U.S. patent application number 09/986108 was filed with the patent office on 2002-03-07 for coated photographic papers.
This patent application is currently assigned to XEROX Corporation. Invention is credited to Gardner, Sandra J., Malhotra, Shadi L., McAneney, T. Brian, Naik, Kirit N., Sharp, James J., Yulo, Fernando P., Zwartz, Edward G..
Application Number | 20020028339 09/986108 |
Document ID | / |
Family ID | 21916056 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020028339 |
Kind Code |
A1 |
McAneney, T. Brian ; et
al. |
March 7, 2002 |
Coated photographic papers
Abstract
A process forms images on a substrate, and develops the images
with toner. The substrate has a coating of a polymer that enables
images of uniform gloss.
Inventors: |
McAneney, T. Brian;
(Burlington, CA) ; Zwartz, Edward G.;
(Mississauga, CA) ; Naik, Kirit N.; (Mississauga,
CA) ; Yulo, Fernando P.; (Mississauga, CA) ;
Gardner, Sandra J.; (Oakville, CA) ; Sharp, James
J.; (Burlington, CA) ; Malhotra, Shadi L.;
(Mississauga, CA) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC.
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
XEROX Corporation
Stamford
CT
|
Family ID: |
21916056 |
Appl. No.: |
09/986108 |
Filed: |
November 7, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09986108 |
Nov 7, 2001 |
|
|
|
09706887 |
Nov 2, 2000 |
|
|
|
09706887 |
Nov 2, 2000 |
|
|
|
09041353 |
Mar 12, 1998 |
|
|
|
6177222 |
|
|
|
|
Current U.S.
Class: |
428/480 ;
428/481 |
Current CPC
Class: |
B41M 5/5272 20130101;
G03G 7/0046 20130101; Y10T 428/31786 20150401; G03G 7/0006
20130101; Y10T 428/3179 20150401 |
Class at
Publication: |
428/480 ;
428/481 |
International
Class: |
B32B 027/06 |
Claims
What is claimed is:
1. A paper comprising: a substrate; and a thin polyester coating
over the substrate, wherein the paper enables the generation of
toner images with a substantially uniform gloss throughout the
images on the coating.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention is directed to papers, and more
specifically, to papers for electrography, such as xerographic
compatible photographic papers, that is for example coated papers
containing a supporting substrate derived from, for example,
natural cellulose and having the appearance of a photographic base
paper with certain coatings thereover and thereunder, and the use
of these papers in imaging, especially xerographic processes and
digital imaging processes, and wherein uniform high gloss images
can be obtained. More specifically, the present invention is
directed to processes for achieving gloss uniformity of xerographic
prints and which gloss is similar or equivalent to silver halide
glossy prints or high quality glossy offset prints in color
intensity and gloss uniformity with coated papers to which has been
applied a substantially clear coating of a polyester resin, such as
a low melt branched polyester, like the known SPAR polyesters,
reference U.S. Pat. No. 3,590,000, the disclosure of which is
totally incorporated herein by reference. The thin, for example
from about 1 to about 10 microns, and preferably about 7 microns,
or other suitable thickness, coating, especially the polyester
coating, absorbs the fused toner particles thereby resulting in a
smooth surface and high uniform gloss, and which gloss is less
dependent on the degree of toner coverage. In embodiments, the
coated photographic papers are capable of recording clear,
brilliant, glossy images of high optical density, and with
lightfastness values of greater than about 98 percent, and more
specifically, from about 98 to about 100 percent for dry colored,
such as pigmented toners, waterfastness values of about 100 percent
and comparable in look and feel to conventional color photographic
camera prints.
PRIOR ART
[0002] Certain polyester coated papers are known, reference for
example U.S. Pat. Nos. 5,627,128; 5,534,479 and 4,692,636.
[0003] There is disclosed in U.S. Pat. No. 4,663,216 a synthetic
paper comprised of: (1) a multilayer support, (2) a layer of a
transparent film of a thermophotographic resin free from an
inorganic fine powder formed on one surface of the support (1), and
(3) a primer layer of a specific material, reference the Abstract
of the Disclosure for example. The support (1) comprises (1a) a
base layer of a biaxially stretched film of a thermophotographic
resin, a surface and a back layer (1b), and (1c) composed of a
monoaxially stretched film of a thermophotographic resin containing
8 to 65 percent by weight of an inorganic fine powder.
[0004] Further, there is disclosed in U.S. Pat. No. 4,705,719 a
synthetic paper of multilayer resin film comprising a base layer
(1a) of a biaxially stretched thermophotographic resin film, and a
laminate provided on at least one of opposite surfaces of the base
layer, the laminate including a paper-line layer (1b) and a surface
layer (1c), the paper like layer containing a uniaxially stretched
film of thermophotographic resin containing 8 to 65 percent by
weight of inorganic fine powder, and wherein the surface layer
contains an uniaxially stretched film of a thermophotographic
resin.
[0005] In U.S. Pat. No. 4,868,581, there is disclosed an opaque
paper-based receiving material for ink jet printing which comprises
a poly(olefin)coated paper overcoated with an ink-receiving layer
which contains a mixture of gelatin and starch. Reportedly, these
receiving materials exhibit gloss, good color density and are
smudge resistant. Although such receiving materials, when
pictorially imaged with an ink jet printing device, may enable
images acceptable in appearance and feel, the images thereon are
still not believed to be of the same high quality that is
customarily expected from and exhibited by photographic prints.
[0006] Also, there is disclosed in U.S. Pat. No. 4,903,039 an
opaque paper-based receiving material for ink jet printing, which
papers comprise a poly(olefin)-coated paper overcoated with an
ink-receiving layer which contains an aqueous dispersion of a
polyester ionomer, namely a
poly[cyclohexylenedimethylene-co-oxydiethylene
isophthalate-co-malonate- -co-sodiosulfo benzenedicarboxylate],
dispersed in vinyl pyrrolidone polymer.
[0007] Further, there is disclosed in U.S. Pat. No. 4,903,040 an
opaque paper-based receiving material for ink jet printing which
comprises a poly(olefin)-coated paper overcoated with an
ink-receiving layer which contains an aqueous dispersion of a
polyester ionomer, namely a poly[cyclohexylenedimethylene
isophthalate-co-sodiosulfobenzene dicarboxylate], dispersed in
vinyl pyrrolidone polymer.
[0008] Moreover, there is disclosed in U.S. Pat. No. 4,903,041 an
opaque paper-based receiving material for ink jet printing which
comprises a poly(olefin)-coated paper overcoated with an
ink-receiving layer which contains an aqueous dispersion of a
polyester ionomer, namely a
poly[cyclohexylenedimethylene-co-xylyleneterephthalate-co-malonate-cosodi-
oiminobis(sulfonylbenzoate], dispersed in vinyl pyrrolidone
polymer.
[0009] U.S. Pat. No. 5,451,458, the disclosure of which is totally
incorporated herein by reference, discloses a recording sheet which
comprises (a) a substrate; (b) a coating on the substrate which
comprises (1) a binder selected from the group consisting of (A)
polyesters; (B) polyvinyl acetals; (C) vinyl alcohol-vinyl acetal
copolymers; (D) polycarbonates; and (E) mixtures thereof; and (2)
an additive having a melting point of less than about 65.degree. C.
and a boiling point of more than about 150.degree. C. and
including, for example, furan derivatives; and developing the
latent image with a toner which comprises a colorant and a resin
selected from the group consisting of (A) polyesters; (B) polyvinyl
acetals; (C) vinyl alcohol-vinyl acetal copolymers; (D)
polycarbonates; and (E) mixtures thereof; and (3) transferring the
developed image to a recording sheet which comprises (a) a
substrate; (b) a coating on the substrate which comprises (1) a
binder selected from the group consisting of (A) polyesters; (B)
polyvinyl acetals; (C) vinyl alcohol-vinyl acetal copolymers; (D)
polycarbonates; and (E) mixtures thereof.
[0010] While the above materials and processes may be suitable for
their intended purposes; a need remains for photographic papers
particularly suitable for use in electrophotographic applications.
In addition, a need remains for photographic papers which can be
employed with xerographic dry toners so that the heat and energy
required for properly fusing the toner to the photographic paper is
reduced by about 14 percent allowing the toner to be fused, for
example, at 150.degree. C. instead of the conventional about
175.degree. C. Further, a need remains for photographic papers
which can be employed with xerographic toners, and wherein jamming
of the photographic papers in the fusing apparatus is reduced.
Additionally, there is a need for photographic papers suitable for
use in electrophotographic applications with reduced energy
demands, by about 14 percent, allowing the toner to be fused at
150.degree. C. instead of the usual in some instances of about 175
to about 180.degree. C., and reduced jamming, and wherein the
photographs also exhibit acceptable image quality, excellent image
fix to the paper, and more importantly, high uniform gloss similar
to silver halide prints which typically have perfectly uniform high
gloss levels of about 70 GU to about 100 GU as measured by a
75.degree. Glossmeter.
SUMMARY OF THE INVENTION
[0011] It is a feature of the present invention to provide
photographic papers with many of the advantages indicated
herein.
[0012] It is another feature of the present invention to provide
photographic papers, inclusive of xerographic photopapers
particularly suitable for use in electrophotographic imaging
systems; and also wherein there are enabled developed images with
uniform gloss, and wherein, for example, the coating on the paper,
such as the polyester illustrated herein, absorbs the fused toner
particles thereby resulting in a smooth image surface.
[0013] It is yet another feature of the present invention to
provide photographic papers which can be employed with xerographic
dry toners, and wherein the heat and energy required for fusing the
toner to the photographic paper is reduced, and wherein there are
obtained images with uniform gloss throughout the visible image and
which gloss is equivalent to, or similar to silver halide
prints.
[0014] It is still another feature of the present invention to
provide photographic papers which can be selected with xerographic
dry toners, and wherein jamming of the photographic papers in the
fusing apparatus is minimized.
[0015] Another feature of the present invention is to provide
photographic papers suitable for use in electrophotographic,
especially xerographic, imaging methods with reduced fusing energy
requirements and reduced jamming, wherein the photographs also
exhibit acceptable image quality, excellent image fix to the
photographic papers, and superior gloss.
[0016] The present invention relates to a coated photographic paper
comprised of (1) a substrate, such as a cellulosic substrate, and a
coating thereover of a polyester or similar polymer and which
coating is preferably thin, for example about 1 to about 15, or
from about 5 to about 10 microns, as measured by a thickness gauge,
model MT-12 from Heidenhain, and wherein there is enabled uniform
glossy images with such papers. More specifically, there are
provided in accordance with the present invention processes for
generating high, for example, from about 50 to about 100 gloss
units as measured with a 75.degree. Glossmeter, Glossgard from
Pacific Scientific, and which gloss is uniform, that is it does not
significantly vary, or change on the image, or wherein the
differential gloss level is reduced or minimized, that is for
example a gloss variance of about 40 GU to about 80 GU is avoided
with the invention polyester coated papers. By uniform gloss is
meant, for example, a gloss variation of between about 20 GU to
about 10 GU and preferably a gloss variation of between about 10 GU
to about 0 GU.
[0017] Aspects of the present invention relate to a process which
comprises forming an image on a substrate, and developing the image
with toner, and wherein the substrate contains a coating of a
polyester and there is enabled images of uniform gloss; a process
wherein the polyester coating is of a thickness of about 1 to about
15 microns; a process wherein the polyester coating is of a
thickness of about 7 microns; a process wherein the polyester
coating is a poly(propoxylated bisphenol A fumarate) resin, a
polyester resin of a terephthalic acid, bisphenol-A-ethylene oxide
adduct, cyclohexane dimethanol or a low, from about 1,000 to about
50,000 M.sub.w, molecular weight, branched copolyester formed from
isophthalic and nonanedioic acids with diols and triols; a process
wherein the gloss value is high, and wherein said high is between
about 50 GU to about 100 GU as measured by a 75.degree. Glossmeter;
a process wherein the gloss value is high, and wherein said high is
between about 80 GU to about 100 GU as measured by a 75.degree.
Glossmeter, and which gloss is the same or similar throughout the
entire developed image; a process wherein the substrate is of a
thickness of from about 80 microns to about 200 microns; a process
wherein the uniform high gloss resides in substantially no gloss
difference in the range of gloss of 70 GU to 100 GU, and wherein
said gloss is equivalent to or similar to silver halide prints; a
process wherein the substrate is a cellulosic substrate and is
comprised of alkaline sized and acid sized blends of hardwood kraft
and softwood kraft fibers, which blends contain from about 10
percent to about 90 percent by weight of softwood and from about 90
to about 10 percent by weight of hardwood; a process wherein the
sizing value of the cellulosic substrate is from about 200 seconds
and about 1,100 seconds, the porosity is from about 50 to about 300
mil/minute, and the thickness is from about 50 microns and about
250 microns; an imaging process which comprises (1) generating an
electrostatic latent image on an imaging member in an imaging
apparatus; (2) developing the latent image with a toner comprised
of a colorant and a resin, such as a known thermoplastic resin, and
more specifically, binder resin selected from the group consisting
of (A) polyesters, (B) styrene-butadiene copolymers, (C)
styrene-acrylate copolymers, and (D) styrene-methacrylate
copolymers; (3) transferring the developed image to a coated paper
and wherein the coating is a polyester; and (4) fixing the image
onto the paper with heat and pressure; an imaging process wherein
the images resulting on a polyester coated substrate, such as paper
possess an optical density between about 1.45 to about 1.56 for a
black toner, between about 1.35 to about 1.40 for a cyan toner,
between about 1.23 to about 1.30 for a magenta toner, and between
about 0.87 to about 0.89 for a yellow toner; an imaging process
wherein the colorant is a pigment and the resin is a polyester; an
imaging process wherein the colorant is a dye; a process which
comprises forming an image on a coated substrate, and developing
the image with a toner, and wherein the substrate contains a
polymer coating and there is enabled images of a high uniform
gloss; a process wherein the coating is a polyester; a process
wherein the substrate is paper or coated reproduction paper having
a thickness in the range of about 80 microns to about 200 microns;
a process wherein the toner is comprised of resin and colorant; a
process wherein the resin is a polyester of poly(propoxylated
bisphenol A fumarate), a polyester resin comprised of terephthalic
acid/bisphenol A ethylene adduct/cyclohexane dimethanol or low
molecular weight, branched copolyesters formed from isophthalic and
nonanedioic acids with diols and triols; a process wherein the
toner is comprised of resin and colorant; a photopaper comprised of
a substrate and a thin coating thereover, and wherein said thin
coating is from about 1 to about 20 microns, and wherein a
photopaper is selected for the generation of images with a uniform
gloss; a photopaper wherein said coating is a polyester wherein
said images are developed with a toner of resin and colorant, and
wherein said polyester possesses a lower melt viscosity than the
toner resin at the temperature used to fuse said images, and
wherein the melt viscosity of the polyester coating is from about
500 poise to about 1,000 poise, and the melt viscosity of the toner
resin is from about 4,000 poise to about 5,000 poise; a process
wherein the gloss variation is between about 20 GU to about 10 GU,
or the gloss variation is between about 10 GU to about 0 GU as
measured by a 75.degree. Glossmeter; a process wherein the gloss
variation is between about 10 GU to about 0 GU as measured by a
75.degree. Glossmeter, a process wherein the toner image is
absorbed into the substrate coating during the fusing process; a
process which comprises forming an image on a substrate, and
developing the image with toner, and wherein the substrate contains
a coating of a polyester, an imaging process which comprises (1)
generating an electrostatic latent image on an imaging member in an
imaging apparatus; (2) developing the latent image with a toner
which comprises a colorant and a resin; (3) transferring the
developed image to a polyester coated substrate; and (4) fixing the
image onto the paper with heat and pressure; and a process wherein
polyester diols are 2,2,4,4-tetraalkyl-1,3-cyclobutane diol,
1,4-butane diol, or 1,3-propane diol; and wherein the triols are
2-(hydroxy methyl)1,3-propane diol, 1,1,1 (trishydroxy methyl)
ethane, 1,2,4-butane triol, or 1,2,3-propane triol.
[0018] The substrates selected are primarily coated papers
comprised of a photopaper of a base sheet and commercially
available as ink jet, off set or xerographic papers, and wherein
there is applied to the paper by solvent coating thereof a polymer,
preferably a polyester, and wherein there is selected a dry toner
for development and more specifically, a toner containing a
polyester resin. The coating, such as the polyester, applied to the
paper preferably possesses a lower melt viscosity at the image
fusing temperature of, for example, about 140.degree. C. to about
170.degree. C. than the toner resin, especially toner polyester
resin. By lower melt viscosity is meant, for example, a viscosity
of, for example, about 500 poise to about 1,000 poise and
preferably about 500 poise to about 700 poise as measured by a
Rheometrics Dynamic Mechanical Spectrometer. The coated substrate,
such as paper, is more specifically comprised of a coated
reproduction paper where the manufacturer's coating is believed to
comprise from about 70 percent by weight to about 90 percent by
weight of a pigment, such as Kaolin clay, calcined clays, calcium
carbonate, titanium dioxide, talc or alumina trihydrate, and about
5 to about 30 weight percent of a binder, such as starch,
poly(vinyl alcohol), styrene-butadiene, polyacrylate or poly(vinyl
acetate). These coated reproduction papers are available from paper
manufacturers, such as the Champion Paper Company, Consolidated
Papers Inc., Asahi Glass Company and Schoeller Papers Inc. Suitable
coated reproduction papers have thicknesses ranging from, for
example, about 80 microns to about 200 microns. The coating, such
as preferably the polyester coating, is more specifically comprised
of a poly(propoxylated bisphenol A fumarate) resin, a polyester
resin comprised of poly(terephthalic acid bisphenol-A-ethylene
oxide adduct), cyclohexane dimethanol or a low, for example from
about 1,000 to about 50,000, and preferably about 20,000 M.sub.w
molecular weight, branched copolyester formed from isophthalic and
nonanedioic acids with diols and triols, such as resin, is Vitel
5833B polyester available from the Bostik Company. Other suitable
coatings may be selected, such as known polyesters, inclusive of
the polyesters of, for example, U.S. Pat. No. 3,590,000.
[0019] Any suitable substrate can be employed; for example, the
substrate can be comprised of sized blends of hardwood kraft and
softwood kraft fibers, which blends contain from about 10 percent
to about 90 percent by weight of softwood and from about 90 to
about 10 percent by weight of hardwood. Examples of hardwood
include Seagull W dry bleached hardwood kraft preferably present,
for example, in one embodiment in an amount of about 70 percent by
weight. Examples of softwood include La Toque dry bleached softwood
kraft present, for example, in one embodiment in an amount of 30
percent by weight. These sized substrates may also contain pigments
in effective amounts of from about 1 to about 60, and preferably
from about 1 to about 25 percent by weight, such as clay (available
from Georgia Kaolin Company, Astro-fil 90 clay, Engelhard Ansilex
clay), titanium dioxide (available from Tioxide Company--Anatase
grade AHR), calcium silicate CH-427-97-8, XP-974 (J. M. Huber
Corporation), and the like. Also, the sized substrates may contain
various effective amounts of sizing chemicals (for example from
about 0.25 percent to about 25 percent by weight of pulp), such as
Mon size (available from Monsanto Company), Hercon-76 (available
from Hercules Company), Alum (available from Allied Chemicals as
Iron free alum), and retention aid (available from Allied Colloids
as Percol 292). The sizing values of papers, including the
commercial papers that can be selected for the present invention in
embodiments thereof, vary between, for example, about 0.4 second to
about 4,685 seconds, and papers in the sizing range of about 50
seconds to about 300 seconds are preferred, primarily to decrease
costs. The porosity values of the substrates, which are preferably
porous, vary from about 100 to about 1,260 mil/minute and
preferably from about 100 to about 600 mil/minute to permit, for
example, the use of these papers for various printing technologies,
such as thermal transfer, liquid toner development, xerography, ink
jet processes, and the like.
[0020] Illustrative examples of commercially available, internally
and externally (surface) sized substrates that may be selected for
the present invention, and which are treated with a desizing agent
dispersed in an optional binder with a substrate thickness of, for
example, from about 50 microns to about 200 microns and preferably
of a thickness of from about 100 microns to about 175 microns
include Diazo papers, offset papers such as Great Lakes offset,
recycled papers such as Conservatree, office papers such as
Automimeo, Eddy liquid toner paper and copy papers from companies
such as Nekoosa, Champion, Wiggins Teape, Kymmene, Modo, Dorntar,
Veitsiluoto and Sanyo with Xerox 4024.TM. papers and sized calcium
silicate-clay filled papers being particularly preferred in view of
their availability, and low print through.
[0021] The Hercules size values recited herein were measured on the
Hercules sizing tester (available from Hercules Incorporated) as
described in TAPPI STANDARD T-530 pm-83, issued by the Technical
Association of the Pulp and Paper Industry. This method is closely
related to the widely used ink flotation test. The TAPPI method has
the advantage over the ink flotation test of detecting the end
point photometrically. The TAPPI method employs a mildly acidic
aqueous dye solution as the penetrating component to permit optical
detection of the liquid front as it moves through the paper sheet.
The apparatus determines the time required for the reflectance of
the sheet surface not in contact with the penetrant to drop to a
predetermined (80 percent) percentage of its original
reflectance.
[0022] The coated xerographic photographic papers of the present
invention exhibit reduced curl upon being printed with toners.
Generally, the term "curl" refers to the distance between the base
line of the arc formed by recording sheet when viewed in
cross-section across its width (or shorter dimension, for example
8.5 inches in an 8.5 by 11 inch sheet, as opposed to length, or
longer dimension, for example 11 inches in an 8.5 by 11 inch sheet)
and the midpoint of the arc. To measure curl, a sheet can be held
with the thumb and forefinger in the middle of one of the long
edges of the sheet (for example, in the middle of one of the 11
inch edges in an 8.5 by 11 inch sheet) and the arc formed by the
sheet can be matched against a pre-drawn standard template
curve.
[0023] The lightfastness values of the xerographic images were
measured in the Mark-V Lightfastness Tester obtained from Microscal
Company, London, England.
[0024] The gloss values recited herein were obtained on a
75.degree. Glossmeter, Glossgard, from Pacific Scientific
(Gardner/Neotec Instrument Division). The edge raggedness values
were measured using an Olympus microscope equipped with a camera
capable of enlarging the recorded xerographic images. The edge
raggedness value is the distance in millimeters for the intercolor
bleed on a checkerboard patter.
[0025] The optical density measurements recited herein were
obtained on a Pacific Spectrograph Color System. The system
consists of two major components, an optical sensor and a data
terminal. The optical sensor employs a 6 inch integrating sphere to
provide diffuse illumination and 2 degrees viewing. This sensor can
be used to measure both transmission and reflectance samples. When
reflectance samples are measured, a specular component may be
included. A high resolution, full dispersion, grating monochromator
was used to scan the spectrum from 380 to 720 nanometers. The data
terminal features a 12 inch CRT display, numerical keyboard for
selection of operating parameters, and the entry of tristimulus
values, and an alphanumeric keyboard for entry of product standard
information. The print through value as characterized by the
printing industry is Log base 10 (reflectance of a single sheet of
unprinted paper against a black background/reflectance of the back
side of a black printed area against a black background) measured
at a wavelength of 560 nanometers.
[0026] A number of different toners can be selected. Illustrative
examples of suitable toner binders are, for example, resins such as
polyesters, polyamides, polyolefins, styrene acrylates, styrene
methacrylate, styrene butadienes, crosslinked styrene polymers,
epoxies, polyurethanes, vinyl resins, including homopolymers or
copolymers of two or more vinyl monomers; and polymeric
esterification products of a dicarboxylic acid and a diol
comprising a diphenol. Vinyl monomers include styrene,
p-chlorostyrene, unsaturated mono-olefins such as ethylene,
propylene, butylene, isobutylene and the like; saturated
mono-olefins such as vinyl acetate, vinyl propionate, and vinyl
butyrate; vinyl esters like esters of monocarboxylic acids
including methyl acrylate, ethyl acrylate, n-butylacrylate,
isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, phenyl
acrylate, methyl methacrylate, ethyl methacrylate, and butyl
methacrylate; acrylonitrile, methacrylonitrile, acrylamide;
mixtures thereof; and the like, styrene butadiene copolymers with a
styrene content of from about 70 to about 95 weight percent. In
addition, crosslinked resins, including polymers, copolymers,
homopolymers of the aforementioned styrene polymers may be
selected.
[0027] As one toner resin, there are selected the esterification
products of a dicarboxylic acid and a diol comprising a diphenol.
These resins are illustrated in U.S. Pat. No. 3,590,000, the
disclosure of which is totally incorporated herein by reference.
Other specific toner resins include styrene/methacrylate
copolymers, and styrene/butadiene copolymers; PLIOLITES.RTM.;
suspension polymerized styrene butadienes, reference U.S. Pat. No.
4,558,108, the disclosure of which is totally incorporated herein
by reference; polyester resins obtained from the reaction of
bisphenol A and propylene oxide; followed by the reaction of the
resulting product with fumaric acid, and branched polyester resins
resulting from the reaction of dimethylterephthalate,
1,3-butanediol, 1,2-propanediol, and pentaerythritol,
styrene-acrylates, and mixtures thereof, Also, waxes with a
molecular weight, M.sub.w of from about 1,000 to about 20,000, such
as polyethylene, polypropylene, and paraffin waxes, can be included
in, or on the toner compositions as fuser roll release agents.
Also, it is preferred that the toner resin be the same as, or
similar to the substrate coating.
[0028] The resin particles are present in a sufficient, but
effective amount, for example from about 70 to about 90 weight
percent. Thus, when 1 percent by weight of a charge enhancing
additive is present, and 10 percent by weight of pigment or
colorant, such as carbon black, is contained therein, about 89
percent by weight of resin is selected.
[0029] Numerous well known suitable colorants, such as pigments or
dyes, can be selected as the colorant for the toner particles
including, for example, carbon black, nigrosine dye, aniline blue,
magnetite, or mixtures thereof. The colorant, which can be carbon
black, cyan, magenta, yellow, red, green, blue, brown, pink,
orange, mixtures thereof and the like should be present in a
sufficient amount to render the toner composition colored.
Generally, the colorant is present in amounts of from about 1
percent by weight to about 20 percent by weight, and preferably
from about 2 to about 10 weight percent based on the total weight
of the toner composition;
[0030] however, lesser or greater amounts can be selected.
Illustrative examples of magentas include, for example,
2,9-dimethyl-substituted quinacridone and anthraquinone dye
identified in the Color Index as CI 60710, CI Dispersed Red 15,
diazo dye identified in the Color Index as CI 26050, CI Solvent Red
19, and the like. Illustrative examples of cyans include copper
tetra-4-(octadecyl sulfonamido) phthalocyanine, X-copper
phthalocyanine pigment listed in the Color Index as CI 74160, CI
Pigment Blue, and Anthrathrene Blue, identified in the Color Index
as CI 69810, Special Blue X-2137, and the like; while illustrative
examples of yellows are diarylide yellow 3,3-dichlorobenzidene
acetoacetanilides, a monoazo pigment identified in the Color Index
as CI 12700, CI Solvent Yellow 16, a nitrophenyl amine sulfonamide
identified in the Color Index as Foron Yellow SE/GLN, CI Disposed
Yellow 33, 2,5-dimethoxy-4-sulfonanilide
phenylazo-4'-chloro-2,5-dimethoxy acetoacetanilide, and Permanent
Yellow FGL.
[0031] When the colorant particles are comprised of magnetites,
thereby enabling- single component toners in some instances, which
magnetites are a mixture of iron oxides (FeO.Fe.sub.2O.sub.3)
including those commercially available as MAPICO BLACK.RTM., they
are present in the toner composition in an amount of from about 10
percent by weight to about 70 percent by weight, and preferably in
an amount of from about 10 percent by weight to about 50 percent by
weight. Mixtures of carbon black and magnetite with from about 1 to
about 15 weight percent of carbon black, and preferably from about
2 to about 6 weight percent of carbon black, and magnetite, such as
MAPICO BLACK.RTM., in an amount of, for example, from about 5 to
about 60, and preferably from about 10 to about 50 weight percent
can be selected.
[0032] There can also be blended with the toner compositions of the
present invention external additive particles including flow aid
additives, which additives are usually present on the surface
thereof. Examples of these additives include colloidal silicas such
as those available from DeGussa Chemicals, AEROSIL.RTM., metal
salts and metal salts of fatty acids inclusive of zinc stearate,
aluminum oxides, titanium oxides, titanates like stronium titanate,
cerium oxides, and mixtures thereof, which additives are each
generally present in an amount of from about 0.1 percent by weight
to about 5 percent by weight, and preferably in an amount of from
about 0.1 percent by weight to about 1 percent by weight. Several
of the aforementioned additives are illustrated in U.S. Pat. Nos.
3,590,000 and 3,800,588, the disclosures of which are totally
incorporated herein by reference.
[0033] Moreover, there can be included in the toner compositions of
the present invention low, such as from about 1,000 to about 20,000
M.sub.w, molecular weight waxes, such as, polypropylenes and
polyethylenes commercially available from Allied Chemical and
Petrolite Corporation, Epolene N-15 commercially available from
Eastman Chemical Products, Inc., Viscol 550-P, a low weight average
molecular weight polypropylene available from Sanyo Kasei K. K.,
and similar materials, The commercially available polyethylenes
selected have a molecular weight of from about 1,000 to about
1,500, while the commercially available polypropylenes utilized for
the toner compositions of the present invention are believed to 20
have a molecular weight of from about 4,000 to about 5,000. Many of
the polyethylene and polypropylene compositions useful in the
present invention are illustrated in British Patent No. 1,442,835,
and U.S. Pat. No. 5,229,242, the disclosures of which are totally
incorporated herein by reference.
[0034] The low molecular weight wax materials are present in the
toner composition of the present invention in various amounts,
however, generally these waxes are present in the toner composition
in an amount of from about 1 percent by weight to about 15 percent
by weight, and preferably in an amount of from about 2 percent by
weight to about 10 percent by weight.
[0035] For the formulation of developer compositions, there are
mixed with the toners carrier components, particularly those that
are capable of triboelectrically assuming an opposite polarity to
that of the toner composition. Accordingly, the carrier particles
can be selected to be, for example, of a negative polarity enabling
the toner particles, which are positively charged, to adhere to and
surround the carrier particles. Illustrative examples of carrier
particles include iron powder, steel, nickel, iron, ferrites,
including copper zinc ferrites, and the like. Additionally, there
can be selected as carrier particles-nickel berry carriers as
illustrated in U.S. Pat. No. 3,847,604, the disclosure of which is
totally incorporated herein by reference. The selected carrier
particles can be used with or without a coating, the coating
generally containing terpolymers of styrene, methylmethacrylate,
and a silane, such as triethoxy silane, reference U.S. Pat. Nos.
3,526,533 and 3,467,634, the disclosures of which are totally
incorporated herein by reference; polymethyl methacrylates; other
known coatings; and the like. The carrier particles may also
include in the coating, which coating can be present in one
embodiment in an amount of from about 0.1 to about 3 weight
percent, conductive substances, such as carbon black, in an amount
of from about 5 to about 30 percent by weight. Polymer coatings not
in close proximity in the triboelectric series can also be
selected, reference U.S. Pat. No. 4,937,166 and U.S. Pat. No.
4,935,326, the disclosures of which are totally incorporated herein
by reference, including for example KYNAR.RTM. and
polymethylmethacrylate mixtures (40/60). Coating weights can vary
as indicated herein; generally, however, from about 0.3 to about 2,
and preferably from about 0.5 to about 1.5 weight percent coating
weight is selected.
[0036] The diameter of the carrier particles, preferably spherical
in shape, is generally from about 50 microns to about 1,000, and
more specifically, from about 75 to about 150 microns thereby
permitting them to possess sufficient density and inertia to avoid
adherence to the electrostatic images during the development
process. The carrier component can be mixed with the toner
composition in various suitable combinations, however, best results
are obtained when about 1 to 5 parts per toner to about 100 parts
to about 200 parts by weight of carrier area selected.
[0037] Specific embodiments of the invention will now be described
in detail. These Examples are intended to be illustrative, and the
invention is not limited to the materials, conditions, or process
parameters set forth in these embodiments. All parts and
percentages are by weight unless otherwise indicated. Comparative
Examples and data are also provided.
[0038] The variation in gloss level of a xerographic color print
can be quantified by using a specially devised differential gloss
test target. The test target consists of an 8 and 1/2 by 11 inch
sheet having nine equally sized squares of 5 centimeter dimension
evenly spaced around the area of the sheet.
[0039] The nine squares have varying optical density which is
achieved by varying the toner coverage on each square as follows: 0
percent coverage (substrate only), 10 percent coverage, 20 percent
coverage, 40 percent coverage, 60 percent coverage, 80 percent
coverage, 100 percent coverage, the color green (2 layers of toner)
and process black (3 layers of toner). A print of this test target
is then produced on a xerographic color copier/printer using a
given substrate. The gloss level of the nine squares on the
resulting xerographic print is measured using a 75.degree.
Glossmeter. The variation in gloss level is then defined as the
difference in gloss between the highest and lowest gloss values
obtained from the nine squares of varying toner coverage.
[0040] The Xerox Corporation 5790 toner set used in the following
Examples was comprised of a terephthalic acid, bisphenol-A-ethylene
adduct, cyclohexane dimethanol polyester resin, and each of the
toners had the following compositions. The cyan toner was composed
of 95.5 percent (by weight throughout) of the polyester resin and
4.5 percent of C.I. Pigment Blue 15:3; the magenta toner was
composed of 94 percent of the polyester resin and 6 percent of C.I.
Pigment Red 57:1; the yellow toner was composed of 92.8 percent of
the polyester resin and 7.2 percent of C.I. Pigment, Yellow 17; and
the black toner was composed of 94 percent of the polyester resin
and 6 percent of carbon black #25B from the Mitsubishi Kasei
Corporation.
COMPARATIVE EXAMPLE I
[0041] A print of the differential gloss test target was produced
on a Xerox 5790 color copier using Xerox Image LX plain paper with
no polymer, such as a polyester coating, as the substrate. The
gloss level of the nine squares, with varying degrees of toner
coverage, were then measured using a 75.degree. Glossmeter and the
values recorded. The highest gloss level of 85 GU was obtained from
the process black square and the lowest gloss level of 10 GU from
the 0 percent toner coverage square. Therefore, this print exhibits
a variation in gloss of 75 GU (85-10 GU). Potentially, any
photographic original printed on a xerographic color copier using
plain paper could exhibit this level of gloss variation which is
highly visible to the eye thus making the print unlike the
photographic original.
COMPARATIVE EXAMPLE II
[0042] A print of the differential gloss test target was produced
on a Xerox 5790 color copier using Warren Lustro Gloss paper (a
typical commercially available coated paper stock) as the
substrate. The gloss level of the nine squares, with varying
degrees of toner coverage, were then measured using a 75.degree.
Glossmeter and the values recorded. The highest gloss level of 90
GU was obtained from the process black square and the lowest gloss
level of 45 GU was obtained from the 80 percent toner coverage
square. Therefore, this print exhibits a variation in gloss of 45
GU (90-45 GU). Potentially any photographic original printed on a
xerographic color copier using currently available coated paper
stocks could exhibit this level of gloss variation, which is highly
visible to the eye, thus making the print unlike the photographic
original.
EXAMPLE III
[0043] An 8 and 1/2 by 11 inch, 152 micron thick sheet of coated
ink jet paper, available from the Asahi Glass Company, was coated
with a 5 micron thick layer of a polyester resin comprised of
terephthalic acid, bisphenol-A-ethylene oxide adduct, cyclohexane
dimethanol, (Xerox Corporation Fe.sub.2O.sub.8 polyester). The
polyester coating was applied to one side of the paper from a 25
percent solution of the polyester resin in methylene chloride using
a #8 draw-down rod. The polyester coating was air dried and a print
of the differential gloss test target was produced on a Xerox 5790
color copier using the resulting polyester coated paper. A print of
the same test target was also produced on a sheet of Asahi Gloss
paper without the polyester top coating. The gloss level of the
nine squares on both prints was measured using a 75.degree.
Glossmeter and the values recorded. A variation in gloss of 42 GU
was obtained for the Asahi Gloss paper without the polyester top
coating whereas a significant lower variation in gloss of 20 GU was
obtained from the polyester coated paper. A print of a photographic
original produced on the polyester coated paper appeared more
photographic like than a print produced on the uncoated paper
because of the lower variation in gloss, and improved gloss
uniformity.
EXAMPLE IV
[0044] A roll of commercially available coated offset paper,
Kromekote 100 pound Enamel, was obtained from the Champion Paper
Company. This paper is manufactured with Champion's coating on both
sides and has a total s thickness of 150 microns. The roll of paper
was coated on one side with a layer of low molecular weight,
branched copolyester resin formed from isophthalic and nonanedioic
acid with diols and triols, and Vitel 5833B, a polyester with an
M.sub.n of 4,600, and an M.sub.w of 9,800, and obtained from the
Bostik Company. The copolyester resin was applied from a 25 percent
solution in ethyl acetate using a pilot scale Faustel Coater.
Approximately 500 feet of paper were coated with the copolyester
resin and the thickness of the resin layer was increased by 2
microns every 100 feet starting with a thickness of 2 microns and
ending with a thickness of 10 microns. The polyester layer was air
dried and prints of the differential gloss test target were
produced on a Xerox 5790 color copier using this set of polyester
coated papers where the thickness of the polyester layer had been
varied. Measurements of the gloss variation and curl were made on
the resulting prints. It was found that a thickness of 6 to 8
microns for the polyester layer provided the optimum combination of
uniform high gloss and low curl.
[0045] Approximately 1,000 feet of the Kromekote 100 pound Enamel
paper were subsequently coated with the optimum polyester coating
Vitel 5833B thickness of 7 microns. A print of the differential
gloss test target was produced on a Xerox 5790 color copier using
the resulting polyester coated paper. A print of the same test
target was also produced on a sheet of Kromekote 100 pound Enamel
paper without the polyester top coating. The gloss level of the
nine squares on both prints was measured using a 75.degree.
Glossmeter and the values recorded. For the Kromekote paper without
the polyester layer, the highest gloss level of 100 GU was obtained
from the process black square and the lowest gloss level of 48 GU
was obtained from the 40 percent toner coverage square resulting in
a significant variation in gloss of 52 GU (100-48 GU). For the
Kromekote paper with the optimum polyester coating thickness, there
was provided the highest gloss level of 100 GU from the process
black square and the lowest gloss level of 88 GU from the 100
percent toner covering square resulting in a significantly lower
variation in gloss of 12 GU (100-88 GU). A print of a photographic
original produced on the polyester coated Kromekote paper appeared
more photographic like than a print produced on the uncoated paper
because of the improvement in gloss uniformity.
[0046] There were generated cross-sectional micrographs of the
prints on the above uncoated and coated Kromekote papers. These
micrographs showed that with the uncoated Kromekote paper the fused
toner still remained above the surface of the paper resulting in a
wide variation in gloss from 100 GU to 48 GU which was highly
dependent on the degree of toner coverage. The fused toner on the
polyester coated sample had sunk, or dispersed into the polyester
layer, away from the surface of the paper, resulting in a much more
uniform gloss across the print which was less dependent on the
degree of toner coverage. The toner particles are able to sink into
the polyester coating on the paper because the resin that is used
for the polyester coating was selected so that it would have a
lower melt viscosity than the toner resin at the fusing temperature
encountered in the color copier.
EXAMPLE V
[0047] A roll of commercially available coated offset paper,
Kromekote 6 PT cover, was obtained from the Champion Paper Company.
This paper was manufactured with Champion's coating on only one
side of the paper and has a total thickness of 150 microns. The
roll of paper was coated on the Champion coated side with a 6.5
micron thick layer of a low molecular weight, branched copolyester,
Vitel 5833B. The copolyester resin was applied from a 25 percent
solution in ethyl acetate using a pilot scale Faustel Coater. A
print of the differential gloss test target was produced on a Xerox
5790 color copier using the resulting polyester coated paper. A
print of the same target was also produced on a sheet of Kromekote
6 PT cover paper without the polyester coating. The gloss level of
the nine squares on both prints was measured using a 75.degree.
Glossmeter and the values recorded. For the paper without the
polyester coating, the highest gloss level of 99 GU was obtained
from the green square (2 layers of toner) and the lowest gloss of
51 GU from the 40 percent toner coverage square resulting in a
significant variation in gloss of 48 GU (99-51 GU). On the other
hand, the polyester coated paper gave the highest gloss level of 98
GU from the process black square and the lowest gloss of 85 GU from
the 10 percent toner coverage square resulting in a significantly
lower variation in gloss of 13 GU (98-85 GU). A print of a
photographic original produced on the polyester coated paper
appeared more photographic like because of the improvement in gloss
uniformity.
EXAMPLE VI
[0048] A roll of commercially available coated offset paper,
Reflection II Gloss, was obtained from Consolidated Papers Inc.
This paper was manufactured with the Consolidated coating on both
sides and has a total thickness of 191 microns. The roll of paper
was coated with a 7.0 micron thick layer of a low molecular weight
branched copolyester, Vitel 5833B. The polyester resin was applied
from a 25 percent solution in ethyl acetate using a pilot scale
Faustel Coater. A print of the differential gloss test target was
produced on a Xerox 5790 color copier using the resulting polyester
coated paper. A print of the same test target was also produced on
a sheet of Reflection II Gloss paper without the polyester coating.
The gloss level of the nine squares on both prints was measured
using a 75.degree. Glossmeter and the values recorded. For the
paper without the polyester coating, the highest gloss level of 92
GU was obtained from the process black square and the lowest gloss
level of 50 GU from the 60 percent toner coverage square resulting
in a significant variation in gloss of 42 GU (92-50 GU). In
contrast, the polyester coated paper provided the highest gloss
level of 99 GU from the 0 percent coverage square and the lowest
gloss of 88 GU from the 100 percent coverage square resulting in a
significantly lower variation in gloss of 11 GU (99-88 GU).
[0049] A print of a photographic original produced on the polyester
coated paper appeared more photographic like because of the
improvement in gloss uniformity, and also because the thickness of
this base paper more closely matches that of typical photographic
papers.
EXAMPLE VII
[0050] A roll of commercially available coated offset paper,
Centura Gloss, was obtained from Consolidated Papers Inc. This
paper was manufactured with Consolidated coating on both sides and
has a total thickness of 142 microns. The roll of paper was coated
with a 6.5 micron thick layer of a low molecular weight, branched
copolyester resin, Vitel 5833B. The resin was applied from a 25
percent solution in ethyl acetate using a pilot scale Faustel
Coater. A print of the differential gloss test target was produced
on a Xerox 5790 color copier using the resulting polyester coated
paper. A print of the same test target was also produced on a sheet
of Centura Gloss paper without the polyester coating. The gloss
level of the nine squares on both papers was measured using a
75.degree. Glossmeter and the values recorded. For the paper
without the polyester coating, the highest gloss level of 90 GU was
obtained from the process black square and the lowest gloss level
of 57 GU from the 40 percent toner coverage square resulting in a
significant variation in gloss of 33 GU (90-57 GU). In contrast,
the invention polyester coated paper provided the highest gloss
level of 96 GU from the 10 percent coverage square and the lowest
gloss level of 90 GU from the green square resulting in a
significantly lower variation in gloss of 6 GU (96-90 GU). A print
of a photographic original produced on the polyester coated paper
appeared more photographic like because of the improvement in gloss
uniformity.
[0051] Other embodiments and modifications of the present invention
may occur to those skilled in the art subsequent to a review of the
information presented herein; these embodiments and modifications,
as well as equivalents thereof, are also included within the scope
of this invention.
* * * * *