JPH05165255A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To improve dispersibility with a resin component. to obtain thermal stability to the temp. for melt kneading, and to give negative charges to the toner by incorporating a specified compd. as a charge controlling agent. CONSTITUTION:A compd. expressed by formula is incorporated as a charge controlling agent. In formula, R1 is a hydrogen atom, alkyl group, substd. or unsubstd. aromatic ring (including condensed ring), R2 is a substd. or unsubstd. aromatic ring (including condensed ring), M is a tervalent metal. X<+> is a cation, and (n)is an integer >=1. In this case, the alkyl group as R) includes a methyl group, ethyl group, n-butyl group, iso-amyl group, n-dodecyl group, n-octadecyl group, cyclohexyl group, etc. The aromatic rings as R1 and R3 include a benzene ring, nephthaline ring, etc., and the substituent is an alkyl group, alkoxy group, halogen atom, aryl group, etc. M is a tervalent metal such as Cr, Al, Fe, Co, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to toners for developing electrostatic latent images in electrophotography.

[0002]

2. Description of the Related Art In electrophotography, a latent image is formed on a photoconductor made of a photoconductive substance, developed with a powder developer to be visualized, and further exposed to heat or a solvent, and in some cases pressure. The method of fixing on paper is common. As such an electrophotographic developer, a two-component developer of a mixture of a toner in which a colorant, a charge control agent, a fluidizing agent, etc. are dispersed in a natural resin or a synthetic resin, and a carrier of iron powder or ferrite powder is used. And natural or synthetic resins and colorants, charge control agents,
It can be roughly classified into a fluidizing agent and a one-component developer including a magnetic material.

The two-component type developer achieves the development by adhering the charged toner to the electrostatic latent image by friction with the carrier, and the one-component type developer has conventionally been used in place of the carrier. A toner that is charged by friction with a brush-shaped or plate-shaped friction member having the same function as this is known, and recently, a magnetic substance powder is kept in a dispersed state and is not interacted with the magnetic substance fine powder. Toners that become charged by friction have become known. The photoconductor layer can be positively or negatively charged so that exposure underneath the original gives a positive or negative electrostatic latent image. The developing toner is kept positive or negative depending on the polarity of the electrostatic latent image.

In order to keep the toner charged, it has been proposed to utilize the triboelectric charging property of the resin which is the main component of the toner. In this method, the toner has a small charge and a solid surface resistance value is large. Therefore, the obtained image is easily fogged,
It becomes unclear. Therefore, in order to impart desired triboelectric chargeability to the toner, dyes and pigments that impart charge, and dyes and pigments called charge control agents are added, and these are practically used in the technical field today. ing.

However, a dye as a charge control agent,
The pigment has a complicated structure and is poor in stability. For example, the pigment is likely to be decomposed or deteriorated due to mechanical friction and impact, changes in temperature and humidity, electrical impact and light irradiation, and the charge control ability is lost. Moreover, since it is a colored substance, it has an essential defect that it cannot be used for toner having a specific hue.

[0006]

SUMMARY OF THE INVENTION A general object of the present invention is to provide a new technique relating to toner charge control that overcomes the above-mentioned problems, and has a stable triboelectric charge amount and a triboelectric charge amount. It is an object of the present invention to provide a toner having a sharp and uniform distribution and capable of controlling the charge amount suitable for the system used. Furthermore, it is not affected by changes in temperature and humidity,
It is to reproduce a stable image and to provide a vivid chromatic color toner.

[0007]

The present inventors have found that the toner has good dispersibility with resin components, has thermal stability up to a temperature at which melt-kneading can be sufficiently performed, and is a colorless substance that is applied to a toner. The inventors have found a compound capable of imparting an electric charge, and have completed the present invention.

That is, the present invention represents the general formula <A> (wherein R ₁ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic ring (including a condensed ring), and R ₂ represents a substituted or unsubstituted Represents an aromatic ring (including a condensed ring), M represents a trivalent metal, X ⁺ represents a cation, and n represents an integer of 1 or more. It is an electrophotographic toner characterized by containing the toner.

[0009]

[Chemical 1]

The compound represented by formula <A> will be described in detail below. Examples of the alkyl group for R ₁ include a methyl group, an ethyl group, an n-butyl group, an iso-amyl group, an n-dodecyl group, an n-octadecyl group and a cyclohexyl group, and an aromatic ring for R ₁ and R ₂ . Examples thereof include a benzene ring and naphthalene ring, and examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an aryl group, an aralkyl group, a nitro group, a cyan group, an amide group and a sulfamide group.

M is a trivalent metal such as Cr, Al,
Fe, Co, Ti, B and the like are included.

As X ⁺ , various inorganic cations and organic cations are used. Examples of the inorganic cations include hydrogen ions and metal ions, and examples of the monovalent or divalent metal ions include Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ and Zn ²⁺ . Examples of the organic cation include ammonium ion, iminium ion, phosphonium ion and the like.

Preferred among the above organic cations are those represented by the following general formula <B>, <C>, <D> or <E>.

[0014]

[Chemical 2]

In the formula, R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ and R
₉ , R ₁₀ , R ₁₁ , R ₁₂ and R ₁₃ are each a hydrogen atom,
A substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, Z ₁ and Z ₂ are non-metal atoms which form a 5-membered ring or a 6-membered ring by combining with a nitrogen atom in each formula. Indicates.

Examples of the alkyl group include methyl group, ethyl group, n-butyl group, iso-amyl group, n-dodecyl group, n-octadecyl group and cyclohexyl group. Examples of the aryl group include a phenyl group and an α-naphthyl group, and these alkyl groups or aryl groups include various substituents such as an alkyl group, an aralkyl group, a halogen atom, an alkoxy group, a hydroxyl group, a cyano group, and an aryl group. It may be substituted.

Examples of Z ₁ and Z ₂ include a non-metal atom group necessary for forming various heterocycles such as a pyridine ring, an isoquinoline ring, a pyrrole ring, an imidazole ring, a piperidine ring and a pyrrolidine ring.

N represents an integer of 1 or more.

Specific examples of the compound represented by formula <A> are shown below. The compound No. is commonly used in the examples.

[0020]

[Chemical 3]

[0021]

[Chemical 4]

[0022]

[Chemical 5]

[0023]

[Chemical 6]

[0024]

[Chemical 7]

The compound represented by the general formula <A> used as the charge control agent of the present invention is, for example, the following general formula <F> (wherein R ₁ and R ₂ are generally represented by the following formula) in an aqueous solution of boric acid and an amine. Expression <
It is easily obtained by adding the compound of A>) and reacting.

[0026]

[Chemical 8]

The compound represented by the general formula <A> added to the toner component is generally 0.1 to 100 parts by weight of the resin.
It is 10 parts by weight, preferably 0.5 to 5 parts by weight.

The toner of the present invention is a styrene resin, a styrene-acrylic resin, a styrene-butadiene resin which is obtained by considering the adhesiveness, storability, fluidity and pulverizability of the compound represented by the general formula <A>. One or several known resins for toners such as epoxy resin, polyester resin, paraffin wax, polystyrene and the like are mixed and used. Although many known dyes and pigments can be used as the colorant, benzidine yellow, quinacdrine, copper phthalocyanine blue, copper phthalocyanine green and the like are particularly excellent as color copying toners.

The toner of the present invention is usually mixed with a carrier to provide a two-component developer, but it can also be used as a one-component developer.

[0030]

The present invention will be described in detail below with reference to examples. In addition, "part" in an Example represents a weight part.

Example 1 100 parts of styrene resin, 6 parts of carbon black and No. 4
A premix was prepared by uniformly premixing 2 parts of the compound represented by Then, after heating, melting, kneading, cooling, coarse pulverization with a vibration mill and fine pulverization with a jet mill, a black toner having a particle size of 8 to 15 μm was obtained.
95 parts of an iron powder carrier was mixed with 5 parts of the obtained toner to prepare a developer. The initial blow-off charge amount of this developer was −29.7 μC / g. When this toner was formed on a commercially available selenium drum by a magnetic brush developing method, a clear image without fog was obtained. This toner is
The copy quality did not deteriorate even after 10,000 continuous copies.

Example 2 100 parts of styrene-acrylic copolymer resin, yellow dye (C.
6 parts of I. Disperse Yellow 33) and 2 parts of the compound represented by No. 1 were treated in the same manner as in Example 1 to obtain a yellow toner. The developer prepared in the same manner as in Example 1 from the obtained yellow toner has an initial blow-off charge amount of −32.5 μC /
It was g. When this developer was copied in the same manner as in Example 1, a clear yellow image without fog was obtained. With this toner, the copy quality did not deteriorate even after 10,000 continuous copies.

Example 3 Styrene-n-butyl methacrylate copolymer resin 100
Part, 8 parts of red dye (CI Pigment Red 12) and N
2 parts of the compound represented by o.2 were treated in the same manner as in Example 1 to obtain a red toner. The initial blow-off charge amount of the developer prepared in the same manner as in Example 1 from the obtained red toner is
It was -35.9 μC / g. When this developer was copied in the same manner as in Example 1, a clear red image without fog was obtained. With this toner, the copy quality did not deteriorate even after 10,000 continuous copies.

Example 4 100 parts of a polyester resin, 6 parts of a blue dye (C.I. Pigment Blue 15) and 2 parts of a compound represented by No. 3 were treated in the same manner as in Example 1 to obtain a blue toner. The initial blow-off charge amount of the developer prepared by using the obtained blue toner in the same manner as in Example 1 was −30.1 μC / g. When this developer was copied in the same manner as in Example 1, a clear blue image without fog was obtained. This toner is a continuous copy 10,0
Copy quality did not deteriorate even after 00 sheets.

Example 5 In Example 1, instead of the compound represented by No. 4, N
A black toner was obtained in the same manner as in Example 1 except that the compound shown in Table 5 was used. The initial blow-off charge amount of the developer prepared by using the obtained black toner in the same manner as in Example 1 was −27.9 μC / g.

Example 6 Instead of the compound represented by No. 1 in Example 2, N was used.
A yellow toner was obtained in the same manner as in Example 2 except that the compound shown in o.6 was used. The initial blow-off charge amount of the developer prepared from the obtained yellow toner in the same manner as in Example 1 was -35.1 μC / g.

Example 7 Instead of the compound represented by No. 2 in Example 3, N was used.
A red toner was obtained in the same manner as in Example 3 except that the compound shown in o.7 was used. The initial blow-off charge amount of the developer prepared in the same manner as in Example 1 from the obtained red toner was -31.4 μC / g.

Example 8 Instead of the compound represented by No. 3 in Example 4, N was used.
A blue toner was obtained in the same manner as in Example 4 except that the compound shown in o.11. The initial blow-off charge amount of the developer prepared from the obtained blue toner in the same manner as in Example 1 was −28.3 μC / g.

Example 9 Instead of the compound represented by No. 4 in Example 1, N was used.
A black toner was obtained in the same manner as in Example 1 except that the compound shown in o.9 was used. The initial blow-off charge amount of the developer prepared by using the obtained black toner in the same manner as in Example 1 was −29.6 μC / g.

Example 10 Instead of the compound represented by No. 1 in Example 2, N was used.
A yellow toner was obtained in the same manner as in Example 2 except that the compound shown in o.14 was used. The initial blow-off charge amount of the developer prepared from the obtained yellow toner in the same manner as in Example 1 was -32.2 μC / g.

Example 11 Instead of the compound represented by No. 2 in Example 3, N was used.
A red toner was obtained in the same manner as in Example 3 except that the compound shown in o.13 was used. The initial blow-off charge amount of the developer prepared in the same manner as in Example 1 from the obtained red toner was -31.5 μC / g.

Example 12 Instead of the compound shown in No. 3 in Example 4, N was used.
A blue toner was obtained in the same manner as in Example 4 except that the compound shown in o.10. The initial blow-off charge amount of the developer prepared from the obtained blue toner in the same manner as in Example 1 was −29.8 μC / g.

Example 13 In Example 1, instead of the compound represented by No. 4, N
A black toner was obtained in the same manner as in Example 1 except that the compound shown in 0.8 was used. The initial blow-off charge amount of the developer prepared by using the obtained black toner in the same manner as in Example 1 was −33.2 μC / g.

Example 14 Instead of the compound shown in No. 3 in Example 4, N was used.
A blue toner was obtained in the same manner as in Example 4 except that the compound shown in o.12. The initial blow-off charge amount of the developer prepared from the obtained blue toner in the same manner as in Example 1 was −29.8 μC / g.

[0045]

The charge control agent used in the present invention is excellent in mechanical friction and impact stability, temperature and humidity stability and the like, and is white or substantially colorless (does not affect coloring of the colorant). Thus, an electrophotographic toner having a clear image and continuously usable (color electrophotographic toner) is obtained.

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[Procedure amendment]

[Submission date] January 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Chemical 1]

Claims (1)

Claims: General formula <A> (wherein R ₁ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic ring (including a condensed ring), and R ₂
Represents a substituted or unsubstituted aromatic ring (including condensed ring),
M represents a trivalent metal, X ⁺ represents a cation, and n represents 1
Or an integer greater than that. ) A toner for electrophotography, comprising a compound represented by the formula (4) as a charge control agent. [Chemical 1]