Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Post imaging process – finishing – or perfecting composition...
Patent
1995-02-17
1996-06-25
Huff, Mark F.
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Post imaging process, finishing, or perfecting composition...
430110, G03G 9097
Patent
active
055298729
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to novel electrostatic toners containing a polymeric hinder and as charge stabilizer a 1:2 zirconium complex of azo dyes of the formula D--N.dbd.N--K, where D is derived from a diazo component D--NH.sub.2 selected from the group consisting of 2-amino -4-nitrophenol, 2-amino-5-nitrophenol, 2-aminophenol-4-sulfonamide, anthranilic acid and picramic acid and K is derived from a coupling component K--H selected from the group consisting of .beta.-naphthol, acetoacetanilide and 1-phenyl-3-methylpyrazol-5-one, and to the use of the abovementioned metal complexes as charge stabilizers in electrostatic toners.
Latent electrostatic image recordings are developed by inductively depositing the toner on the electrostatic image. The charge stabilizers stabilize the electrostatic charge of the toner. This makes the image stronger and crisper.
The charge stabilizers used have to meet various requirements: visible image. crisp, uniform image.
U.S. Pat No. 4,623,606, EP-A-144 377, EP-A-180 655, EP-A-393 479, JP-A-129 358/1987 and JP-A-236 567/1990 disclose electrostatic toners containing metal complexes of azo dyes as charge stabilizers.
However, the prior art charge stabilizers have frequently been found to have defects in their property profile.
Similarly DE-A-2 317 469, EP-A-251 326, EP-A-255 925, JP-A-170 657/1988 and EP-A-503 861 describe electrostatic toners which contain 1:2 metal complexes of azo dyes as charge stabilizers, but the complexes are derived from the metals chromium, manganese, iron or cobalt.
It is an object of the present invention to provide a novel electrostatic toner equipped with charge stabilizers having advantageous application properties.
We have found that this object is achieved by the electrostatic toners defined at the beginning.
The 1:2 zirconium complexes of azo dyes are preferably the symmetrical 1:2 complexes.
The proportion of the 1:2 metal complex dye in the electrostatic toner is in general from 0.01 to 10% by weight, based on the weight of the toner.
The polymeric binders present in the novel electrostatic toners are known. They are in general thermoplastic and have a softening point of from 40.degree. to 200.degree. C., preferably of 50.degree. to 130.degree. C., in particular of from 65.degree. to 115.degree. C. Examples of polymeric binders are polystyrene, copolymers of styrene with an acrylate or methacrylate, copolymers of styrene with butadiene and/or acrylonitrile, polyacrylates, polymethacrylates, copolymers of an acrylate or methacrylate with vinyl chloride or vinyl acetate, polyvinyl chloride, copolymers of vinyl chloride with vinylidene chloride, copolymers of vinyl chloride with vinyl acetate, polyester resins, epoxy resins, polyamides and polyurethanes.
In addition to the abovementioned 1:2 metal complex dyes and the polymeric binders, the toners of the invention may contain known amounts of colorants, a magnetically attractable material, waxes and free-flow agents.
The colorants can be organic dyes or pigments, such as nigrosine, aniline blue, 2,9-dimethylquinacridone, C.I. Disperse Red 15 (C.I. 6010), C.I. Solvent Red 19 (C.I. 26 050), C.I. Pigment Blue 15 (C.I. 74 160), C.I. Pigment Blue 22 (C.I. 69 810) or C.I. Solvent Yellow 16 (C.I. 12 700), or inorganic pigments, such as carbon black, red lead, yellow lead oxide or chromium yellow. In general, the amount of colorant present in the toner does not exceed 15% by weight, based on the weight of the toner.
The magnetically attractable material can be for example iron, nickel, chromium oxide, iron oxide or a ferrite of the formula MeFe.sub.2 O.sub.4 where Me is a divalent metal, e.g. iron, cobalt, zinc, nickel or manganese.
The 1:2 metal complex dyes can be obtained in a conventional manner, for example by first using an azo dye of the formula respective chlorides or sulfates or else the corresponding zirconyl compounds) to prepare the 1:1 metal complex and reacting it with an azo dye of the formula 1:2 complex.
As mentioned earlier, however, it is also possible to prepare the 1:2 metal co
REFERENCES:
patent: 4265990 (1981-05-01), Stolka et al.
patent: 4623606 (1986-11-01), Ciccarelli
patent: 4824751 (1989-04-01), Matuura et al.
patent: 5164283 (1992-11-01), Niimura et al.
patent: 5439770 (1995-08-01), Taya et al.
Beck Karin H.
Dyllick-Brenzinger Rainer
Grychtol Klaus
BASF - Aktiengesellschaft
Huff Mark F.
LandOfFree
Electrostatic toners containing a metal complex dye as charge st does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrostatic toners containing a metal complex dye as charge st, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrostatic toners containing a metal complex dye as charge st will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2187874