JPS61262746A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain a photosensitive body capable of reproducing good color without installing a device, such as a filter, in the main body of a copying machine by forming an electrostatic charge generating layer absorbing light of lambda by >=60% and transmitting the other light, and an undercoat absorbing a part of the light of lambda by >=80% and transmitting the other light. CONSTITUTION:The resins for dissolving or dispersing a dye or pigment to be used can be adopted so long as they satisfy the requirements; strong adhesion to a substrate, sufficient solvent resistance, and low volume resistivity of the resin coat, and the like, and resins, such as epoxy, alkyd, and polyamide, are especially suitable. The charge generating layer is formed by dispersing a charge generating material into a binder resin, such as polyester, polystyrene, or cellulose ester, and its thickness is 0.01-1mum, preferably, 0.05-0.5mum. The charge transfer layer is formed by dissolving a positive hole transfer material, such as compds. having polycyclic groups, e.g., anthracene, pyrene, or coronene, on the main chain or side chains, N-contg. compds., hydrazone compds. in a film-forming resin.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an improved electrophotographic photoreceptor, and more specifically, in order to sharpen the latent images on the electrophotographic photoreceptor for blue and red originals, mirror surface The present invention relates to a barrier layer that absorbs a specific wavelength and is provided between a substrate and a charge generation layer.

[Prior Art] Conventionally, in a laminated electrophotographic photoreceptor, when the spectral absorption of the charge generation layer has a peak at 550 nm or less, when copying a blue original whose spectral reflectance peaks at 550 nm or less, the electrophotographic photosensitive material There is a drawback that the formation of an image on the body is significantly worse than that of a black original, and when the spectral absorption has a peak at 570 nm or more, the formation of a latent image with a red original is worse than with a blue original. To compensate for this drawback, it is common to apply a filter to the image exposure axis, but this method not only increases the cost of the machine itself, but also increases the charge on the photoreceptor because the machine body must be treated to improve reproducibility. There are disadvantages such as the inability to change the generation layer and the fact that the light absorption by the filter reduces the emission intensity of light of wavelengths that do not need to be cut.

[Problems to be Solved by the Invention] The present invention provides an electrophotographic photoreceptor that solves the above-mentioned drawbacks.

[Means and effects for solving the problems] The present invention provides a method of applying light of different wavelengths depending on the materials used for the undercoat layer and the charge generation layer on a substrate having a reflectance of 30% or more for nine colors of light. In an electrophotographic photoreceptor having a charge generation layer that absorbs light and a charge transport layer that is substantially transparent to light of λ, the charge generation layer has a property of absorbing 60% or more of light of λ but transmitting the rest. The subbing layer absorbs 80% of the incoming light.
The undercoat layer is composed of an electrophotographic photoreceptor characterized by having the property of absorbing light of 630 nm or more and transmitting other light, and furthermore, using a photoreceptor with an absorption wavelength of 630 nm or more. Regarding the electrophotographic photoreceptor that absorbs light of 560 nm or less, the undercoat layer is composed of the electrophotographic photoreceptor that absorbs light of 500 nm or less. .

It is well known that a barrier layer is provided between the charge generation layer and the substrate in a laminated electrophotographic photoreceptor in order to stably carry charges and improve the adhesion of the charge generation layer. When using a substrate with a reflectance of 30% or more and a charge generation layer with an absorbance of 0.4 or less, a considerable amount of light reflected from the substrate is required to generate photocarriers in the charge generation layer. It is well known that when using a light source that has a substantially constant exposure intensity over the entire visible region, the color of the portion of the charge generation layer where the absorption peak is located is difficult to appear.

However, as mentioned above, in the case where the absorbance of the charge generation layer is 0.4 or less, the present invention uses only complementary color light of the light absorbed by the charge generation layer as the light reflected from the substrate, thereby making it possible to install a device such as a filter in one machine body. This makes it possible to provide a photoreceptor with good color reproducibility without providing any.

The main dyes and pigments used in the present invention are illustrated below.

(1) Nitron Dye C,1, Mordant Green 4 (2) Nitro Dye C,1, Disburs Yellow 14 (3) Azo dye (divided into mono, bis, tris, tetrakisazo dye, etc. depending on the number of azo groups) c, r, Direct Red 28 (4) Azoic dye (something that generates an azo group on the fiber) C・■・Azoic diazo component 37C,I.

Azoic coupling component 2 (5) Condensate of stilbene azo dye C,1, Direct Orange 71 (8) Ketoimine (diphenylmethane) dye (:, 1.
Paysic Yellow 2 (7) Triphenylmethane Dye C, 1, Paysic Blue 1 (8) Xanthine Dye C, 1, Acid Red 52 (9) Acridine Dye C, 1, Paysic Orange 23 (10,) Quinoline Dye C, 1, Acid Yellow 2 (11) Methine, polymethine dye C, 1, Gisbar's Yellow 31 (12) Thiazole dye C, R, Direct Yellow 59 (13) Indamine, indophenol dye C, 1, Rubento Blue 22 (14) Azine dye C, 1, Acid Blue 58 (15) Oxazine dye C, 1, Mordant Blue 10 (1B) Thiazine dye C, r, Pacic Blue S (17) Sulfur dye (many have unknown structures) (18) Aminoketone, oxyketone dye C,1, Bat Red 33 (18) Anthraquinone dye C,1, Acid Blue 45 H-N0OH (20) Indigoid dye C,1, Bat Blue 41 (21) Phthalocyanine dye with phthalocyanine bone core, such as C, 1,
In (1) to (21) above, dyes suitable for the present invention, such as Direct Blue 86, are described in terms of their chromophores and color-forming systems, and representative dyes are exemplified, but the dyes are not limited thereto.

Examples of pigments are shown below, but the pigments are not limited to the exemplified pigments as being suitable for the present invention.

(22) Watching Red (23) Green Gold (24) Diamond Black Oxidized Condensate of Aniline (25) ) Luizine Maroon (26) Permanent Red 4RG (Rake Red 4R) (27) Rose Red (28) Brilliant Scarlet G (29) Benzidine Yellow (30) Benzidine Orange 2G (31) Bordeaux 5B H (32) Hansa Yellow G, Hansa Yellow 10G (First 2 Row) COCH.

1'! nrLL II (33) Pigment Green B (30 Pigment Scarlet 3B (Brilliant Carmine 3B) (35) Pyrazolone Red (3B) Fast Sky Blue 1N-y Talocyanine-Disulfonic Acid/Thurium Salt (3
7) Phthalocyanine Green (Cyanine Green) Chlorinated Copper Phthalocyanine (38) Phthalocyanine Blue (Cyanine Blue) Copper Phthalocyanine (39) Brilliant Carmine 6B (40) Bordeaux 10B (4I) Madder Lake (42) Methyl Violet Lake (Fernal Violet, Fast) (43) Linur Red R (44) Lake Red C (45) Lake Red D These dyes and resins for dissolving or dispersing pigments must have strong adhesion to the substrate, sufficient solvent resistance, Any resin that satisfies conditions such as low volume resistivity of the coating film can be used, but resins such as epoxy resin, AJL-Kito resin, phenol resin, and polyamide are particularly suitable. Dyes and pigments are dissolved or dispersed in these resins (dispersion is done by conventional means such as roll mills, ball mills, attritors, sand mills, colloid mills, etc.), and applied to a sheet or cylindrical cylinder. When applying to this re-sheet, wire barcode, blade coat,
Knife coat, screen coat, etc. are suitable, and for cylinders, dip coating is suitable.

Methods such as spray application are used.

In order to produce a complementary color to the light absorbed by the photoreceptor, one or more of the above-mentioned dyes and pigments may be mixed, or one barrier layer of different colors may be applied in multiple layers to produce a complementary color.

The charge generating layer in the present invention is an azo pigment such as Sudan Red, Guianpoule, and Jenas Green B, a quinone pigment such as Algol Yellow, Pyrenequinone, and Indanthrene Brilliant Violet RRP, an indigo pigment such as quinocyanine pigment, perylene pigment, indigo, and thioindigo. pigment.

Charge-generating substances such as bisbenzimidazole pigments such as India Fast Orange Toner, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, and azlenium salt compounds, polyester, polystyrene, polyvinyl butyral, polyvinyl pyrrolidone, methyl cellulose, polyacrylic acid esters, and cellulose. It is formed by being dispersed in a binder resin such as ester. Its thickness is 0
It is about 1 to 1 °O, preferably about 0.05 to 0.5 °.

Further, the charge transport layer contains a polycyclic aromatic compound such as anthracene, pyrene, phenanthrene, coronene, or indole or carbazole in the main chain or side chain.

Oxazole, inoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline,
It is formed by dissolving a nitrogen-containing compound such as thiadiazole or triazole, or a hole-transporting substance such as a hydrazone compound in a resin that has film-forming properties. This is because the charge transporting substance generally has a low molecular weight and has poor film-forming properties by itself.

Such resins include polycarbonate, polymethacrylic acid esters, polyarylate, polystyrene,
Examples include polyester, polysulfone, styrene-acrylonitrile copolymer, styrene-methyl methacrylate copolymer, and the like.

The thickness of the charge transport layer is approximately 5 to 20 IL.

Also, in the present invention, the substrate can be selected from a wide variety of electrically conductive materials. Specifically, aluminum, brass,
Examples include metals such as stainless steel and nickel shaped into cylinders or plates, and aluminum, indium oxide, and tin oxide deposited or laminated on plastic or paper.

This will be explained below using examples.

Example 1 A 60φ×260mm aluminum cylinder with a reflectance of 80% or more was prepared as a base.

Said example (15): 8 parts by weight of oxazine dye C, 1, Mordant Blue 10, 10 parts by weight of copolymerized nylon resin (trade name: Amilan CM8000, manufactured by Tsukushishi ■), 60 parts by weight of methanol, 40 parts by weight of butanol. The mixed solution 1 was dissolved and applied onto a substrate by dip coating to form a subbing layer with a thickness of 0.5p.

Next, 10 parts by weight of a disazo pigment having the following structure, 6 parts by weight of cellulose acetate butyrate resin (trade name CAB-381, Eastman chemical type) and 60 parts by weight of cyclohexanone were added.
Dip coating on the layer using φ glass beads and
The film was dried by heating for 10 minutes to form a charge generation layer with a coating weight of 1 g/m of O.

Next, 10 parts by weight of a hydrazone compound having the following structure and 15 parts by weight of a styrene-methyl methacrylate copolymer resin (trade name: MS200, manufactured by Seitetsu Kagaku) were dissolved in 80 parts by weight of toluene.

This liquid was applied onto the charge generation layer and dried with hot air at 100° C. for 1 hour to form a charge transport layer having a thickness of tSIL.

Example 2 An electrophotographic photoreceptor was prepared using 8 parts by weight of the exemplified (7) triphenylmethane dye C, 1, Paysic Blue 1 in place of the oxazine dye of Example 1, and the other conditions were the same as in Example 1. It was created.

Example 3 The same substrate as in Example 1 was used.

5 parts by weight of the exemplary pigment (37) butalocyanine green was added to a phenol resin (trade name: Pryophen 5010).
, manufactured by Dainippon Ink Co., Ltd.) and 100 parts by weight of toluene, and dispersed in a ball mill for 2 hours.

This dispersion was applied onto a substrate by a dipping method and heated to 150°C for 30 minutes.
It was heat cured for a minute to form a subbing layer with a final thickness of 1 minute.

Next, 100 parts by weight of CdS powder, 12 parts by weight of vinyl chloride-vinyl acetate copolymer resin as a binder, and 400 parts by weight of methyl ethyl ketone were thoroughly stirred and dispersed using a roll mill, and after coating on the undercoat layer by dip coating, It was dried at 80° C. for 5 minutes to form a charge generation layer with a thickness of 5 IL.

Next, on top of this, 80 parts by weight of 2,5-diphenyl-1,3゜4-oxadiazole, polymethyl methacrylate SO
A well-mixed solution of weight S and 120 parts by weight of monochlorobenzene was applied by dip coating, and heated and cured at 110°C for 20 minutes.
12. A thick charge transport layer was formed to produce an electrophotographic photoreceptor.

Comparative Example 1 An electrophotographic photoreceptor was prepared in Example 1 without adding any dye to the undercoat layer.

Comparative Example 2 Electrophotography comparative example without adding pigment to the undercoat layer in Example 3!
A euphotoreceptor was created.

Comparative Example 3 An electrophotographic photoreceptor was produced in the same manner as in Example 1 except that the substrate used in Example 1 was replaced with a conductive plastic having a reflectance of 25%.

The electrophotographic photoreceptors prepared in Example 1.2.3 and Comparative Examples 1.2 and 3 were subjected to -5,6 KV corona charging, image exposure, dry toner development, toner transfer to plain paper, and urethane rubber blade (hardness 700). , a pressure of 10 gw/cm, and an angle of 20° relative to the photoreceptor).

A red original with the spectral reflectance shown in Figure 1 and a second original with a development setting that can copy an original with a density of 0.3 (using Macbeth RD-514 density measuring device, hereinafter the same method) to a density of 0.5 are used.
A blue original having the spectral reflectance shown in the figure was copied, and the density of each copy was measured.

Copy density red original Blue original Example 1 0.38 0.38 Example 2
0.35 0.42 Example 3 0.35
0.33 Comparative Example 1 0.18 0.55
Comparative example 2 0.21 0.22 Comparative example 3
0.25 o, 34, Example 1 and Comparative Example 1
The spectral sensitivities of the two were compared. The result is shown in the third graph.
As shown in the figure.

[Brief explanation of the drawing]

FIG. 1 shows the spectral reflectance of a red original, FIG. 2 shows the spectral reflectance of a blue original, and FIG. 3 is a graph comparing the spectral sensitivities of Example 1 and Comparative Example 1.

Claims (3)

[Claims] (1) On a substrate with a reflectance of 30% or more for white light, there is a charge generation layer that absorbs light at a wavelength λ that differs depending on the materials used for the undercoat layer and the charge generation layer, and a charge generation layer that absorbs light at a wavelength λ. In an electrophotographic photoreceptor having a charge transport layer that is substantially transparent to the charge transport layer, the charge generation layer has a property of absorbing 60% or more of the light of λ but transmitting the rest, and the undercoat layer has the property of absorbing 60% or more of the light of λ. 1. An electrophotographic photoreceptor having a property of absorbing 80% or more of a part of light and transmitting other light. (2) An electrophotographic photoreceptor according to claim 1, in which the undercoat layer absorbs light of 600 nm or more, using a photoreceptor with an absorption wavelength of 630 nm or more. (3) The electrophotographic photoreceptor according to claim 1, in which the undercoat layer absorbs light of 500 nm or less, using a photoreceptor having an absorption wavelength of 560 nm or less.