JPH04328575A - Developing method for nonmagnetic one component color toner - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing non-magnetic one-component color toner used in electrophotography. Electrophotography, which is used in copiers, laser printers, etc., generally applies a uniform electrostatic charge to a photoconductive insulating layer and irradiates a light image onto the insulating layer. The static charge is partially removed to form an electrostatic latent image, and a fine powder called toner is attached to the remaining part of the static charge to visualize the latent image to form a toner image (referred to as development). Printed matter is obtained by fixing (referred to as fixing) the toner image on the recording paper.

0002

BACKGROUND OF THE INVENTION The developer mentioned above may be a two-component developer consisting of a magnetic carrier and a non-magnetic or magnetic toner, or a one-component developer consisting of a magnetic or non-magnetic toner. Among these, two-component developers charge the toner due to friction between the carrier and toner, so as the number of prints increases, the toner adheres to the magnetic carrier surface, deteriorating the carrier and extending the lifespan of the developer. But it has shortcomings. On the other hand, a one-component developer does not use a carrier and only consumes toner, so toner fusion to the carrier does not occur, so it has the advantage of having a long life as a developer. However, when a magnetic toner is used as a one-component developer, it is difficult to produce color because it needs to contain magnetic powder (black). Furthermore, when a non-magnetic toner is used, colorization is easy and the life of the developer is long, but the toner is required to have various characteristics. Next, a developing method will be explained using the apparatus shown in FIG.

In FIG. 1, a movable surface is provided between a storage means 2 for storing developer 1 and a developer carrier 3 for transporting developer 1 along a predetermined circulation path including a developing area. A roller-shaped developer recovery means 4 on which a material is adhered is provided so as to be in contact with the developer carrier 3, and between the developer carrier 3 and the developer recovery means 4, the developer 1 is A bias voltage (hereinafter referred to as
By applying a recovery bias) and performing not only mechanical recovery by contact but also electrical recovery by recovery bias, mechanical and electrical history on the developer carrier 3 is stably and reliably eliminated. do. Therefore, the developer 1 stored in the storage means 2 is newly supplied to the developer support 3 by the developer supply means 5 while in contact with the developer support 3, and the developer is charged by mechanical friction. A charged toner layer is formed on the developer carrier 3, and the layer thickness is regulated to a desired thickness by a triboelectric charging member 6, and then transported to a developing area and developed.

Reference numeral 7 denotes a latent image carrier, which conveys the latent image formed on its surface to a developing section, and conveys the formed image of developer 1 to a position where it is transferred onto recording paper 14. As the latent image carrier 7, a photoconductive material such as a photoconductive material (organic photoconductor, selenium photoconductor, amorphous silicon photoconductor, etc.) or an insulator can be used depending on the latent image forming method. In the figure, 8 is an exposure device, 9 is a pre-charger, 10 is a cleaner unit, 11 is a static elimination lamp, 12 is a fixing device, and 13 is a transfer device.

[0005] When the above development method is used, the following problems occur. When the toner on the developer carrier 3 is strongly tribo-electrified by the tribo-charging member 6, it is charged with good rising characteristics, but if the softening point of the toner binder resin is low, the tribo-charging member is The toner is fused to the toner 6, causing printing defects such as fog due to charging failure, and printing quality is significantly degraded by long-term continuous printing. For this reason,
Toners are required to have properties that prevent them from fusing.

[0006] Furthermore, when a multicolor image is obtained by electrophotography, it is generally achieved by using toners of three colors, yellow, magenta, and cyan, and by overlapping toner layers of each color and mixing the colors. Therefore, during fixing, the quality of the color mixture between toners affects the image quality.
Characteristics unique to color toners are required. In order to improve the color mixing properties of toner, it is possible to lower the softening point of the binder resin and improve the leveling properties of toner, but on the other hand,
Toner fusion to the frictional charging member described above occurs, making it difficult to achieve both.

[0007] Furthermore, the following conditions apply to the coloring agent used in color toners. (1) Good dispersibility in the binder resin and excellent transparency. (2) Good spectral reflection characteristics in order to widen the color reproduction range. The present invention has been made in view of these conventional problems, and has excellent color mixing properties during fixing, and even when continuous printing is performed, toner is difficult to fuse to the frictional charging member, and printing stability is improved. It is an object of the present invention to provide a good non-magnetic one-component color toner developing method.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a rotating developer carrier that is in pressure contact with a latent image carrier, and a friction member that is in pressure contact with the outer periphery of the developer carrier. A charging member is provided, and a non-magnetic one-component color toner is supplied on the upstream side of the tribo-charging member, the non-magnetic one-component color toner is charged by the tribo-charging member, and the developer carrier is used to charge the non-magnetic one-component color toner with the latent image carrier. In a non-magnetic one-component color toner developing method in which an electrostatic latent image on a latent image carrier is developed by being conveyed to a pressure contact part, a small amount of submicron particles is added to the non-magnetic one-component color toner as a developer. The hardness is 100 (Rockwell R) or more, and the compressive breaking strength is 10 kg/mm 2 or more.

The present invention will be explained in more detail below. In order to improve the color mixing properties of color toners, it is necessary to use a resin with a low softening point as the toner binder resin. However, when a low softening point resin is used, toner fusion occurs on the triboelectric charging member. Toner fusion occurs due to friction with the toner, so toner made of a low softening point resin tends to occur. Therefore, the present inventors investigated materials that have the effect of polishing and scraping off the toner fused to the triboelectric charging member, and as a result, it was found that it is useful to use fine particle resin with high hardness as an external additive for toner. Understood. Note that when a finely powdered resin with low hardness was used as an external additive, no effect as an abrasive was observed.

Using this externally added toner, non-magnetic one-component color toner development is performed using the apparatus shown in FIG. As the high hardness resin, those represented by the following structural formula were particularly effective.

[0011]

[C4]

0012

[C5]

[0013]

[C6]

[0014] As the toner binder resin, epoxy resin, styrene-acrylic ester copolymer, polyester resin, polyurethane resin, etc. can be considered, and when polyester resin is used in particular, good color mixing properties and transparency can be obtained. Next, as the benzidine organic pigment used in the present invention, for example, Color Index No. C. I. 2
1090 (Pigment Yellow 12, KET Yellow
ow 406, Dainippon Ink Chemical Industries), C. I. 21
095 (Pigment Yellow 14, KET Yellow
w 404, Dainippon Ink Chemical Industries), C. I. 211
00 (Pigment Yellow 13, KET Yellow
405, Dainippon Ink Chemical Industries), etc. This pigment has excellent dispersibility in the binder resin and good spectral reflection properties.

Next, as the quinacridone organic pigment used in the present invention, Color Index No. C. I. 7
3916 (Pigment Red 122, KET Red
309, Dainippon Ink Chemical Industries). This pigment has excellent dispersibility in the binder resin and good spectral reflection properties. Next, as the rhodamine organic pigment used in the present invention, Color Index No. C. I. 45
160 (Pigment Red 81, UltraRose
R, Toyo Ink Manufacturing). This pigment has excellent dispersibility in the binder resin and good spectral reflection properties.

Next, as the phthalocyanine organic pigment used in the present invention, for example, Color Index No. C
．． I. 74160 (Pigment Blue 15, KET B
blue 102, KET Blue 103, KETB
blue 104, KET Blue 105, KET
Blue 106, KETBlue 111, Dainippon Ink & Chemicals), C. I. 74260 (Pigment Green 7, KET Green 201, Dainippon Ink and Chemicals), and the like. This pigment has excellent dispersibility in the binder resin and good spectral reflection properties.

Further, as a charge control agent, a metal-containing dye, a fatty acid ester, or a compound having an amino group may be added. The toner used in the present invention can be manufactured by a conventionally known method. That is, the binder resin and the pigment are melted and kneaded by, for example, a pressure kneader, an extruder, etc., with addition of wax, charge control agent, etc., if necessary.
A desired toner can be obtained by uniformly dispersing the toner and classifying it using, for example, a wind classifier.

[0018]

[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. Example 1 Binder resin: Polyester resin (softening point 100°C)
92 parts by weight Pigment: C.I. I.
21090, KET Yellow 406 (manufactured by Dainippon Ink) 4 parts by weight Charge control agent: BONTRON
E84 (manufactured by Orient Chemical) 2 parts by weight Wax: Viscol 550-P (manufactured by Sanyo Chemical) 2
Part by weight The above composition was mixed and stirred in a ball mill, and 14
The mixture was melt-kneaded with an extruder heated to 0°C, cooled and solidified, coarsely ground with a grinder, and further finely ground with a jet mill. The obtained fine powder is classified using a wind classifier and 5
A toner of ~20 μm was obtained.

Next, as an external additive, a resin condensate having the following structure (particle size 0.3 μm, hardness 120 (Rockwell R
), compression breaking strength 14 kg/mm 2 , spherical shape, Nippon Shokubai) was mixed using a Henschel mixer to obtain a high hardness fine powder resin externally added toner.

[0020]

[C7]

[0021] Next, a printing test was carried out using a laser printer capable of simultaneous three-color printing and employing a non-magnetic one-component method and a hot roll fixing device for the above-mentioned high-hardness fine powder resin externally added toner. Note that toners with different coloring agents were used for both magenta and cyan. As a result, the printed image had excellent color mixing properties and transparency, and good transparency was confirmed in OHP printing. Further, even after printing 50,000 sheets, toner fusion did not occur on the frictional charging member, and printing stability was good. Example 2 Binder resin: Polyester resin (softening point 100°C)
92 parts by weight Pigment: C.I. I.
21090, KET Yellow 406 (manufactured by Dainippon Ink) 4 parts by weight Charge control agent: BONTRON E84 (manufactured by Orient Chemical) 2 parts by weight Wax: Viscoel 550-P (manufactured by Sanyo Chemical)
2 parts by weight The above composition was mixed and stirred using a ball mill, melted and kneaded using an extruder heated to 140°C, cooled and solidified, coarsely ground using a grinder, and further finely ground using a jet mill. The obtained fine powder was classified using an air classifier to obtain a toner having a size of 5 to 20 μm.

Next, as an external additive, a resin condensate having the following structure (particle size 0.3 μm, hardness 120 (Rockwell R
), compression breaking strength 14 kg/mm 2 , spherical shape, Nippon Shokubai) was mixed using a Henschel mixer to obtain a high hardness fine powder resin externally added toner.

[0023]

[Chemical formula 8]

Next, a printing test was conducted using a laser printer capable of simultaneous printing in three colors and employing a non-magnetic one-component method and a hot roll fixing device for the above-mentioned high-hardness fine powder resin externally added toner. Note that toners with different coloring agents were used for both magenta and cyan. As a result, the printed image had excellent color mixing properties and transparency, and good transparency was confirmed in OHP printing. Further, even after printing 50,000 sheets, toner fusion did not occur on the frictional charging member, and printing stability was good. Example 3 Binder resin: Polyester resin (softening point 100°C)
92 parts by weight Pigment: C.I. I.
21090, KET Yellow 406 (manufactured by Dainippon Ink) 4 parts by weight Charge control agent: BONTRON E84 (manufactured by Orient Chemical) 2 parts by weight Wax: Viscoel 550-P (manufactured by Sanyo Chemical)
2 parts by weight The above composition was mixed and stirred using a ball mill, melted and kneaded using an extruder heated to 140°C, cooled and solidified, coarsely ground using a grinder, and further finely ground using a jet mill. The obtained fine powder was classified using an air classifier to obtain a toner having a size of 5 to 20 μm.

Next, as an external additive, a resin condensate having the following structure (particle size 0.3 μm, hardness 120 (Rockwell R
), compression breaking strength 14 kg/mm 2 , spherical shape, Nippon Shokubai) was mixed using a Henschel mixer to obtain a high hardness fine powder resin externally added toner.

[0026]

[Chemical formula 9]

Next, a printing test was carried out using a laser printer capable of simultaneous three-color printing and employing a non-magnetic one-component method and a hot roll fixing device for the above-mentioned high-hardness fine powder resin externally added toner. Note that toners with different coloring agents were used for both magenta and cyan. As a result, the printed image had excellent color mixing properties and transparency, and good transparency was confirmed in OHP printing. Further, even after printing 50,000 sheets, toner fusion did not occur on the frictional charging member, and printing stability was good. Example 4 Quinacridone pigment KET Red as organic pigment
A magentan was produced as a prototype in the same manner as in Example 1 except that 309 (Dainippon Ink & Chemicals) was used. Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1. Example 5 Rhodamine pigment Ultra Ros as organic pigment
A magentan sample was prepared in the same manner as in Example 1 except that eR (manufactured by Toyo Ink Manufacturing) was used. Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1. Example 6 Phthalocyanine pigment KET BLU as organic pigment
A cyan toner was prototyped in the same manner as in Example 1 except that E 111 (Dainippon Ink and Chemicals) was used. Next, as a result of evaluation in the same manner as in Example 1, good results were obtained as in Example 1. Comparative Example 1 A toner was prototyped in the same manner as in Example 1 except that no additive particles were used. Next, as a result of evaluation in the same manner as in Example 1,
After printing approximately 1,000 sheets, toner fusion occurred on the frictional charging member and print deterioration was observed. Comparative Example 2 A toner was prototyped in the same manner as in Example 1, except that PMMA (MP-1000, hardness 50 or less, Soken Kagaku) was used as the additive particles. Next, as a result of evaluation in the same manner as in Example 1, it was found that after approximately 3,000 sheets had been printed, toner fusion occurred on the frictional charging member and deterioration of printing was observed. Comparative Example 3 As an external additive, a benzoguanamine/melamine/formaldehyde condensate (Epostor M,
A toner was prototyped in the same manner as in Example 1, except that the particle size was 0.3 μm, the hardness was 120 (Rockwell R), and the compressive breaking strength was 14 kg/mm 2 (Nippon Shokubai). Next, Example 1
As a result of evaluation in the same manner as above, the fixing property was poor. Comparative Example 4 A cyan toner was obtained in the same manner as in Example 1, except that KET Blue 101 (Thren-based, Pigment Blue 60, C.I. No. 69800, Dainippon Ink and Chemicals) was used as the pigment, and a cyan toner was obtained in the same manner as in Example 1. They were evaluated in the same way. As a result, it was found that the color mixing property and transparency were poor.

[0028]

As explained above, according to the present invention, color mixing properties were excellent, toner was less likely to be fused to the triboelectric charging member, and printing stability was good.

[Brief explanation of drawings]

[Figure 1] Diagram showing an electrophotographic recording device

[Explanation of symbols]

1: Developer 2: Storage means 3: Developer carrier 4: Developer recovery means 5: Developer supply means 6: Frictional charging member 7: Latent image carrier 8: Exposure device 9: Front charger 10: Cleaner unit 11: Static elimination lamp 12: Fixing device 13: Transfer device 14: Recording paper

Claims

[Claims] 1. A developer carrier that rotates in pressure contact with a latent image carrier, and a triboelectric charging member that is in pressure contact with the outer periphery of the developer carrier, and on an upstream side of the triboelectric charging member, A non-magnetic one-component color toner is supplied, the non-magnetic one-component color toner is charged with a triboelectric charging member, and is conveyed by a developer carrier to a pressure contact portion with a latent image carrier, so that the electrostatic charge on the latent image carrier is In a non-magnetic one-component color toner developing method for developing a latent image, the developer is made of a small amount of submicron additive particles for the non-magnetic one-component color toner, and has a hardness of 100 (Rockwell R) or more. A non-magnetic one-component color toner developing method characterized by using a non-magnetic one-component color toner which is externally added and has a compressive breaking strength of 10 kg/mm2 or more. 2. The non-magnetic one-component color toner developing method according to claim 1, wherein a polyester resin and an organic pigment are used as constituent materials of the non-magnetic one-component color toner. 3. The nonmagnetic one-component color toner developing method according to claim 2, wherein a benzidine-based yellow organic pigment is used as the organic pigment. 4. The nonmagnetic one-component color toner developing method according to claim 2, wherein a quinacridone-based magenta organic pigment is used as the organic pigment. 5. The nonmagnetic one-component color toner developing method according to claim 2, wherein a rhodamine-based magenta organic pigment is used as the organic pigment. 6. The non-magnetic one-component color toner developing method according to claim 2, wherein a phthalocyanine-based organic pigment is used as the organic pigment. 7. Claim 1, wherein a compound represented by the following general formula is used as the submicron additive particles.
A non-magnetic one-component color toner development method. [Chemical formula 1] 8. Claim 1, wherein a compound represented by the following general formula is used as the submicron additive particles.
A non-magnetic one-component color toner development method. [Chemical 2] 9. Claim 1, wherein a compound represented by the following general formula is used as the submicron additive particles.
A non-magnetic one-component color toner development method. [C3] 10. The nonmagnetic one-component color toner developing method according to claim 1, wherein the submicron additive particles have a particle size of 0.01 to 1 μm.