting at 250 ° C. for 2 hours, and performing a hydrophobic treatment. 2 parts by weight of the hydrophobized inorganic fine powder was added to 100 parts by weight of the colored fine particles and mixed by a Henschel mixer to obtain a non-magnetic one-component developer. The particle size of the silicon dioxide used was 2.5 μm, the weight loss upon heating (150 ° C., 1 hour) was 0.3% by weight, and the blow-off charge amount was −105 μc / g, which was high and sufficient.

The fluidity of the obtained developer was as high as 35, and the fluidity was sufficient. As a durability test, 20,000 copies were made with the developing device shown in FIG. 1, but the image was stable from the beginning and no change in image quality was observed even after 20,000 copies were made. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as high as 50 V and was stable. Furthermore, 10
Even at low humidity of 20% RH at 80 ° C or 80% R at 30 ° C
Even at high humidity of H, the change in image density was small and it was good. The results are shown in Table 1 (same below).

[Comparative Example 1] The same silicon dioxide used in Example 1 was allowed to stand under high humidity to reduce the weight by heating (150).
When measured at 1 ° C. for 1 hour, it was 1.6% by weight. Using this inorganic fine powder, a non-magnetic single-component developer was obtained in the same manner as in Example 1.

The fluidity of the obtained developer was as low as 15, and the fluidity was not sufficient. Further, a durability test was conducted, but the image density was low from the beginning and fog was also observed. Two
When 10,000 sheets were copied, unevenness was found in the image, which was unbearable for use. When the development was stopped halfway and the surface potential on the developing roll was measured, it was as low as 25 V and the charge amount was insufficient.

[Comparative Example 2] The particle size of the inorganic fine powder was 0.
A non-magnetic one-component developer was obtained in the same manner as in Example 1 except that silicon dioxide having a small size of 016 μm was used. The fluidity of the obtained developer was as high as 75, showing sufficient fluidity. The durability test was stopped halfway because there was a lot of fog and the image density was low from the beginning. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 20 V and was insufficient.

[Comparative Example 3] The particle size of the inorganic fine powder was 15
A non-magnetic one-component developer was obtained in the same manner as in Example 1 except that silicon dioxide having a large value of μm was used. The resulting developer had a low fluidity of 8 and did not show sufficient fluidity. When a durability test was conducted, the image density was low from the initial stage, fog was observed, and after copying 20,000 sheets, the image was uneven and the result was unbearable for use. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 20 V and was insufficient.

Examples 2 to 3 As inorganic fine powders, Table 1
As shown in FIG. 2, aluminum silicate was used in Example 2, magnesium silicate was used in Example 3, methyl hydrogen silicone oil was used as the silicone oil, and otherwise a developer was obtained in the same manner as in Example 1, It evaluated similarly.

The resulting developer had a high fluidity and a stable and good image was obtained. The development was stopped halfway, and the surface potential of the developer on the developing roll was measured.
It was as high as 5 V and 45 V, and sufficient chargeability was obtained.

Comparative Example 4 A developer was obtained and evaluated in the same manner as in Example 1 except that the amount of the hydrophobically treated inorganic fine powder obtained in Example 1 was changed to 0.1 part by weight. Although the obtained developer had a sufficiently high fluidity of 60, fog was observed when the image density was low and the number of copies increased. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 20 V and was insufficient.

Comparative Example 5 A developer was obtained and evaluated in the same manner as in Example 1 except that the amount of the hydrophobically treated inorganic fine powder obtained in Example 1 was changed to 15 parts by weight. The developer had low fluidity and the image density was low. As the number of copied sheets increased, fog was observed, which was unbearable for use.

When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as high as 50 V and the chargeability was sufficient. It is considered that the cause of the fog is that the amount of the inorganic fine powder added is large.

[Comparative Example 6] A developer was obtained in the same manner as in Example 1 except that the inorganic fine powder as it was without the hydrophobizing treatment carried out in Example 1 was carried out and evaluated in the same manner. The fluidity of the obtained developer was as low as 8, and in the durability test, the image density was low from the initial stage and many fog was observed. As the number of copies increased, fogging and image unevenness became more severe, and the result was unbearable for use.

When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 23 V, which was insufficient. In addition, even at high temperature and high humidity, the image density was lower from the beginning and the fog became severe.

[Examples 4 to 5] Inorganic fine powders are shown in Table 1.
As shown in, a developer was obtained in the same manner as in Example 1 except that aluminum silicate was used in Example 4, magnesium silicate was used in Example 5, and methyl hydrogen silicone oil was used as silicone oil. , And evaluated in the same manner.

The resulting developer had a high fluidity and a stable and good image was obtained. In Example 4, although some fog occurred, it was of a level that caused no practical problems.
When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as high as 60 V and 52 V, respectively, and sufficient chargeability was obtained.

[0064]

[Table 1]

[Examples 6 to 8] In Example 1, Table 2
As shown in, a developer was obtained in substantially the same manner as in Example 1 except that the color of the developer was changed by changing the type of the colorant.
It evaluated similarly. In Example 6, a yellow toner using a benzidine dye, in Example 7, a magenta toner using a dimethylquinacdrine dye, and in Example 8, a cyan toner using a copper phthalocyanine dye, Got each. As a result, as in Example 1, high fluidity and chargeability, and a stable and good image was obtained. The results are shown in Table 2 (same below).

[Comparative Example 7] A developer was obtained in the same manner as in Example 1 except that a commercially available zinc complex type charge control agent was used as the charge control agent. The obtained developer had a high fluidity of 40, which was sufficient, but in the durability test, the image density was low from the initial stage, fog was observed, and when 20,000 copies were made, the image was uneven. The result was unbearable. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 25 V and was insufficient.

Comparative Example 8 A developer was obtained in the same manner as in Example 1 except that a commercially available aromatic carboxylic acid complex charge control agent was used as the charge control agent. The obtained developer is
The fluidity was as high as 43, which was sufficient, but the image density was low and the color tone was brownish. As the number of copies increased, fogging occurred. When the development was stopped halfway and the surface potential of the developer on the developing roll was measured, it was as low as 20 V and was insufficient.

[0068]

[Table 2]

[0069]

According to the present invention, as a developer used in a contact or non-contact developing system, it has sufficient chargeability and fluidity, environmental stability, high image density, little fog, and image quality level. Provided is a non-magnetic one-component color developer having high efficiency. The non-magnetic one-component color developer of the present invention has excellent properties such that the image quality does not change even when used for a long period of time without forming a film due to the adhesion of the developer to the developing roll, the developing blade, and the photoconductor. It is a thing.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a developing device and a developing method to which a non-magnetic one-component color developer of the present invention is applied.

[Explanation of symbols]

 1 photoconductor, 2 developing roll, 3 developing blade, 4 developing agent, 5 developing agent container, 6 stirring rod, 7 cleaning blade, 8 screw, 9 charger line, 10 optical signal, optical image, 11 transfer charger line, 12 fixing roll. 13 Developer support member such as paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jun Saito 1-2-1 Yokou, Kawasaki-ku, Kawasaki City, Kanagawa Nihon Zeon Co., Ltd. Research and Development Center (72) Inventor, Katsuyuki Ito 1-7 Toranomon, Minato-ku, Tokyo No. 12 Oki Electric Industry Co., Ltd.

Claims (3)

[Claims] 1. A developing blade for controlling the layer thickness of the developer is arranged so as to be in pressure contact with the surface of the developing roll, the developer is uniformly applied to the surface of the developing roll, and the developing roll is formed on the electrostatic latent image on the photoreceptor. A colored fine particle containing a binder resin, a colorant, and a boron metal complex compound represented by the following formula as a charge control agent, which is a developer used in the method of developing in direct contact or in non-contact with each other. With respect to 100 parts by weight, the inorganic fine powder (1) having an average particle size of 0.1 to 10 μm and a loss on heating (drying condition at 150 ° C. for 1 hour) of 1% by weight or less was hydrophobized with silicone oil. A non-magnetic one-component color developer obtained by mixing the inorganic fine powder (2) in a proportion of 0.3 to 10 parts by weight. [Chemical 1] (However, A is an alkali metal.) 2. The non-magnetic one-component color developer according to claim 1, wherein the inorganic fine powder (2) has a blow-off charge amount of −50 to −200 μc / g. 3. The inorganic fine powder (1) is at least one selected from the group consisting of silicon dioxide, aluminum silicate, magnesium silicate and alumina.
The non-magnetic one-component color developer described.