JPH0336225B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a toner for developing electrical latent images in electrophotography, electrostatic recording, electrostatic printing, and the like. Generally, when developing an electrical latent image, there are two methods: a liquid developing method in which fine powders such as application materials, pigments, and fixing resin are dispersed and dissolved in an insulating petroleum-based solvent and developed by immersion in a developer; The cascade method, bristle brush method, magnetic brush method uses a developer made by mixing a fine particle toner containing a pigment and a dye as a charge control agent in a synthetic resin with a carrier such as glass beads or iron powder. There is a dry developing method in which a developing method such as a powder cloud method, an impression method, or a powder cloud method is used, and the present invention relates to a toner used in the dry developing method. Conventional dry developer toner is made by adding a pigment such as carbon black and a charge control agent to a thermoplastic natural resin or synthetic resin, melting and dispersing the mixture, and pulverizing this into a fine powder with a diameter of 5 to 20 μm. is used. Charge control agents used in such dry developer toners include, for example, Fetschewalz NBM (CI No. 26150), Nigrosine (C.
I.No.50415), Sudan Cheeksyuwartu BB (CI
No.26150), Brilliant Spirits
TN (manufactured by Halben, Huabriken, Bayer)
or pomegranate powder (Halbwerke, manufactured by Hoechst), etc., and as a negative charge control agent, Ceres powder (R) G (Halbenfabriken, manufactured by Bayer), chromogen powder LTCO (CI No.
14651) or Azo Oil Black R(R) (National, manufactured by Aniline Co., Ltd.), etc. are known. Since these charge control agents are mainly selected from dye-based materials, they have a complex structure and lack stability, and are decomposed or altered by mechanical friction and impact, changes in temperature and humidity, electrical shock, and light irradiation, resulting in poor charge control properties. is easily damaged. Furthermore, many conventional charge control agents are extremely difficult to uniformly disperse and dissolve in thermoplastic resins.
The amount of charge of the resulting toner particles differs between particles,
The distribution of the amount of charge becomes uneven. A toner containing such a charge control agent cannot faithfully visualize an electrical latent image, and the reliability of the visualization means as a system cannot be ensured. An object of the present invention is to provide a toner for electrical latent image development that improves the above-mentioned drawbacks. Specifically, it is an object of the present invention to provide a toner for electrical latent image development that has improved the above-mentioned drawbacks. It is an object of the present invention to provide a charge control agent for toner that has no variation in the amount of charge and can have stable characteristics in a system of visualization means. As a result of various studies in view of the above object of the present invention, the present inventors have found that a toner for visualizing an electrical latent image contains one or more of the compounds represented by the following general formula or as a charge control agent. The inventors have discovered that the above object can be achieved by the following methods, and have completed the present invention. general formula (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ represent an alkyl group or an aracyl group, and may be the same or different.) General formula (In the above formula, R ₅ , R ₆ and R ₇ represent an alkyl group or an aralkyl group, and may be the same or different.) The above general formula used as a charge control agent in the present invention Typical specific examples of the compound represented by are as follows.

[Table] Furthermore, the following compounds are exemplified as compounds represented by the general formula.

[Table] Compounds represented by the above general formula and are prepared by the general formula,
It can be easily obtained by dropwise mixing an aqueous solution of a salt such as ammonium chloride having an ammonium skeleton. An example of its synthesis is shown below. Synthesis Example 10.27 g of sodium tetraphenylboronate was dissolved in 200 ml of ion-exchanged water, and 5.6 g of phenyltrimethylammonium chloride (commercially available from Tokyo Kasei Kogyo Co., Ltd.) was dissolved in 150 ml of ion-exchanged water. The solution was collected by filtration, washed with ion-exchanged water, and then dried to obtain compound No. B1 as a white powder. Yield 13.5g (yield 95.7%) Elemental analysis value (as C ₃₄ H ₃₇ NB) Actual value Calculated value C% 86.84% 86.79% H% 7.73% 7.93% N% 3.06% 2.96% In the present invention, the above-mentioned charge One kind or a combination of two kinds of control agents can be contained in the toner. Further, in the present invention, a wide range of conventionally known binder resins can be used for the toner, for example,
Styrenes such as styrene and parachlorostyrene, vinylnaphthalene, vinyl esters such as vinyl chloride, vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, methyl acrylate,
Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloro-ethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate, ethyl methacrylate , esters of α-methylene aliphatic monocarboxylic acids such as butyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether, vinyl ethyl ether, such as vinyl methyl ketone, vinyl hexyl Vinyl ketones such as ketones, e.g.
-vinylpyrrole, N-vinylcarbazole, N
- Polymers obtained by polymerizing monomers such as N-vinyl compounds such as vinyl indole and N-vinylpyrrolidone, copolymers obtained by copolymerizing a combination of two or more of these monomers, or mixtures thereof;
Alternatively, non-vinyl resins such as non-vinyl thermoplastic resins such as rosin-modified phenol-formalin resins, oil-modified epoxy resins, polyurethane resins, cellulose resins, and polyether resins, or mixtures of these and the above-mentioned vinyl resins are mentioned. be able to. In addition, there are the following materials which are specifically limited to pressure fixing materials. Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, chlorinated polyethylene, poly 4
fluorinated ethylene, etc.), epoxy resin, polyester resin (acid value 10 or less), styrene-butadiene copolymer (monomer ratio 5-30:95-70), olefin copolymer (ethylene-acrylic acid copolymer, ethylene - Acrylic ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic ester copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, ionomer resin), polyvinylpyrrolidone, methyl vinyl ether -Maleic anhydride copolymer, maleic acid-modified phenolic resin, phenol-modified terpene resin. Further, in addition to the above-mentioned resin, optional coloring agents such as pigments and dyes can be added to the toner of the present invention, if necessary. These colorants are known, such as carbon black, nigrosine dye,
With aniline blue, calco oil blue, chrome yellow, ultramarine blue, duPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green zuxalate, lamp black, oil black, azo oil black, rose pengal and mixtures thereof. be. The toner of the present invention may further contain a magnetic material and be used as a magnetic toner. As the magnetic material contained in the magnetic toner of the present invention, magnetite (triiron tetroxide) is most preferable because it is chemically stable and can be easily obtained in the form of fine particles with a particle size of 1 μ or less. . Typical magnetic or magnetizable materials include metals such as cobalt, iron, nickel: aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, Alloys and mixtures of metals such as manganese, selenium, titanium, tungsten, vanadium: metal compounds including metal oxides such as aluminum oxide, iron oxide, copper oxide, nickel oxide, zinc oxide, titanium oxide, and magnesium oxide : Refractory titanium such as vanadium titanide and chromium titanide:
Carbides such as tungsten carbide and silica carbide: ferrites and mixtures thereof, and the like. It is desirable that these ferromagnetic materials have an average particle size of about 0.1 to 1 μm, and the amount to be included in the toner is about 50 to 300 parts by weight per 100 parts by weight of the resin component, particularly preferably 100 parts by weight of the resin component. against 90
~200 parts by weight. The toner of the present invention may be used alone as a one-component developer, but when used as a two-component developer such as a non-magnetic toner, it is used in combination with a known carrier. Further, the toner of the present invention can be used together with a fluidizing agent if necessary, and the fluidizing agent may include hydrophobic silica, titanium oxide,
Fine powder such as aluminum oxide is preferred, and the amount used is preferably 0.1 to 1 part by weight based on the toner. A method for forming a latent image by, for example, electrophotography using a developer containing the toner of the present invention will be described below. As a photoreceptor, a selenium photoreceptor, a selenium telluride photoreceptor, or an inorganic photoconductive material such as zinc oxide, cadmium oxide, cadmium selenide, cadmium selenide oxide, lead oxide, or mercury sulfide is dispersed in a binder resin. A photoreceptor is provided on a conductive support via an intermediate layer of casein treated with ammonia if necessary, or an organic photoconductive material such as anthracene, anthrone, poly-N-vinylcarbasol, etc. is required. A photoreceptor is used in which a photoreceptor layer containing a binder resin is provided on a conductive support via an intermediate layer made of casein or a water-soluble polymer compound as required. The surface of the photosensitive layer of such a photoreceptor is fully charged by corona discharge using, for example, a corotron or scorotron charger, and then imagewise exposed to light or the like to form an electrostatic latent image on the surface of the photosensitive layer. Next, this electrostatic latent image is developed with the developer according to the present invention by, for example, a magnetic brush method to form a toner image. For example, this toner image is transferred to a transfer body under corona discharge, or
Transfer to a transfer body using adhesive transfer. The toner image transferred to this transfer body is transferred onto the transfer body by, for example, a hot plate fixing method, a hot roll fixing method, a pressure fixing method, or a flash fixing method. Similar handling can be done even when a latent image for electrostatic recording is created without using electrophotography. The present invention will be explained below with reference to examples, but the present invention is not limited to these examples. In the following, "parts" refer to "parts by weight" unless otherwise specified. The charge control agent used in the examples is shown as the compound number in the above-mentioned specific example. Example 1 A mixture consisting of 100 parts by weight of polystyrene, 10 parts by weight of carbon black, 100 parts of compound No. A1, 2 magnetite (0.1μ), was heated and kneaded using a hot roll, and after cooling, it was crushed and dispersed to obtain a powder with a volume average particle size of 12μ. A magnetic toner having a resistance of 4×10 ¹² Ω·cm was obtained. next,
An electrostatic latent image formed on a ZnO photoreceptor using a normal electrophotographic method was developed using a developing device, transferred to plain paper while applying a corona discharge, and then thermally fixed.
A clear copy image with no white spots was obtained. Example 2 A mixture consisting of 100 parts by weight of polyester resin, 10 parts of carbon black, and 2 parts of compound No. A2 was heated and kneaded using a hot roll to obtain a non-magnetic toner having a volume average particle diameter of 12 μm. 3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to prepare a developer. This developer was placed in a magnetic brush developing device, and an electrostatic latent image formed on the organic photoreceptor by a conventional electrophotographic method was developed. Even after repeating this process over 100,000 copies, the resulting images remained clear. Initial image density (measured with a Macbeth reflection densitometer)
was 1.25, and the image density of the 100,000th sheet was 1.31, with little change in density. In addition, the charge amount of the toner is +16.8μC/g at the beginning, and + at the end.
The amount of change was 14.9μC/g, which was small.
Furthermore, the image density in a high temperature and high humidity environment of 30℃ and 90RH% is 1.35, and the toner charge amount is +14.5μC/
There was a small difference in g from that under normal temperature and normal humidity environment. Example 3 Epoxy resin 100 parts by weight Compound No. A3 3 〃 Magnetite 100 〃 An electrostatic latent image formed on an organic photoreceptor by ordinary electrophotography was developed by a developing device, and this was applied to plain paper by applying corona discharge. When the image was transferred and heat-fixed, a clear copy image with no white spots was obtained. Example 4 A mixture consisting of 100 parts by weight of styrene-acrylic resin, 10 parts of carbon black, and 3 parts of compound No. A3 was treated in the same manner as in Example 1 to obtain a non-magnetic toner having a volume average particle diameter of 12 μm. 3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to prepare a developer. When this developer was tested in the same manner as in Example 1, clear images were maintained. The initial image density was 1.21, and the 100,000th image density was 1.30, with little change in density. In addition, the amount of charge of the toner is +18.4μC/g at the beginning,
At the end of the test, the change was only +16.1 μC/g. Further, the image density under a high temperature and high humidity environment of 30° C. and 90RH% was 1.33, and the toner charge amount was +15.2 μC/g, which was a small difference from that under a normal temperature and normal humidity environment. Example 5 A mixture consisting of 100 parts by weight of polystyrene, 10 parts by weight of carbon black, 2 Compound No. B1, 100 parts of magnetite (0.1μ) was heated and kneaded using a hot roll, and after cooling, it was pulverized and dispersed to obtain a powder with a volume average particle size of 12μ and an electric A magnetic toner having a resistance of 4×10 ¹² Ω·cm was obtained. next,
An electrostatic latent image formed on a ZnO photoreceptor using a normal electrophotographic method was developed using a developing device, transferred to plain paper while applying a corona discharge, and then thermally fixed.
A clear copy image with no white spots was obtained. Example 6 A mixture consisting of 100 parts by weight of polyester resin, 10 parts of carbon black, and 2 parts of compound No. B2 was heated and kneaded using a hot roll to obtain a non-magnetic toner having a volume average particle diameter of 12 μm. 3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to prepare a developer. This developer was placed in a magnetic brush developing device, and an electrostatic latent image formed on an organic photoreceptor by a conventional electrophotographic method was developed. Even after repeating this process over 100,000 copies, the resulting images remained clear. The initial image density was 1.30, and the 100,000th image density was 1.27, with little change in density. In addition, the amount of charge of the toner is +17.1μC/g at the beginning,
At the end of the test, the change was only +15.3 μC/g. Further, the image density under a high temperature and high humidity environment of 30° C. and 90RH% was 1.31, and the charge amount of the toner was +15.5 μC/g, which was a small difference from that under a normal temperature and normal humidity environment. Comparative Example 1 In place of the compound of the present invention in Example 2, The developer was prepared in the same manner as in Example 2, except that the developer was used, and a copying test was conducted. The first image density was as low as 0.64, and the image was poor with background fog. The amount of charge was also low at +7.5 μC/g. Comparative Example 2 In place of the compound of the present invention in Example 2, The developer was prepared in the same manner as in Example 2, except that the developer was used, and a copying test was conducted. The image density of the first sheet was 1.28, and the image was clear. However, after about 10,000 copies, the image density became extremely low to 0.82, and the background fog started to increase. The initial charge amount of the toner was +17.3 μC/g, and the charge amount after copying 10,000 sheets had decreased to +11.45 μC/g. Further, the amount of charge of the toner under a high temperature and high humidity environment of 30° C. and 90RH% was +9.1 μC/g, which was significantly lower than that under a normal temperature and normal humidity environment. Example 7 Epoxy resin 100 parts by weight Compound No. B3 3 〃 Magnetite 100 〃 An electrostatic latent image formed on an organic photoreceptor by ordinary electrophotography was developed by a developing device, and this was applied to plain paper by applying corona discharge. When the image was transferred and heat-fixed, a clear copy image with no white spots was obtained. Example 8 A mixture consisting of 100 parts by weight of styrene-acrylic resin, 10 parts by weight of carbon black, and 3 parts by weight of compound No. B4 was treated in the same manner as in Example 1 to obtain a non-magnetic toner having a volume average particle diameter of 12 μm. 3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to prepare a developer. When this developer was tested in the same manner as in Example 5, clear images were maintained.

Claims (1)

[Scope of Claims] 1. A toner for electrical latent image development, characterized in that the toner contains one or more compounds represented by the following general formula or as a charge control agent. general formula (In the formula, R ₁ , R ₂ , R ₃ , and R ₄ represent an alkyl group or an aralkyl group, and may be the same or different.) General formula (In the formula, R ₅ , R ₆ and R ₇ represent an alkyl group or an aralkyl group, and may be the same or different.)