Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Reexamination Certificate
1999-09-21
2003-03-18
Rodee, Christopher (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
C430S108100, C430S108500
Reexamination Certificate
active
06534231
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a toner for developing electrostatic latent images in electrophotography, electrostatic recording, electrostatic printing, etc., and a charge control agent capable of controlling the amount of charges of said toner.
2. Description of the Prior Art
In copying machines, printers and other instruments based on electrophotography, various toners containing a coloring agent, a fixing resin and other substances are used to visualize the electrostatic latent image formed on the photoreceptor having a light-sensitive layer containing an organic or inorganic photoconductive substance. Such toners are required to show satisfactory performance in terms of chargeability, fixability, offset resistance, etc. Toner chargeability is a key factor in electrostatic latent image-developing systems. Thus, to appropriately control the chargeability of a toner, a charge control agent providing a positive or negative charge is often added to the toner.
In recent years, to achieve image quality improvement, while copying and printing speeds are increased, there have been increased demands for improved charge characteristics of toners, such as increased charge rise speeds, and for toner fixability on recording papers, such as excellent low-temperature fixability and offset resistance. Such demands for improved toner performance are intensifying with the advance in performance sophistication of copying machines and printers.
As charge control agents and charge control auxiliaries coping with these problems, a toner including eight phenol derivatives is disclosed in Japanese Patent Unexamined Publication No. 266462/1988. Also, Japanese Patent Unexamined Publication No. 230163/1990 discloses a toner containing a compound obtainable by dimerizing salicylic acid or a derivative thereof using a ligand group. Japanese Patent Unexamined Publication Nos. 237467/1991 and 139456/1992 disclose toners each containing an oligomer obtainable by condensing a particular p-phenylphenol compound and formaldehyde. Furthermore, Japanese Patent Unexamined Publication Nos. 216277/1993 and 216278/1993 disclose toners each containing a phenol derivative. Also, Japanese Patent Unexamined Publication No. 166691/1996 discloses a toner containing a condensed cyclic compound of a resorcinol and aldehyde.
However, the developers incorporating these toners remain unsatisfactory in terms of charge characteristics.
The present invention is directed to provide a charge control agent wherein the active ingredient is a compound having an excellent charge control property and a stable chemical structure, which is sharp in charge amount distribution, high in charge amount uniformity, excellent in general-purpose applicability (colorlessness or color lightness) and charge rise property, low in environmental dependency, and excellent in toner durability in multiple repeated use, and which does not adversely affect toner fixability and offset property when used in toners; and a toner for developing electrostatic images incorporating said charge control agent.
SUMMARY OF THE INVENTION
(1-1) The charge control agent of the present invention comprises as an active ingredient a metal compound obtainable by reacting one or two or more molecules of a compound having a phenolic hydroxy group and one or two or more molecules of a metal alkoxide. In this specification, “metal” include “semimetal” which is exemplified by Si, etc.
This reaction is a reaction between a phenolic hydroxy group (—OH) and a metal alkoxide (M(OR)
n
); the H of the phenolic hydroxy group (—OH) and some or all of the alkoxy groups (—OR) in the metal alkoxide cooperatively produce and liberate a corresponding alcohol (ROH) to metallize the phenolic hydroxy group.
The aforementioned metal alkoxide may be one represented by M(OR)
n
[in this formula, M is a metal, R is a linear or branched alkyl group, and n is an integer of 2-4].
(1-2) The charge control agent of the present invention contains as an active ingredient a metal compound represented by General Formula [I] below.
(Af)
x
(Ld)
y
[I]
In General Formula [I], each of x and y, whether identical or not, is an integer of 1 or 2 or more.
Af is a compound containing one or two or more aromatic hydrocarbon rings, each of which rings has one or two or more phenolic hydroxy groups or has no phenolic hydroxy group; provided that x is 2 or more, all Af are identical or some or all of them are mutually different.
Ld is (—O—), M(OR)
s
, wherein M is a metal, OR is an alkoxy group, r is an integer of 1 or more, s is an integer of 0 or more, and the sum of r and s is 1 or more provided that when y is 2 or more, all Ld are identical or some or all of them are mutually different. In different embodiments, one or two or more of r, M, R and s are mutually different.
Each Ld is bound to one or two or more aromatic hydrocarbon rings in Af via the aforementioned —O—; each Af is bound with one or more Ld, provided that when x is 2 or more, all Af are bound together via Ld.
The metal compound represented by General Formula [I] above can be obtainable by reacting one or two or more molecules of a compound having a phenolic hydroxy group and one or two or more molecules of a metal alkoxide.
With respect to the above formula, r is an integer of 1-4, s is an integer of 0-3, and the sum of r and s is 2-4; each Ld may be bound to 1-4 Af via —O—.
(2-1) In (1-1), the alkoxy group (OR) in the metal alkoxide is preferably a linear or branched alkoxy group having 1-8 carbon atoms (e.g., methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, nonyloxy, octyloxy).
(2-2) In (1-2), R is preferably a linear or branched alkyl group having 1-8 carbon atoms (e.g., methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isoamyl, octyl, tert-octyl, 2-ethylhexyl).
(3-1) The charge control agent of (1-1) or (2-1) is preferably a compound wherein at least one of the compounds having a phenolic hydroxy group has two or more aromatic hydrocarbon rings, such as benzene or naphthalene rings each having a phenolic hydroxy group, in its molecular structure.
(3-2) The charge control agent of (1-2) or (2-2) is preferably one wherein at least one of the Af contains two or more aromatic hydrocarbon rings, such as benzene or naphthalene rings to each of which a phenolic hydroxy group and/or Ld is bound.
(4-1) The charge control agent of (1-1), (2-1) or (3-1) is preferably a compound wherein at least one of the compounds each having a phenolic hydroxy group has three or more aromatic hydrocarbon rings, such as benzene or naphthalene rings each having a phenolic hydroxy group, in its molecular structure.
(4-2) The charge control agent of (1-2), (2-2) or (3-2) is preferably one wherein at least one of the Af contains three or more aromatic hydrocarbon rings, such as benzene or naphthalene rings to each of which a phenolic hydroxy group and/or Ld is bound.
(5-1) The charge control agent of (1-1), (2-1), (3-1) or (4-1) is preferably one wherein the compound having a phenolic hydroxy group is one or two or more selected from the group consisting of calixarenes or derivatives thereof, acyclic compounds obtainable by condensing phenols and aldehydes or derivatives of said acyclic compounds these acyclic compounds may be phenolic resins, calixresorcinarenes or derivatives thereof, bisphenols or derivatives thereof, and compounds obtainable by condensing bisphenols and aldehydes.
(5-2) The charge control agent of (1-2), (2-2), (3-2) or (4-2) is preferably one wherein Af is one or two or more selected from the group consisting of calixarenes or derivatives thereof, acyclic compounds obtainable by condensing phenols, and aldehydes or derivatives of said acyclic compounds (these acylic compounds may be phenolic resins), calixresorcinarenes or derivatives thereof, bisphenols or derivatives thereof, and condensates of bisphenols or derivatives thereof and aldehydes or derivatives of said condensates.
(6) The M in (1-1), (2-1), (3-1), (4-1), (5-1), (1
Isoda Akihide
Yamanaka Shun-ichiro
McGlew & Tuttle P.C.
Orient Chemical Industries Ltd.
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