Black toners containing infrared transmissive
View Patent ↗A toner formulation is disclosed comprising a binder, an IR absorbing colorant, and one or more infrared transmissive colorants, wherein the colorants are configured to provide a low reflectivity in the visible region of the spectrum and an intermediate reflectivity in the near infrared region of the spectrum when the toner is printed and fused onto paper.
1. A black toner formulation comprising:
a binder;
an infrared absorbing black colorant at a concentration of 0.25-2.0% by weight; and
a plurality of infrared transmissive colorants other than an infrared transmissive black colorant configured to provide a black color, wherein said plurality of infrared transmissive colorants comprise two or more of the following: blue pigment, cyan pigment, green pigment, yellow pigment, orange pigment, brown pigment, red pigment, magenta pigment and violet pigment;
wherein the toner formulation indicates the following spectral characteristics when fused on white paper at a L* value of 9-24:
% R 800-1200 nm ≧(0.00082× R vis+0.0078)(λ)+1.98 R vis−9.6
and
% R 800-1200 nm ≦(0.00082× R vis+0.0078)(λ)+1.98 R vis+10.0
wherein % R 800-1200 nm is the percent reflectance for a given wavelength (λ) in the range 800-1200 nm, Rvis is the average percent reflectance of the fused toner formulation for the 380-730 nm region of the spectrum, and the value of % R 800-1200 nm at said given wavelength is less than or equal to 70%; and
wherein the toner formulation has a chroma C* of less than or equal to 15.0 for all half-tone shade levels printed on white paper.
2. The toner formulation of claim 1 wherein the infrared absorbing black colorant comprises carbon black.
3. The toner formulation of claim 1 wherein said black color comprises a color having a chroma C* of less than or equal to 15.0 for all half-tone shade levels printed on white paper.
4. The toner formulation of claim 1 wherein said blue pigment absorbs at a wavelength of 510-700 nm, said cyan pigment absorbs at a wavelength of 550-700, said green pigment absorbs at a wavelength of 400-450 nm and 580-700 nm, said yellow pigment absorbs at a wavelength of 400-500 nm, said orange pigment absorbs at a wavelength of 400-550, said brown pigment absorbs at a wavelength of 400-580 nm, said red pigment absorbs at a wavelength of 400-580 nm, said magenta pigment absorbs at a wavelength of 500-580 nm, and said violet pigment absorbs at a wavelength of 500-600 nm.
5. The toner formulation according to claim 1 wherein said plurality of infrared transmissive colorants comprise one of the following color combinations:
(a) cyan and orange;
(b) cyan and red; and
(c) cyan, orange and red.
6. The toner formulation of claim 1 wherein said plurality of infrared transmissive colorants are present at a level of less than or equal to 15.0% by weight.
7. The toner formulation of claim 1 wherein said formulation exhibits a bulk reflectivity at about 940 nanometers, for toner particle sizes of 5.5 to 10 microns, of greater than 7.5% and less than or equal to 60%.
8. The toner formulation of claim 1 wherein said formulation is contained in an image forming apparatus.
9. The toner formulation of claim 1 wherein said formulation is contained in a printer cartridge.
10. The toner formulation according to claim 1 wherein said plurality of infrared transmissive colorants comprises pigment blue 15:3 and pigment red 185 at a ratio of about 1:2.