JPS63250662A - Triboelectrostatic charge imparting member - Google Patents

Abstract

PURPOSE:To obtain an excellent triboelectrostatic charge imparting member which imparts positive electrostatic charge to a toner by providing at least one kind of the metal salt of the salicylic acid expressed by the specific formula and the metal salt of the salicylic acid deriv. to the surface of said member. CONSTITUTION:At least one kind of the metal salt of the salicylic acid expressed by the formula (where, R<1>, R<2>, R<3> are an alkyl group or aryl group of 1-10C; Me is zinc, etc.; n is 2 or 3) and the metal salt of the salicylic acid deriv. are provided on the surface of the triboelectrostatic charge imparting member. The toner 6 contained in a toner tank 7 is forcibly attracted by an agitating vane 5 to a sponge roller 4, by which the toner 6 is supplied to the roller 4. The toner 6 taken to the roller 4 is carried to a toner conveying member 2 and is rubbed by the member, by which the toner is electrostatically or physically attracted thereto. A uniform and thin toner layer is formed by an elastic blade 3 and is triboelectrostatically charged as the member 2 rotates. The toner is thereafter carried to the surface of an electrostatic latent image carrier 1 coming into contact and proximity with and to the member 2, by which the latent image is developed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a triboelectric charging member having the function of imparting triboelectric charge to toner for developing electrostatic images used in electrophotography, electrostatic printing, etc. The present invention relates to a carrier that imparts triboelectric charge to toner, a conveyance regulating member such as a sleeve or a doctor blade, or other triboelectric charge imparting member.

Conventionally, as disclosed in Japanese Patent Application Laid-open No. 147261/1983, methods for developing electrostatic images using toner are roughly divided into two-component developers consisting of a mixture of toner and carrier. and the method used.

There is a method using a one-component developer in which the toner is used alone without being mixed with a carrier.

In the above method, toner and carrier are stirred and rubbed to charge each other to different polarities, and the charged toner visualizes an electrostatic charge image having opposite polarity, and the species of toner and carrier are Depending on the top, there are a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, a fur brush method, etc.

The latter one-component development method includes a powder cloud method in which toner particles are sprayed, a contact development method (also referred to as touchdown development) in which toner particles are brought into direct contact with the electrostatic latent image surface for development, and There is an induction development method in which a magnetic conductive toner is brought into contact with an electrostatic latent image surface.

Toners applicable to these various developing methods include:
Fine powder is used in which a colorant such as carbon black is dispersed in a binder resin made of natural or synthetic resin. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and pulverizing the particles to about 1 to 30 μm are used as the toner. Further, a toner containing these components further contains a magnetic material such as magnetite is used as a magnetic toner.

As mentioned above, toners used in various developing methods are:
Depending on the polarity of the electrostatic charge image that is Q-imaged, a positive or negative charge is held, but in order to make the toner hold a charge, it is also possible to utilize the triboelectricity of the resin that is a component of the toner. However, in this method, since the toner has low chargeability, the image obtained by development is likely to be foggy and unclear. Therefore, in order to impart desired triboelectric chargeability to the toner, dyes, pigments, or charge control agents that impart chargeability are added to the toner.

However, dyes and pigments or charge control agents added to these toners must be exposed to some extent on the toner surface in order to impart charging properties. Therefore, these additives fall off from the toner surface due to friction between the toners, collision with the carrier, friction with the electrostatic latent image holder, etc.
Contamination of the carrier, etc., and contamination of the electrostatic latent image carrier, such as the photoreceptor belt or drum, etc. occur. As a result, the charging property deteriorates, and as the number of durable sheets increases, the deterioration progresses, the image'a degree decreases, and fine line reproducibility, fogging, etc. become problems in practice.

Therefore, attempts have been made to improve the above-mentioned problems by improving the affinity and dispersibility of the binder resin of the toner and dyes and pigments that impart chargeability or charge control agents.

For example, there is a method of surface-treating these additives in order to increase their affinity, but the surface treatment often results in a decrease in charge imparting properties. Furthermore, in order to improve the dispersibility, there is a method of increasing the mechanical shearing force and finely dispersing the toner, but this tends to reduce the proportion of the additive appearing on the toner surface and not impart sufficient chargeability.

For these reasons, additives for imparting a charge that are sufficiently satisfactory for practical use are extremely limited, and only a small number of them have been put into practical use.

Also, in order to obtain not only black and white images but also color images,
It is preferable that the additives added to toner be colorless, but most of the dyes, pigments, and charge control agents conventionally used are dark-colored, and at present, there are very few of them that have been put to practical use. , intensive research is continuing.

Therefore, it has been proposed that charge is not imparted by toner additives, but by means of conveyance regulation such as carriers, sleeves, doctor blades, or other frictional charge imparting members.

Here, the triboelectric charge imparting member refers to a member that comes into contact with the toner to impart or auxiliary charge necessary for development, and hereinafter these are collectively referred to as triboelectric charge imparting members.

Is the present invention an excellent solution that overcomes the drawbacks of the conventional technology? ii' It is an object of the present invention to provide a triboelectric charge imparting member that imparts electrification, and another object is to provide a triboelectric charge imparting member suitable for charging bright color toners, and to maintain the initial image even after continuous copying. It is an object of the present invention to provide a triboelectric charging member that provides equivalent image quality.

In order to achieve the above object, the inventors of the present invention conducted extensive research and found that the following general formula: (However, R1, R2 and R3 are hydrogen or have 1 to 1 carbon atoms.
0 alkyl group or aryl group, particularly preferably hydrogen or an alkyl group or aryl group having 1 to 6 carbon atoms.

Here, R1, R2 and R3 may be the same or different at the same time. Further, Me is any metal selected from zinc, nickel, cobalt, lead, chromium, and aluminum, and zinc is particularly desirable. n is 2 or 3. It has been found that the above object can be achieved by providing a positive polarity frictional Tf electricity imparting member characterized by having on its surface at least one of salicylic acid metal salts and salicylic acid derivative metal salts represented by:

The above compound may be used as it is by being dispersed in a solvent or dispersion medium, or may be used by being dispersed in a resin. Common resins can be used as such resins, such as polystyrene, polyacrylic ester,
Polymethacrylic acid ester, polyacrylonitrile, rubber resins such as polyisoprene and polybutadiene, polyester, polyurethane, polyamide, epoxy resin,
These include rosin, polycarbonate, phenolic resin, chlorinated paraffin, polyethylene, polypropylene, silicone resin, Teflon, derivatives thereof, copolymers thereof, and mixtures thereof.

The triboelectric charge imparting member of the present invention can be obtained by applying the above coating liquid to the base material of the triboelectric charge imparting member by dipping, spraying, brushing, etc. and drying it. Further, the resin in which the above compound is dispersed may be molded as it is to form the triboelectric charging member. In this case, inorganic fillers such as silica, carbon, carbon fiber, glass fiber, etc. may be included in order to enhance reinforcement and anti-wear effects.

All known carriers can be used as the base material of the triboelectric charge imparting member in the form of a carrier, including metals or alloys such as iron, nickel, and aluminum, particles of metal compounds such as metal oxides, glass, and carbide. Ceramic particles such as silicon are used. Furthermore, as the base material of the frictional charging member in the form of a sleeve or doctor blade, conventionally used sleeves and doctor blades are used, such as metals or alloys such as iron, aluminum, and stainless steel, and non-metallic compounds such as plastic and rubber. can.

The present invention is based on the knowledge that, as a result of repeated various experiments, it was confirmed that by using the compound of the above general formula in a triboelectric charging member, a high positive charge can be obtained and a good copy can be obtained.

Examples of the chargeability imparting agent added to the above-mentioned triboelectric charge imparting member include Japanese Patent Publications Nos. 41-20153 and 43-27.
Total complex salts of monoazo dyes described in No. 586, No. 44-6397, No. 45-26478, etc. Nitrohumic acid and its salts or C,1,14645 described in JP-A-50-133338 dyes and pigments such as

Co, Cr, and Fe of thilic acid, naphthoic acid, and dicarboxylic acid described in Japanese Patent Publication No. 55-42752, Japanese Patent Publication No. 41508-1988, Japanese Patent Publication No. 7384-1984, Japanese Patent Publication No. 7385-1985, etc. metal complexes such as sulfonated copper phthalocyanine pigments, nitro groups, styrene oligomers with halogens introduced, chlorinated paraffins, melamine resins, etc.

The toner used in combination with the triboelectric charge imparting member of the present invention as described above may be any toner used as a conventional electrophotographic toner. That is, the toner may be either magnetic or non-magnetic. More specifically, the toner is a colored fine particle containing a colorant in a binder resin, and may contain magnetic powder if necessary. Furthermore, these toners may contain a small amount of a charge-imparting agent such as a dye or pigment, a charge control agent, etc. in order to impart a more efficient charge, but this amount is much smaller than conventional toners.

Examples of charge-imparting agents added to toner include the following. Nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 1627/1983), basic dyes (e.g. C,1, Basic Yellow 2 (C0
1,41000), C,1, Basic Yellow 3
, C,1, Basic Red 1 (C,I.

45160), C,1, Basic Red 9 (C,
1,42500).

C,1, Basic Violet 1 (C,1,425
35).

C,1, Basic Violet 3 (C,I,425
55).

C,1, Basic Violet 10 (C,1,45
170).

C,1, Basic Violet 14 (C,1,42
510).

C,1, Basic Blue 1 (C,1,42025)
, C,1, Basic Blue 3 (C,1,510
05) , C,1, Basic Blue 5 (C,1,4
2140), C,1, Basic Bruch (C,1
, 42595), C, 1, Basic Blue 9 (C
01,52015), C, ■, Basic Blue 24
(C,1,52030), C,1, Basic Blue 25 (C,1,52025), C,I.

Basic Blue 26 (C, 1,44045), C
,1,Basic Green 1 (C,1,42040)
,C,1,Basic Green 4 (C,1,4200
0), C, L42510. Lake pigments of these basic dyes, such as C, 1,45170 (lake-forming agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferricyanide, Russian compounds, etc.) c
, ■, Solvent Black 3 (C, 1, 26150)
, Hansa Yellow G (C, 1, 11680), C, 1,
Molplant Black 11. C.

■, Pigment Black 1. Gilt night, asphalt, etc.

Quaternary ammonium salts, such as benzylmethyl-hexadecyl ammonium chloride, decyl-trimethylammonium chloride, organic tin compounds such as dibutyltin oxide, metal salts of higher fatty acids, inorganic fine powders such as glass, mica, zinc oxide, EDTA, acetylacetone There are polyamine resins such as metal complexes, vinyl polymers containing amino groups, condensation polymers containing amino groups, and the like.

Further, if necessary, a fluidizing agent such as colloidal silica, a metal oxide such as titanium oxide or aluminum oxide, an abrasive such as silicon carbide, a lubricant such as fatty acid metal salt, etc. may be contained.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to the following examples, but the present invention is not limited thereto. Note that all parts are parts by weight.

Example 1 50 g of 3,5-ditertiary-butylsalcylic acid zinc salt was dissolved and dispersed in toluene IQ, and 5 kg of spherical ferrite carrier (average particle size: 100 μm) was coated with the solution using a fluidized bed coating device.

The toner was prepared from the following composition.

Styrene-〇-butyl methacrylate 100 parts Carbon black 10 parts The mixture having the above composition was mixed, pulverized, and classified to obtain a black toner having a particle size of 5 to 20 μm. Three parts of this toner was added to 100 parts of the carrier and mixed to obtain a developer. Next, the above developer was subjected to reversal development using FT4060 manufactured by Ricoh Co., Ltd., and an image test was conducted, and a good image was obtained. The image remained unchanged even after printing 100,000 images.

Furthermore, when the toner charge was measured using the blow-off method, the initial charge amount was 16.2 μc/g, and the toner band tfiJt after running 100,000 sheets was 16.8 μc/g.
g, there was almost no difference from the initial value.

In addition, under a high temperature and high humidity environment of 35°C 90% R11 and 10
Even at a low temperature and low humidity of 15% RH, images with almost no difference from normal humidity were obtained.

Example 2 A coated carrier was prepared in the same manner as in Example 1 using 3.5-ditertiary-butylsalicylic acid aluminum salt.

A toner was prepared using the following composition.

Styrene-n-butyl methacrylate 100 parts Polypropylene 5 parts C.1, Pigment Blue 15 5 parts The mixture having the above composition was mixed, crushed and classified to obtain a blue toner having a particle size of 5 to 20 μm. This toner was added to 100 parts of the carrier,
4 parts were added and mixed to obtain a developer. Next, add the above developer to
When reversal development was performed using Ricoh's FT4060 and an image test was performed, a good blue image was obtained. The image remained unchanged even after printing 100,000 images.

Furthermore, when the toner charge was measured using the blow-off method, the initial charge amount was 17.6 μc/g, and the toner charge amount after running 100,000 sheets was 17.9 μc/g, which was almost the same as the initial value. Ta.

In addition, under a high temperature environment of 35℃90%RH and 10℃
Even at a low temperature and low humidity of 15% RH, images with almost no difference from room temperature were obtained.

Example 3 100 g of silicone resin was dissolved in toluene IQ, and 50 parts of 3,5-ditertiary-butylsalicylic acid zinc salt was further mixed therewith. This was coated on a spherical ferrite carrier in the same manner as in Example 1.

A toner was prepared using the following composition.

Styrene-2-ethylhexyl acrylate copolymer 1
00 part C, 1, pigment blue 15
Part 2 C, 1, Pigment Yellow 17
Mix 5 parts of the mixture with the above composition, crush it,
It was classified to obtain a green toner having a particle size of 5 to 20 μm. 2.5 parts of this toner was added to 1.00 parts of the carrier and mixed to obtain a developer.The above developer was subjected to reversal development using Ricoh glFT4060 and an image test was conducted. , a good green image was obtained. The image did not change even after printing 100,000 images. When the toner charge was measured using the blow-off method, the initial charge amount was 17.9 μc/g.

The amount of charge on the toner when running 100,000 sheets is 18.0
μc/g, there was almost no difference from the initial value.

In addition, under a high temperature environment of 35℃90%RH and 10℃
Even at a low temperature and low humidity of 15% RH, images with almost no difference from normal humidity were obtained.

Example 4 100 g of MMA resin was dissolved in toluene IQ, and 50 parts of 3,5-ditertiary-butylsalicylic acid aluminum salt was further mixed therein. This was coated on a spherical ferrite carrier in the same manner as in Example 1.

A toner was prepared using the following composition.

Polyester resin 100 parts C, 1,
Pigment Red 81 5 parts C.1, Pigment Red 48 3 parts The mixture of the above composition was mixed, crushed, classified, and red 1-
I got a na. 2.5 parts of this toner was added to 100 parts of the carrier and mixed to obtain a developer. Next, the developer was subjected to reversal development using Ricoh's FT4060.
When an image test was performed, a good red image was obtained. The image did not change even after 100,000 sheets were printed. Also, when the toner charge was measured using the blow-off method, the initial charge amount was 15.8 μc/g, and the toner charge amount after 100,000 sheets was printed. It was 16.2 μc/g, which was almost no difference from the initial value.

In addition, under a high temperature and high humidity environment of 35°C and 90% RH, and at 10°C.
Even at a low temperature and low humidity of 15% R1, an image with almost no difference from room temperature was obtained.

Example 5 50 g of 3.5-ditertiary-butylsalicylic acid zinc salt was dissolved and dispersed in toluene IQ, and the toner conveying member (2) shown in FIG. 1 was coated by dipping and set in the developing section. .

Silicon carbide (particle size 2μ) was added to 100 parts of the toner of Example 1.
m) 3 parts were sufficiently stirred and mixed in a speed kneader to prepare a toner.

This toner was loaded into a developing device as shown in FIG. 1, and continuous copying was carried out. When an image test I. was conducted, a good image was obtained. The image remained unchanged even after printing 50,000 images.

To explain this developing method, as shown in the drawing, the toner 6 contained in the toner tank 7 is forcibly brought to the sponge roller 4 by the stirring blade 5, and the toner is supplied to the sponge roller 4. Then, as the sponge roller rotates in the direction of the arrow, the toner taken into the sponge roller 4 is carried to the toner conveying member 2, where it is rubbed and electrostatically or physically attracted.

The toner conveying member 2 rotates strongly in the direction of the arrow, and a uniform toner thin layer is formed by the elastic blade 3, and N triboelectric charging is performed. Thereafter, the toner is transported to the surface of the electrostatic latent image carrier 1 that is in contact with or in close proximity to the toner transport member 2, and the latent image is developed.

The electrostatic latent image is generated by applying a negative 1F DC voltage of 800 V to the organic photoreceptor and then exposing it to light to form a latent image, which is then developed.

In addition, in order to measure the specific charge amount (Q/M) of the toner on the toner conveying member, the toner on the toner conveying member is sucked through a Faraday cage equipped with a filter layer on the exit side, and the toner is sucked into the Faraday cage. When the Q/M was measured using an attractive specific charge measurement device that measures the specific charge of the trapped toner, it was confirmed that the toner was sufficiently charged at 7.9 μc/g.

Also, the amount of charge during 50,000 sheets running is 8.1 μc/g.
There was almost no difference from the initial value.

Furthermore, image quality equivalent to that under normal humidity was obtained even under high humidity and low humidity conditions.

Example 6 100 g of silicone resin was dissolved in toluene IQ, and 50 g of 3,5-ditertiary-butylsalicylic acid aluminum salt was mixed therein. This was spray coated on the toner conveying member (2) shown in FIG. 1, and the toner conveying member (2) was set in the developing section.

A toner was prepared using the following composition.

Styrene-2-ethylhexyl acrylate copolymer 1
00 parts polyethylene
5 parts C, 1, pigment red 81
5 parts C, 1, pigment red 48
Mix 3 parts of the mixture with the above composition and crush 9
It was classified to obtain a red toner having a particle size of 5 to 20 μm. 2 parts of silicon carbide (particle size 2 μm) per 100 parts of this toner.

0.1 part of hydrophobic colloidal silica was sufficiently stirred and mixed with a speed kneader to prepare a toner.

When this toner was put into the developing section shown in the drawing and an image test was conducted in the same manner as in Example 5, a clear and good red image was obtained.

Further, when the Q/M was measured in the same manner as in Example 5, it was 9.3 μc/g at the initial stage and 9.6 μc/(4) after 50,000 sheets, and there was almost no change in Q/M.

Furthermore, image quality equivalent to that at normal humidity was obtained under both high and low humidity.

Example 7 3,5-ditertiary-butylsalicylic acid zinc salt was dissolved and dispersed in toluene IQ, and this was spray coated on the elastic blade (made of stainless steel) shown in Fig. 1, which was set in the developing section. .

When an image test was conducted using the toner of Example 6 in the same manner as in Example 5, clear and good images were obtained.

In addition, when Q/M was measured in the same manner as in Example 5, it was 10.3 μc/g at the initial stage and 10.9 μc/g after 50,000 sheets.
, and there was almost no change.

Furthermore, image quality equivalent to that at normal humidity was obtained under both high and low humidity.

Example 8 100 g of silicone resin was dissolved in toluene IQ, and 50 g of 3,5-ditertiary-butylsalicylic acid aluminum salt was mixed therein. This was spray coated onto the elastic blade (made of stainless steel) shown in FIG. 1, and the blade was set in the developing section.

When an image test was conducted in the same manner as in Example 5 using the toner of Example 6, a clear and good red image was obtained.

Further, when the Q/M was measured in the same manner as in Example 5, it was 11.3 μc/g at the initial stage and 11.6 μc/g after 50,000 sheets, and there was almost no change in Q/M.

Furthermore, even under high temperature and low humidity conditions, image quality equivalent to that under normal humidity conditions was obtained.

Effects As explained above, 1. According to the present invention, an image of the same quality as the initial image can be obtained even after continuous copying, there is no change in the amount of charge, there is little environmental variation, and there is good chargeability even in high temperature and high humidity. can be shown.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a developing device used in an example of the present invention. 1... Static @ latent image carrier 2... Toner transport member 3.
・Elastic plate 4 ・Sponge roller 5 ・Stirring blade 6 ・Toner 7 ・1~ner tank

Claims (1)

[Claims] 1. General formula▲ Numerical formula, chemical formula, table, etc.▼ (However, R_1, R_2 and R_3 are hydrogen or an alkyl group or aryl group having 1 to 10 carbon atoms, and here, R 1, R^2 and R^3 may be the same or different at the same time, Me is any metal selected from zinc, nickel, cobalt, lead, chromium and aluminum, and n is 2 or 3) A triboelectric charge imparting member for positive polarity, characterized in that it has on its surface at least one of salicylic acid metal salts and metal salts of salicylic acid derivatives.