JPH0679169B2 - Toner for electrostatic image development - Google Patents

Description

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

[Prior Art] Conventionally, as an electrophotographic method, various methods have been described in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748, but they are not essential. Forming a static latent image by applying a uniform electrostatic charge on the photoconductive insulator layer and irradiating the insulator layer with a light image,
Then, the latent image is developed and visualized by fine powder called toner in the art, and if necessary, the powder image is transferred to paper or the like, and then fixed by heating, pressurizing, or solvent vapor.

As a developing method applied to these electrophotographic methods,
It is roughly classified into a dry development method and a dry 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 (contact developing or (Also referred to as toner development), a jumping development method in which toner particles are not brought into direct contact 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 a volatile toner is brought into contact with an electrostatic latent image surface for development.

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 a toner. 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. Also, the toner is
Depending on the polarity of the electrostatic latent image to be developed, positive or negative electric charge is held.

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. Will be things. Therefore, in order to impart a desired triboelectric chargeability to the toner, a dye, a pigment or a charge control agent which imparts the chargeability is added.

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

(1) Toner control for positive charge 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 (CI 41000), CI Basic Yellow
3, CI Basic Red 1 (CI 45160), CI Basic Red
9 (CI 42500), CI Basic Violet 1 (CI 4253
5), CI Basic Violet 3 (CI 42555) CI Basic V
iolet 10 (CI 45170), CI Basic Violet 14 (CI
42510), CI Basic Blue 1 (CI 42025), CI Ba
sic Blue 3 (CI 51005), CI Bsic Blue 5 (CI 4
2140), CI Basic Blue 7 (CI 42595), CI Basi
c Blue 7 (CI 42595), CI Basic Blue 9 (CI 52
015), CI Basic Blue 24 (CI 52030), CI Basi
c Blue 25 (CI 52025), CI Basic Blue 26 (CI
44045), CI Basic Green 1 (CI 42040), CI Ba
sic Green 4 (CI 42000), CI 42510, CI 4517
0, CI Basic Blue 9, etc.) Lake pigments of these basic dyes (as the laker, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), CI Solvent Black
3 (CI 26150), Hansa Yellow G (CI 11680),
CI Morelant Black 11, CI Pigment Black 1, Gilsonite, asphalt, etc.

And quaternary ammonium salts such as benzolmethyl-
Hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, organic tin compounds such as dibutyltin oxide, metal salts of higher fatty acids, inorganic fine powders of glass, mica, zinc oxide, etc., metal complexes of EDTA, acetylacetone, etc., containing amino groups Vinyl polymer,
Polyamine resins such as condensation polymers containing amino groups.

(2) The following is what controls the toner to be negatively charged.

Japanese Patent Publications No. 41-20153, No. 43-27596, No. 44-6397, and No.
Monoazo dye metal complex salt represented by the following general formula described in No. 45-26478, etc. [Wherein M is Cr or Co, R ₁ and R ₂ are phenylene residues which are unsubstituted or substituted by a substituent, and R ₃ and R ₄ are non-coupling groups at the ortho position of the metallizable group. Represents a residue of a coupling component substituted with a substituent or a substituent, X ₁ and X ₂ are —O— or —COO—, and X ₃ and X ₄ are —O.
Represents-, -NH- or -N-alkyl-, and represents [A] ⁺
Represents hydrogen ion, ammonium ion, aliphatic ammonium ion, alicyclic ammonium ion, heterocyclic ammonium ion alkali metal or alkaline earth metal. ] Nitrohumic acid and its salts described in JP-A-50-133338 or dyes and pigments such as CI 14645.

And JP-B-55-42752, JP-B-58-41508 and JP-B
Metal complexes of Co, Cr, Fe and the like of salicylic acid, naphthoic acid, and dicarboxylic acid described in 59-7384 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 derived 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 and 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 the triboelectric charge amount between toner particles obtained by pulverization causes a difference. is doing. For this reason, various methods have been conventionally used for more uniform dispersion. For example, a basic nigrosine dye is used in the form of a salt with a higher fatty acid in order to improve the compatibility with a thermoplastic resin, but the unreacted fatty acid or a dispersion product of the salt is often used.
It is exposed on the surface of the toner and contaminates the carrier or the toner carrier, which causes deterioration of the fluidity of the toner, fog, and deterioration of the 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 agent powder and the resin powder in advance and then hot-melt kneading is used. But,
Under the present circumstances, the original dispersion failure cannot be avoided, and sufficient charge uniformity for practical use has not yet been obtained.

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

Thus, when the conventional charge control agent is used in the toner,
Between the toner particles, between the toner and the carrier, or between the toner carrier such as the toner and the sleeve, the amount of electric charge generated on the surface of the toner particles varies, and development fog, toner scattering, carrier contamination, etc. Life is easy to occur. In addition, this obstacle appears as a remarkable phenomenon when a large number of copies are piled up, and is substantially unsuitable for a copying machine.

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 those that 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 is a developer that faithfully develops and transfers a latent image, that is, adhesion of toner in the background area at the time of development, that is, fog and scattering of toner around the edge of the latent image, High image density is obtained,
This is to provide a developer having good halftone reproducibility.

Still another object 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.

Still another object is to provide a bright chromatic color developer.

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

Still another object is to provide a developer which can be easily cleaned in a cleaning step without causing the electrostatic latent image surface to be soiled, worn or scratched.

Still another object is to provide a developer having good fixing characteristics, particularly a developer having no problem in high temperature offset and the like.

[Means and Actions for Solving Problems] The present invention provides a binder resin, a colorant, a wax, and a compound represented by the following general formula: [Wherein R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or an alkyl group,
It represents either a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, a substituent having an alkylene group or an arylene group as a basic skeleton, a heterocyclic group containing a nitrogen atom, a sulfur atom or an oxygen atom, or a substituent group combining these. , Y represents a divalent group having the same substituents as R ₁ , R ₂ , R ₃ and R ₄ (provided that Y is not a biphenylene group), and X ⁻ represents Cl ⁻ , Br ⁻ , I ^{_{-, SO 4 2-, SO 3}} 2-, NO 3 - or represents one of the C ^₂ O ₄ ^2- organic acid residue anion. ] A toner for developing an electrostatic charge image containing a compound represented by

The present inventors have found that the compound represented by the general formula [1] is thermally and temporally stable, has a low hygroscopic property, and when contained in a developer, has a high quality which gives a developer having excellent electrophotographic characteristics. It was found to be a charge control agent.

Typical examples of the compound represented by the general formula [1] are as follows.

In the above compounds, the anion is _{^{Br -, I -, SO 4}} 2-, SO 3
^2-, NO ₃ ^- and C ^₂ O ₄ ^2- may be changed to any of the anions of organic acids like.

As a method of incorporating the above compound into the developer, there are a method of adding it inside the toner particles and a method of adding it externally. When internally added, the amount of these compounds used is determined by the type of binder resin and wax, the presence or absence of additives used as necessary, and the toner production method including the dispersion method. Although not limited, it is preferably used in the range of 0.1 to 30 parts by weight (more preferably 1 to 10 parts by weight) with respect to 100 parts by weight of the binder resin.

It is also possible to use a conventionally known charge control agent 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, nigrolen 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 such as poly-p-chlorostyrene and polyvinyltoluene and their substitution products; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers,
Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Coal, 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 ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene- Maleic acid copolymer Styrene-based copolymers such as styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic Examples thereof include acid resins, rosins, modified rosins, terpene resins and phenol resins, which can be used alone or in combination.

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 that 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 their surfaces 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 such as aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium. Examples include metal alloys and mixtures thereof.

It is desirable that these ferromagnetic materials have an average particle size of about 0.1 to 2 μm.
It is about 20 to 200 parts by weight based on 0 parts by weight, particularly preferably 40 to 150 parts by weight based on 100 parts by weight of the resin component.

Examples of the wax include 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 wax and a pigment or dye as a colorant, and if necessary, a magnetic material. After thoroughly mixing the additives and the like with a ball mill or other mixing machine, the resins are mutually compatibilized by melting, kneading and kneading using a heat kneader such as a heating roll, kneader or extruder. A pigment or dye may be dispersed or dissolved in the solution, cooled and solidified, and then 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 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 type copying system in which the operations of charging, exposing, developing and transferring are continuously repeated, the effect is further expanded.

Further, since there is little color disorder due to the charge control agent, 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 (weight average molecular weight w: about 300,000) 100 parts 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 product to cool naturally, it is roughly crushed with a cutter mill, then 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 μ (that is, , Toner).

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

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

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 1.15, no fog at all, and a good image with high resolution without toner scattering around the image was obtained. A transfer image was continuously formed using the above-mentioned developer, and the durability was examined. The transfer image after 30,000 sheets was also an image having no amber color as compared with the initial image.

Further, at the time of durability, the above-mentioned filming phenomenon relating to the toner on the photosensitive member was not observed, and no problem was found in the cleaning process. At this time, there were no troubles in the fixing process, and at the end of the durability test of 30,000 sheets, the fixing machine was observed, but there were no scratches or damage on the rollers, there was almost no stain by the offset toner, and there was no problem in practice. .

Comparative Example 1 Instead of using 3 parts of Compound Example 1, 2 nigrosine dyes were used.
A developer was obtained and developed in the same manner as in Example 1 except for using parts.
Images were similarly obtained by transferring and 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.

Also, at the time of endurance, from around 10,000 sheets, the toner material formed a thin streak-like coating 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.

In addition, at the time of endurance, a fixed image tends to be easily 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 2 was used instead of 3 parts of Compound Example 1, and development, transfer and fixing were carried out, and an image was similarly obtained.

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 an image was similarly obtained by performing development, transfer and fixing.

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 (weight average molecular weight w: about 300,000) 100 parts Ferrous tetroxide 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 product to cool naturally, it is roughly crushed with a cutter mill, then 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 μ (that is, , Magnetic toner) was obtained.

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.

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 were obtained almost in the same manner as in Example 1.

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 Instead of using 3 parts of Compound Example 1 in Example 4, benzylmethyl-hexadecyl ammonium chloride 2
A developer was obtained in the same manner as in Example 4 except that parts were used, and an image was obtained in the same manner. There is little fog at room temperature and humidity, but the image density is 0.
As low as 81, line drawings were scattered and 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.

Table 1 shows the evaluation results of each example and comparative example.

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

(2) A developer that allows development and transfer faithful to a latent image.

(3) A developer capable of maintaining the initial characteristics even when the developer is continuously used for a long period of time, and obtaining a vivid chromatic color image without toner aggregation or change in charging characteristics.

(4) A developer having excellent long-term storage stability and good fixing properties.

(5) A developer that can be easily cleaned by a cleaning process that does not stain, wear, or scratch the electrostatic latent image surface.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuhiko Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-59-78365 (JP, A) JP-A-59 -177565 (JP, A) JP-A-59-200253 (JP, A) JP-A-61-38951 (JP, A)

Claims (2)

[Claims] 1. A binder resin, a colorant, a wax and the following general formula: [Wherein R ₁ , R ₂ , R ₃ and R ₄ are hydrogen or an alkyl group,
It represents either a cyclic alkyl group, an alkenyl group, an aryl group, an aralkyl group, a substituent having an alkylene group or an arylene group as a basic skeleton, a heterocyclic group containing a nitrogen atom, a sulfur atom or an oxygen atom, or a substituent group combining these. , Y represents a divalent group having the same substituents as R ₁ , R ₂ , R ₃ and R ₄ (provided that Y is not a biphenylene group), and X ⁻ represents Cl ⁻ , Br ⁻ , I ^{_{-, SO 4 2-, SO 3}} 2-, NO 3 - or represents one of the C ^₂ O ₄ ^2- organic acid residue anion. ] A toner for developing an electrostatic charge image, comprising a compound represented by: 2. The binder resin comprises a styrene-based copolymer,
Claim 1 wherein the wax 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.