JPH0764345A - Member for imparting electrostatic charge image developing tribielectric charge - Google Patents

Abstract

PURPOSE:To obtain an image having the same quality as that of an initial image after continuously copying and to obtain a clear color image small in change after positively electrifying and in the fluctuation of image quality due to environment by incorporating a specific compound at least in the surface. CONSTITUTION:The compound expressed by a formula is incorporated at least in the surface. And the triboelectric charge member is composed of a carrier particle, a cylindrical sleeve or a doctor blade. The compound expressed by the formula can be used by dispersing as it is in a solvent or a dispersing medium or dispersing in a resin. As the resin in this case, a common resin such as polystyrene, polyacryric ester, polymethacyric ester, polyacryronitrile, polyisoprene, a rubber based resin such as polybutadiene, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin or the like can be used alone or by mixing two or more kinds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention imparts positive triboelectrification to a toner for developing an electrostatic charge image used for developing an electrostatic charge image formed by an electrophotographic method, an electrostatic printing method, an electrostatic recording method or the like. The present invention relates to a triboelectrification imparting member having the function of

[0002]

2. Description of the Related Art As described in, for example, Japanese Unexamined Patent Publication No. 61-147261, methods for developing an electrostatic charge image by using toner are roughly classified, and a so-called two-phase method in which toner and carrier are mixed. There are a method of using a component type developer and a method of using a one component type developer which is used alone as a toner without being mixed with a carrier.

In the former method, the toner and the carrier are agitated and frictionally charged so that the toner and the carrier are charged with different polarities, and the electrostatically charged image having the opposite polarity is visualized by the charged toner. Depending on the type of carrier, there are a magnetic brush method using an iron powder carrier, a cascade method using a bead carrier, and a fur brush method. On the other hand, the latter one-component developing method includes a powder cloud method in which toner particles are sprayed and used, a contact developing method (touch down development) in which toner particles are directly brought into contact with an electrostatic latent image surface to develop the toner. There is an induction developing method in which a magnetic conductive toner is brought into contact with the electrostatic latent image surface.

As the toner applied to these various developing methods, fine powder in which a colorant such as carbon black is dispersed in a binder resin made of natural resin or synthetic resin is used. For example, particles in which a colorant is dispersed in a binder resin such as polystyrene and finely pulverized to about 1 to 30 μm are used as toners. Further, a magnetic toner such as those containing a magnetic material such as magnetite is used as a magnetic toner.

As described above, the toner used in various developing methods has a positive or negative charge depending on the polarity of the electrostatic image to be developed. It is also possible to utilize the triboelectrification property of the component resin. However, in this method, since the chargeability of the toner is small, the image obtained by development is liable to be fogged and unclear. Therefore, in order to impart a desired triboelectric chargeability to the toner, a dye / pigment (a dye and a pigment) that imparts a chargeability, a charge control agent, or the like is added.

However, the dye / pigment or charge control agent added to these toners must be exposed to some extent on the toner surface in order to impart chargeability to the toner. Therefore, friction between toners, collision with carrier,
These additives fall off from the toner surface due to friction with the electrostatic latent image holding member, resulting in carrier contamination and contamination of the surface of the electrostatic latent image holding member such as the photosensitive belt or drum. As a result, the charging property is deteriorated, the deterioration progresses as the number of times of continuous use increases, the image density and the fine line reproducibility decrease, and the increase in fog becomes a practical problem.

Therefore, the above-mentioned problems are solved by improving the affinity and dispersibility of the binder resin of the toner and the additive such as the dye / pigment or the charge control agent for imparting the charging property. ing. For example, in order to increase the affinity between these additives and the binder resin of the toner, there is a method of surface-treating the additives, but the surface treatment often lowers the charge imparting property. Further, in order to improve the dispersibility of the additive, there is also a method of increasing the mechanical shearing force to finely disperse the additive, but the proportion of the additive appearing on the toner surface decreases, and there is a tendency that the charging property is not sufficiently imparted. Out. From these facts, there are very few additives for imparting electrostatic charge that are sufficiently satisfactory for practical use, and few have been put into practical use.

In order to obtain not only a black and white image but also a color image, it is preferable that the toner is colorless, but most of the conventionally used dyes and pigments or charge control agents are dark. Therefore, there are few that have been put to practical use, and it is at the stage where the research is being continued.

Therefore, it has been proposed that the charging is not carried out by the additive of the toner, but by a carrier regulating member such as a carrier, a sleeve, a doctor blade or the like, or another friction charging member. Here, the triboelectrification imparting member means a member that is in contact with the toner to impart an electric charge necessary for development, or a member that can be supplementarily imparted, and hereinafter, these are collectively referred to as a triboelectric charge imparting member. To call.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a triboelectrification imparting member which overcomes the above-mentioned drawbacks, that is, imparts excellent positive electrification property to toner, and yet another object. It is an object of the present invention to provide a triboelectric charging member suitable for charging vivid color toners, and to provide a triboelectric charging member that can provide image quality equivalent to the initial image even after continuous copying.

[0011]

As a result of intensive studies, the inventors of the present invention have achieved the above-mentioned object by a triboelectrification imparting member characterized by containing a compound represented by the following formula (1) on at least the surface thereof. The inventors have found what has been achieved and have reached the present invention.

That is, according to the present invention, there is provided a triboelectrification imparting member for developing an electrostatic charge image, which comprises at least a compound represented by the following formula (1) on its surface.

[Chemical 1] Further, according to the present invention, there is provided a triboelectrification imparting member for electrostatic charge image development, wherein the triboelectrification imparting member is a carrier particle, a cylindrical sleeve or a doctor blade.

The compound represented by the above formula (1) may be used by being dispersed in a solvent or a dispersion medium as it is, or may be used by being dispersed in a resin. As the resin in this case, general resins can be used, and examples thereof include rubber resins such as polystyrene, polyacrylic acid ester, polymethacrylic acid ester, polyacrylonitrile, polyisoprene, and polybutadiene, polyethylene, polypropylene, polyester, polyurethane. , Polyamide, epoxy resin, polycarbonate, rosin, phenol resin, chlorinated paraffin, silicone resin, Teflon and their derivatives or copolymers thereof, etc., which may be used alone or in combination of two or more. .

The coating solution obtained by dissolving or dispersing the compound represented by the above formula (1) is applied to the base material of the triboelectrification imparting member by dipping, spraying, brush coating, etc. and dried. Thus, the triboelectric charging member of the present invention can be obtained. Further, the resin in which the compound is dispersed may be molded as it is to form a triboelectrification imparting member. in this case,
Silica, carbon,
An inorganic filler such as carbon fiber or glass fiber may be contained.

As the base material of the carrier type frictional charge imparting member, all known carriers can be used, such as iron,
Particles of metals such as nickel and aluminum, particles of metal compounds such as alloys and metal oxides, and ceramic particles such as glass and silicon carbide are used. Further, as the base material of the sleeve or the blade of the frictional charge imparting member, a conventionally used sleeve or doctor blade such as metal or alloy of iron, aluminum, stainless steel or non-metal compound such as plastic or rubber is used. it can.

According to the present invention, as a result of repeating various experiments, it was confirmed that a high positive charge was obtained by using the compound represented by the above formula (1) in the frictional charge imparting member and a good copy was obtained. It is based on knowledge.

In order to impart a more appropriate charge imparting property to the frictional charge imparting member of the present invention, a charge imparting agent may be supplementarily added to the imparting member. Examples of the charge-imparting agent in this case include, for example, metal complex salts of monoazo dye, nitrohumic acid and its salts, salicylic acid, naphthoic acid, metal complexes of dicarboxylic acid such as Co, Cr and Fe,
Examples thereof include sulfonated copper phthalocyanine pigment, nitro group, halogen-introduced styrene oligomer, chlorinated paraffin, and melamine resin.

The toner used in combination with the frictional charge imparting member of the present invention may be the one used as a conventional toner for electrophotography. That is, the toner may be either magnetic or non-magnetic. More specifically, the toner is a colored fine particle in which a colorant is contained in a binder resin, and may contain magnetic powder as necessary. Further, these toners may contain a small amount of a charge imparting agent such as dyes and pigments and a charge control agent in order to impart charge more efficiently. The content is quite low.

Examples of the charge imparting agent in this case include nigrosine, azine dyes containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), basic dyes, lake pigments of basic dyes, and C. .I Solvent Black 3,
Hansa Yellow G, CI Molderant Black 11,
CI Pigment Black 1, Gilsonite, asphalt, quaternary ammonium salt, metal salt of higher fatty acid, metal complex of acetylacetone, vinyl polymer containing amino group, polyamine resin such as condensation polymer containing amino group, etc. There is.

If necessary, the toner may contain a fluidizing agent such as colloidal silica, a metal oxide such as titanium oxide and aluminum oxide, an abrasive such as silicon carbide, and a lubricant such as fatty acid metal salt. You may let me.

[0021]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto. All parts shown below are based on weight.

Example 1 30 g of terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), in 1 liter of toluene and a styrene / MMA copolymer. 70 g was dissolved and dispersed, and 5 kg of spherical ferrite carrier (average particle size 100 μm) was coated with a fluidized bed type coating device.

The toner was made of the following composition. Styrene / n-butylmethacrylate 100 parts Polypropylene 6 parts CI Pigment Blue 15 6 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a blue toner having a particle size of 5 to 20 μm. 97.5 parts of the carrier was mixed with 2.5 parts of this toner by a ball mill to obtain a developer.

Next, the above-mentioned developer is applied to a copying machine FT manufactured by Ricoh Company.
When set to 4820 and subjected to an image test, a good image was obtained, and the image did not change after 100,000 images were printed. When the toner charge amount was measured by the blow-off method, the initial charge amount was +18.0 μC / g, and the toner charge amount after running 100,000 sheets was +14.6 μC / g, which is almost the initial value. There was no difference. Also, in a high humidity environment of 35 ° C. and 90% RH, and 10
Even under a low humidity environment of 15 ° C. and 15% RH, an image equivalent to normal humidity was obtained.

Example 2 Example 2 was repeated except that the toner composition was as follows. Crosslinked polyester (RN-201; manufactured by Kao) 100 parts Polypropylene 6 parts Quaternary ammonium salt 2 parts (Bontron P-51; manufactured by Orient Chemical Co.) Carbon black 10 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a black toner having a particle size of 5 to 20 μm. 97 parts of the carrier was mixed with 3 parts of the toner by a ball mill to obtain a developer.

Next, the above-mentioned developer is applied to a copying machine FT manufactured by Ricoh Company.
When set to 4820 and subjected to an image test, a good image was obtained, and the image did not change after 100,000 images were printed. When the toner charge amount was measured by the blow-off method, the initial charge amount was +21.3 μC / g, and the toner charge amount after running 100,000 sheets was +19.2 μC / g, which is almost the initial value. There was no difference. Also, in a high humidity environment of 35 ° C. and 90% RH, and 10
Even under a low humidity environment of 15 ° C. and 15% RH, an image equivalent to normal humidity was obtained.

Example 3 100 g of a silicone resin was dissolved in 1 liter of toluene, and terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point: 85 ° C., purity: 90%), which was a compound represented by the above formula (1), was dissolved in the solution. ) 50 g were mixed. This was coated on a spherical ferrite carrier in the same manner as in Example 1.

The toner was prepared with the following composition. Styrene / 2-ethylhexyl acrylate copolymer 100 parts Quaternary ammonium salt 1.0 part (Bontron P-51; manufactured by Orient Chemical Co.) CI Pigment Blue 15 3 parts CI Pigment Yellow 17 6 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a green toner having a particle diameter of 3 to 15 μm. 2.5 parts of this toner was mixed with 91.5 parts of the carrier by a ball mill to obtain a developer.

Next, the above-mentioned developer is applied to a copying machine FT manufactured by Ricoh Company.
When set to 4820 and subjected to an image test, a good image was obtained, and the image did not change after 100,000 images were printed. When the toner charge amount was measured by the blow-off method, the initial charge amount was +18.4 μC / g, and the toner charge amount after running 100,000 sheets was +17.2 μC / g, which is almost the initial value. There was no difference. Also, in a high humidity environment of 35 ° C. and 90% RH, and 10
Even under a low humidity environment of 15 ° C. and 15% RH, an image equivalent to normal humidity was obtained.

Example 4 100 g of MMA resin was dissolved in 1 liter of toluene,
50 g of terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), was further mixed with this. This was coated on a spherical ferrite carrier in the same manner as in Example 1.

The toner was prepared with the following composition. Polyester resin 100 parts (Luna Pale 1467M; Arakawa Chemical Co., Ltd.) CI Pigment Red 57 6 parts CI L Pigment Red 48 4 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a red toner having a particle size of 5 to 20 μm. 97 parts of the carrier was mixed with 3 parts of the toner by a ball mill to obtain a developer.

Next, the above developer is applied to a copying machine FT4 manufactured by Ricoh Company.
When set to 820 and subjected to an image test, a good image was obtained, and the image did not change even after 100,000 images were printed. Further, when the charge amount of the toner was measured by the blow-off method, the initial charge amount was +16.6 μC / g, and the charge amount of the toner after running 100,000 sheets was +.
There was almost no difference from the initial value, which was 15.4 μC / g. Also,
35 ° C, 90% RH high humidity environment, 10 ° C, 1
An image equivalent to normal humidity was obtained even in a low humidity environment of 5% RH.

Example 5 30 g of terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), in 1 liter of toluene and a styrene / MMA copolymer. 70 g was dissolved and dispersed, and the developing sleeve of the toner conveying member 2 shown in FIG. 1 was coated with this by dipping and set in the developing section.

Next, with respect to 100 parts of the toner of Example 1,
4 parts of silicon carbide (particle size 2 μm) and 0.3 parts of hydrophobic colloidal silica were sufficiently stirred and mixed with a speed kneader to obtain a toner.

When this toner was loaded into a developing device as shown in FIG. 1 and continuous copying was carried out and an image test was conducted, a good image was obtained. The image did not change after 50,000 images were printed.

This developing method will be described in detail with reference to FIG. FIG. 1 is a schematic sectional view of an example of the electrostatic image developing device. In FIG. 1, the toner 6 contained in the toner tank 7 is forcibly drawn to the sponge roller 4 by the stirring blade 5, and the toner is supplied to the sponge roller 4. Then, the toner taken into the sponge roller 4 is rotated by the sponge roller in the arrow direction,
The toner carrying member 2 is carried and rubbed and electrostatically or physically adsorbed, the toner carrying member 2 strongly rotates in the direction of the arrow, and a uniform thin toner layer is formed by the elastic blade 3 and frictionally charged. . After that, the toner is conveyed to the surface of the electrostatic latent image carrier 1 that is in contact with or in the vicinity of the toner conveying member 2, and the latent image is developed. The electrostatic latent image is developed by forming a latent image by exposing the electrostatic latent image carrier 1 made of an organic photoconductor to 800 V of negative DC charge, and then exposing.

In order to measure the specific charge amount Q / M of the toner on the toner conveying member [Q; charge amount Coulomb (C), M; toner weight (g)], a filter layer is provided on the outlet side. A suction method specific charge amount measuring device for measuring the specific charge of the toner trapped in the Faraday cage by sucking the toner on the toner conveying member through the Faraday cage was used. When Q / M was measured by this method, it was 8.9 μC / g
It was confirmed that it was sufficiently charged. Also,
+50,000 μC / g electrification amount for 50,000 rung
There was almost no difference from the initial value. Further, even under high humidity or low humidity, image quality equivalent to normal humidity was obtained. There was no toner filming on the photoconductor.

Example 6 100 g of a silicone resin was dissolved in 1 liter of toluene, and terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), was dissolved in the solution. ) 50 g were mixed. This was coated on the toner conveying member 2 shown in FIG. 1 by spraying and set in the developing section.

The toner was prepared with the following composition. Styrene / 2-ethylhexyl acrylate copolymer 100 parts Polyethylene 6 parts Quaternary ammonium salt 0.4 parts (Bontron P-51; manufactured by Orient Chemical Co.) C.I. Pigment Red 576 C.I. Pigment Red 48 4 copies

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a red toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 3 parts of silicon carbide (particle size 2 μm),
0.2 part of hydrophobic colloidal silica was sufficiently stirred and mixed with a speed kneader to obtain a toner.

When this toner was put in the developing section of FIG. 1 and an image test was conducted in the same manner as in Example 5, a clear and good red image was obtained. Further, when Q / M was measured in the same manner as in Example 5, the initial value was +12.0 μC / g, and the value after 50,000 sheets was +9.5 μC / g, showing almost no change. In addition, even under high humidity or low humidity, image quality similar to normal humidity was obtained.

Example 7 30 g of terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), in 1 liter of toluene and 70 g of styrene / MMA copolymer. Was melted, and this was spray-coated on the elastic blade (made of stainless steel) shown in FIG. 1 and set in the developing section.

An image test was conducted in the same manner as in Example 5 using the toner of Example 6, and a clear and good red image was obtained. Further, when Q / M was measured in the same manner as in Example 5, the initial value was +12.2 μC / g, and the value after 50,000 sheets was +1.
It was 0.8 μC / g, which was almost unchanged. Further, even under high humidity or low humidity, image quality equivalent to normal humidity was obtained.

Example 8 100 g of a silicone resin was dissolved in 1 liter of toluene, and terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point: 85 ° C., purity: 90%), which was a compound represented by the above formula (1), was dissolved in the solution. ) 50 g were mixed. This was spray-coated on the elastic blade (made of stainless steel) shown in FIG. 1 and set in the developing section.

An image test was conducted in the same manner as in Example 5 using the toner of Example 6, and a clear and good red image was obtained. Further, when Q / M was measured in the same manner as in Example 5, the initial value was +13.1 μC / g and the value after 50,000 sheets was +1.
It was 1.9 μC / g, which was almost unchanged. Further, even under high humidity or low humidity, image quality equivalent to normal humidity was obtained.

Example 9 100 g of a silicone resin was dissolved in 1 liter of toluene, and terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C., purity 90%), which is a compound represented by the above formula (1), was dissolved in the solution. ) 50 g were mixed. This is the elastic blade (made of stainless steel) 3 shown in FIG.
Was spray-coated on and set in the developing section.

The toner was made of the following composition. Epoxy resin 100 parts Polypropylene 6 parts CI Pigment Blue 15 3 parts CI Pigment Yellow 17 4 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified in the same manner as in Example 1 to obtain a green toner having a particle diameter of 3 to 20 μm. To 100 parts of this toner, 3 parts of silicon carbide (particle size: 2 μm) and 0.2 part of zinc stearate fine powder were sufficiently stirred and mixed with a speed kneader to obtain a toner.

Using this toner, an image test was conducted in the same manner as in Example 5. As a result, a clear and good green image was obtained. When Q / M was measured in the same manner as in Example 5,
Initially + 7.8μC / g, after 50,000 sheets + 6.7μC / g
It was g and there was almost no change. Further, even under high humidity or low humidity, image quality equivalent to normal humidity was obtained.

Example 10 Terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C.), which is a compound represented by the above formula (1),
50g of purity 90%) is mixed with 100g of urethane rubber,
A resin blade was produced by heating and melting. When an image test was conducted in the same manner as in Example 5 using the toner of Actual Rotation Example 6, a clear and favorable red image was obtained. Also,
When Q / M was measured in the same manner as in Example 5, the initial value was +.
It was 9.6 μC / g, and after 50,000 sheets, it was +8.0 μC / g, showing almost no change. Further, even under high humidity or low humidity, image quality equivalent to normal humidity was obtained.

Example 11 Terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C.), which is a compound represented by the above formula (1),
Purity 90%) 50 g, styrene resin 100 g, and carbon black 35 g were mixed and heat-melted to form a resin blade.

The toner was prepared from the following composition. Styrene / n-butyl methacrylate 100 parts Polypropylene 6 parts Carbon black 11 parts Charge control agent (nigrosine dye) 1.5 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a black toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 3 parts of carbon carbide (particle size 2 μm),
0.4 part of titanium oxide was thoroughly stirred and mixed with a speed kneader to obtain a toner.

An image test was conducted in the same manner as in Example 5 using this toner, and a clear and good image was obtained. Further, when Q / M was measured in the same manner as in Example 5, the initial stage was +12.4 μC / g, and the 50,000 stage was +.
It was 10.1 μC / g, which was almost unchanged. Also,
Image quality equivalent to normal humidity was obtained even under high or low humidity.

Example 12 Terpene diphenol YP-90 (manufactured by Yasuhara Chemical Co .; melting point 85 ° C.), which is a compound represented by the above formula (1),
Purity 90%) 50 g, MMA resin 100 g, and calcium carbonate 35 g were mixed, and a resin blade was prepared in the same manner as in Example 11.

The toner was prepared with the following composition. Polyester resin 100 parts Polyethylene 8 parts CI Pigment Blue 15 6 parts

The mixture having the above composition was kneaded, cooled, pulverized and classified to obtain a blue toner having a particle size of 5 to 20 μm. To 100 parts of this toner, 3 parts of silicon carbide (particle size 2 μm),
1.0 part of titanium oxide was sufficiently stirred and mixed with a speed kneader to obtain a toner.

Using this toner, an image test was conducted in the same manner as in Example 5. As a result, a clear and good image was obtained. Further, when Q / M was measured in the same manner as in Example 5, it was +10.0 μC / g at the initial stage and 8.4 μC after 50,000 sheets.
There was almost no change. Also, image quality equivalent to normal humidity was obtained under high temperature and low humidity.

[0063]

As described above, when the toner is positively charged by the frictional charge imparting member having the compound represented by the formula (1) on the surface thereof, the toner is positively charged even after continuous copying. An image showing quality can be obtained, a positive charge amount does not change, the image quality does not change much due to the environment, and a clear color image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a developing device having a cylindrical sleeve as a toner conveying member.

[Explanation of symbols]

l ... Electrostatic latent image carrier, 2 ... Toner transport member, 3 ...
... elastic blade, 4 sponge roller, 5 stirring blade, 6 toner, 7 toner tank.

Claims (4)

[Claims] 1. A triboelectrification imparting member for developing an electrostatic charge image, which comprises at least a compound represented by the following formula (1) on its surface. [Chemical 1] 2. The triboelectric charge imparting member for electrostatic charge image development according to claim 1, wherein the triboelectric charge imparting member is carrier particles. 3. The triboelectric charge imparting member for developing an electrostatic charge image according to claim 1, wherein the triboelectric charge imparting member is a cylindrical sleeve. 4. The triboelectrification imparting member for electrostatic charge image development according to claim 1, wherein the triboelectrification imparting member is a doctor blade.