JPS59181361A - Color toner for electrophotography and electrophotographic method using color toner - Google Patents

Abstract

PURPOSE:To improve a cleaning characteristic and filming preventiveness by incorporating a specific ratio of a photoconductive pigment in a color toner consisting essentially of a binder resin and a pigment to accelerate the attenuation in the electrostatic charge of the toner on a photosensitive body after development. CONSTITUTION:A toner contg. 10-35wt% a photoconductive pigment consisting of ZnO, TiO2 or the like or a photoconductive pigment consisting of a phthalocyanine pigment, bis-benzoimidazole pigment or the like as the whole or a part of the pigment together with a binder resin in a color toner is prepd. A fixed image is obtd. by using such toner and providing an irradiatng stage of a destaticizing lamp between a developing stage and a cleaning stage or providing the irradiating stage of the destaticizing stage between a transferring stage and the cleaning stage. The attenuation in the electrostatic charge of the toner on a photosensitive body after development is accelerated by the photoconductive pigment and the color toner having an excellent cleaning characteristics and a preventive characteristic of drum filming is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field: The present invention relates to Kameko photographic color toner 2 and an electrophotographic method using the same. More specifically, the present invention (d) is directed to a color toner containing a photoconductive pigment in at least a portion of the pigment in a specific proportion, and an electrophotographic method using the same.

Conventional technology: Conventionally, charging process, image exposure process, development process, transfer process,
In the electrophotographic method, which consists of a cleaning process and a fixing process, in order to always obtain a stable image, it is necessary to remove untransferred toner remaining on the surface of the photoreceptor after transfer to plain paper. Therefore, it is necessary to provide a toner composition having excellent cleaning properties or a toner composition containing the same.

It is known from the developer that one way to improve this cleaning property is to adjust the resistance value of the toner itself to an appropriate value. For example, in two-component black plasticizers, the resistance of carbo, which is commonly used as the color pallor component, can be more easily controlled so that the black toner always maintains excellent cleaning properties.

For two-component developers containing color toners,
Naturally, since carbon black cannot be used as a resistance control agent, the toner itself tends to have high resistance.

In order to prevent color toner from becoming highly resistive, surfactants are generally used. However, this surfactant itself causes so-called breathing, which oozes out onto the toner surface, so it is affected by humidity, etc.
At present, this is not preferred because the resistance of the toner surface is significantly reduced and the properties as a developer, especially the charging properties, etc. are deteriorated.

Purpose of the Invention: An object of the present invention is to develop a color toner for electrophotography which has excellent cleaning properties and drum swimming prevention properties in order to promote the attenuation of the charge on the toner on the photoreceptor after development. The aim is to provide photography methods. The purpose of this invention is:

The object of the present invention is to provide a color toner for electrophotography which has high transfer efficiency and forms clear images without causing edge effects, and a complete electrophotographic method using the same.

Summary of the Invention: The color toner of the present invention mainly consists of a binder resin and a pigment, and contains a photoconductive pigment, which constitutes at least a part of the pigment, in a proportion of 10 to 35% of the total weight, thereby achieving the above-mentioned properties. The purpose is achieved. 9 The electrophotographic method of the present invention also includes:
An electrophotographic method that includes a main charging step, an exposure step, a developing step, a transfer step, a cleaning step, and a fixing step. Using a color toner containing a proportion of 10 to 35%, a static elimination lamp irradiation step is provided between the viewing step and the cleaning step,
In addition, the above objectives are achieved.

The colored pigment used in the present invention does not need to be special, and any known pigment can be used. Examples of yellow pigments include yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, and mineral fast yellow. Examples of orange pigments include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, and palkan orange. Red pigments include red pigment, cadmium red, fast red, and red lead.

Examples include valued mercury and cadmium. Examples of purple pigments include mankan purple, fast violet B, and methyl violet lake, and examples of blue pigments include deep blue, cobalt blue, and alkali blue lake. Examples of green pigments include chrome green, chromium oxide, pigment green B, malachite green lake, and phthalocyanine clean, and examples of white pigments include dolphin oxide, titanium oxide, antimony white, and zinc sulfide. Further, examples of the monolithic pigment include palite powder, barium carbonate, clay, silica, and white carbon.

Examples of the photoconductive pigment contained as at least a part of the pigment include zinc oxide and titanium oxide as inorganic pigments. Examples of organic pigments include phthalocyanine pigments such as LEi β-type gold-free maple phthalocyanine (C, 1,74100); perinone (C, i.

71105); indigo pigments such as Thioindico (C01,73360); and azo pigments such as Diane Blue (C, 1.21180). Perylene pigments are also effective, examples include N-N'-di(3,5-dimethylphenyl)-perylene-3,4,9,10-tetracarboxylic acid diimide, (4-Chlorphenyl)-perylene-3,4,9,10-tetracarboxylic acid diimide;
10-Tetracarboxylic acid diimide; There are perylene pigments such as N-N'-diphenyl-4,9,10-tetracarboxylic acid diimide. Quinacridone pigments such as C0l, 46500, where k is hydrogen or a quinacridone atom, are also effective. These photoconductive pigments can be used alone or in combinations of two or more silk But it can be used.

It is contained in a proportion of 30% by weight. When the weight exceeds 35, the mechanical strength of the color toner decreases, so that spent toner tends to occur and the durability as a developer decreases significantly. In addition, when a static elimination lamp is provided before transfer in the electrophotographic method described later, the resistance value is extremely reduced, resulting in a significant decrease in transfer efficiency, white spots in the transferred image, and toner scattering on the edges. If the content of the photoconductive pigment that produces 0 is less than 10% by weight, the toner charge will not be effectively attenuated during photoirradiation, and as a result, the object of the present invention cannot be achieved.

Furthermore, photoconductive toners have been known as toners containing photoconductive pigments.

Image formation using photoconductive toner is basically based on the Shukerman method (U, S, P, 275893).
9). Moreover, the photoconductive pigment contained in the conductive toner requires at least 40M of photoconductive pigment to the total amount.9 In the electrophotographic method using the so-called Carlson method of the present invention, the above-mentioned drawbacks occur. Therefore, photoconductive toners cannot be used.

When using the phototetraelectric zinc oxide or titanium oxide as the pigment, known sensitization methods can be employed. For example, #! Sensitizing dyes such as acridine orange, rhodamine, erythrosin, fluorescein, eosin, auramine, methylene blue, IJ star violet, and bromophenol blue can be adsorbed on the surface of zinc chloride particles in a single layer or in layers.

Color toners of the present invention may also contain dyes.

The dye may also be a known dye. To give an example: Eisen Spin Yellow GRl ((C0
I, 5olvent Yellow 61), Huissenshine Yellow 3RH, etc. As an orange dye, Eisen Spin Yellow G IL H (C, 1, S
olventQrange 37)
nge 4Q). As a red dye, Eisen Spin Yellow GEH (C,I.

5olvent Red 134), Eisenspiron Red BEH (C,1,5olvent Red 13
3) etc. As a purple dye, Eisensviron Violet RH ((:, l.

5olvent Violet 21). As a blue dye, Eisenspiron Blue GNH, Sumi Plus Dob/L/-OA (C, l, 5olven
t Blue '35), and as a green dye, Eisenspijen 3 G N HCo
n+c 5special, dial resin green A
L (C1l, 5olvent Green 3), etc.

The binder resin used in the present invention does not need to be particularly specific, and any known natural, semi-synthetic or synthetic resin that exhibits lubricity under the application of heat or pressure may be used. These resin shaving agents can be used for thermoplastic resins as well.
It may be an uncured or initial condensate of a thermosetting resin. Useful natural ingredients include l#j, balsam resin, rosin, shellac, and copal. These natural 'aIl
It may be modified with one or more of the following: j4 U, vinyl resin, acrylic resin, alkyd resin, phenol resin/epoxy resin, oleorange (oil-based resin), etc.

Examples of synthetic resins include vinyl acetal resins such as vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, and polyvinyl butyral; vinyl resins such as t-govinyl ether 1; polyacrylic esters and polymethacrylic esters. , acrylic acid copolymers, methacrylic acid copolymers; styrene resins such as polystyrene, hydrogenated styrene resins/polyvinyltoluene, styrene copolymers; nylon-12, nylon-6, polymerized fatty acids Polyamide m resins such as modified polyamide; polyesters such as polyethylene terephthalate/isophthalate, polytetramethylene terephthalate/isophthalate; phthalic acid resin, maleic acid 41
phenol-formaldehyde resin; Kent resin; coumaron-indene resin; terpene resin; amino resin such as urea-formaldehyde resin, melamine-formaldehyde resin; and epoxy*
You can use fat, etc. These synthetic resins may be a combination of two or more such as phenol-epoxy resin or amino-epoxy resin.

The electrophotographic method of the present invention uses a color toner containing a photoconductive pigment as at least a part of the pigment, and includes an irradiation step with a neutralizing lamp after the development step and before the cleaning step. The photoconductive pigment contained in the color toner acquires conductivity through irradiation with the static eliminating lamp, and the resistance value of the toner as a whole is reduced. Therefore, charge neutralization occurs between the toner charge and the photoreceptor surface charge at the contact portion between the toner particles and the photoreceptor. Therefore, the electrostatic attraction between the photoreceptor and the toner particles is weakened as a whole, the toner is more likely to separate from the photoreceptor, and the cleaning properties are improved. At the same time, drum filming is also effectively prevented. By providing the charge eliminating lamp 11θ irradiation step between the development step and the transfer step and between the transfer step and the cleaning step, toner transfer efficiency and cleaning characteristics can be simultaneously improved. By adding a removal process using a static elimination charger after the transfer process, cleaning assistance can be further improved.

Known means can be used for each step in the spear and child photography method of the present invention. In particular, in the cleaning step, a cleaning method using an elastic blade or a fur brush may be employed even when used as a developing means for both development and cleaning.

Example: The present invention will be explained below based on examples.

Color toner production example 1 (N-type) oxidizing lead (ZnO) powder (manufactured by Sakai Chemical Co., Ltd.: trade name SAZEX2000) 100g,! 1: C1-7: 0.15 g of benfj was dispersed in 400 g of ethanol. This was sufficiently mixed with a homomixer and then dried to give Rose Bengal Dongyin (P type) ZnO powder. That io
og and 0.2 g of crystal violet (N type) were dispersed in 300 g of isopropyl alcohol in which Rose Bengal is hardly dissolved. These were thoroughly mixed in a homogeneous swamp and dried to obtain a ZnO powder with a three-layer structure.

Thoroughly mix the composition with a Henschel mixer.

The mixture was melt-kneaded using a pressure kneader. After cooling, it was coarsely ground using a hammer mill. Next, it is pulverized using an ultrasonic jet mill pulverizing rock. The fine powder thus obtained was classified using a zigzag Alpine classifier to obtain a red toner (ZnO content: 30 parts) having a particle size distribution of 5 to 20 μm and an average diameter of 12.2 μm.

Toner Production Example 2 A red toner (Zn
O content: 20) was obtained.

Toner production example 3 ZnO powder, 5AZEX2000 (Sakai Chemical Co., Ltd. W) 10
0 g of bromophenol blue and 0.2 g of bromophenol blue were dispersed in 400 g of ethanol and thoroughly mixed with a homomixer.

This is dried to create a two-layered bromophenol blue dye N.
(P type) ZnO powder was poured.

A composition consisting of
A green toner (ZnO content: 20 parts) was obtained.

Toner Production Example 4 A red toner (Zn
An O content of 45% was obtained.

Toner Production Example 5 The composition of Production Example 1 except for the ZnO powder was changed to Production Example 1.
A red toner having an average diameter of 12.2 μm was obtained by processing in the same manner as above.

Toner Production Example 6 The composition of Production Example 3 except for the ZnO powder was changed to Production Example 1.
A green toner having an average diameter of 12.2 μm was obtained by processing in the same manner as above.

A composition consisting of
1 μm blue toner (contains photoconductive pigment, i17.7)
Nita.

A composition consisting of
A .mu.m red toner (optical 4N pigment content: 12 parts) was obtained.

A composition consisting of
A black toner of μm was obtained.

Gong, preparation of the image side each f! A developer was prepared by stirring and mixing 10 parts by weight of the color toner prepared by Li with 100 parts by weight of an iron powder carrier.

Electrophotographic copying test Two types of copying tests were conducted using each of the above-mentioned areas and the image side, and the image density, background fog density, transfer seedlings, and cleaning characteristics of each developer were evaluated.

[Copying Test 1] As shown in FIG. 1, a conductive substrate 1 having a photoconductive layer 1o made of selenium on one surface is rotated in the direction of the arrow. Main charging charger in round 4tt@1o
(+6.5KV) Apply a uniform charge of +720V. Next, image fogging is performed through the optical system 3 to form an electrostatic latent image on the photoconductive layer (C8e layer) 10 in accordance with the document to be copied. Magnet) 4Off, fixed conductive non-magnetic sleeve rotating two-component one-component developing device f
Using each of the color developers 41 arranged and housed in if4, a -yt4 charge toner image is emitted by a static elimination lamp (white tungsten lamp: 25W) 5, and then transferred to a transfer charger (+6.3KV). 6, the image is transferred onto transfer paper 7.

The transfer paper 7 is directly sent to a fixing device 8, such as a heat roller, and the toner image is fixed on the transfer paper.

Untransferred toner remaining on the photoconductive layer 10 after transfer.

It is removed and cleaned by a cleaning device 9 consisting of an elastic comb blade 90. Table 1 shows the copying results using the toners of Production Examples 1-9 that were subjected to such copying tests. The transfer seedling is calculated by the following formula: Transfer aid (%) - (1 - (cleaning collected toner amount /
Toner consumption) x lo.

The cleaning properties and drum filming prevention properties are indicated by "+" when particularly good; "+" when good; and - when poor.

Table 1 [Copying Test 2] iM<2 The same procedure as Copying Test 1 was conducted except that the static elimination lamp 5 was placed between the transfer charger 6 and the cleaning device 9 as shown in the figure. The results are shown in Table 2. Method for calculating the amount of transfer movement The display of cleaning properties and drum filmk prevention properties is the same as in Table 1 above.

From Table 2 Table 1 Table 2 and Table 2, when toner containing photoconductive pigment at a predetermined concentration (Production Examples 1.2, 3.7.8) is used, black toner (Production Example 9) is used. It can be seen that the transfer aid and cleaning properties (almost the same) can be obtained. Further, it can be seen that it is preferable to provide the discharge lamp irradiation step between the development step and the transfer step in order to improve the transfer assistance to 0%.

The cleaning process can be further improved by providing a static elimination charger 11 after the transfer process.

Effects of the invention: Since the color toner of the present invention contains a photoconductive pigment in a specific proportion, the weight-reducing lamp is used between the developing process and the cleaning process, between the developing process and the transfer process, or between the developing process and the developing process. By performing this both between the transfer process and the transfer process and the cleaning process, the transfer effectiveness, cleaning properties, and drum filming adhesion properties can be significantly improved. As a result, a clear image without background fog and edge effects can be obtained.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are two views of the electrophotographic method of the present invention, respectively.
FIG. 2 is a side view of a main part showing an example of an electrophotographic setup for explaining each step of the process. 1... 4-electroelectric substrate, 2... Main charging charger. 3...Optical system, 4...Two-component thread image enhancement compensation, 5...
lll Electric lamp 6... Transfer charger, 7...
- Transfer paper, 8... Fixing device, 9... Cleaning device, 10... Photoconductive layer, 11... Removal charger,
41...Developer containing the color toner of the present invention. Applicant: Sanda Kogyo Co., Ltd. Agent: Patent Attorney: Shusaku Yamamoto

Claims (1)

[Scope of Claims] 1. A colored color for electrophotography, which is mainly composed of a binder resin and a pigment, and contains a photoconductive pigment, which constitutes at least a part of the pigment, in a proportion of 10 to 35 parts by weight. 2. The color toner according to claim 1, wherein the photochromatic pigment is zinc oxide, titanium oxide, or an organic pigment. 3. The organic pigment is a 7-thalocyanine pigment, a bisbenzimidazole pigment, or an indigo pigment. Azo pigments, perylene pigments, and the present Nacridone H1
The color according to claim 2, which is at least one kind selected from the group consisting of -
. 4. Main charging process, Kojisen process, viewing, image process, transfer process,
An electrophotographic method comprising two types of "cleaning" and a fixing step, which mainly consists of a binder resin and a pigment, and contains a photoconductive pigment, which constitutes at least a part of the pigment, in a proportion of 10 to 35% of the total weight. An electrophotographic method that uses color toner and includes a static elimination lamp irradiation step between the dust image step and the cleaning step. 5. The electrophotographic method according to claim 4, wherein the static elimination lamp darkening step is provided between the imaging step and the transfer step and between the transfer step and the cleaning step. 6. The electrophotographic method according to claim 1, paragraph 4, wherein the photochromic pigment is zinc oxide, titanium oxide, or a @ pigment. 7. The organic pigment is a 7-talocyanine pigment, a bisbenzimidazole pigment, or an indigo pigment. Electrophotographic method 0 according to claim 6, which is at least one selected from the group consisting of azo pigments, perylene pigments, and quinacridone pigments.