JPH0736083B2 - Toner for electrostatic image development - Google Patents

Description

The present invention relates to a novel toner for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing and the like.

[Prior Art] Conventionally, various methods of electrophotography have been described in US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748. They provide a uniform electrostatic charge on the photoconductive insulator layer and form an electrostatic latent image by irradiating the insulator layer with a light image, which is then referred to in the art as toner. Visualize development with fine powder, transfer the powder image to paper, etc., if necessary, then heat,
The fixing is performed by applying pressure or solvent vapor.

As a developing method applied to these electrophotographic methods,
It is roughly classified into a dry development method and a wet development method. The former is further divided into a method of using a two-component developer and a method of using a one-component developer. Depending on the type of carrier that carries the toner, the two-component developing method
Magnet brush method using iron powder carrier, beads
There are a cascade method using a carrier and a fur brush method using a fur.

Further, those belonging to the one-component developing method include a powder cloud method in which toner particles are sprayed, and a contact developing method in which toner particles are directly brought into contact with an electrostatic latent image surface to develop (contact development, or Toner development), a jumping development method in which toner particles are not directly contacted with the electrostatic latent image surface, but the toner particles are charged and fly toward the latent image surface by the electric field of the electrostatic latent image, magnetic conductivity. There is a magnetic dry method in which toner is brought into contact with the electrostatic latent image surface to develop the toner.

As a toner applied to these developing methods, a fine powder in which a dye or a pigment is dispersed in a natural or synthetic resin is conventionally 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. A magnetic toner containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder before use. Further, the toner has a positive or negative charge depending on the polarity of the electrostatic latent image to be developed.

To retain the electric charge in the toner, it is possible to utilize the triboelectric charging property of the resin which is a component of the toner, but since the toner charging property is small in this method, the image obtained by development is easily fogged and unclear. It is easy to become a thing.
Therefore, in order to impart desired triboelectric chargeability to the toner,
Dyes and pigments that impart chargeability, and charge control agents have been added.

The charge control agents currently known in the art include the following.

(1) The following are examples of controlling the toner to be positively charged.

Nigrosine, azine dyes containing alkyl groups having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), basic dyes (eg CI
Basic Yellow 2 (CI41000), CIBasic Yellow 3,
CIBasic Red 1 (CI45160), CIBasic Red 9 (C.
I.42500), CIBasic Violet 1 (CI42535), CIBa
sic Violet 3 (CI42555), CIBasic Violet 10 (C.
I.45170), CIBasic Violet 14 (CI42510), CIB
asic Blue 1 (CI42025), CIBasic Blue 3 (CI51
005), CIBasic Blue 5 (CI52140), CIBasic Bl
ue 7 (CI42595), CIBasic Blue 9 (CI52015),
CIBasic Blue24 (CI52030), CIBasic Blue 25
(CI52025), CIBasic Blue 26 (CI44045), C.
I.Basic Green 1 (CI42040), CIBasic Green 4
(CI42000, CI42510, CI45170, etc. Lake pigments of these basic dyes (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide Compounds, etc.), CISolven
t Black 3 (CI26150), Hansa Yellow G (CI1168
0), CIMordlant Black 11, CI Pigment Black 1,
Gilsonite, asphalt, etc.

Quaternary ammonium salts, for example, benzoylmethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, organotin compounds such as dibutyltin oxide, metal salts of higher fatty acids, glass, mica, inorganic fine powder such as zinc participating, EDTA, Polyamine resins such as amino group-containing vinyl polymers and amino group-containing condensation polymers such as metal complexes of acetylacetone.

(2) The following are examples of controlling the toner to be negatively charged.

Japanese Patent Publications No. 41-20153, No. 43-27596, No. 44-6397, and No.
Metal complex salts of monoazo dyes described in 45-26478 and the like.

Nitrohumic acid and its salts or dyes and pigments such as CI14645 described in JP-A-50-133338.

JP-B-55-42752, JP-B-58-41508, JP-B-59-73
Metal complexes of salicylic acid, naphthoic acid and dicarboxylic acid such as Co, Cr and Fe described in JP-B No. 84 and JP-B-59-7385. Sulfonated copper phthalocyanine pigment. Styrene oligomer with nitro group and halogen introduced. Chlorinated paraffin, melamine resin, etc.

Many of these charge control agents are generated from dyes and pigments,
Generally, the structure is complicated and most of them have strong coloring properties.

Among the newly proposed ones, there are some that are of a different system from these, but there is no one that outperformed the dye-pigment system in terms of overall performance, and there are still examples of dyes that are unsatisfactory. Mostly.

These are usually added to a thermoplastic resin, thermally melt-dispersed, finely pulverized, and adjusted to an appropriate particle size as needed before use.

However, these dyes as charge control agents have a complicated structure and inconsistent properties, and are poor in stability. In addition, decomposition or deterioration is likely to occur due to decomposition during thermal kneading, mechanical shock, friction, changes in temperature / humidity conditions, etc., and a phenomenon in which charge controllability is deteriorated is likely to occur.

Therefore, when a toner containing these dyes as a charge control agent is developed using a copying machine, the charge control agent may be decomposed or deteriorated as the number of times of copying increases, and the toner may deteriorate during its durability.

Further, since it is extremely difficult to uniformly disperse these charge control agents in the thermoplastic resin, there is a fatal problem that a difference in the triboelectric charge amount between the toner particles obtained by pulverization causes a difference. Have For this reason, various methods have been conventionally used for more uniform dispersion. For example, a basic nigrosine dye is used by forming a salt with a higher fatty acid in order to improve the compatibility with a thermoplastic resin, but a dispersion product of an unreacted fatty acid or salt is, so to speak, a toner surface. When exposed to water, it contaminates the carrier or the toner carrier, causing a decrease in toner fluidity, fog, and a decrease in image density. Alternatively,
In order to improve the dispersion of these charge control agents in the resin, a method of mechanically pulverizing and mixing the charge control powder and the resin powder in advance and then hot-melt kneading is used. However, the original poor dispersion cannot be avoided, and in the current situation, sufficient charge uniformity for practical use has not yet been obtained.

In addition, most of the substances generally known as charge control agents have a dark color, and thus there is a problem that they cannot be contained in a vivid chromatic color developer.

Further, many charge control agents are hydrophilic, and due to poor dispersion in these resins, the dye is exposed on the toner surface when pulverized after melt kneading. Therefore, when the toner is used under high humidity conditions, there is a problem that a high quality image cannot be obtained because the charge control agent is hydrophilic.

As described above, when the conventional charge control agent is used in the toner, it occurs on the surface of the toner particles between the toner particles, between the toner and the carrier, or between the toner and the toner carrier such as the sleeve. Variations in the amount of charge are likely to occur, and problems such as development fog, toner scattering, and carrier contamination are likely to occur. Further, this obstacle appears as a remarkable phenomenon when the number of times of copying is increased, and is substantially unsuitable for a copying machine.

Further, under high humidity conditions, the transfer efficiency of toner images is significantly reduced, and many of them cannot be used. Even at room temperature and normal humidity, when the toner is stored for a long period of time, it deteriorates due to instability of the charge control agent used and often becomes unusable due to poor chargeability.

Furthermore, when a conventional charge control agent is used for toner, the charge control agent adheres to the surface of the photoconductor or promotes the adhesion of the toner due to long-term use, which adversely affects latent image formation (filming phenomenon). ), Those that cause scratches on the surface of the photoreceptor or cleaning members such as cleaning blades, or accelerate the wear of the members, have many adverse effects on the cleaning process of the copying machine.

Furthermore, when a conventional charge control agent is used in toner, there are not a few that greatly affect the heat melting characteristics of the toner and deteriorate the fixing performance. In particular, there are those that deteriorate the high temperature offset performance, increase the sticking property of the transfer material to the roller at the time of heat roll fixing, and reduce the durable life of the roller.

As described above, the conventional charge control agent has many problems, and there is a strong demand in the technical field to improve them, and many improvements have been proposed so far, but they are still in practical use. Above all, the actual situation is that nothing has been found that is totally satisfactory.

[Problems to be Solved by the Invention] An object of the present invention is to provide a new technique of toner charge control that overcomes such problems.

Another object of the present invention is to provide a stable triboelectrification amount between toner particles, a toner and a carrier, a toner and a toner carrier such as a sleeve in the case of one-component development, and a triboelectrification amount distribution. The purpose of the present invention is to provide a developer that is sharp and uniform and that can control the charge amount suitable for the developing system used.

Still another object of the present invention is to provide a developer that faithfully develops and transfers a latent image, that is, the adhesion of toner in the background area during development, that is, fog or toner around the edge of the latent image. The purpose of the present invention is to provide a developer having high image density and high halftone reproducibility.

Further, another object of the present invention is to provide a developer which maintains the initial characteristics even when the developer is continuously used for a long period of time and does not cause aggregation of toner or change in charging characteristics.

Further, another object of the present invention is to develop a developer that reproduces a stable image that is not affected by changes in temperature and humidity, and particularly to improve transfer efficiency without scattering and transfer omission during transfer at high humidity and low humidity. To provide high developer.

Still another object of the present invention is to provide a bright chromatic color developer.

Still another object of the present invention is to provide a developer having excellent storage stability, which retains initial characteristics even after long-term storage.

Furthermore, another object of the present invention is to stain the electrostatic latent image surface,
The purpose of the present invention is to provide a developer that can be easily cleaned without being worn or damaged.

Further, another object of the present invention is to provide a developer having good fixing properties, particularly a developer having no problem in high temperature offset and the like.

[Means and Actions for Solving Problems] Specifically, the present invention provides a binder resin, a coloring resin, and a fixing aid.
And the following general formula(In the formula, R₁, R₂, R₃And R_FourHas an aryl group as the basic skeleton
Is represented by the formula, Y is an arylene group having an alkoxy group
Represents X Is BF_Four , PF₆ ,Of any of the above), and an electrostatic charge containing a compound represented by
The present invention relates to an image developing toner.

The present inventors have found that the compound represented by the general formula [I] is
It has been found that the charge control agent is stable in time, has no hygroscopicity, and when contained in a developer, gives a developer having excellent electrophotographic properties and is a good quality charge control agent.

The following are typical specific examples of the compound represented by the general formula [I].

In the above compound, the anion is PF₆,You can change to.

These compounds can be easily obtained by exchange of counter ions.

As a method of incorporating the above compound into the toner particles, there are a method of adding it inside the developer and a method of adding it externally. When internally added, the amount of these compounds used is determined by the types of the binder resin and the fixing aid, the presence or absence of additives used as necessary, and the toner production method including the dispersion method. Although not particularly limited, it is preferably used in the range of 0.1 to 20 parts by weight (more preferably 1 to 10 parts by weight) with respect to 100 parts by weight of the binder resin.

Also, a conventionally known charge control agent can be used in combination with the charge control agent of the present invention.

Examples of the colorant used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6G, lake,
Calco oil blue, chrome yellow, quinacridone,
Any conventionally known dyes and pigments such as benzidine yellow, rose bengal, triallylmethane dyes monoazo dyes, disazo dyes and dyes may be used alone or in combination.

As the binder resin used in the present invention, polystyrene,
Monopolymers of styrene and its substitution products such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene Copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene -Ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether Copolymer, styrene-vinyl methyl Styrene-based copolymers such as ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers Combined; polymethylmethacrylate, polybutylmethacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene,
Examples thereof include polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin and phenol resin, which may be used alone or in combination.

Further, as the binder resin particularly suitable for pressure fixing, the following can be used alone or in combination.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resin, polyester resin, styrene-butadiene copolymer (monomers 5 to 30:95 to 70), olefin copolymer (ethylene -Acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer Resin), polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride copolymer, maleic acid-modified phenol resin, phenol-modified terpene resin.

Further, when the toner of the present invention is used as a two-component developer, it is used as a mixture with carrier powder.

As the carrier which can be used in the present invention, all known carriers can be used, for example, magnetic powder such as iron powder, ferrite powder and nickel powder, glass beads and the like, and those whose surface is treated with resin or the like. And so on.

Further, the toner of the present invention can be used as a magnetic toner by further containing a magnetic material. The magnetic material contained in the magnetic toner of the present invention includes iron oxide such as magnetite, hematite, and ferrite. Metals such as iron, cobalt, nickel or aluminum, cobalt, copper, etc. of these metals
Mention may be made of alloys of metals such as lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof.

It is desirable that these ferromagnetic materials have an average particle size of about 0.1 to 2 μm, and the amount contained in the toner is a resin component.
It is about 20 to 200 parts by weight based on 100 parts by weight, and particularly preferably 40 to 150 parts by weight based on 100 parts by weight of the resin component.

Examples of the fixing aid include waxes such as low molecular weight polyethylene wax and low molecular weight polypropylene wax used in Examples described later.

Further, the toner of the present invention may be mixed with an additive as required. Examples of the additive include lubricants such as Teflon and zinc stearate, abrasives such as cerium oxide and silicon carbide, fluidity imparting agents such as colloidal silica and aluminum oxide, anti-caking agents, or carbon black and tin oxide. And other conductivity-imparting agents.

To prepare the toner for developing an electrostatic image according to the present invention, the charge control agent according to the present invention is used as a vinyl-based or non-vinyl-based thermoplastic resin, a fixing aid and a pigment or dye as a colorant, and if necessary. Thoroughly mix magnetic materials, additives, etc. with a ball mill or other mixing machine, and then melt, knead and knead the resin using a heat kneader such as a heating roll, kneader or extruder to make the resins compatible with each other. A pigment or dye may be dispersed or dissolved in the mixture, cooled, solidified, pulverized and classified to obtain a toner having an average particle size of 5 to 20 μm.

Alternatively, a method in which the material is dispersed in a binder resin solution and then spray-dried, or a predetermined material is mixed with a monomer to form the binder resin to form an emulsified suspension and then polymerized A method such as a polymerization method for obtaining a toner and a toner manufacturing method can be applied.

The toners produced by these methods can all be used for development for visualizing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, etc. by conventionally known means and are excellent as follows. It has a great effect.

That is, the positive triboelectric charge amount between the toner particles is uniform, and the control of the electric charge amount is easy. Further, the toner is extremely stable without deteriorating during use so that the triboelectric charge amount does not vary or decrease.

Therefore, the above-mentioned obstacles such as the development fog, toner scattering, contamination of the electrophotographic photosensitive material and the copying machine are removed, and the toner of the present invention is extremely excellent. It is a toner that can withstand long-term storage without causing phenomena such as aggregation, agglomeration, and low-temperature flow, and also has excellent abrasion resistance, fixability, and adhesiveness of toner images.

The excellent effect of such a toner is that when it is used in a repetitive transfer copying system in which the operations of charging, exposing, developing, and transferring are continuously repeated, the effect is further expanded.

Further, since the charge control agent causes less color disorder, it is possible to form a color image of excellent color when used as a color electrophotographic toner.

[Examples] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. All parts in the following formulations are parts by weight.

Example 1 Styrene / butyl acrylate (80/20) copolymer 100 parts (weight average molecular weight w: about 300,000) carbon black (Mitsubishi ^# 44) 10 parts low molecular weight polyethylene wax 2 parts Compound Example 1 3 parts After mixing well with a blender, the mixture was kneaded with two rolls heated to 150 ° C. After allowing the kneaded material to cool naturally, it is roughly crushed with a cutter mill, crushed with a fine crusher using a jet stream, and further classified with an air classifier to obtain a fine powder having a particle size of 5 to 20 μm (ie, , Positively chargeable toner) was obtained.

A developer was prepared by mixing 100 parts of an iron powder carrier having an average particle size of 50 to 80 μm with 5 parts of an external fine powder.

Further, the triboelectric charge amount of the developer was measured by a usual blow-off method. As a result, the charge amount was +5.6 μC / g.

Then, a negative electrostatic image is formed on the OPC photosensitive member by a conventionally known electrophotographic method, and this is powder-developed by the magnetic brush method using the above developer to form a toner image, which is transferred to plain paper. Heated and fixed. The obtained transferred image had a sufficiently high density of 1.20, no fog, no toner scattering around the image, and a good image with high resolution was obtained. Transfer images were continuously prepared using the above-mentioned developers and durability was examined. The transferred images after 30,000 sheets were completely achromatic images as compared with the initial images.

Further, at the time of durability, the above-mentioned filming phenomenon related to the toner on the photoconductor was not observed at all, and no problem in the cleaning step was found. Also, at this time, there was no trouble in the fixing process, and at the end of the durability test of 30,000 sheets, the fixing machine was observed, but the roller was not scratched or damaged, there was almost no stain by the offset toner, and there was no problem in practice. .

Comparative Example 1 A developer was obtained in the same manner as in Example 1 except that 2 parts of the nigrosine dye was used instead of 3 parts of the compound example 1, and development, transfer, and
An image was similarly obtained by fixing.

Fog was small at room temperature and normal humidity, but the image density was low at 1.06, and line drawings were scattered, and solid black was noticeable. When the durability was examined, the density decreased to 0.83 after 30,000 sheets.

In addition, at the time of running, from around 10,000 sheets, the toner material formed a thin streak-like film on the surface of the photoconductor and appeared as lines on the image. This is so-called filming, and it is considered that the charge control agent changes the lubricity of the toner powder.

Further, at the time of endurance, a fixed image tends to be caught in the fixing roller in the fixing step, and there is a difficulty in peeling off the roller.

Example 2 A developer was obtained in the same manner as in Example 1 except that 2 parts of Compound Example 3 was used instead of 3 parts of Compound Example 1, and development, transfer and fixing were performed, and an image was similarly obtained.

The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 1 were obtained.

Example 3 A developer was obtained in the same manner as in Example 1 except that 2 parts of Compound Example 3 was used instead of 3 parts of Compound Example 1, and development, transfer and fixing were carried out, and an image was similarly obtained.

The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 1 were obtained.

Example 4 Styrene / butyl acrylate (80/20) copolymer 100 parts (weight average molecular weight w: about 300,000) Iron trioxide EPT-500 (manufactured by Toda Kogyo) 60 parts Low molecular weight polypropylene wax 2 parts Compound Example 1 3 parts The above materials were mixed well with a blender and then kneaded with two rolls heated to 150 ° C. After allowing the kneaded material to cool naturally, it is roughly crushed with a cutter mill, crushed with a fine crusher using a jet stream, and further classified with a wind force classifier to obtain a fine powder with a particle size of 5 to 20 μm. It was

Next, 100 parts of the fine powder was mixed with 0.4 part of hydrophobic colloidal silica by a sample mill to prepare a one-component magnetic toner.

Further, the triboelectric charge amount of this toner was measured by a usual blow-off method.

When this toner was applied to a commercially available copying machine (trade name: NP-150Z, manufactured by Canon Inc.) and image formation was performed, good results almost similar to those in Example 1 were obtained.

Example 5 A developer is obtained in the same manner as in Example 4 except that 2 parts of Compound Example 2 is used instead of 3 parts of Compound Example 1, and development, transfer and fixing are performed, and an image is similarly formed. Obtained.

Detailed results are shown in Table 1, and almost the same satisfactory results as in Example 4 were obtained.

Comparative Example 2 A developer was obtained in the same manner as in Example 4 except that 2 parts of benzylmethyl-hexadecyl ammonium chloride was used instead of 3 parts of Compound Example 1 in Example 4, and an image was similarly obtained. Fog was small at room temperature and normal humidity, but the image density was as low as 0.81 and line drawings were scattered, and the solid black was noticeable. When the durability was examined, the density decreased to 0.48 after 30,000 sheets.

Further, the filming phenomenon at the time of endurance and the problem in the fixing step were almost the same as those in Comparative Example 1 and were not the same.

[Effects of the Invention] The effects obtained by the present invention are as follows.

(1) The triboelectric charge amount between toner particles or between toner and carrier, between toner and a toner carrier such as a sleeve in the case of one-component development is stable, and the triboelectric charge amount distribution is sharp and uniform. , A developer that can control the charge amount suitable for the developing system used.

(2) A developer capable of developing and transferring faithfully to a latent image.

(3) It is a developer which is capable of maintaining the initial characteristics even after continuous use for a long period of time and has excellent storage stability without toner aggregation or change in charging characteristics.

(4) A developer that gives a stable and vivid chromatic image that is not affected by changes in temperature and humidity.

Front Page Continuation (72) Inventor Hiroshi Fukumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Katsuhiko Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-59-78365 (JP, A) JP-A-56-11461 (JP, A) JP-A-49-51951 (JP, A) JP-A-59-111154 (JP, A) Kai 59-78364 (JP, A) JP 61-38951 (JP, A)

Claims (3)

[Claims] 1. A binder resin, a colorant, a fixing aid, and one of the following:
General formula(In the formula, R₁, R₂, R₃And R_FourHas an aryl group as the basic skeleton
Is represented by the formula, Y is an arylene group having an alkoxy group
Represents X Is BF_Four , PF₆ ,Electrostatic charge containing a compound represented by
Toner for image development. 2. The toner for developing an electrostatic charge image according to claim 1, wherein the fixing aid is wax. 3. The binder resin comprises a styrene-based copolymer,
The first fixing agent comprises a low molecular weight polyethylene wax or a low molecular weight polypropylene wax.
Item 6. The toner for developing an electrostatic charge image according to item.