JPH0644163B2 - 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 such as pigments, dyes and fixing resins are dispersed and dissolved in an oil-based solvent having an insulating property, and a natural or synthetic method A fine particle toner in which a pigment and a dye as a charge control agent are contained in a resin, and a developer made by mixing 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 fine powder having a diameter of 0 μ is used.

As a charge control agent used in such a dry developer toner, for example, Fettschwartz NBM as a positive charge control agent as described in JP-B-41-2427.
(CI No. 26150), Nigrosine (CI No. 5041
5), Sudan Teak Schwarz BB (CI No. 2615
0), Brilliant Spirit Schwartz TN (Halben, Fapliken, manufactured by Bayer) or Zavon Schwarz (Harpberge, manufactured by Hoechst), and Ceres Schwarz (R) G (Halben Fabryken, manufactured by Bayer) as a negative charge control agent. , Chromogen Schwarz LTCO (CIN
14645) or Azo Oil Black R (R) (National, manufactured by Aniline).

Many of these dye-based charge control agents have an unclear structure, and even if a large variation in the charge amount between lots is recognized, it is difficult to grasp what is the cause of the variation. 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, Japanese Patent Laid-Open No. 52-10141,
JP-A-49-51951, JP-A-54-134441 and the like correspond to each of them, but the hue is white, which is advantageous, but the charge amount is insufficient. This is 4
This is due to the hygroscopicity of the high-grade ammonium salt, and therefore lacks humidity stability.

OBJECT The object of the present invention is to provide a toner for electrostatic latent image development in which the above-mentioned drawbacks have been improved. Specifically, a sufficient charge amount of the toner particles can be obtained, and the toner particles Another object of the present invention is to provide a positive charge control agent for toner, which has no variation in the amount of electric charge, and is not colored so 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 that visualizes an electrostatic latent image. The inventors have found that the above can be achieved and completed the present invention.

General formula (In the above formula, R ₁ , R ₂ and R ₃ represent an alkyl group having 10 or less carbon atoms, an aralkyl group having or not having a substituent, and an aryl group, which may be the same or different. good. the aralkyl group, the aryl group a benzyl group, a phenyl group, a naphthyl group, as a substituent nitro group, a halogen group, a cyano group, an alkoxy group, is .R _4, R ₅ represents an alkyl group Hydrogen, halogen, cyano group, alkoxy group, acyl group, alkyl group having 11 or less carbon atoms, aralkyl group with or without substituent, aryl group, aryloxy group,
It may be the same or different. Examples of the aralkyl group, aryl group and aryloxy group include benzyl group, phenyl group, naphthyl group and phenoxy group, and the substituents thereof include halogen, nitro group, alkyl group and alkoxy group. R ₄ and R ₅ may combine to form a ring such as cyclopentane, cyclohexane or fluorene. In the present invention, typical examples of the compound of the above general formula used as the charge control agent 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 vinyl type resin as described above.

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 mixtures thereof.

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 chemically stable, and that fine particles having a particle size of 1 μ 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 ferromagnetic 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 with respect to 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.

Example 1 Styrene / 2-ethylhexyl acrylate / n-butyl methacrylate copolymer
100 parts of carbon black 13 parts A mixture of 2 parts of charge control agent (Compound No. 1) was heated and kneaded by a hot roll, cooled, pulverized and dispersed to obtain a toner having a volume average particle diameter of 10.5 μ. 1.55 g of this toner and 58.5 g of silicon-coated carrier were mixed and milled for 30 minutes, and the blow-off charge amount (Q /
M) was measured and found to be 16.5 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
100 parts of carbon black 13 parts A mixture of 2 parts of charge control agent (Compound No. 2) was kneaded by heating with a hot roll, cooled, pulverized and dispersed to obtain a toner having a volume average particle size of 10.5 μ. When 1.55 g of this toner and 58.5 g of silicon carrier were mixed and milled for 30 minutes and the blow-off charge amount (Q / M) was measured, it was 15.3 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 parts Carbon black 13 parts except that a mixture was used to prepare a toner in the same manner as in Example 1 and then mix with a silicon carrier to blow off charge. When the amount was measured, Q / M was 15.7 μC / g. Also in this case, a clear copy image was obtained on plain paper by developing-transferring the electrostatic latent image.

Example 4 100 parts by weight of styrene resin A charge control agent (compound No. 4) 2 〃 Carbon black 13 〃 was used to prepare a toner, 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 19.9 μC / g.
A clear transfer 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 _{formulas, R 1, R 2, R} 3 is an alkyl group, an aralkyl group which is not or has has a substituent, an aryl group, which may be identical or different .R _4, R ₅ is hydrogen, halogen, cyano group, alkoxy group, acyl group,
It represents an alkyl group, an aralkyl group with or without a substituent, an aryl group, and an aryloxy group, which may be the same or different. )