JPH0644162B2 - Toner for electrostatic latent image development - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a toner for developing an electrostatic latent image in electrophotography, electrostatic recording, electrostatic printing and the like. Generally, when developing an electrostatic latent image, a liquid developing method of developing by immersing in a developer in which fine powders of pigments, dyes, fixing resins, etc. are dispersed and dissolved in an oil-based solvent having an insulating property, and a natural or synthetic method Using a developer made by mixing a fine particle toner in which a pigment and a dye as a charge control agent are contained in a resin and a carrier such as glass beads or iron powder, a cascade method,
There is a dry developing method in which a developing method such as a hair brush method, a magnetic brush 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.

2. Description of the Related Art A conventional toner for a dry developer is prepared by adding a pigment such as carbon black and a charge control agent to a thermoplastic natural resin or a synthetic resin, melt-dispersing the mixture, and cooling and solidifying the mixture to pulverize it to 5-2.
A differentiator having a diameter of 0 μ is used.

As a charge control agent used for such a dry developer toner, for example, Fettschwartz NBM (CIN) as a positive charge control agent as described in JP-B-41-2427.
o.26150), Nigrosine (CINo.50415), Sudan Teak Schwarz BB (CINo.26150), Brilliant Spirit Schwarz TN (Halben, Fabryken, Bayer) or Savonne Schwarz (Harpberke, Hoechst) and negative charge. Ceres Schwarz as a control agent
(R) G (Halben Fabryken, manufactured by Bayer), Chromogen Schwarz LTCO (CI No. 14645) or Azo Oil Black R (R) (National manufactured by Aniline) are known.

Many of these dye-based charge control agents have an unclear structure, and even if a large variation in the amount of charge between lots is recognized, it is difficult to grasp what is causing it. Many of the dye-based dyes are colored black, dark blue, dark brown or the like, and are therefore unsuitable as color toners such as yellow. On the other hand, there are some proposals of quaternary ammonium salts as charge control agents other than dye-based ones. For example, JP-A-52-10141 and JP-A-49
-51951, JP-A-54-134441 and the like correspond to them, but the hue is white, which is advantageous, but the charge amount is insufficient. This is due to the hygroscopicity of the quaternary ammonium salt, and therefore lacks humidity stability.

OBJECT The object of the present invention is to provide a toner for developing an electrostatic latent image in which the above-mentioned drawbacks have been improved. Specifically, a sufficient charge amount of toner particles can be obtained, and the toner particles are An object of the present invention is to provide a positive charge control agent for toner, which has no variation in the amount of charge, is not colored much, and is easy to use for color.

As a result of various studies in view of the above-mentioned object of the present invention, the present inventors have achieved the above-mentioned object by including a compound represented by the following general formula as a positive charge control agent in a toner for developing an electrostatic latent image. The inventors have found that they can be achieved and have completed the present invention.

General formula (In the above formula, R ₁ and R ₂ represent an alkyl group, an aryl group or an aralkyl group having 10 or less carbon atoms, and may be the same or different. R ₃ , R ₄ , R ₅ and R ₆ are aromatic. Represents a substituent on the ring, and the substituent represents a halogen, a lower alkyl group, a nitro group, etc. X represents an anion functional group such as halogen, paratoluenesulfonate, tetrafluoroborate and hexafluorophosphate.) Typical examples of the compound of the above general formula used as the charge control agent in the present invention include the following.

The amount of the charge control agent in the present invention contained in the toner is preferably 0.5 to 7 parts by weight with respect to 100 parts by weight of the resin component. If it is less than 0.5 part by weight, the toner is not positively charged, which is not practical. On the other hand, when the amount exceeds 7 parts by weight, the chargeability of the toner is too large and the electrostatic attraction with the carrier increases, so that the fluidity of the developer and the image density decrease.

The charge control agent for toner according to the present invention is synthesized by a conventionally known method.

In the present invention, one kind or a combination of two kinds of the above charge controlling agents may be contained in the toner.

In the toner of the present invention, conventionally known binder resins can be widely used, and examples thereof include styrenes such as styrene and parachlorostyrene, vinyl naphthalenes such as vinyl chloride, vinyl bromide and vinyl fluoride. Vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-acrylate.
Esters of α-methylene aliphatic monocarboxylic acids such as octyl, 2-chloro-ethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylonitrile, methacryloyl Nitrile, acrylamide, vinyl ethers such as vinyl methyl ether, vinyl isobutyl ether and vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone, such as N-vinyl pyrrole, N-vinyl carbazole and N-vinyl indole,
Polymers prepared by polymerizing monomers such as N-vinyl compounds such as N-vinylpyrrolidone, copolymers prepared by copolymerizing two or more of these monomers, or mixtures thereof, or rosin-modified phenol, for example. Examples thereof include non-vinyl type resins such as non-vinyl type thermoplastic resins such as formalin resin, oil-modified epoxy resin, polyurethane resin, cellulose resin and polyether resin, or a mixture of these with the above vinyl type resins.

In addition, the following materials can be specifically mentioned as the pressure fixing material.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polytetrafluoroethylene, etc.), epoxy resin, polyester resin (oxidation 10 or less), styrene-butadiene copolymer (monomer ratio 5 to 5)
30: 95-70), 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, in addition to the above-mentioned resin, the toner of the present invention can be added with an optional colorant such as a pigment or dye. These colorants are known, for example, carbon black, nigrosine dye, aniline blue, chalco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite greens oxalate. , Lamp black, oil black, azo oil black, rose bengal and its mixture.

The toner of the present invention may be used as a magnetic toner by further containing a magnetic material.

Magnetite (ferric tetroxide) is most preferable because it is desirable that the magnetic material contained in the magnetic toner of the present invention is scientifically stable and that a particle having a particle size of 1 μm or less can be easily obtained. . 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 of metals such as manganese, selenium, titanium, tungsten, vanadium and mixtures thereof: aluminum oxide, iron oxide,
Metal compounds including metal oxides such as copper oxide, nickel oxide, zinc oxide, titanium oxide, and magnesium oxide: refractory nitrides such as vanadium nitride, chromium nitride: carbides such as tungsten carbide and silica carbide. : Ferrite and mixtures thereof may be mentioned. It is desirable that these tough materials have an average particle size of about 0.1 to 1 μm, and the amount contained in the toner is about 50 to 300 parts by weight, and particularly preferably 100 parts by weight of the resin component based on 100 parts by weight of the resin component. It is 90 to 200 parts by weight.

The toner of the present invention may be used alone as a one-component developer, but may be used as a two-component developer such as a non-magnetic toner in a mixture 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 is preferably fine powder of hydrophobic silica, titanium oxide, aluminum oxide, etc. On the other hand, 0.1 to 1 part by weight is preferable.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts" means "parts by weight" unless otherwise specified.
Indicates.

Example 1 Styrene / 2-ethylhexyl acrylate / normal butyl methacrylate copolymer
A mixture of 100 parts of carbon black and 13 parts of a charge control agent (compound No. 1) was kneaded by heating with a heating roll, cooled, pulverized and dispersed to obtain a toner having a volume average particle diameter of 10.5 μ. When 1.55 g of this toner and 58.5 g of silicon-coated carrier were mixed and milled for 30 minutes to measure the amount of blow-off charge (Q / M), it was 12.7 μC / g.

For comparison, a toner was prepared in the same manner as in Example 1 except that the following quaternary ammonium salt was used as the charge control agent, and the charge amount was measured. As a result, Q / M was 5.0 μC / g.

Next, an electrostatic latent image formed on a ZnO photoconductor by a normal electrophotographic method was developed by a developing device and transferred onto a plain paper while corona discharge was applied and heat-fixed. An image was obtained.

Example 2 Styrene .2-ethylhexyl acrylate / normal butyl methacrylic acid copolymer
A mixture consisting of 100 parts of carbon black 13 〃 charge control agent (compound No. 2) 2 〃 was heated and kneaded by a hot roll, cooled, pulverized and dispersed to obtain a toner having a volume average particle diameter of 10.5µ. 1.55g of this toner and 58.5g of silicon carrier are mixed and 3
When the blow-off charge amount (Q / M) was measured by milling for 0 minutes, it was 14.9 μC / g.

For comparison, a toner was prepared in the same manner as in Example 1 except that the following quaternary ammonium salt was used as the charge control agent, and the charge amount was measured. As a result, Q / M was 8.0 μC / g.

Next, an electrostatic latent image formed on a ZnO photoconductor by a normal electrophotographic method was developed by a developing device and transferred onto a plain paper while corona discharge was applied and heat-fixed. An image was obtained.

Example 3 Styrene resin 100 parts Charge control agent (Compound No. 3) 2 〃 Carbon black 13 〃 except that a mixture was used, toner was prepared in the same manner as in Example 1 and then mixed with silicon carrier to blow off charge amount. When measured, Q / M was 14.3 μC / g.
Also in this case, a clear copy image was obtained on plain paper by developing-transferring the electrostatic latent image.

Example 4 Styrene resin 100 parts by weight Charge control agent (Compound No. 4) 2 〃 Carbon black 13 〃 A toner was prepared using a mixture, and 57 g of an iron powder carrier was mixed with 3 g of the obtained toner. Was tested in the same manner as in Example 1, and as a result, Q / M was 10.8 μC / g, and a clear transferred image was obtained on plain paper.

Effects As described above, the toner of the present invention can obtain a sufficient charge amount, and since there is no variation in the charge amount, a stable copy image can always be obtained.

Claims (1)

[Claims] 1. A toner for developing an electrostatic latent image, characterized in that the toner contains a compound represented by the following general formula as a positive charge control agent. General formula (In the above formula, R ₁ and R ₂ represent an alkyl group, an aryl group or an aralkyl group, and may be the same or different.
R ₃ , R ₄ , R ₅ and R ₆ represent substituents on the aromatic ring. X represents an anionic functional group. )