JPS59123849A - Developing method - Google Patents

Abstract

PURPOSE:To provide a developing method having durability and stability against changes of the circumstances by incorporating a fine silica powder made hydrophobic in a magnetic developer. CONSTITUTION:A magnetic developer contains a product obtained by treating a fine silica powder produced by vapor phase oxidation of silicon halide with a siliane compd. having a cationic unsatd. amine function as shown by the general formula in which X is OH or a hydrolyzable group; R is 1-6C alkyl; n is an integer of 1-3; Q is a divalent hydrocarbon group alone or having O as -COC-, -(C=O)OC-, -(C=O)-, or -COH, or N as R'N=; R' is H, 1-6C alkyl or a heterocyclic org. compd. having an N-contg. ring; m is 1 or 2; Z is a divalent org. group having a double bond conjugated with -(C-R''= CH2) and Z combines with N through a C-N bond; R'' is H or 1-6C alkyl; and Y is an acid anion. This developer is held in a thickness smaller than the gap between a latent image bearing body and a developer carrying body on this body, and is transferred to the latent image bearing body to develop the image. Since, in this developing method, there is used a developer contg. said fine silica powder as a charge controlling component, the developer layer is uniformly triboelectrified, and an excess charge is allowed to leak through the fine silica powder to a proper satd. value, resulting in forming a stable developer layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing method using an insulating magnetic developer.

Conventionally, developing methods for electrophotography, electrostatic recording, etc. are broadly classified into dry developing methods and wet developing methods. The former is
Furthermore, there are two layers: a method using a two-component developer and a method using a -component developer. Two-component developing methods include the type of carrier used to transport the toner, a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method using fur, and the like.

In addition, methods belonging to the -component type development method include the powder cloud method, in which toner particles are sprayed, and the contact development method (contact development, or (also referred to as toner development), jumping development method in which toner particles are not brought into direct contact with the electrostatic latent image surface, but are charged and flown towards the latent image surface due to the electric field of the electrostatic latent image; There is the MagneDry method, which develops by bringing a conductive toner into contact with the electrostatic latent image surface.

In the two-component development method, a mixed developer of carrier particles and toner particles is inevitably used. It inherently has drawbacks such as a change in the ratio, resulting in fluctuations in the density of the suspended image, and a reduction in image quality due to deterioration of carrier particles that are difficult to consume due to long-term use.

On the other hand, in -component-based development methods, the Magne Dry method using magnetic toner and the contact development method not using magnetic toner, the toner contacts the entire surface of the surface to be developed, that is, the image area and the non-image area, indiscriminately. As a result, there is a problem in that toner tends to adhere even to non-image areas, resulting in so-called smearing. (This fog spotting was a drawback that also occurred in the two-component developing method.) Also, in the powder cloud method, it is inevitable that powdered toner particles adhere to non-image areas. Similarly, it has the disadvantage that Jiryokupuri cannot be removed.

Furthermore, in the so-called jumping development method, which belongs to the -component-based development method, after toner is uniformly applied to a carrier such as a sheet, the toner is placed facing an electrostatic holding surface with a small gap, and an electrostatic image is transferred from the toner carrier. A method is known in which toner is attracted to a holding surface by the electric charge of an electrostatic image, and developed by causing the toner to adhere to the holding surface.

(U.S. Pat. No. 2,839,400, etc.) In this method, in the non-image area where there is no static charge, the toner is not attracted9 or the toner and the non-image area do not come into contact, so the above-mentioned fogging is avoided. It has the advantage of being difficult to produce. In addition, since carrier particles are not used, there is no variation in the mixing ratio as described above, and there is no deterioration of the carrier particles.However, in this method, an electric field is applied in advance to adhere the toner to the toner carrier sheet. However, it is difficult to apply evenly and thinly, and uneven coating tends to occur. Another drawback is that when a single layer of applied toner faces an electrostatic image, it is difficult to release the toner uniformly onto the electrostatic image.

In this regard, JP-A-54-43027, JP-A-55-186
In the developing device proposed in No. 56, which has magnetic toner, a movable toner carrier (sleeve roller), and a stationary magnet inside the carrier, a magnetic toner is proximate to the outer surface of the sleeve roller, facing the magnetic pole of the magnet. The developing device is equipped with a toner thickness regulating member made of a magnetic material and is capable of uniformly and thinly applying toner on the outer surface of the sleeve roller, which eliminates the above drawbacks and provides high fidelity and stable image quality. It can be said to be an electrostatic image developing device.

An object of the present invention is to provide a developing method with excellent durability such as continuous use characteristics.

Another object of the present invention is to provide a developing method that is stable against environmental changes such as high temperature and high humidity, and low temperature and low humidity.

The feature is that an electrostatic image carrier that holds an electrostatic image on its surface and a developer carrier that carries an insulating magnetic developer on its surface are arranged with a certain gap in the developing section, A fine silica powder produced by vapor phase oxidation of a silicon halide compound, the fine silica powder having the formula (wherein, X is a hydroxyl group or a hydrolyzable group; R is a carbon number 1
-6 alkyl group: n is an integer of 1 to 3; Q is a divalent hydrocarbon group or oxygen -COC-;

Divalent hydrocarbon group having nitrogen as R#N= group: R'
is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a heterocyclic organic compound having a nitrogen atom in the ring: m is 1 or 2; Z is -
C= 21 bonds conjugated with CH, ■ A divalent organic group with R# 2 is bonded to the nitrogen atom with a C-N bond = R' is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms ;Y is an acid anion. ), a hydrolyzate thereof, and a copolymer of the above adduct and an unsaturated monomer. A magnetic developer containing fine silica powder that has been hydrophobized so as to exhibit a value in the range of 8o is supported on a developer carrier to a thickness thinner than the gap, and the magnetic developer is transferred to the developer in the developing section. It is a developing method in which the image is transferred to an electrostatic image holder and developed.

Inventor Z discovered that when copying is continued repeatedly using a conventionally known jumping developer, the uniformity of the developer layer supported on the developer carrier may be impaired in some cases. ,
There may be coating defects in the form of streaks in the circumferential direction of the support, or the thickness of the supported developer layer may be extremely thick in some areas compared to the initial thickness, resulting in spot-like unevenness. ,
Sazawa-like coating defects occur. The former is observed as white streaks on the image when developed, and the latter is observed as dot-like or serpentine density irregularities.

Although this phenomenon hardly occurs in normal repeated copying, it may occur particularly in continuous use under extremely low temperature and low humidity environmental conditions for a long period of time, and is therefore undesirable.

Further, the thickness of the developer layer changes even under high temperature and high humidity, often becoming thinner, which often causes a decrease in image density, which is undesirable.

゛ As a result of repeated studies on this point, we found that one of the reasons for this is the stability and reliability of the charge control component, and that these causes cause the developer powder to adhere to the sleeve and the developer powder to transfer from the sleeve. It was found that this is due to the change in

More specifically, this phenomenon is caused by the occurrence of non-uniform areas of triboelectric charge in the developer layer supported on the carrier due to changes in environmental conditions. That is,
Under extremely low temperature and low humidity environmental conditions, friction between the surface of the carrier and the developer generates an extremely large component of triboelectric charge on the developer, and due to the mirroring force caused by this charge, a component is generated near the carrier. The extremely large component of such triboelectric charge is
It is easy to accumulate, and this affects the uniformity of the developer coating on the upper layer of the developer layer and the ease of development due to continuous durability, etc., and the phenomena include the above-mentioned white streaks, patch-like unevenness, and saturation. This results in wavy coating defects. Further, the decrease in the thickness of the developer layer at high temperatures and high humidity also occurs due to uneven triboelectric charging between the developer and the carrier, and is due to instability in the amount of triboelectricity of the developer near the surface of the carrier.

Conventionally, known charge control agents used in such dry developing toners include amine compounds, quaternary ammonium compounds, organic dyes, especially basic dyes and their salts, and benzyldimethyl-hexadecyl ammonium chlorite. , tesyl trimethylammonium chloride, diyo cy base t nigrosine hydrochloride.

Safranin γ, crystal violet, etc. are used. Nigrosine base and nigrosine hydrochloride are often used as positive charge control agents. These are usually added to thermoplastic resins, heated, melted and dispersed,
This is finely pulverized and adjusted to an appropriate particle size as necessary for use.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability. In addition, decomposition or deterioration occurs due to mechanical shock, friction, changes in temperature and humidity conditions, etc. during thermal kneading, resulting in a phenomenon in which charge controllability is deteriorated.

Therefore, when a toner containing these dyes as a charge control agent is used for development in a copying machine, as the number of copies increases,
The dye decomposes or changes in quality, causing toner deterioration during durability.

Furthermore, since it is extremely difficult to uniformly disperse these dyes as charge control agents in thermoplastic resins, this has the fatal drawback of causing a difference in the amount of triboelectric charge between toner particles obtained by pulverization. have. For this reason, various methods have been used to more uniformly disperse these dyes into resins. For example, basic nigrosine dyes are used by forming salts with higher fatty acids to improve compatibility with thermoplastic resins, but unreacted fatty acids or salt dispersion products are often exposed on the toner surface. Therefore, the carrier S contaminates the toner carrier and causes a decrease in toner fluidity, capri, and image density. Alternatively, in order to improve the dispersion of these dyes into the resin, a method has been adopted in which the dye powder and the resin powder are mechanically pulverized and mixed in advance and then hot-melted and kneaded. cannot be avoided, and the reality is that sufficient uniformity of charge has not yet been obtained for practical use.

Further, most of the charge control dyes are hydrophilic, and due to poor dispersion in these resins, the dyes are exposed on the toner surface when the dyes are melted and mixed and then crushed. When these toners are used under high humidity conditions, they have the disadvantage that good quality images cannot be obtained because these dyes are hydrophilic.

In this way, when a conventional dye with charge controllability is used in a toner, there is a possibility that the toner particle surface may be damaged between the toner particles, between the toner and the carrier, or between the toner and the toner carrier such as a sleeve. This causes variations in the amount of charge generated, leading to problems such as development fog, toner scattering, and carrier contamination. Furthermore, these phenomena become particularly noticeable when a large number of copies are made, resulting in a result that is practically unsuitable for copying machines.

Furthermore, under high humidity conditions, the toner image transfer efficiency is significantly reduced, making it unusable. Furthermore, when the toner is stored for a long period of time even at room temperature and humidity, the toner often aggregates and becomes unusable due to the instability of the charge control dye used.

The inventor of the present invention solved the various problems associated with the conventional chargeable toner as described above, and as a result of intensive research aimed at providing a high-quality image by being strongly charged uniformly and visualizing the electrostatic charge image, A fine silica powder produced by vapor phase oxidation of a silicon halide compound, wherein the fine silica powder is treated with the above-described cationically unsaturated amine-functional silane and has a degree of hydrophobicity determined by a methanol titration test. It has been found that if a developer contains fine silica powder that has been hydrophobized so that the silica powder exhibits a value in the range of 30 to 80, an electrophotographic developer exhibiting various excellent properties can be obtained. Furthermore, it has been found that it is very effective to apply this developer to a developing device having a sleeve roller.

The developing process used in the present invention will be explained.

FIG. 1 shows a cross-sectional view of one embodiment of the developing process used in the present invention. In the figure, the electrostatic image holder 1 moves in the direction of the arrow. The non-magnetic cylinder 4, which is a developer carrier, rotates in the developing section so as to move in the same direction as the surface of the electrostatic image carrier. A multipolar permanent magnet 9 is arranged inside the nonmagnetic cylinder 4 so as not to rotate. The one-component insulating magnetic developer 11 sent from the developer container 12 is applied onto a non-magnetic cylindrical surface, and the friction between the cylindrical surface and the toner particles imparts a charge of opposite polarity to the electrostatic image charge to the toner particles. give. Furthermore, an iron doctor blade 10 is placed close to the cylindrical surface (at intervals of 50 μm to 5 μm).
00μ), and are arranged opposite to one magnetic pole (in the figure, the S pole) of the multipolar permanent magnet 9, thereby regulating the thickness of each toner layer to be thin (30μ to 300μ) and uniform. By adjusting the rotation speed of the cylinder 4, the surface speed and preferably the internal speed of the developer layer are made to be substantially equal to or close to the speed of the electrostatic image holding surface. As the doctor blade 10, a permanent magnet may be used instead of iron to form opposing magnetic poles. Further, an alternating current bias may be applied between the developer carrier and the electrostatic image holding surface in the developing section. This AC bias has f of 200 to 40
It is sufficient if the frequency is 00Hz and Vpp is 500 to 3000V.

As described above, in this developing step, the non-magnetic cylinder 4 containing the multipolar permanent magnet 9 was used in order to stably hold the one-component magnetic developer on the developer carrier. Further, in order to form a thin and uniform developer layer, a doctor blade 10 made of a thin magnetic plate or a permanent magnet was placed close to the surface of the cylinder 4. When a magnetic doctor blade is used in this way, opposing magnetic poles are formed between the magnetic poles of the permanent magnet contained in the developer carrier, and the toner particles are forced to stand up between the doctor blade and the developer carrier. This is advantageous in controlling the thickness of the developer layer in other parts of the developer carrier, for example, in the development part facing the electrostatic image surface.

Furthermore, by imparting such forced movement to the developer, the developer layer becomes more uniform, thereby achieving a thin and uniform layer of toner that could not be achieved with a non-magnetic doctor blade.

Moreover, since the gap between the doctor blade and the sleeve can be set wide, there is also the effect of preventing the destruction and aggregation of toner particles. When the toner particles are transferred in the developing area, they are transferred to the electrostatic image side due to the attraction action of the electrostatic image or the action of an alternating current bias.

As the binder resin for toner used in the developing method of the present invention, various material resins conventionally known as toner binder resins for electrophotography are used.

For example, polystyrene, styrene-butadiene copolymer,
Styrenic copolymers such as styrene-acrylic copolymers,
Ethylene-based copolymers such as polyethylene, polyethylene vinyl acetate copolymers, and polyethylene vinyl alcohol copolymers.

These include phenolic resins, epoxy resins, allyl chloride resins, polyamide resins, polyester resins, maleic acid resins, and the like. In addition, the manufacturing method of each resin was particularly restricted, and the resins tended to contain impurities and were difficult to use.However, the present invention has made it possible to use them easily, and the range of resin selection is wide. spread. This is also a great effect of the present invention.

The magnetic powder to be contained in the toner includes ferromagnetic elements, alloys and compounds containing these, magnetite,
There are conventionally known magnetic materials such as hematite, ferrite, and other alloys and compounds of iron, cobalt, nickel, and manganese, and other ferromagnetic alloys. The average particle size of the magnetic powder usually used is 0.05.
-5μ, preferably 0.1-1μ. This magnetic powder is
The toner preferably contains 10 to 70% by weight, preferably 15 to 35% by weight. With this content, an appropriate magnetic moment will work in the above-mentioned development method and a good image can be created, and the fixing properties are also excellent.As the coloring material used in the 0 toner, conventionally known carbon blanks, Iron black, etc. can be used, and all of the conventionally known dyes as positive charge control agents can be used in combination with the treated silica fine powder used in the present invention.

For example, various dyes such as benzyldimethyl-hexadecyl ammonium chloride, decyl-trimethylammonium chloride, nigrosine base, nigrosine hydrochloride, safranin gamma and crystal violet.

The silica fine powder produced by the vapor phase oxidation of a silicon compound/compound used in the present invention is so-called dry process silica or fumed silica, and is produced by a conventionally known technique. For example, this method utilizes a thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows.

5iC1, + 2 H, +02→5int+ 4 HC
I! Also, in this manufacturing process, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halide compounds such as aluminum chloride or titanium chloride together with a silicon halide compound. Also includes.

The particle size is preferably within the range of 0.001 to 2μ as an average primary particle size, particularly preferably O, OO
It is preferable to use silica fine powder within the range of 2 to 0.2 microns.

Examples of commercially available silica fine powders include those available under the following trade names.

AERO8IL 130 (Japan Aerosil Co., Ltd.) 200 00 80 TT 600 reduction) X80 MOX 170 COK 84 Cab-0-8iI! M-5 (CABOT) MS-7 5-75 Embryo-5 Positive-5 Waeker HDK N 20 (WAC
KER-CHEMIE V15GMBH) N2
0E 30 40 D-CFin/5ilica (Dow Corning Company) Fransol (FransiI! Company) Conventionally, examples of adding these silica fine powders to toner are known. However, such substances do not necessarily have sufficient stability, and addition of such silica to toners that require positive charge control properties changes the chargeability, making them unsuitable.

The cationic unsaturated amine functional silane represented by the formula used in the present invention is:
As mentioned above, X is a hydroxyl group or a hydrolyzable group such as an alkoxy group, an aryloxy group, a hydrogen atom, an acyloxy group, a ketoxime group, or an amino group. The term "hydrolyzable group" as used herein means a group that reacts with water at room temperature to form silanol.

R is a lower alkyl group having 6 or less carbon atoms.

R groups attached to the same silicon atom may be the same or different.

For the purposes of the present invention, the group Q between the silicon atom and the nitrogen atom is carbon, hydrogen, oxygen or lanary, the latter being in the form of a carbonyl, ether, ester, hydroxyl group or a It is in the form of a base.

Specific examples of Q are a divalent hydrocarbon group, a carbonyl group, an ether group, an ester group or. Q may also be -CH, CH2CH2NHCH, CH, -.

R' is a hydrogen atom, and as mentioned in R, the number of carbon atoms is 1
-6 alkyl group or 11 1 1 1 11I
II II IICI(-
independently selected from the group consisting of heterocyclic compounds having nitrogen in the ring, such as CHC)l -C-CH3 Of course, when R is such a heterocyclic compound, m is 1, but when R' is hydrogen or a lower alkyl group, m is 2.

As mentioned in connection with the Q group, Z is a divalent organic group made of carbon, hydrogen, and oxygen, and is further characterized by having a double bond conjugated with a vinyl component. . 2
is bonded to nitrogen through a carbon-nitrogen bond. Examples of such divalent groups include arylene groups, carbonyl groups and vinyl groups.

R# is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Y is a hydrogen atom; chlorine, bromine, iodine; or an acidic anion such as a carboxyl salt anion, such as a formate, acetate, phosphate, sulfate or nitrate anion.

Below are examples of such compounds.

These compounds are made by reaction of amino-functional silanes with conjugated unsaturated alkyl halides. or
It can also be produced by reacting a silicon alkyl halide with a conjugated unsaturated aliphatic amine. In order to process the silane into the silica fine powder used in the present invention, since the silane is soluble in an aqueous solvent to the extent of at least a 5% solution by weight,
It can be processed using conventionally known techniques. For example, there are methods such as immersion in a silane aqueous solution and spraying a silane aqueous solution onto fine silica powder. The silica fine powder treated in this manner has a hydrolyzate represented by the formula (wherein all groups are the same as those described above) attached to its surface.

In addition, in order to perform the hydrophobization treatment so that the degree of hydrophobization required for the silica fine powder used in the present invention, that is, the degree of hydrophobization measured by a methanol titration test is in the range of 30 to 80, conventional methods are required. A known hydrophobization method is used, and hydrophobization is imparted by chemical treatment with an organosiliconization compound that reacts with or physically adsorbs to fine silica powder.A preferred method is hydrophobization by vapor phase oxidation of a silicon halide compound. After the silica fine powder thus produced is treated with the silane coupling agent described above, or simultaneously with the silane coupling agent, it is treated with an organosilicon compound. An example of such an organosilicon compound is hexamethyldisilazane. .

Trimethylsilane, trimethylchlorosilane.

Trimethylethoxysilane, dimethyldichlorosilane,
Methyltrichlorosilane, allyldimeflL''lorsilane, allyl phenyldichlorosilane, benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α
-Chlorethyltrichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane,
Chlormethyldimethylchlorosilane l) IJ organosilyl mercaptans, e.g. trimethylsilyl mercaptan, triorganosilylacrylates, e.g.
Vinyldimethylacetoxysilane and further dimethylethoxysilane.

Dimethyldimethoxysilane, hexamethyldisiloxane, 1.3-divinyltetramethyldisiloxane, 1.3
-diphenyltetramethyldisiloxane, and dimethylpolysiloxane having from 2 to 12 siloxane units per molecule and containing one St-bonded hydroxyl group in each terminally located unit. These may be used alone or in a mixture of two or more. The preferred weight ratio of the unsaturated cationic amine compound and the hydrophobizing agent used to treat the silica fine powder is 15:85 to 85:15.
The total amount of the unsaturated cationic amine compound and the hydrophobizing agent is preferably 0.1-3 based on the silica fine powder.
It is desirable that the amount is 0 wt%, more preferably 0.5 to 20 wt%.

The degree of hydrophobicity of the final treated silica fine powder is 30 to 30 as measured by methanol titration test.
A preferred developer for use in the development method of the present invention is obtained when it is hydrophobized to exhibit a value in the range of 80.

Here, the methanol titration test is an experimental test to confirm the degree of hydrophobization of fine silica powder having a hydrophobized surface.

The methanol titration test specified herein to evaluate the degree of hydrophobization of the treated silica fine powder is carried out as follows.
50ml of water in an Erlenmeyer flask! Add to. The methanol is titrated from the burette until the entire amount of silica is wetted. The degree of hydrophobicity is expressed as the percentage of methanol in the liquid mixture of methanol and water upon reaching the end point.

In addition, the applied amount of these treated silica fine powders is 0.01 to 20 inches based on the weight of the developer, and the effect is exhibited, and it is especially effective when added in an amount of 0.1 to 3%. It exhibits positive chargeability with excellent stability. A preferred form of addition is that 0.01 to 3% by weight of treated silica fine powder based on the weight of the developer is attached to the surface of the toner particles.

In the developing method of the present invention configured in this manner, since the developer used contains the above-described fine silica powder as a charge control component, it is applied to the developer layer supported on the developer carrier. The amount of triboelectric charge generated is made uniform, and only the excess charge that tends to occur during durability at ultra-low temperature and low humidity is leaked through the silica fine powder to an appropriate saturation value, resulting in the formation of a stable developer layer. Under high temperature and high humidity conditions, it is easy to maintain the amount of triboelectric charge necessary to provide a stable coating state, and no decrease in concentration occurs.

Another feature is that it is easy to form a stable developer layer, so there is no development capri, which could not be solved in the past, and no toner scattering around the etch of the latent image, resulting in high image density. -7) The reproducibility of - is good.

The basic configuration and features of the present invention have been described above, and the method of the present invention will be specifically explained below based on Examples. However, this does not limit the embodiments of the present invention in any way. The parts in the examples are parts by weight. [Example 1] 3-Chlorprobyltrimethoxysilane The above mixture was added to 9 parts by weight.
The reaction was carried out for 50 hours under reflux at 5°C to obtain a product. Next, fine silica powder Aerosil 200 was stirred for 1 hour. Thereafter, it was dried for 10 hours in a mouth filter of 100'0 to obtain fine silica powder treated with a cationic unsaturated amine.The silica was mixed in a Henschel mixer. Then, while stirring, dimethyldichlorosilane was sprayed at a concentration of 10% to the silica.The mixer was stirred at high speed for 2 hours at room temperature, further stirred at 80°C for 24 hours, and then the mixer was opened to atmospheric pressure. This mixture was further dried at low speed at atmospheric pressure for 60°0.5 hours.The degree of hydrophobicity was 6.
It was 0.

Next, styrene-butadiene copolymer (70:30) 10
0 parts by weight Magnetite 60 Nigrosine 3 The above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. After the kneaded material was allowed to cool naturally, it was roughly pulverized with a cutter mill, and then pulverized using a pulverizer using a jet stream.
Further, the mixture was dispersed using a wind disperser to obtain a fine powder having a particle size of 5 to 20 μm.

A developer was prepared by adding 0.6% by weight of the above-mentioned treated silica to the fine powder and mixing with a Henschel mixer.

Next, the OPC photoreceptor was subjected to corona discharge of 16 KV to uniformly charge the entire surface, and then the original image was irradiated to form an electrostatic latent image.

The developer carrier is a stainless steel cylindrical sleeve with an outer diameter of 50 mm. The magnetic flux density on the sleeve surface was 700 Gauss, and the distance between the surfaces of the cut blade sleeve was 0.2 rnn. This sleeve rotation magnet fixation (sleeve circumferential speed is the same as that of the drum, rotation direction is opposite) type developing device was set at a distance between the photosensitive drum surface and the sleeve surface of 0.25 JllK, and the sleeve was supplied with 400Hz 1000V AC and -150V.
A DC bias of (2) was applied.

It was developed using the developer described above, and then the powder image was transferred while irradiating a DC corona of 17 KV from the back side of the transfer paper to obtain a copy image. For fixing, use a commercially available plain paper copier (product name: N
P-5000, manufactured by Canon). The resulting transferred image had a sufficiently high density of 1°29, had no fogging, and had no toner scattering around the image, resulting in a good image with high resolution. At this time, the weight per unit area of the single layer of toner coated on the sleeve is 1.4xlO
-3 (f/cm).

Transfer images were continuously created using the above developer and durability was examined, and the transferred images after 100,000 copies were also completely dull compared to the initial images.

Next, when the environmental conditions were set to 35°C and 185%, the image density was 1.25, a value that was almost unchanged from normal temperature and humidity, and clear images were obtained without fogging or scattering, and the durability was up to 100,000 sheets. There was almost no change. At this time, the weight per unit area of one layer of toner is 1.35 x 10-
3 (f/art).

Next, when a transferred image was obtained at a low temperature and low humidity of 10°, 010%, the image density was as high as 1.31, and solid black was developed and transferred extremely smoothly, resulting in an excellent image with no scattering or hollow spots. Durability was carried out under these environmental conditions, and the density variation was ±0.1 up to 100,000 copies, which was sufficient for practical use, and no white streaks or unevenness occurred. The change in the weight per unit area of one layer of the toner at this time is shown in FIG. 2, and there was almost no change.

[Comparative Example 1] A developer was obtained in the same manner as in Example 1 except that Aerosil 200 was not treated with the compound produced in Example 1 and dimethyldichlorosilane, and development and transfer were performed, but an inverted image was not obtained. The only result was that

[Comparative Example 2] A developer was obtained in the same manner as in Example 1, except that the treatment with dimethyldichlorosilane was not performed, and an image was obtained in the same manner.

The image at normal temperature and humidity is a little dark, but the image density is 0.7
The image had a low value of 0 and had a tendency to be rough. I checked the durability, but the density decreased to ti o, s s after 500 sheets.
The initial weight per unit area of one layer of toner is 1.3 x 10
-3 fl/crd, 4.8 x 10 at 500 sheets
-3F〆go.

When images were obtained under conditions of 10"010%, the image density was as low as 0.58, and the scattering, fogging, and roughness were severe.I tried to print images continuously, but after about 500 sheets...
Dot-like unevenness occurred. The toner weight per unit area of one layer of toner was 4.5 x 10-31/CI/L.

[Comparative Example 3] Example 1 except that the amount of dimethyldichlorosilane was changed to 0.3 weight ratio relative to silica.
I did the same thing. The degree of hydrophobicity of the silica at this time was 18. At normal temperature and humidity, a good image was obtained up to 50,000 sheets, and the toner weight per unit area of one toner layer did not change, but at 35°085%, the initial image density was 1.0 and 5000 sheets. It decreased to 0.63 when printed. The single layer toner was 1.4 x 10' f/cd, but when 5000 sheets were produced, it was 0.63 x 10' f/c.
It decreased to dt.

After being stored for one month at 10°C and 10%, when it was tested for durability in this environment, the initial image density was as high as 1.3 and good results were obtained, but after 5,000 sheets, unevenness appeared.
The image density decreased to 0.50, and white streaks appeared on the image after 10,000 sheets were printed. The size of the toner layer at this time is 4.3 x 10'
It had increased to 97cm. FIG. 2 shows the change in toner weight per unit area of one layer of toner at this time.

[Examples 2 to 4] The amount of the compound produced in Example 1 and dimethyldichlorosilane relative to Aerosil 200 was 0.3% by weight) and 1.0% by weight, respectively.
1.0 weight percent, i, o weight percent, and
Good results were obtained by carrying out the procedure in substantially the same manner as in Example 1, except that the amount was changed to 5.0% by weight) and 1.0% by weight.

[Example 5] CH2=C(CHs)COOcH2CH,N(CHa)
z 4 y methyl iodide
o, 59t-butyl alcohol
50f sulfur 0.
3f The above mixture was refluxed at 100°C for 1 hour to obtain a product. Next, an aqueous solution of the above product was mixed with a Henschel mixer while being sprayed so as to have a concentration of 5% by weight based on the silica fine powder Aerosil 200. then 100
A fine silica powder treated with a cationic unsaturated amine was obtained by drying in O for 10 hours.The silica was put into the Henschel mixer again and while stirring, the amount of dimethyldichlorosilane was 5% by weight based on the silica. After that, it was treated in the same manner as in Example 1. The degree of hydrophobicity was 50.

Next, 100 parts by weight of polyethylene oxide, 3 parts by weight of carbon black, 70 parts by weight of magnetite, 3 parts by weight of nigrosine, and the above materials were subjected to the same operation as in Example 1 to obtain a fine powder of 5 to 25 microns. A product obtained by adding and mixing 0.3 weight of the above-mentioned treated silica to the fine powder.

Then, an image was obtained in the same manner as in Example 1 and pressure fixed. The image density was 1.41, which was sufficiently high, and the image was faithful to the latent image. The durability of the image is sufficient for practical use up to 100,000 sheets, and it can withstand 35°C, 285% high temperature and high humidity conditions, and 10°0
It showed excellent properties even under low temperature and low humidity conditions of 10%.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of a developing process applicable to the present invention. Figure 2 shows Example 1 and Comparative Example 3 at 10°C and 10%.
FIG. 3 is a diagram showing a change in toner weight per unit area of one layer of toner during durability in an environment of . 1... Electrostatic image holder, 4... Non-magnetic cylinder, 10.
Doctor blade, 11... Insulating developer, a...
Results of Example 1, b...Results of Comparative Example 3. Applicant: Canon Co., Ltd. 41 Kabiq Manual amendment (voluntary) January 1980, Commissioner of the Patent Office Kazuo Wakasugi 1 Indication of the case 1980 Patent layer No. 231526 2 Name of the invention Developing method 3 Make an amendment Relationship with 11 patent applicants 1 zr
Tosha Tojin 1.11-ku Shimomaruko 3-30-2 Address 1F
J+46 3-30-25 Shimomaruko, Ota-ku, Tokyo, Specification subject to amendment 6, Contents of amendment (1) The scope of claims is amended as shown in the attached sheet. (2) "m is 1 or 2" in page 7, line 11 of the specification
is corrected as 2. (3) On page 26 of the specification, line 9 from the bottom to line 6 from the bottom of the same page, "Of course, if R is such a heterocyclic compound, m is 1, but if R' is hydrogen or when it is a lower alkyl group, m is 2.'' is changed to ``However, if one of R/ is such a heterocyclic compound, the remaining R' is preferably other than a heterocyclic compound. ”, he corrected. (4) The chemical structural formula on page 61, line 7 of the specification is corrected as follows. Claims: An electrostatic image carrier that holds an electrostatic image on its surface and a developer carrier that carries an insulating magnetic developer on its surface are arranged with a certain gap in a developing section, and silicon halogen compound A fine silica powder produced by vapor phase oxidation of (wherein X is a hydroxyl group or a hydrolyzable group:
R is an alkyl group having 1 to 6 carbon atoms; n is an integer of 1 to 6: Q
represents a divalent hydrocarbon group or oxygen -coc-, -coc
−. 1 = divalent hydrocarbon group having as a group:'B! is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a heterocyclic organic compound having a nitrogen atom in the ring: m is 2; Z is a divalent organic group having a double bond conjugated with -C=CH2; is bonded to the nitrogen atom through a C--N bond: W is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Y is an acid anion. ), a hydrolyzate thereof, and a cationic unsaturated amine-functional silane comprising a copolymer of the compound and an unsaturated monomer, and
Moreover, a magnetic developer containing fine silica powder that has been hydrophobized so that the degree of hydrophobicity measured by a methanol titration test is in the range of 60 to 80 is placed on the developer carrier with a thickness thinner than the gap. A developing method characterized in that the magnetic developer is transferred to the electrostatic image holder in a developing section to perform development.

Claims (1)

[Claims] An electrostatic image carrier that holds an electrostatic image on its surface and a developer carrier that carries an insulating magnetic developer on its surface are arranged with a certain gap in a developing section, and silicon ... fine silica powder produced by vapor phase oxidation of a rogen compound, the fine silica powder having the formula (wherein, X is a hydroxyl group or a hydrolyzable group; R is a carbon number 1
-6 alkyl group: n is an integer of 1 to 3: Q is a divalent hydrocarbon group or oxygen =C0C-. Divalent hydrocarbon group having R'N = group: R'
is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a heterocyclic organic compound having a nitrogen atom in the ring; m is 1 or 2. ; z is a divalent organic group having R' a double bond conjugated with -C=CH, 2 is bonded to the nitrogen atom through a C-N bond = R' is a hydrogen atom or a carbon atom with 1 to 1 carbon atoms; 6 alkyl group; Y is an acid anion. ), a hydrolyzate thereof, and a cationic unsaturated amine-functional silane consisting of a copolymer of the above compound and an unsaturated monomer, and treated with at least ← or two or more types, and a methanol titration test. A magnetic developer containing fine silica powder that has been hydrophobized so that the degree of hydrophobization as measured by the method shows a value in the range of 30 to 80 is supported on a developer carrier to a thickness thinner than the gap. . A developing method, characterized in that the magnetic developer is transferred to the electrostatic image holder in a developing section for development.