JPS5893067A - Development method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables triboelectric charging of an electrical latent image formed in electrophotography, electrostatic recording, etc., without using carrier particles. -Regarding a developing method for obtaining a developed image by developing with a component-insulating toner.

Conventionally, as an electrophotographic method, U.S. Patent No. 2,297,69
1 specification, Japanese Patent Publication No. 42-I23910, Japanese Patent Publication No. 43-24748, etc., a number of methods are known, but in general, a photoconductive proboscis is used to perform various methods. An electrical latent image is formed on the photoreceptor by the means described above, and then the latent image is developed using toner, and if necessary, after the toner image is transferred to a transfer material such as paper, heat, pressure, or a solvent is applied. Copies are obtained by applying an electric layer using steam or the like.

Furthermore, methods for visualizing i[air images using toner are well known.

For example, the magnetic roller method described in U.S. Pat. No. 2,874.063, the cascade development method described in U.S. Pat.
A number of development methods are known, such as the powder cloud method, fur brush development method, and liquid visual imaging method described in No. 1,776.

Among these developing methods, a magnetic brush method, a cascade method, a liquid developing method, etc., which use a developer mainly consisting of toner and carrier particles, have been widely put into practical use. All of these methods are excellent methods that can produce good images relatively stably, but on the other hand, they have common drawbacks associated with two-component developing agents, such as deterioration of carrier particles and fluctuations in the mixing ratio of toner and carrier particles. .

In order to avoid such drawbacks, various development methods have been proposed that use a one-component developer consisting only of toner.

For example, US Pat. No. 3,909,258 proposes a developing method using an electrically conductive magnetic toner. In this system, a conductive magnetic developer is supported on a cylindrical conductive sleeve having magnetism inside, and is brought into contact with an electrostatic image to develop it. At this time, a conductive path is formed between the surface of the recording medium by the toner particles in the developing section, and through this conductive path, an electric charge is transferred from the sleeve to the toner particles, and due to the Coulomb force between them and the image area of the electrostatic image, the toner particles adheres to the image area and is developed.

This developing method using conductive magnetic toner is a method that avoids the problems of conventional two-component developing methods, but on the other hand, since the toner is conductive, the developed material cannot be exposed to light. It has the disadvantage that it is difficult to electrostatically transfer it from the body to the final support member such as plain paper.

As a developing method using a high-resistance magnetic toner that can be electrostatically transferred, JP-A-52-94141 discloses a developing method that utilizes dielectric polarization of toner particles. However, such a method has drawbacks such as an inherently slow development speed and an inability to obtain a developed image with sufficient density, making it difficult in practice.

Other developing methods using high-resistance magnetic toner include
A known method is to triboelectrically charge toner particles by friction between toner particles, friction between toner particles and a sleeve, etc., and develop the toner particles by contacting them with an image holding member. However, with these methods, the number of times the toner particles come into contact with the friction member is small, and the frictional charging tends to be insufficient.The Coulomb force between the charged toner particles and the sleeve is strong. It has disadvantages such as being easy to use, and there are many practical difficulties.

The present applicant previously proposed a new developing method that eliminates the above-mentioned drawbacks in JP-A-54-43036. This involves applying a very thin layer of magnetic toner onto the sleeve, triboelectrically charging it, and then placing it in close proximity to the electrostatic image under the action of a magnetic field, facing it without touching it, causing the toner particles to fly. Use something to develop it.

According to this method, by applying a very thin layer of sulfuric toner on the sleeve, the chances of contact between the sleeve and the toner are increased, and sufficient frictional electrification is possible.The toner is supported by magnetic force, and the magnet and toner By moving the toner particles relative to each other, the agglomeration of the toner particles is released, and the toner particles are sufficiently rubbed against the sleeve.The toner is supported by magnetic force and is developed by facing the electrostatic image without coming into contact with it. Excellent images can be obtained by preventing blurring and other factors.

However, the performance of this method is largely affected by humidity conditions or the surface properties of the frictional charging member and the toner holding member. For example, when the fluidity of the toner is reduced due to high humidity or high temperature, the toner agglomeration cannot be sufficiently dissolved by magnetic force, resulting in a decrease in image quality and image density; , unevenness tends to occur in the toner coating layer on the toner holding member.

The toner in the uneven area aggregates and bulges up, and if it gets worse, it will appear as density unevenness on the image. Furthermore, the toner in the uneven area is not loosened by the magnetic force, and if development is repeated in this state, the uneven area may be fused onto the sleeve.

The object of the present invention is to provide a developing method that improves the above-mentioned drawbacks.

Another object of the present invention is to provide a developing method in which toner has good developability and clear images can be obtained.

An eastern object of the present invention is to allow for lower moisture sensitivity, uniform triboelectric properties, and uniform application of toner to the carrier.

In particular, it is an object of the present invention to provide a developing method that does not cause unevenness.

The present invention provides a method for developing an electrical residue using an insulating toner triboelectrically charged without using carrier particles, in which at least the surface of a member imparting a triboelectric charge to the toner is Snug.

8n01-'r1o, system mixed crystal, 8nO1-Ba804
A developing method characterized by containing an organic silicone polymer to which at least one fine powder of a mixed crystal system is added.

FIG. 1 shows a schematic configuration of an example of a copying device or a recording device to which the developing method according to the present invention can be applied, but the present invention is not limited thereto.

1 corresponds to an electrostatic image holder, and is a photosensitive drum containing a photoconductive layer.It can be used with or without an insulating layer on the surface.
A belt-shaped one is also possible. 2 is a well-known photosensitive charging device; 3 is a light image irradiation device that projects a document image, a light image, or a light beam modulated by an image signal; thereby, an electrostatic image is formed on the photoreceptor 1; . 4 is a developing device;
It has a developer carrier 4st, which allows the photoreceptor 1 to
A toner particle microscopic image is formed according to the electrostatic image above. 5 is a device for transferring the toner image onto a transfer material 6. Incidentally, in order to improve the transferability, the visible image may be charged in advance by corona discharge or the like before transfer. Also, the electrostatic image on the photoreceptor 1 is temporarily transferred to another carrier, and then transferred to the developing device 4.
It is also possible to adopt a so-called electrostatic image transfer method in which a visible image is created by

Reference numeral 7 denotes a fixing device for fixing the toner image on the transfer target member 6, and is composed of at least two rollers having pressure or heating pressure means. Reference numeral 8 denotes a cleaning device for cleaning and removing residual toner on the photoreceptor 1 after transfer, so that the photoreceptor 1 can be reused.

Next, the developing process used in the present invention will be explained. FIG. 2 shows a cross-sectional view of one embodiment of the developing process used in the present invention. In the same figure, the electrostatic image holding surface l
When the multipolar permanent magnet 9 moves in the direction of the arrow, the multipolar permanent magnet 9 is fixed so as not to rotate. .

- The one-component insulating magnetic developer sent from the developer container 12 is rotated in the same direction as the electrostatic image holding surface 1 by rotating the non-magnetic cylinder 4b having a coating layer containing ultrafine powder such as Ba804 mixed crystal. A magnetic agent 11 is applied onto a non-magnetic cylindrical surface, and friction between the cylindrical surface and the toner particles gives the toner particles a charge of opposite polarity to the electrostatic image charge. Furthermore, an iron doctor blade 10 is placed close to the cylindrical surface (distance + ns).

μ to 500 μ), and is arranged to face one magnetic pole (S pole in the figure) of the multipolar permanent magnet 9, thereby regulating the thickness of toner particles to be thin (30 μ to 300 μ) and uniform. By adjusting the rotational speed of the cylinder 4b, 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, in the developing portion, an alternating current bias may be applied between the developer carrier and the electrostatic image holding surface.

The organosilicone polymer used in the present invention generally has a 5-in.
s # CHs8i0Vs *(CHsh8i0. (
CHs)s8i0t/m.

(C1,) @ S iQ C4H68i0s/* e
((4HI) (CHs) S 10e(C@Hs
)s 8 io structural units, which are collectively called organopolysiloxanes, and active silicone intermediates with silanol or methoxyl groups, which can be condensed with active hydroxyl groups and bonded to siloxane. So-called silicone-modified resins, such as silicone-modified alkyd juge-cod silicone-modified phenol resin, silicone-modified melamine resin, silicone-modified epoxy resin, silicone-modified polyester resin, silicone-modified acrylic resin, silicone-modified urethane resin, etc. included. These polymers are used alone or in combination with other thermoplastic or thermosetting resins for the purpose of improving adhesion to the sleeve base or improving properties such as charge control.

Maku8n02.8a02-Ties mixed crystal, 8n01
-Ba804-based mixed crystal ultrafine powder has been shown to be effective as a tribocontrol agent under any environment.

In other words, a visual sleeve coated with an organic silicone polymer has no problems under normal humidity, but under low humidity, the friction between the developing sleeve and the toner particles causes an abnormally high tripod, which tends to cause unevenness as described above. This will reduce the amount of money.

However, even under high humidity conditions, good results can be obtained due to the effects of the organic silicone polymer.

In particular, the 8n01, 8n02-Ties mixed crystal, and 8nO@-BaSO4 mixed crystal ultrafine powder of the present invention has the effect of leaking an appropriate amount of triboelectric charge under low humidity, and has the effect of leaking an appropriate amount of triboelectric charge under high humidity.
However, it does not leak much and is more effective as a tripocontrol agent. The ultrafine powder is 5 to 5 Q vvt%, preferably 10 to 3 Q, based on the organic silicone polymer.
It is a wt sludge, and if it is less than 5%, it has little effect on improving ore unevenness, and if it is more than 50%, it has little effect under high humidity.
Also, these super-ridged powders had different effects in combination with one type of binder, and in particular, the effect in combination with an organic silicone resin was extremely large compared to other types of biciders.

In the present invention, the member that applies a triboelectric charge to the -component insulating toner is a member that can contact the toner and apply or supplementally apply the necessary electric charge for development, and includes, for example, A toner retaining member such as a sleeve, a toner thickness regulating member such as a doctor blade, a scraper member for removing residual toner on the sleeve after cleaning, and a member that comes into contact with the toner to impart a low frictional charge. There are flexible pillar members installed in the

These members that impart a frictional charge to toner include metals such as aluminum, iron, and stainless steel, synthetic rubber, glass,
Engineering: Snug or Snow-T is added to the organic silicone polymer on the surface of a substrate such as an elastic body such as a lastomer.
Preferably used in the present invention is one in which a coating layer containing ultrafine powder such as an iO1-based mixed crystal or an 8n01-HaSOa-based mixed crystal is formed.

The insulating toner of the present invention is composed of a binder resin, a colorant, and additives such as a charge control agent, a fixing aid, and an anti-caking agent depending on the taste, and any known additives may be used. .

For example, as the binder resin, monopolymers of styrene and its substituted products such as polystyrene, polyP-chlorostyrene, and polyvinyltoluene, styrene-P-chlorostyrene copolymers, styrene-propylene copolymers, styrene-
Vinyl toluene copolymer, 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, styrene-α chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer,
Styrene-vinylethyl ether copolymer, styrene-
Vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-inoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Styrenic copolymer, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polyfluorhylene, polyester, polyurethane, polyamide, epoxy resin,
Polyvinyl methyl, polyacrylic acid resin, rosin, modified rosin, alpine resin, phenolic resin, aliphatic or 13W cyclic hydrocarbon resin, aromatic petroleum resin, chlorinated rough-in wax, etc. can be used alone or in combination.

Further, additives such as colorants, charge control agents, fixing aids, and anti-caking agents include carpon black, various dyes and pigments, plasticizers, colloidal silica, and talc.

Furthermore, when used as a magnetic toner, ferromagnetic elements and alloys and compounds containing them, such as iron, cobalt, nickel, manganese, etc., such as magnetite, hematite, and ferrite, can be appropriately used as magnetic powder. It is sufficient to contain about 1 to 80% by weight of fine powder of substances conventionally known as magnetic materials, such as alloys, compounds, and other ferromagnetic alloys, with an average particle size of about 0.1 to 5 microns.

Hereinafter, the present invention will be specifically explained with reference to Examples.

Example 1 After thorough degreasing and drying, dimethylpolysiloxane (trade name: 882410: ) - manufactured by Resilicone Co., Ltd.) 1,' 100 ml K Sn0g ultrafine powder (trade name, T = 1
．． (manufactured by Mitsubishi Metals Co., Ltd.) was immersed in a uniformly dispersed solution and pulled up, and then heat-treated with ioo'o for 30 minutes to obtain a cylinder having a dimethyl silicone coating containing SnO and ultrafine powder with a thickness of approximately 10 μm. This was made into a sleeve.

On the other hand, a mixture consisting of 100 parts by weight of zinc oxide, 2 parts by weight of styrene-butadiene copolymer, 40 parts by weight of n-butyl methacrylate, 120 parts by weight of toluene, and 4 parts by weight of a methanol solution of 1 part rose bengal was mixed into Pall Meal. At 6
Time fractions made sense. This was applied to an aluminum drum with a thickness of 0.005 fl using a wire bar so that the dry coating thickness was 40 μm, and the solvent was evaporated with hot air to prepare a zinc oxide binder-based photoreceptor. This photoreceptor was subjected to corona discharge of 16 KV to uniformly charge the entire surface, and then an original image was irradiated to form electrostatic latent scratches.

This latent image was formed by using the cylinder as a sleeve and fixing the sleeve to a rotating magnet with a sleeve surface magnetic flux density of 700 Gauss and a distance between the ear cutting blade and the healing sleeve surface of 0.2 tm (the sleeve peripheral speed was the same as that of the drum, but the rotation direction was opposite). The distance between the photosensitive drum surface and the sleeve surface was set to 0.25 mm in the current device, and the sleeve was set at 400 Hz.
By applying 1200 V O AC and -150 V DC bias, styrene-butyl acrylate copolymer 901
1 part 1 10 parts by weight of styrene-butyl acrylate-aminoethyl methacrylate copolymer and 60 parts by weight of magnetic powder were used to drill the transfer paper, and then a direct current of 17 KV was applied from the back side of the transfer paper. The powder image was transferred while being irradiated with corona and fixed by heating.

The resulting image was clear and had high resolution, and no fogging was observed.Even in a high-humidity environment, there was only a slight decrease in image density, and even in a low-humidity environment, uneven coating of toner on the sleeve was prevented. It never occurred.

Example 2 Dimethylpolysiloxane (trade name: SR, -2410
A 3011Xφ stainless steel cylinder was immersed in a solution containing 100 parts by weight of styrene (manufactured by Toichire Silicone Co., Ltd.) dissolved therein, then pulled out and thoroughly dried at 100°C. Then, the temperature was gradually raised to 140'O, and heat external embedding was performed at this temperature for 1 hour to obtain a cylinder having a coating of about 15 μm thickness, which was used as a sleeve.

On the other hand, a developing powder consisting of 10011 parts by weight of polyethylene and 80 parts by weight of magnetic powder was prepared.

Example 1 except that this developing powder and the sleeve were used.
A # image was formed in the same manner as above, and after being drawn, a transferred image was obtained which was transferred to paper.

This transferred image was passed between two rolls to which a linear pressure of 15 Ac9/cML was applied to obtain a fixed image.

The resulting image was clear and had high resolution, and no fogging phenomenon was observed. Even in a high-humidity environment, there was only a slight decrease in the toner density, and even in a low-humidity environment, there was no uneven coating of the toner on the sleeve.

In addition, dimethylpolysiloxane was used as a phenyl silicone face (product name: KRr-316, Shin-Etsu Chemical Co., Ltd.
Although it was carried out in place of the previous method, it had the same effect.

Example 3 Silicone modified epoxy resin (product name: E81001
゜Manufactured by Shin-Etsu Chemical Co., Ltd.) 250 heavy weight section 8nO! -Bm
80a mixed crystal (trade name T-10. manufactured by Mitsubishi Metals) 25
3G in a solution diluted with 750 parts by weight of Xyref
After immersing a 101φ stainless steel exchange cylinder, pull it out and
It was thoroughly dried at ℃. Then, the temperature was raised to 150° C. and heat-cured for 20 minutes. A cylinder with a coating of about 15 μm was obtained and used as a sleeve.

Using this cylinder in the same manner as in Example 1, II! When Ii came out, there was a clear I with no capri! 111I! 9. Even under a low i1 km condition, there was no occurrence of leprosy unevenness in the toner on the sleeve.

Comparative Example 1 The sleeve surface was prepared in the same manner as in Example 1 except that 8n01 super-ridged powder was not added.

- Image density was high and a clear image was obtained. However, under high humidity conditions, the image immersion level decreased, and under low humidity conditions, the toner layer formed ripples on the sleeve with uneven shading, resulting in uneven density on the first copy. In addition, in the areas that were uneven and dark, a soil precipitate occurred.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an example of a copying device or a recording device to which a developing method according to the present invention can be applied. FIG. 2 is a cross-sectional view of one embodiment of the developing process used in the present invention 1. 1...Photosensitive drum, 4...Developing device, 4
a... Toner carrier, 4b... Non-magnetic cylinder, 9°°
° Magnet roll 10...Doctor blade 11
・−・Absolutely phobic magnetic toner. Applicant Canon Co., Ltd.

Claims (1)

[Claims] In a method of frictionally developing an electrical layer using a charged insulating toner without using carrier particles, at least the surface of the member that imparts a triboelectric charge to the toner is Sn (%, 8n01). -Ti (% mixed crystal,
A developing method comprising an organic silicone polymer to which at least one side of a S^-8m80a-based mixed crystal powder is added.