U.S. patent application number 09/813167 was filed with the patent office on 2001-12-27 for imaging transfer system and process for transferring image and non-image areas thereof to a receptor element.
This patent application is currently assigned to Foto-Wear, Inc.. Invention is credited to Hare, Donald S., Williams, Scott A..
Application Number | 20010055724 09/813167 |
Document ID | / |
Family ID | 21856764 |
Filed Date | 2001-12-27 |
United States Patent
Application |
20010055724 |
Kind Code |
A1 |
Hare, Donald S. ; et
al. |
December 27, 2001 |
Imaging transfer system and process for transferring image and
non-image areas thereof to a receptor element
Abstract
The present invention relates to an imaging system, which
comprises a support having a front and rear surface, at least one
layer of microcapsules or at least one layer of microcapsules and
developer in the same layer or at least one layer of microcapsules
and developer in separate layers, on said front surface of the
support, wherein the microcapsules or developer or microcapsules
and developer are dispersed in a carrier of the invention, said
carrier is capable of transferring and adhering developed image and
non-image areas from said front surface of said support upon the
application of heat energy to the rear surface of the support, said
carrier strips from said front surface of the support by liquefying
and releasing from said support when heated, said liquefied carrier
providing adherence to a receptor element by flowing onto said
receptor element and solidifying thereon, said adherence does not
require an external adhesive layer, with the proviso that the
carrier is not capable of reacting to form an image, and when the
microcapsules are present together in the same layer as the
carrier, the carrier has a particle size which is the same as or
smaller than that of the microcapsules, and an optional protective
layer of clear thermoplastic.
Inventors: |
Hare, Donald S.; (Hawley,
PA) ; Williams, Scott A.; (Rochester, NY) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Foto-Wear, Inc.
|
Family ID: |
21856764 |
Appl. No.: |
09/813167 |
Filed: |
March 21, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09813167 |
Mar 21, 2001 |
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09539711 |
Mar 31, 2000 |
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09539711 |
Mar 31, 2000 |
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08970424 |
Nov 14, 1997 |
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6265128 |
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60030933 |
Nov 15, 1996 |
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Current U.S.
Class: |
430/200 ;
430/211; 430/235; 430/256; 430/259; 430/262; 430/263 |
Current CPC
Class: |
B41M 5/0256 20130101;
B41M 5/38207 20130101; B41M 5/03 20130101; B41M 5/38235 20130101;
G03C 1/7642 20130101; G03C 11/12 20130101; B41M 5/34 20130101; G03F
7/002 20130101; B41M 5/30 20130101; B41M 5/035 20130101; G03C 1/002
20130101; D06P 5/003 20130101; B41M 5/287 20130101; G03C 11/02
20130101 |
Class at
Publication: |
430/200 ;
430/211; 430/235; 430/256; 430/259; 430/262; 430/263 |
International
Class: |
G03C 008/10; G03C
011/12; G03C 008/26 |
Claims
What is claimed is:
1. An imaging system, which comprises: a support having a front and
rear surface, and at least one layer of microcapsules or at least
one layer of microcapsules and developer in the same layer or at
least one layer of microcapsules and developer in separate layers,
on said front surface of the support, wherein the microcapsules or
developer or microcapsules and developer are dispersed in a carrier
which is capable of transferring and adhering developed image and
non-image areas from said front surface of said support upon the
application of heat energy to the rear surface of the support, said
carrier strips from said front surface of the support by liquefying
and releasing from said support when heated, said liquefied carrier
providing adherence to a receptor element by flowing onto said
receptor element and solidifying thereon, said adherence does not
require an external adhesive layer, with the proviso that the
carrier is not capable of reacting to form an image, and when the
microcapsules are present together in the same layer as the
carrier, the carrier has a particle size which is the same as or
smaller than that of the microcapsules, wherein the carrier is
cumulatively present in all layers on said support in an amount
from about 15 g/m.sup.2 to about 30 g/m.sup.2, and wherein the
carrier is capable of melting, flowing and transferring said image
and non-image areas to the receptor at temperatures in the range of
from more than 100.degree. C. to about 180.degree. C.
2. An imaging system, which comprises: a support having a front and
rear surface, and at least one layer of microcapsules on said front
surface of the support, wherein the microcapsules are dispersed in
a carrier which is capable of transferring and adhering developed
image and non-image areas from said front surface of said support
upon the application of heat energy to the rear surface of the
support, said carrier strips from said front surface of the support
by liquefying and releasing from said support when heated, said
liquefied carrier providing adherence to a receptor element by
flowing onto said receptor element and solidifying thereon, said
adherence does not require an external adhesive layer, with the
proviso that the carrier is not capable of reacting to form an
image, and when the microcapsules are present together in the same
layer as the carrier, the carrier has a particle size which is the
same as or smaller than that of the microcapsules, wherein the
carrier is cumulatively present in all layers on said support in an
amount from about 15 g/m.sup.2 to about 30 g/m.sup.2, and wherein
the carrier is capable of melting, flowing and transferring said
image and non-image areas to the receptor at temperatures in the
range of from more than 100.degree. C. to about 180.degree. C.
3. An imaging system, which comprises: a support having a front and
rear surface, and at least one layer of microcapsules and developer
in the same layer on said front surface of the support, wherein the
microcapsules and developer are dispersed in a carrier which is
capable of transferring and adhering developed image and non-image
areas from said front surface of said support upon the application
of heat energy to the rear surface of the support, said carrier
strips from said front surface of the support by liquefying and
releasing from said support when heated, said liquefied carrier
providing adherence to a receptor element by flowing onto said
receptor element and solidifying thereon, said adherence does not
require an external adhesive layer, with the proviso that the
carrier is not capable of reacting to form an image, and when the
microcapsules are present together in the same layer as the
carrier, the carrier has a particle size which is the same or
smaller than that of the microcapsules, wherein the carrier is
cumulatively present in all layers on said support in an amount
from about 15 g/m.sup.2 to about 30 g/m.sup.2 and wherein the
carrier is capable of melting, flowing and transferring said image
and non-image areas to the receptor at temperatures in the range of
from more than 100.degree. C. to about 180.degree. C.
4. In an imaging system comprising (i) an imaging sheet and
developer material carried on said imaging sheet, or (ii) an
imaging sheet and a developer carried on a separate developer
sheet, the imaging sheet having a layer of microcapsules, said
imaging system capable of forming images by image-wise exposing
said imaging sheet to radiation actinic with respect to said
photosensitive composition, and rupturing or dissolving said
microcapsules in the presence of said developer material to form an
image, wherein the improvement comprises at least one layer of
microcapsules or at least one layer of microcapsules and developer
in the same layer, or at least one layer of microcapsules and
developer in separate layers, on said front surface of the support,
wherein the microcapsules or developer or microcapsules and
developer are dispersed in a carrier which is capable of
transferring and adhering developed image and non-image areas from
said front surface of said support upon the application of heat
energy to the rear surface of the support, said carrier strips from
said front surface of the support by liquefying and releasing from
said support when heated, said liquefied carrier providing
adherence to a receptor element by flowing onto said receptor
element and solidifying thereon, said adherence does not require an
external adhesive layer, with the proviso that the carrier is not
capable of reacting to form an image, and when the microcapsules
are present together in the same layer as the carrier, the carrier
has a particle size which is the same as or smaller than that of
the microcapsules, wherein the carrier is cumulatively present in
all layers on said support in an amount from about 15 g/m.sup.2 to
about 30 g/m.sup.2, and wherein the carrier is capable of melting,
flowing and transferring said image and non-image areas to the
receptor at temperatures in the range of from more than 100.degree.
C. to about 180.degree. C.
5. The imaging system of claim 1, which comprises an imaging sheet
useful in forming images by exposure-controlled, image-wise
reaction of a chromogenic material and a developer, said sheet
comprising: a support having a front and rear surface, a layer of
microcapsules dispersed in said carrier on said support, said
microcapsules having discrete capsule walls which encapsulate an
internal phase, said internal phase, including a photosensitive
composition which undergoes a change in viscosity sufficient to
control the release of the internal phase from said microcapsules,
a chromogenic material associated with said microcapsules such
that, upon image-wise exposing said layer of microcapsules to
actinic radiation and subjecting said layer of microcapsule to a
uniform rupturing force, said chromogenic material image-wise
becomes available for reaction with a developer to form an
image.
6. The imaging system of claim 1, in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising: a substrate having front and
back surfaces, a chromogenic material, a radiation curable
composition which undergoes an increase in viscosity upon exposure
to actinic radiation, a coating containing said carrier and said
chromogenic material and said radiation curable composition on one
of said front and back surfaces, and a developer material capable
of reacting with said chromogenic material to form a visible image,
said radiation curable composition being encapsulated in rupturable
capsules as an internal phase, wherein images are formed by
image-wise exposing said coating to actinic radiation and rupturing
said capsules in the image areas such that said internal phase is
released from said capsules in the image areas and said chromogenic
material and said developer react pattern-wise to form an
image.
7. The imaging system of claim 1, which comprises a self-contained
imaging sheet in which images are formed by image-wise reaction of
one or more chromogenic materials and a developer material, said
sheet comprising: a substrate having a front and back surface, a
chromogenic material, a radiation curable composition which
undergoes an increase in viscosity upon exposure to actinic
radiation, a coating containing said carrier and said chromogenic
material and said radiation curable composition on one of said
front and back surfaces, a developer material capable of reacting
with said chromogenic material to form a visible image codeposited
on said substrate with said coating containing said chromogenic
material, said radiation curable composition being encapsulated in
rupturable capsules as an internal phase, wherein images are formed
by image-wise exposing said coated substrate to actinic radiation,
and rupturing said capsules in the image areas such that said
internal phase is released from said capsules in the image areas
and said chromogenic material pattern-wise reacts with said
developer material to form an image.
8. The imaging system of claim 1, in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising: an imaging sheet comprising a
first substrate, a radiation curable composition which undergoes an
increase in viscosity upon exposure to actinic radiation, a coating
on one surface of said first substrate comprising said chromogenic
material and said radiation curable composition and optionally said
carrier, said radiation curable composition being encapsulated in
rupturable capsules as an internal phase, and a developer sheet
comprising a second substrate having a front and rear surface, a
developer material dispersed in said carrier on said second
substrate, said developer capable of reacting with said chromogenic
material to form an image on the surface of said second substrate,
wherein images are formed by image-wise exposing said coating to
actinic radiation, and rupturing capsules in the image areas with
said coating in facial contact with said developer sheet such that
said internal phase is image-wise released from said ruptured
capsules and there is image-wise transfer of said chromogenic
material to said developer sheet and a patterned image-forming
reaction occurs between said chromogenic material and said
developer material.
9. The imaging system of claim 1 in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising: an imaging sheet comprising a
first substrate, a chromogenic material, a photodepolymerizable
composition which undergoes a decrease in viscosity upon exposure
to actinic radiation, a coating on one surface of said first
substrate comprising said chromogenic material and said
photodepolymerizable composition and optionally said carrier, said
photodepolymerizable composition being encapsulated in rupturable
capsules as an internal phase, and a developer sheet comprising a
second substrate having a front and rear surface, a developer
material dispersed in said carrier on said second substrate, said
developer capable of reacting with said chromogenic material to
form an image on the surface of said second substrate, wherein
images are formed by image-wise exposing said coating to actinic
radiation, and rupturing said capsules in the exposed areas with
said coating in facial contact with said developer sheet such that
said internal phase is image-wise released from said ruptured
capsules and there is image-wise transfer of said chromogenic
material to said developer sheet and a patterned image-forming
reaction occurs between said chromogenic material and said
developer material.
10. The image system of claim 1, in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising a substrate having front and back
surfaces, a chromogenic material, a composition which undergoes a
decrease in viscosity upon exposure to actinic radiation, a coating
containing said carrier and said chromogenic material and said
composition on one of said front and back surfaces, and developer
material optionally dispersed in said carrier and capable of
reacting with said chromogenic material to form a visible image,
said composition being encapsulated in rupturable capsules as an
internal phase, wherein images are formed by image-wise exposing
said coating to actinic radiation and rupturing said capsules in
the exposed areas and said chromogenic material and said developer
react pattern-wise to form an image.
11. The imaging system of claim 1, which comprises an imaging sheet
useful in forming images onto a receptor surface, said sheet
comprising: a support having a front and rear surface, a plurality
of photosensitive microcapsules and a developer on the surface
thereof, said microcapsules and said developer being present on the
same layer along with said carrier or in contiguous layers on the
surface of said support wherein either a layer containing said
microcapsules or a layer containing said developer, or both
contains said carrier, said microcapsules containing a color former
which is capable of reacting with said developer and forming a
visible dye image, said imaging sheet being useful for transferring
images and non-image areas onto a receptor surface.
12. The imaging system of claim 1, which comprises: an imaging
sheet and a background dye or a combination of a dye precursor and
a dye developer which react to form a background dye, said imaging
sheet including: a support having a front and rear surface, a
plurality of capsules dispersed in said carrier in a layer on one
surface of said support, and an internal phase contained within
said capsules comprising a decolorizing agent and a photohardenable
or photosoftenable radiation sensitive composition, wherein images
can be formed by image-wise exposing said sheet to actinic
radiation and rupturing said capsules such that said decolorizing
agent is image-wise released from said capsules and reacts with
said associated background dye to decolorize it or inhibits,
prevents or reverses the color forming reaction of said dye
precursor and dye developer to produce a color difference in the
form of an image.
13. An imaging material comprising a support having a front and
rear surface, and a layer of photosensitive microparticles on one
surface of said support, wherein the microparticles are dispersed
in a carrier which is capable of transferring and adhering
developed image and non-image areas from said front surface of said
support upon the application of heat energy to the rear surface of
the support, said carrier strips from said front surface of the
support by liquefying and releasing from said support when heated,
said liquefied carrier providing adherence to a receptor element by
flowing onto said receptor element and solidifying thereon, said
adherence does not require an external adhesive layer, with the
proviso that the carrier is not capable of reacting to form an
image, and when the microparticles are present together in the same
layer as the carrier, the carrier has a particle size which is the
same as or smaller than that of the microparticles, said
microparticles including an image-forming agent and a
photosensitive composition containing a polymer which is capable of
undergoing cationically-initiated depolymerization and
photoinitiator including a silver halide and an organo silver salt,
wherein, after exposing said microparticle to radiation, said
microparticles, directly or with additional processing, release
said image-forming agent or become permeable to a developer which
reacts with said image-forming agent to form a visible image,
wherein the carrier is cumulatively present in all layers on said
support in an amount from about 15 g/m.sup.2 to about 30 g/m.sup.2,
and wherein the carrier is capable of melting, flowing and
transferring said image and non-image areas to the receptor at
temperatures in the range of from more than 100.degree. C. to about
180.degree. C.
14. The imaging material of claim 13, wherein said microparticles
comprise a first set of microparticles containing a cyan
image-forming material having a first wavelength sensitivity, a
second set of microparticles containing a magenta image-forming
material having a second wavelength sensitivity, and a third set of
microparticles containing a yellow image-forming material having a
third wavelength sensitivity, said first, second, and third
sensitivities being sufficiently different that upon exposing said
imaging material to a first radiation, substantially only said
first microparticles release said image-forming material, upon
exposing said imaging material to a second radiation different than
said first radiation, substantially only said second set of
microparticles release said image-forming material, and upon
exposing said imaging material to a third radiation different than
said first and second radiations, substantially only said third set
of microparticles release said image-forming material.
15. The imaging system of claim 1 comprising: an imaging sheet
having a front and rear surface, and dry developer material
dispersed in said carrier on said imaging sheet, or an imaging
sheet, a separate image receiving developer sheet having a front
and rear surface and a dry developer material dispersed in said
carrier on said front surface, said imaging sheet having on one
surface thereof a coating comprising a cyan color precursor, a
radiation curable photosensitive composition associated with said
cyan color precursor, a magenta color precursor, a radiation
curable photosensitive composition associated with said magenta
color precursor, a yellow color precursor, and a radiation curable
photosensitive composition associated with said yellow color
precursor, said radiation curable photosensitive compositions
having distinct sensitivities and being encapsulated in pressure
rupturable capsules as an internal phase, said capsules having
discrete capsule walls, said cyan, magenta and yellow color
precursors being soluble in said associated photosensitive
compositions or solvents for said color precursors being
encapsulated with said associated photosensitive compositions and
said color precursors being present in said capsules with said
photosensitive compositions or in said discrete walls; said imaging
system being capable of forming images by image-wise exposing said
imaging sheet to radiation actinic with respect to said
photosensitive compositions, and rupturing at least said capsules
containing photosensitive compositions unexposed by said actinic
radiation in the presence of said developer material to form an
image by reaction of said color precursors with said developer
material.
16. A method of transferring image and non-image areas to a
receptor element which comprises the steps of: (a) exposing
image-wise an imaging element having a front surface and a rear
surface of claims 1, 2, 3, 4 or 13, (b) developing the image-wise
exposed element to form an image, (c) positioning the front surface
of the developed element or positioning the undeveloped element
prior to development against a receptor element, said developed
element or undeveloped element containing the transfer layer of the
invention, and (d) applying heat to the rear surface of the
developed or undeveloped element to transfer the developed image
and non-image area to the receptor element.
17. The imaging system of claim 1, wherein the carrier comprises
(i) particles of a thermoplastic polymer having dimensions of about
1 to about 50 micrometers, from about 10 to about 50 weight percent
of a film-forming binder, based on the weight of the thermoplastic
polymer, and optionally from about 0.2 to about 10 weight percent
of a fluid viscosity modifier, based on the weight of the
thermoplastic polymer, (ii) about 15 to about 80 percent by weight
of a film-forming binder selected from the group consisting of
ethylene-acrylic acid copolymers, polyolefins, and waxes and from
about 85 to about 20 percent by weight of a powdered thermoplastic
polymer selected from the group consisting of polyolefins,
polyesters, polyamides, waxes, epoxy polymers, ethylene-acrylic
acid copolymers, and ethylene-vinyl acetate copolymers, wherein
each of said film-forming binder and said powdered thermoplastic
polymer melts in the range of from about 100.degree. C. to about
180 degrees Celsius and particles of about 1 to about 50
micrometers, (iii) a film forming binder selected from the group
consisting of ethylene-acrylic acid copolymers having particles of
about 1 to about 50 micrometers, polyolefins, and waxes and which
melts in the range of from about 100.degree. C. to about 180
degrees Celsius, (iv) a thermoplastic polymer having particles of
about 1 to about 50 micrometers selected from the group consisting
of polyolefins, polyesters, and ethylene-vinyl acetate copolymers
and which melts in the range of from about 100 to about 180 degrees
Celsius or, (v) a thermoplastic polymer having particles of about 1
to about 50 micrometers selected from the group consisting of
polyolefins, polyesters, and ethylene-vinyl acetate copolymers,
ethylene-methacrylic acid copolymers, and ethylene-acrylic acid
copolymers and which melts in the range of from about 100 to about
180 degrees Celsius.
18. The imaging system of claim 1, wherein the carrier comprises
particles of a thermoplastic polymer having dimensions of about 1
to about 50 micrometers, from about 10 to about 50 weight percent
of a film-forming binder, based on the weight of the thermoplastic
polymer, and from about 0.2 to about 10 weight percent of an
viscosity modifier, based on the weight of the thermoplastic
polymer.
19. The imaging system of claim 1, wherein the carrier melts from
about 100 to about 180 degrees Celsius and comprises particles of a
thermoplastic polymer having dimensions of about 1 to about 50
micrometers, from about 10 to about 50 weight percent of a
film-forming binder, based on the weight of the thermoplastic
polymer, and from about 2 to about 20 weight percent of a cationic
polymer, based on the weight of the thermoplastic polymer.
20. The imaging system of claim 1, wherein the carrier comprises
from about 15 to about 80 percent by weight of a film-forming
binder selected from the group consisting of ethylene-acrylic acid
copolymers, polyolefins, and waxes and from about 85 to about 20
percent by weight of a powdered thermoplastic polymer selected from
the group consisting of polyolefins, polyesters, polyamides, waxes,
epoxy polymers, ethylene-acrylic acid copolymers, and
ethylene-vinyl acetate copolymers, wherein each of said
film-forming binder and said powdered thermoplastic polymer melts
in the range of from about 100 to about 180 degrees Celsius and
said powdered thermoplastic comprises particles which are from
about 1 to about 50 micrometers in diameter.
21. The imaging system of claim 1, wherein the carrier comprises a
film forming binder selected from the group consisting of
ethylene-acrylic acid copolymers, polyolefins, and waxes and which
melts in the range of from about 100 to about 180 degrees
Celsius.
22. The imaging system of claim 1, wherein the carrier comprises a
thermoplastic polymer selected from the group consisting of
polyolefins, polyesters, and ethylene-vinyl acetate copolymers and
which melts in the range of from about 100 to about 180 degrees
Celsius.
23. The imaging system of claim 1, wherein the carrier comprises a
thermoplastic polymer selected from the group consisting of
polyolefins, polyesters, and ethylene-vinyl acetate copolymers,
ethylene-methacrylic acid copolymers, and ethylene-acrylic acid
copolymers and which melts in the range of from about 100 to about
180 degrees Celsius.
24. The imaging system of claim 1, wherein said layer of
microcapsules contains three sets of microcapsules sensitive to
red, green and blue light respectively and said sets of
microcapsules contain cyan, magenta and yellow image-forming
agents, respectively.
25. The imaging system of claim 1, wherein at least one layer of
microcapsules and developer are in separate layers, and the
microcapsules are dispersed in said carrier.
26. The imaging system of claim 1, wherein at least one layer of
microcapsules and developer are in separate layers, and the
developer is dispersed in said carrier.
27. The imaging system of claim 1, wherein at least one layer of
microcapsules and developer are in separate layers, and both
microcapsules and developer are dispersed in said carrier.
28. The imaging system of claim 1, wherein the microcapsules are
photosensitive.
29. The imaging system of claim 1, wherein the microcapsules are
heat sensitive.
30. The imaging system of claim 1, wherein the microcapsules
contain a diazonium salt compound as a color forming material, and
the layer containing the microcapsules further comprises a coupler
and a reaction-accelerating organic base.
Description
[0001] The contents of Provisional Application U.S. Serial No.
60/030,933 filed Nov. 15, 1996 on which the present application is
based, is herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a transfer element,
preferably using CYCOLOR or THERMO-AUTOCHROME technology, and to a
method of transferring developed image areas and non-image areas to
a receptor element.
[0004] 2. Description of the Prior Art
[0005] CYCOLOR technology provides full color imaging generally
associated with photography. With CYCOLOR technology, for example,
a polyester base may be coated with light-sensitive microcapsules
called cyliths, which are sensitive to red, green and blue light.
Each cylith resembles a water-filled balloon and is about one-tenth
the diameter of a human hair. The cyliths contain a liquid monomer
in which is dissolved a light sensitive photoinitiator and a color
forming substance called a leuco dye.
[0006] The support (e.g., polyester) is exposed to light
transmitted through or reflected from an original color image. The
resulting latent image resembles the negative used in conventional
photography. Exposure to light hardens the cyliths in proportion to
the amount of exposure, rendering them resistant to physical
rupture. Thus, the latent image is a pattern of hard (exposed) and
soft (unexposed) cyliths.
[0007] The final image is developed by bringing the cyliths into
contact with a sheet of CYCOLOR paper or transparency. Full color
is obtained by mixing three different types of cyliths and coating
them on a support (e.g., polyester). Each of the three types of
cyliths contain either a cyan, magenta or yellow leuco dye, along
with photoinitiators that are sensitive respectively to red, green
or blue light. Exposure to red light hardens the capsules
containing the cyan dye. Pressure development results in the
release of magenta and yellow dyes which mix to form a red image.
Exposure to green light controls the magenta dye. Pressure
development results in the cyan and yellow dyes mixing to form a
green image. Blue light controls the yellow dye. Pressure
development results in the mixing of the cyan and magenta dyes to
form a blue image. Exposure of all cyliths (white light) results in
non color (white or non-image area) and exposure of none of the
cyliths results in black. Any color can be reproduced by
controlling the relative proportion of the three dyes.
[0008] Applications of CYCOLOR technology include use in color
copiers to make color copies, or this technology may be used to
create hard copy prints from 35 mm slides. Other applications
include use with color computer printers to provide prints from
computer systems. CYCOLOR technology also works with digital
imaging techniques by providing hard copies of images produced by
electronic cameras.
[0009] Provisional application 60/029,917 requires that the silver
halide light-sensitive grains are dispersed within a carrier which
functions as a transfer layer and does not have a separate transfer
layer. Provisional application 60/056,446 requires that the silver
halide transfer element has a separate transfer layer. Provisional
application 60/030,933 relates to a transfer element using Cycolor
technology, but having no separate transfer layer.
[0010] U.S. Pat. No. 4,751,165 discloses an imaging system which
provides an imaging sheet and a layer of microcapsules containing a
photosensitive composition and a color former. However, the
developed image and non-image areas thereof are not capable of
being simultaneously transferred to a receptor element.
[0011] Accordingly, imaging systems based on photosensitive
encapsulates are known. U.S. Pat. No. 3,219,446 by Berman discloses
the selected transfer of dye to a copy sheet. U.S. Pat. No.
3,700,439 by Phillips discloses a photocopy process involving
development of capsules without transfer.
[0012] U.S. Pat. No. 4,771,032 discloses a thermo-autochrome
system, which is a direct thermal full color hardcopy system
involving thermal media capable of producing color images with the
use of microcapsules.
[0013] U.S. Pat. No. 5,139,917 discloses an imaging system wherein
the developed image and non-image areas are transferred to a
receptor element by a separate transfer coating layer. Unlike the
imaging system of U.S. Pat. No. 5,139,917, the imaging system of
the invention does not have a separate transfer coating layer.
[0014] Provisional application titled "IMAGING TRANSFER SYSTEM AND
PROCESS FOR TRANSFERRING LIGHT-FIXABLE THERMAL IMAGE TO A RECEPTOR
ELEMENT" (Inventors--Donald S. Hare and Scott Williams; Attorney
Docket No. 175-180P) filed on Nov. 14, 1997, relates to
transferring thermo-autochrome materials with a separate transfer
layer.
SUMMARY OF THE INVENTION
[0015] Accordingly, the present invention is directed to an imaging
system which comprises, a support having a front and rear surface,
at least one layer of (e.g. photosensitive or thermal-sensitive )
microcapsules, or at least one layer of (e.g. photosensitive or
thermal-sensitive) microcapsules and developer (e.g. generally for
photosensitive microcapsules) in the same layer, or at least one
layer of (e.g. photosensitive or thermal-sensitive) microcapsules
and developer in separate layers, on said front surface of the
support, wherein said microcapsules, or developer or both are
dispersed in the carrier of the invention, said carrier preferably
having a melting point of at least 100.degree. C., and which is
capable of transferring and adhering developed image and non-image
areas from said front surface of said support upon the application
of heat energy to the rear surface of the support, said carrier
strips from said front surface of the support by liquefying and
releasing from said support when heated, said liquefied carrier
providing adherence to a receptor element by flowing onto said
receptor element and solidifying thereon, said adherence does not
require an external (e.g. surface) adhesive layer and preferably
occurs in an area at least coextensive with the area of said
microcapsules, with the proviso that the carrier is not capable of
reacting (e.g. with a color precursor) to form an image, and an
optional layer of clear thermoplastic material. Preferably, the
particle size of the carrier is the same as or smaller than that of
the microcapsules, for example, from 1-20 micrometers.
[0016] The present invention also relates to a method of applying
an image to a receptor element, which comprises the steps of:
[0017] (a) exposing imagewise the imaging element described
above,
[0018] (b) developing the imagewise exposed element to form an
image,
[0019] (c) positioning the front surface of said developed element
(or positioning the undeveloped element prior to development)
against said receptor element, and
[0020] (d) applying energy (e.g heat) to the rear surface of the
element to transfer the developed image and non-image area to said
receptor element.
[0021] The receptor element may be textile, leather, ceramic, wool,
glass or plastic. Preferably, the receptor element is a shirt or
the like. Other suitable receptor surfaces include canvas, paper,
glass, or receptor supports used by the museum or conservatory
industry. Energy applied to the rear surface of the element is heat
and/or pressure (e.g via ironing)
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present invention will become more fully understood from
the detailed description given hereinbelow, and the accompanying
drawings which are given by way of illustration only, and thus are
not limitative of the present invention, and wherein:
[0023] FIG. 1 is a cross-sectional view of the preferred embodiment
of an imaging sheet or element of the present invention; and
[0024] FIG. 2 illustrates the step of ironing the imaging sheet or
element onto a tee shirt or the like.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The term "encapsulated" refers to both so-called resin
dispersion or open phase systems in which the internal phase
containing a chromogenic material is dispersed as droplets
throughout a dispersing medium (e.g. carrier) and systems in which
the capsule is formed with a discrete capsular wall, the latter
encapsulation typically being in the form of microcapsule. The term
"microcapsule" includes both microcapsules having discrete walls
and microcapsules within a so-called open phase system comprising a
dispersion of the internal phase constituents in a binder.
"Pressure rupturable capsules" are, accordingly, considered to
exist in either of these "encaosulated" systems. Furthermore, while
the capsules are described herein as "pressure rupturable" means
other than pressure may be used to rupture them (e.g. heat).
[0026] The term "actinic radiation" includes the entire
electromagnetic spectrum including ultraviolet (U.V.) and infrared
(I.R.) radiation.
[0027] The (e.g. photosensitive) microcapsules used in the present
invention can be prepared as described in U.S. Pat. Nos. 4,751,165,
4,399,209, 4,440,846, 4,842,980, 4,772,530, 4,772,541, 4,482,624
and 4,771,032.
[0028] Typically, CYCOLOR copiers/printers utilize a paper
containing a vast number of colored microcapsules which, when
exposed to varying degrees of energy (e.g. heat, light or pressure)
form a color image. In the present invention a carrier for the
microcapsules is coated on the base support layer. As a result of
the invention, the carrier will release under energy (e.g. heat)
and carry the image and non-image areas to the receptor (e.g.
textile) in washproof color.
[0029] Furthermore; in a further representative use of CYCOLOR
technology two sheets of paper are required. A color encapsulated
"donor" roll marries a second paper at the point of light/heat. The
donor sheet comprises a support and a top coating containing image
(e.g. color) forming microcapsules optionally embedded in the
carrier of the invention, wherein the "latent" image is transferred
to a receptor sheet comprising a support and a developer containing
layer comprising developer and the carrier of the invention. As a
result of the invention, the developed image and non-image areas
may then be transferred to a receptor element (e.g textile).
[0030] Therefore, in a single self-contained imaging sheet
comprising a support, at least one layer of image forming
microcapsules, plus optional developer in the same or different
layer, and carrier of the invention combined with at least the
microcapsules or developer or both, and optional layer of clear
thermoplastic, the image and non-image areas may be directly
transferred to a receptor element (e.g. textile). In a two sheet
system, the sheet ultimately containing the developed image should
have the carrier of the invention so that the image and non-image
areas may be directly transferred to the receptor element.
[0031] A representative imaging sheet of the invention is based on
the imaging sheet of U.S. Pat. No. 4,751,165 except that it
incorporates the carrier of the present invention. This imaging
sheet is set forth in FIG. 1 and is generally represented by
reference numeral 10. The imaging sheet 10 includes a support 12
and a photosensitive layer 14 containing the carrier of the
invention on one surface thereof. The layer 14 includes
photosensitive microcapsules 16 and a developer resin (e.g.,
phenolic) 18 embedded in the instant carrier. The microcapsules 16
and developer resin 18 do not need to be coated in the same layer,
but can be coated in contiguous layers with the microcapsules
underlying or overlying a layer of the developer resin. However, at
least one of these layers must contain the instant carrier. The
support 12 may be a polymeric film. If the support 12 is
transparent, the imaging sheet can be exposed from either surface.
The developer layer 18 is not necessarily a film but may consist of
finely divided dispersion particles, optionally including the
instant carrier. Similarly, developer layer 18 is not necessarily
contiguous but may be interrupted by pores or capillaries.
[0032] Techniques for exposing and developing the above-described
imaging sheet 10 are known in the art (see FIG. 2 of U.S. Pat. No.
4,751,165).
[0033] The mechanism whereby the microcapsules rupture and release
the internal phase is explained in more detail in U.S. Pat. Nos.
4,751,165 and 4,399,209. Exposure alone or in conjunction with
heating effects a change in the viscosity of the internal phase
such that the internal phase is differentially released from the
microcapsules in the exposed and unexposed areas upon subsequent
application of rupture and transfer force.
[0034] After exposure, the imaging sheet 10 is developed alone or
is assembled with the receptor element prior to development. The
imaging sheet is developed by applying a rupturing force such as
with pressure rollers.
[0035] The imaging sheet/receptor element assembly is heated to
melt the carrier coating so that the image and non-image areas are
transferred to the receptor element.
[0036] The color former reacts with the developer to produce a
visible dye image. The entire image and non-image area is
transferred to the receptor element. This is contrary to the
teachings of U.S. Pat. No. 4,751,165, wherein the image areas
selectively adhere to the paper while the non-image areas remain
attached to the support.
[0037] Full color imaging systems are described in more detail in
U.S. Pat. No. 4,842,976.
[0038] Representative developer containing resins include phenolic
developer resins, as described in U.S. Pat. No. 4,751,165.
[0039] The developer-containing resin and microcapsule composition
can be coated using conventional coating techniques such as blade
coating, roll coating, etc.
[0040] The photosensitive composition may comprise photohardenable
or photosoftenable compositions. Examples of both are provided in
U.S. Pat. No. 4,399,209.
[0041] In one embodiment of the invention full color images are
formed. In this embodiment, the photosensitive layer 14 contains a
mixture of microcapsules having distinct wavelength sensitivities
and containing cyan, magenta, yellow and optionally black color
formers. See U.S. Pat. Nos. 4,751,165 and 4,842,976. The
microcapsules are mixed and coated with a developer-containing
resin as described above, plus carrier of the invention. If the
microcapsules are respectively sensitive to red, green, and blue
light, the imaging sheet can be exposed by direct transmission or
reflection imaging. In most cases, however, the microcapsules have
distinct sensitivities in the ultraviolet spectrum. In this case,
color separation or image processing is required to expose the
imaging sheet. Using color separations, the imaging sheet is
exposed to three distinct bands of ultraviolet radiation through
the color separation in order to control the release and transfer
of the cyan, magenta, and yellow color formers. Alternatively, a
color image is resolved into its red, green, blue, and optionally
black components each of which is then respectively electronically
translated into radiation to which the photosensitive composition
associated with the complimentary color former is sensitive. The
exposure device will control three or four distinct bands of
radiation which may be emitted from a single radiation source or a
plurality of sources. For example, a Dunn or matrix camera may be
used to produce electronic signals corresponding to the cyan,
magenta, and yellow (and optionally black) images that are desired.
This output drives the electronic control means for an exposure
device which may include a conventional multiplexer logic package
and timing means. The exposure device selectively drives a
radiation source to which the microcapsules on the imaging sheet
are sensitive and thereby image-wise exposes the imaging sheet.
Various imaging apparatuses are described in U.S. Pat. No.
4,751,165.
[0042] The receptor surface for the image and non-image areas is
preferably a textile such as a shirt (e.g., tee shirt) or the like.
However, any receptor capable of receiving the imaging material
(e.g. image and non-image areas) of the imaging sheet and imparting
the desired washproof properties is within the scope of the
invention. Other suitable receptor surfaces include canvas, wool,
plastic, ceramic, leather, paper, glass or receptor supports used
by the museum or conservatory industry.
[0043] The imaging sheet comprises a suitable support or substrate
which may be any type of known material ordinarily used as a
support for imaging materials (e.g. paper, plastic coated papers,
PET resins, etc.). The carrier material capable of holding
developed image and non-image areas which can then be transferred
to a receptor surface is coated on the support or substrate with
either microcapsules or developer, or both.
[0044] One requirement of a suitable carrier of the invention is
that it adhere strongly to fibrous supports, and optionally to
glassy supports. Moreover, the carrier of the invention must not
necessarily be entirely "inert". That is, since the life of a
transferred product (e.g. image transferred to a tee shirt) is
measured in months or years rather than decades, adverse affect on
image stability is not considered problematic. This expected short
life of the ultimate product allows for the selection of less
expensive materials. Further, other properties may be similarly
reoptimized, if necessary, in view of the expected short life of
the product.
[0045] The carrier of the invention must also be capable of
transfer from the support (e.g. imaging sheet) and adherence to a
receptor support without the requirement of a separate surface
adhesive layer. Without being bound by any theory, upon back
surface heating of the support, the carrier would undergo a solid
to solution phase transition resulting in a transfer to the
receiving layer. Edge to edge adhesion, to the receiving layer,
would occur upon cooling of the carrier onto the receiving layer.
Upon cooling, an image layer would be completely transferred onto
the receiving element. The carrier of the invention provides
mechanical and thermal stability, as well as washability.
[0046] The carrier should provide a colorfast image (e.g. washproof
or wash resistant) when transferred to the receptor surface. That
is, upon washing the receptor element (e.g. tee shirt), the image
should remain intact on the receptor element.
[0047] Suitable carriers of the invention are exemplified below.
However, it is easy to screen for suitable carriers without undue
experimentation in view of the performance criteria discussed in
this application. For instance, see the Examples discussed below
for suitable screening protocol. Further, the carriers of the
invention may be mixed with conventional carriers so long as the
amount of conventional carrier does not adversely affect the
transfer properties of the carrier.
[0048] The clear thermoplastic protective material of the invention
includes, for instance, vinyl resins such as ethylene/vinyl acetate
copolymers, resin esters, vinyl alcohol/vinyl acetate copolymers,
vinyl alkyl ether/maleic anhydride copolymers, polyvinyl chloride,
vinyl chloride/vinyl acetate copolymers and the like, acrylic
resins such as polyethyl acrylate, polybutyl methacrylate,
polymethyl cyanoacrylate and the like, styrene resins, polyamide
resins and waxes. The selected thermoplastic material should
liquify under heat/pressure during transfer and resolidify when
cool. This material protects against abrasion and inadvertent
exposure to water.
[0049] Suitable carrier materials include the compositions from
U.S. Pat. Nos. 5,501,902, 5,271,990 and 5,242,739. The contents of
U.S. Pat. Nos. 5,501,902, 5,271,990 and 5,242,739 are herein
incorporated by reference. These patents are discussed in turn
hereinbelow.
[0050] The carrier of the present invention utilizes the materials
of the second layer of U.S. Pat. No. 5,501,902.
[0051] The carrier preferably includes particles of a thermoplastic
polymer having dimensions of from about 1 to about 50 micrometers,
preferably about 1 to about 20 micrometers. The particles will more
preferably have dimensions of from about 2 to about 10 micrometers.
In general, the thermoplastic polymer can be any thermoplastic
polymer which meets the criteria set forth herein. Desirably, the
powdered thermoplastic polymer will be selected from the group
consisting of polyolefins, polyesters, and ethylene-vinyl acetate
copolymers.
[0052] The carrier also includes from about 10 to about 50 weight
percent of a film-forming binder, based on the weight of the
thermoplastic polymer. Desirably, the amount of binder will be from
about 10 to about 30 weight percent. In general, any film-forming
binder may be employed which meets the criteria set forth herein.
When the second layer includes a cationic polymer, a nonionic or
cationic dispersion or solution may be employed as the binder.
Suitable binders include polyacrylates, polyethylenes, and
ethylenevinyl acetate copolymers. The latter are particularly
desired because of their stability in the presence of cationic
polymers. The binder desirably will be heat softenable at
temperatures of about 120.degree. Celsius or lower.
[0053] The basis weight of the carrier layer may vary as desired,
but preferably the carrier is cumulatively present amongst all the
layers in an amount from about 5 to about 30 g/m.sup.2. Desirably,
the basis weight will be from about 10 to about 20 g/m.sup.2. The
carrier layer(s) can be applied to the support, either directly or
over another layer, by means well known to those having ordinary
skill in the art. For example, the layer may be applied by curtain
coating, Meyer rod, air knife, and gravure coating, by way of
illustration only.
[0054] When the imaging element is intended to be used as a
heat-transfer material, the carrier will have a melting point of
from about 65 to about 180 degrees Celsius. The term "melts" and
variations thereof are used herein only in a qualitative sense and
are not meant to refer to any particular test procedure. Reference
herein to a melting temperature or range is meant only to indicate
an approximate temperature or range at which a polymer or binder
melts and flows under the conditions of a melt-transfer process to
result in a substantially smooth film.
[0055] Manufacturers' published data regarding the melt behavior of
polymers or binders correlate with the melting requirements
described herein. It should be noted, however, that either a true
melting point or a softening point may be given, depending on the
nature of the material. For example, materials such a polyolefins
and waxes, being composed mainly of linear polymeric molecules,
generally melt over a relatively narrow temperature range since
they are somewhat crystalline below the melting point.
[0056] Melting points, if not provided by the manufacturer, are
readily determined by known methods such as differential scanning
calorimetry. Many polymers, and especially copolymers, are
amorphous because of branching in the polymer chains or the
side-chain constituents. These materials begin to soften and flow
more gradually as the temperature is increased. It is believed that
the ring and ball softening point of such materials, as determined
by ASTM E-28, is useful in predicting their behavior. Moreover, the
melting points or softening points described are better indicators
of performance than the chemical nature of the polymer or
binder.
[0057] When the material is intended to be used as a heat-transfer
material, the carrier desirably also will contain from about 2 to
about 20 weight percent of a cationic polymer, based on the weight
of the thermoplastic polymer. The cationic polymer may be, for
example, an amide-epichlorohydrin polymer, polyacrylamides with
cationic functional groups, polyethyleneimines, polydiallylamines,
and the like. When a cationic polymer is present, a compatible
binder should be selected. The binder desirably will be a nonionic
binder, either in the form of a solution or a nonionic or cationic
dispersion or emulsion. As is well known in the paper coating art,
many commercially available binders have anionically charged
particles or polymer molecules. These materials are generally not
compatible with the cationic polymer which may be used in the
present invention.
[0058] One or more other components may be used in the carrier. For
example, the carrier may contain from about 1 to about 20 weight
percent of a humectant, based on the weight of the thermoplastic
polymer. Desirably, the humectant will be selected from the group
consisting of ethylene glycol and poly(ethylene glycol). The
poly(ethylene glycol) typically will have a weight average
molecular weight of from about 100 to about 40,000. A poly(ethylene
glycol) having a weight-average molecular weight of from about 200
to about 800 is particularly useful.
[0059] The carrier also may contain from about 0.2 to about 10
weight percent of a fluid (e.g. ink) viscosity modifier, based on
the weight of the thermoplastic polymer. The viscosity modifier
desirably will be a poly(ethylene glycol) having a weight-average
molecular weight of from about 100,000 to about 2,000,000. The
poly(ethylene glycol) desirably will have a weight-average
molecular weight of from about 100,000 to about 600,000.
[0060] Other components which may be present in the carrier layer
include from about 0.1 to about 5 weight percent of a weak acid and
from about 0.5 to about 5 weight percent of a surfactant, both
based on the weight of the thermoplastic polymer. A particularly
useful weak acid is citric acid. The term "weak acid" is used
herein to mean an acid having a dissociation constant less than one
(or a negative log of the dissociation constant greater than
1).
[0061] The surfactant may be an anionic, a nonionic, or a cationic
surfactant. When a cationic polymer is present in the carrier, the
surfactant should not be an anionic surfactant.
[0062] Desirably, the surfactant will be a nonionic or cationic
surfactant. However, in the absence of the cationic polymer, an
anionic surfactant may be used, if desired. Examples of anionic
surfactants include, among others, linear and branched-chain sodium
alkylbenzenesulfonates, linear and branched-chain alkyl sulfates,
and linear and branched-chain alkyl ethoxy sulfates. Cationic
surfactant include, by way of illustration, tallow
trimethylammonium chloride. Examples of nonionic surfactants,
include, again by way of illustration only, alkyl polyethoxylates,
polyethoxylated alkylphenols, fatty acid ethanol amides, complex
polymers of ethylene oxide, propylene oxide, and alcohols, and
polysiloxane polyethers. More desirably, the surfactant will be a
nonionic surfactant.
[0063] For heat transfer applications, the material of the
invention may optionally have a melt-transfer layer located above
the support and below the layers containing microcapsules,
developer or both. Such a melt-transfer film layer typically
comprises a film forming binder, as already described, or other
polymer. The layer desirably is applied by extrusion coating, but
other methods also may be used. The melt-transfer film layer
desirably is formed from a polyethylene or a copolymer of ethylene
with acrylic acid, methacrylic acid, vinyl acetate, or acrylic acid
esters such as ethyl acrylate. The polymer desirably will have a
melt flow rate of at least about 30 grams per 10 minutes (g/10
minutes), as determined in accordance with ASTM Method D-1238,
although the melt flow rate may be as high as about 4,000 g/10
minutes. More desirably, the melt flow rate of the polymer will be
from about 300 to about 700 g/10 minutes. The basis weight of the
melt-transfer film layer desirably will be from about 10 to about
50 grams per square meter (g/m.sup.2), with a basis weight of from
about 30 to about 50 being more desired.
[0064] A release layer may be included, either in place of or in
addition to the melt-transfer film layer. In the former instance,
the release layer will be placed above the support and below the
microcapsule containing layer(s). In the latter instance, the
release layer will be placed between the support and the
melt-transfer film layer. The release layer desirably will be a low
molecular weight ethylene-acrylic acid copolymer applied from an
aqueous dispersion. The melt flow rate of the ethylene-acrylic acid
copolymer desirably will be at least about 200 g/10 minutes, more
desirably from about 800 to about 1,200 g/10 minutes. Such
dispersion also may contain a paraffin wax, which is mixed as an
emulsion with the ethylene-acrylic acid copolymer dispersion. The
paraffin wax emulsion can be any of those which are commercially
available, such as Chemwax .RTM.40 (Chematron, Inc., Charlotte,
N.C.). The ratio of paraffin wax to the copolymer may vary from 0
to about 4, with a ratio of about 1 being more desirable. The basis
weight of the release layer desirably will be from about 2 to about
20 g/m.sup.2, more desirably from about 6 to about 10 g/m.sup.2.
The release coating as described melts easily and provides easy
release from the first layer for hand ironing of images onto a
fabric; such characteristic is especially useful if heating of the
image is irregular, which is not atypical of hand-ironing
techniques.
[0065] The various layers of the imaging material are formed by
known coating techniques, such as by roll, blade, curtain coating
and air-knife coating procedures. The resulting material, then is
dried by means of, for example, steam-heated drums, air
impingement, radiant heating, or some combination thereof. Some
care must be exercised, however, to assure that drying temperatures
are sufficiently low so that the particles of thermoplastic polymer
present in the carrier layer do not melt during the drying process
(e.g. air impingement for 5 minutes or more at 80.degree.
Celsius).
[0066] Heat transfer of an image in the imaging material of the
present invention may be by any known means, such as by a hand-held
iron or a heat transfer press. The transfer temperature typically
will be from about 120.degree. to about 205.degree. Celsius, for
from about 5 seconds to about 2 minutes.
[0067] Accordingly; the carrier of the invention may comprise
particles of a thermoplastic polymer preferably having dimensions
of from about 1 to about 50 micrometers, preferably about 1 to
about 20 micrometers, and more preferably from about 2 to about 10
micrometers, from about 10 to about 50 weight percent of a
film-forming binder, based on the weight of the thermoplastic
polymer, and from about 0.2 to about 10 weight percent of a
viscosity modifier, based on the weight of the thermoplastic
polymer.
[0068] The carrier preferably has a melting point of more than
100.degree. C. and more preferably from about 100 to about 180
degrees Celsius. The carrier may also contain from about 2 to about
20 weight percent of a cationic polymer, based on the weight of the
thermoplastic polymer. The carrier may also contain from about 1 to
about 20 weight percent of a humectant, based on the weight of the
thermoplastic polymer. The humectant may be (1) ethylene glycol or
(2) polyethylene glycol (e.g. having a weight-average molecular
weight of from about 100 to about 40,000, preferably about 200 to
about 800) The viscosity modifier may be a polyethylene glycol
having a weight average molecular weight of from 100,000 to about
2,000,000, preferably from about 100,000 to about 600,000. The
viscosity modifier may be low or high viscosity methyl cellulose or
polyvinyl alcohol.
[0069] The carrier may also include about 0.1 to about 5 weight
percent of a weak acid, based on the weight of the thermoplastic
polymer. The carrier may also include about 0.5 to about 5 weight
percent of a surfactant (e.g. nonionic or cationic), based on the
weight of the thermoplastic polymer.
[0070] A release layer is optionally interposed between the support
and the layers containing carrier of the invention.
[0071] The carrier preferably melts above 100.degree. C., more
preferably, from about 100 to about 180 degrees Celsius and may
comprise particles of a thermoplastic polymer having dimensions of
about 1 to about 20 micrometers, more preferably from about 2 to
about 10 micrometers, from about 10 to about 50 weight percent of a
film-forming binder, based on the thermoplastic polymer, and from
about 2 to about 20 weight percent of a cationic polymer, based on
the weight of the thermoplastic polymer.
[0072] The carrier may further comprise from about 1 to about 20
weight percent of a humectant, based on the weight of the
thermoplastic polymer (and optionally from about 0.2 to about 10
weight percent of a fluid (e.g. ink) viscosity modifier, based on
the weight of the thermoplastic polymer), and from 0.5 to about 5
weight percent of a surfactant, based on the weight of the
thermoplastic polymer.
[0073] The carrier of the present invention also utilizes the
materials of the image receptive melt-transfer film layer of U.S.
Pat. No. 5,271,990.
[0074] The carrier may be comprised of a thermoplastic polymer
which preferably melts at above 100.degree. C., and preferably in
the range of from about 100 to about 180 degrees Celsius(.degree.
C.). In another embodiment, the thermoplastic polymer melts in the
range of from about 100.degree. C. to about 120.degree. C.
[0075] The nature of the thermoplastic polymer (e.g. carrier) is
not known to be critical, but generally it should be inert (e.g.
not adversely affecting the properties relating to the image). That
is, any known thermoplastic polymer can be employed so long as it
meets the criteria specified herein (e.g. image life of months or
years rather than decades). Preferably, the thermoplastic polymer
is selected from the group consisting of polyolefins, polyesters,
and ethylene-vinyl acetate copolymers, preferably having a particle
size of less than 50, preferably less than 20 and more preferably
less than 10 micrometers.
[0076] If desired, as already noted, the imaging material
containing the carrier of the invention may optionally have a
melt-transfer film layer. In this instance, the melt-transfer film
layer overlays the top surface of the base sheet and the
microcapsule layers overlays the melt transfer film layer.
[0077] In general, the melt-transfer film layer is comprised of a
first thermoplastic polymer and the microcapsule containing layers
are comprised of a second thermoplastic polymer, each of which
melts preferably above 100.degree. C., and preferably in the range
of from about 100.degree. C. to about 180.degree. C. Preferably,
the first thermoplastic polymer is selected from the group
consisting of polyolefins, polyesters, ethylene-vinyl acetate
copolymers, ethylene-methacrylic acid copolymers, and
ethylene-acrylic acid copolymers. In addition, the second
thermoplastic polymer preferably is selected from the group
consisting of polyolefins, polyesters, and ethylene-vinyl acetate
copolymers.
[0078] The term "melts" and variations thereof are used herein only
in a qualitative sense and are not meant to refer to any particular
test procedure. Reference herein to a melting temperature or range
is meant only to indicate an approximate temperature or range at
which a thermoplastic polymer melts and flows under film forming
conditions to result in a substantially smooth film.
[0079] The carrier may comprise a thermoplastic polymer selected
from the group consisting of polyolefins, polyesters, and
ethylene-vinyl acetate copolymers and which melts preferably above
100.degree. C., and preferably in the range of from about 100 to
about 180 degrees Celsius, and preferably in the range of about 100
to about 120 degrees Celsius.
[0080] An example of the carrier of the invention is Elvax 3200
supplied by E. I. Du Pont de Nemours & Company, Inc., Polymer
Products Department, Ethylene Polymers Division, Wilmington, Del.
Elvax 3200 is an ethylene-vinyl acetate copolymer containing
approximately 25% vinyl acetate and modified with wax. It has a
melt index of 32 g/10 minutes. Another carrier of the invention is
Surlyn 1702 also supplied by DuPont. Surlyn 1702 is an ionomer
consisting of a cross-linked ethylene-methacrylic acid copolymer
having a melt index of 14 g/10 minutes. These carriers may be
utilized separately or together.
[0081] The carrier of the present invention also utilizes the
materials of the image-receptive melt-transfer film layer of U.S.
Pat. No. 5,242,739.
[0082] The carrier may comprise from about 15 to about 80 percent
by weight of a film-forming binder selected from the group
consisting of ethylene-acrylic acid copolymers, polyolefins, and
waxes and from about 85 to about 20 percent by weight of a powdered
thermoplastic polymer selected from the group consisting of
polyolefins, polyesters, polyamides, waxes, epoxy polymers,
ethylene-acrylic acid copolymers, and ethylene-vinyl acetate
copolymers, wherein each of said film-forming binder and said
powdered thermoplastic polymer melts about 100.degree. C.,
preferably in the range of from about 100 to about 180 degrees
Celsius and said powdered thermoplastic is of particles which are
from about 1 to about 50 micrometers, preferably about 1 to about
20 micrometers in diameter.
[0083] Thus, the carrier comprises from about 15 to about 80
percent by weight of a film-forming binder and from about 85 to
about 20 percent by weight of a powdered is thermoplastic polymer.
Each of the film-forming binder and powdered thermoplastic polymer
melts above 100.degree. C., preferably in the range of from about 1
to about 180 degrees Celsius (.degree. C.). In addition, the
powdered thermoplastic polymer is preferably composed of particles
having diameters of from about 1 to about 20 micrometers.
[0084] In other embodiments, each of the film-forming binder and
powdered thermoplastic polymer preferably melt above 100.degree.
C., preferably in the range of from about 100.degree. C. to about
120.degree. C.
[0085] The function of the powdered thermoplastic polymer is to
assist in the transferring of an image to a fabric, both in terms
of ease of transfer and the permanence of the transferred
image.
[0086] The nature of the film-forming binder is not known to be
critical. That is, any film-forming binder can be employed so long
as it meets the criteria specified herein. In preferred
embodiments, the film-forming binder has, at the transfer
temperature, a lower melt viscosity than the powdered thermoplastic
polymer. As a practical matter, water-dispersible ethylene-acrylic
acid copolymers have been found to be especially effective film
forming binders.
[0087] In general, the powdered thermoplastic polymer can be any
thermoplastic polymer which meets the criteria set forth herein.
Preferably, the powdered thermoplastic polymer is selected from the
group consisting of polyolefins, polyesters, and ethylene-vinyl
acetate copolymers.
[0088] The powdered thermoplastic polymer flow partially into the
fiber matrix of the fabric to which an image is being transferred.
The result is a fabric having an image which does not render the
fabric stiff. Moreover, the image itself is neither rubbery nor
rough to the feel and is stable to repeated washings.
[0089] If desired, as already noted, the imaging material
containing the carrier of the invention may optionally have a
melt-transfer film layer. In this instance, the melt-transfer film
layer overlays the top surface of the base sheet and the imaging
layers overlay the melt-transfer film layer.
[0090] The melt-transfer film layer comprises a film-forming binder
as already described. The image-receptive film layer preferably
comprises from about 15 to about 80 percent by weight of a
film-forming binder (e.g. ethylene-acrylic acid copolymers;
polyolefins and waxes which melt in the range of about 65 to about
180 degrees Celsius). The melt transfer layer may also contain from
about 85 to about 20 percent by weight of a powdered thermoplastic
polymer, each of which are as already defined.
[0091] As a general rule, the amount of powdered thermoplastic
polymer employed can be reduced if larger particle sizes are
employed. However, it is believed that the smaller the
thermoplastic bead, the better. Particle sizes are 1-50
micrometers, preferably from 1-20 micrometers and more preferably
2-10 micrometers.
[0092] If desired, any of the foregoing film layers can contain
other materials, such as processing aids, release agents,
deglossing agents, antifoam agents, and the like. The use of these
and other like materials is well known to those having ordinary
skill in the art.
[0093] Representative binders and powdered thermoplastic polymers
are as follows:
Binder A
[0094] Binder A is Michem.RTM. 58035, supplied by Michelman, Inc.,
Cincinnati, Ohio. This is a 35 percent solids dispersion of Allied
Chemical's AC 580, which is approximately 10 percent acrylic acid
and 90 percent ethylene. The polymer reportedly has a softening
point of 102.degree. C. and a Brookfield viscosity of 0.65 pa s
(650 centipoise) at 140.degree. C.
Binder B
[0095] This binder is Michem.RTM. Prime 4983 (Michelman, Inc.,
Cincinnati, Ohio). The binder is a 25 percent solids dispersion of
Primacor.RTM. 5983 made by Dow Chemical Company. The polymer
contains 20 percent acrylic acid and 80 percent ethylene. The
copolymer has a Vicar softening point of 43.degree. C. and a ring
and ball softening point of 100.degree. C. The melt index of the
copolymer is 500 g/10 minutes (determined in accordance with ASTM
D-1238).
Binder C
[0096] Binder C is Michem.RTM. 4990 (Michelman, Inc., Cincinnati,
Ohio). The material is 35 percent solids dispersion of
Primacor.RTM. 5990 made by Dow Chemical Company. Primacor.RTM. 5990
is a copolymer of 20 percent acrylic acid and 80 percent ethylene.
It is similar to Primacor.RTM. 5983 (see Binder B), except that the
ring and ball softening point is 93.degree. C. The copolymer has a
melt index of 1,300 g/10 minutes and Vicat softening point of
39.degree. C.
Binder D
[0097] This binder is Michem.RTM. 37140, a 40 percent solids
dispersion of a Hoechst-Celanese high density polyethylene. The
polymer is reported to have a melting point of 100.degree. C.
Binder E
[0098] This binder is Michem.RTM. 32535 which is an emulsion of
Allied Chemical Company's AC-325, a high density polyethylene. The
melting point of the polymer is about 138.degree. C. Michem.RTM.
32535 is supplied by Michelman, Inc., Cincinnati, Ohio.
Binder F
[0099] Binder F is Michem.RTM. 48040, an emulsion of an Eastman
Chemical Company microcrystalline wax having a melting point of
88.degree. C. The supplier is Michelman, Inc., Cincinnati,
Ohio.
Powdered Thermoplastic Polymer A
[0100] This powdered polymer is Microthene.RTM. FE 532, an
ethylenevinyl acetate copolymer supplied by Quantum Industries,
Cincinnati, Ohio. The particle size is reported to be 20
micrometers. The vicat softening point is 75.degree. C. and the
melt index is 9 g/10 minutes.
Powdered Thermoplastic Polymer B
[0101] Powdered Thermoplastic Polymer B is Aqua Polysilk 19. It is
a micronized polyethylene wax containing some
polytetrafluoroethylene. The average particle size is 18
micrometers and the melting point of the polymer is
102.degree.-118.degree. C. The material is supplied by Micro
Powders, Inc., Scarsdale, N.Y.
Powdered Thermoplastic Polymer C
[0102] This material is Microthene.RTM. FN-500, a polyethylene
powder supplied by USI Chemicals Co., Cincinnati, Ohio. The
material has a particle size of 20 micrometers, a Vicat softening
point of 83.degree. C., and a melt index of 22 g/10 minutes.
Powdered Thermoplastic Polymer D
[0103] This polymer is Aquawax 114, supplied by Micro Powders,
Inc., Scarsdale, N.Y. The polymer has a reported melting point of
91.degree.-93.degree. C. and an average particle size of 3.5
micrometers; the maximum particle size is stated to be 13
micrometers.
Powdered Thermoplastic Polymer E
[0104] Powdered Thermoplastic Polymer E is Corvel.RTM. 23-9030, a
clear polyester from the Powder Coatings Group of the Morton
Chemical Division, Morton Thiokol, Inc., Reading, Pa.
Powdered Thermoplastic Polymer F
[0105] This material is Corvel.RTM. natural nylon 20-9001, also
supplied by Morton Thiokol, Inc.
Powdered Thermoplastic Polymer G
[0106] This polymer powder is Corvel.RTM. clear epoxy 13-9020,
supplied by Morton Thiokol, Inc.
Powdered Thermoplastic Polymer H
[0107] Powdered Thermoplastic Polymer H is AClyn.RTM. 246A, which
has a melting temperature of about 95.degree. C. as determined by
differential scanning calorimetry. The polymer is an
ethylene-acrylic acid magnesium ionomer. The material is supplied
by Allied-Signal, Inc., Morristown, N.J.
Powdered Thermoplastic Polymer I
[0108] This polymer is AC-316A, an oxidized high density
polyethylene. The material is supplied by Allied Chemical Company,
Morristown, N.J.
Powdered Thermoplastic Polymer J
[0109] This polymer is Texture 5380, supplied by Shamrock
Technologies, Inc., Newark, N.J. It is powdered polypropylene
having a melting point of 165.degree. C. and an average particle
size of 40 micrometers.
[0110] The binders and thermoplastic polymers may be combined and
blended as desired. For example, Binder A (e.g. 80 parts) may be
blended with powdered thermoplastic polymer A (e.g. 80 parts) and
optionally with a fluorocarbon dispersion such as Zonyl 7040 (e.g.
0.20 parts) obtained from Du Pont. Another example includes
combining Binder B (e.g. 400 parts) and Polymer B (e.g. 70 parts)
and blending in a standard laboratory colloid mill. Also, Binder A
(e.g. 286 parts) may be combined with Polymer C (e.g. 65 parts).
Binder B (e.g. 400 parts) may be combined with Polymer D (e.g. 70
parts). Binder C (e.g. 200 parts) may be combined with Polymer E
(e.g. 35 parts) and optionally with propylene glycol (e.g. 20
parts) and water (e.g. 20 parts). Similarly, Binder C (e.g. 200
parts) may be combined with Polymer F (e.g. 54 parts) and
optionally with propylene glycol (e.g. 20 parts) and water (e.g. 20
parts). Also, Binder A (e.g. 200 parts) may be combined with
Polymer G (e.g. 30 parts) and optionally with propylene glycol
(e.g. 20 parts) and water (e.g. 20 parts). Binder D (e.g. 200
parts) may be combined with Polymer H (e.g. 30 parts) and
optionally water (e.g. 40 parts) and blended. Binder A (e.g. 286
parts) may be combined with Polymer J (e.g. 40 parts) and
optionally with propylene glycol (e.g. 50 parts)
[0111] The carrier material is present in sufficient quantity so as
to provide a colorfast image when transferred to the receptor
surface and to provide for the desired transfer. More specifically,
the carrier of the invention may be preferably present in an amount
of at least 50% by coating weight based on the total weight of the
layers present in the imaging element (excluding support). For
instance, at least 10% by weight of the thermoplastic based on the
total weight of the layer and at least 40% by weight of the binder
based on the total weight of the layer may be present in the layer.
This leaves 50% by weight based on the total weight of the layer
available for other components such as microcapsules, developer or
both. If necessary, multilayer systems can be used. In such an
imaging element, the layer or layers closest to the support may
contain the carrier of the invention, whereas the uppermost layer
or layers may contain conventional carrier(s), or a mixture of the
carrier of the invention and conventional carrier. In this way, the
bottom-most layer(s) basically serve as the transfer layer(s),
without the need of an additional transfer layer(s).
[0112] Therefore, if one layer is present, 50% by coating weight
based on the total weight of the layer may be carrier. If two
layers are present, the carrier may be present in an amount of 50%
by weight based on the total weight of the two layers. If three
layers are present, the carrier may be present in an amount of 50%
by weight based on the total weight of the three layers, and so
on.
[0113] Referring to FIG. 1, there is generally illustrated a
cross-sectional view of the element 10 of the present invention.
The element 10 comprises a suitable support or substrate 20 which
may be any type of material ordinarily used as a support for
imaging materials. Examples thereof include cellulose acetate
films, cellulose acetate propionate films, cellulose nitrate films,
cellulose acetate butyrate films, polyethylene terephthalate films,
polystyrene films, polycarbonate films, and laminated sheets of
these films and papers. Suitable papers include papers coated with
a polymer of an alpha olefin and preferably an alpha olefin having
2 to 10 carbon atoms, such as polyethylene, polypropylene, etc.,
and baryta coated papers, etc. The only limitation on the support
is that it must separate from the carrier material 30 upon
application of heat. If conventional polyolefin paper interferes
with transfer due to poor separation from the carrier material,
fiber based paper which does not contain a resin coated layer
nearest the support layer or on both surfaces is preferably
used.
[0114] The microcapsule layer(s) containing the carrier of the
invention may be optionally coated on known transfer papers such as
a transfer paper manufactured by Kimberly-Clark Corporation under
the trademark "TRANSEEZE".
[0115] An imaging support or substrate may be coated with the
desired microcapsules in a conventional manner by methods known to
one of ordinary skill in the art. The carrier of the present
invention may simply be substituted for conventional carrier(s), or
mixed with conventional carrier(s), or may replace the conventional
carrier in the bottom-most layer(s) in contact with the support. In
the latter embodiment, the number of bottom-most layers which
should be replaced is easily determined by first replacing the
bottom-most layer and then optionally subsequent layers in order to
ensure adequate transfer and adhesion.
[0116] One preferred application of this invention is directed to
transfer elements capable of producing multicolor dye images. Such
a transfer element comprises a support and a plurality of color
forming layers coated thereon. The color forming layers include at
least one blue recording yellow dye image forming layer, at least
one green recording magenta dye image forming layer, and at least
one red recording cyan dye image forming layer. Interlayers may be
positioned between the color forming layers. Each image forming
layer includes at least one microcapsule layer. The interlayers may
contain 100% carrier of the invention, or may contain conventional
materials, or a combination thereof.
[0117] Accordingly, the present invention is directed to an imaging
system (e.g. donor sheet or a self-contained single sheet system),
which comprises a support having a front and rear surface, a layer
of either microcapsules (e.g. photosensitive; heat-sensitive; color
forming), or developer or both, at least one of the layer(s) of
microcapsules or developer contains the carrier of the invention,
and an optional layer of clear thermoplastic material.
[0118] The carrier of the present invention is applicable to any
imaging system based on photosensitive or heat-sensitive
encapsulates. Thus, in an imaging system comprising (i) an imaging
sheet and developer (e.g. generally for photosensitive
microcapsules) material carried on said imaging sheet, or (ii) an
imaging sheet and a developer (e.g. generally for photosensitive
microcapsules) carried on a separate developer sheet, the imaging
sheet having a layer of an encapsulated radiation curable
photosensitive or heat sensitive composition, said imaging system
capable of forming images by image-wise exposing said imaging sheet
to radiation actinic with respect to said photosensitive or with
heat for the heat sensitive composition, and rupturing or otherwise
dissolving capsules in the presence of said developer material to
form an image, wherein the improvement comprises at least one layer
of (e.g. photosensitive or heat sensitive) microcapsules, or at
least one layer of (e.g. photosensitive or heat sensitive)
microcapsules and developer (e.g. generally for photosensitive
microcapsules) in the same layer, or at least one layer of
microcapsules and developer in separate layers, on said front
surface of the support, wherein said microcapsules, or developer or
both are dispersed in a carrier, said carrier preferably having a
melting point of at least 100.degree. C., and which is capable of
transferring and adhering developed image and non-image areas from
said front surface of said supports upon the application of heat
energy to the rear surface of the support, said carrier strips from
said front surface of the support by liquefying and releasing from
said support when heated, said liquefied carrier providing
adherence to a receptor element by flowing onto said receptor
element and solidifying thereon, said adherence does not require an
external (e.g. surface) adhesive layer and preferably occurs in an
area at least coextensive with the area of said microcapsules, with
the proviso that the carrier is not capable of reacting (e.g. with
a color precursor) to form an image, and an optional layer of clear
thermoplastic material. Preferably, the particle size of the
carrier is the same or smaller than that of the microcapsules, for
example, from 1-20 micrometers.
[0119] The present invention further relates to a developer sheet
which comprises a support having a front and rear surface, and an
optional developer material capable of reacting with a color
forming substance to form an image dispersed in the carrier of the
invention.
[0120] Another embodiment of the present invention is directed to
an imaging sheet useful in forming images onto a receptor surface,
said sheet comprising: a support having a front and rear surface, a
plurality of photosensitive or heat sensitive microcapsules and an
optional developer on the surface thereof, said microcapsules and
said developer being present on the same layer or in contiguous
layers on the surface of said support, wherein when both said
microcapsules and developer are present in the same layer, said
same layer comprises the carrier of the invention, and when the
developer and microcapsules are present in different layers, at
least one of the different layers comprises the carrier of the
invention, said microcapsules containing a color former which is
capable of reacting with said developer and forming a visible dye
image, said imaging sheet being useful for transferring image and
non-image areas onto a receptor surface. In this embodiment, the
developer may be a thermoplastic developer-containing resin.
Moreover, the microcapsules may contain an internal phase which
includes a photosensitive composition which changes in viscosity in
response to exposure to actinic radiation.
[0121] The present invention further relates of a method of
transferring image and non-image areas to a receptor element, which
comprises the steps of:
[0122] (a) exposing image-wise any of the imaging sheets of the
invention having a front surface and a rear surface,
[0123] (b) developing the image-wise exposed element to form an
image,
[0124] (c) positioning the front surface of the developed element
or positioning the undeveloped element prior to development against
a receptor element, said developed element or undeveloped element
containing the carrier of the invention, and
[0125] (d) applying heat to the rear surface of the developed or
undeveloped element to transfer the developed image and non-image
area to the receptor element.
[0126] The present invention is further directed to the
photosensitive imaging system and self-contained imaging sheet of
U.S. Pat. No. 4,440,846, which further comprises the carrier of the
present invention.
[0127] More specifically, the present invention is directed to a
photosensitive imaging system in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising:
[0128] a substrate having front and back surfaces,
[0129] a chromogenic material,
[0130] a radiation curable composition which undergoes an increase
in viscosity upon exposure to actinic radiation,
[0131] a coating containing said chromogenic material and said
radiation curable composition on one of said front and back
surfaces, and
[0132] a developer material capable of reacting with said
chromogenic material to form a visible image,
[0133] wherein either the layer containing said coating or
developer material, or both contains the carrier of the
invention,
[0134] said radiation curable composition being encapsulated in
rupturable capsules as an internal phase,
[0135] wherein images are formed by image-wise exposing said
coating to actinic radiation and rupturing said capsules in the
image areas such that said internal phase is released from said
capsules in the image areas and said chromogenic material and said
developer react pattern-wise to form an image. The internal phase
may be encapsulated in a microcapsule having a discrete capsule
wall. The chromogenic material may be encapsulated with said
radiation curable composition.
[0136] The invention further relates to a self-contained imaging
sheet in which images are formed by image-wise reaction of one or
more chromogenic materials and a developer material, said sheet
comprising:
[0137] a substrate having a front and back surface,
[0138] a chromogenic material,
[0139] a radiation curable composition which undergoes an increase
in viscosity upon exposure to actinic radiation,
[0140] a coating containing said chromogenic material and said
radiation curable composition in the carrier of the invention on
one of said front and back surfaces,
[0141] a developer material capable of reacting with said
chromogenic material to form a visible image codeposited on said
substrate with said coating containing said chromogenic
material,
[0142] said radiation curable composition being encapsulated in
rupturable capsules as an internal phase,
[0143] wherein images are formed by image-wise exposing said coated
substrate to actinic radiation, and rupturing said capsules in the
image areas such that said internal phase is released from said
capsules in the image areas and said chromogenic material
pattern-wise reacts with said developer material to form an image.
The internal phase may be encapsulated in a microcapsule having a
discrete capsule wall. The chromogenic material may be encapsulated
with said radiation curable composition.
[0144] The present invention is also directed to the transfer
imaging system of U.S. Pat. No. 4,399,209, which further comprises
the carrier of the present invention. More specifically, the
present invention is directed to a transfer imaging system in which
images are formed by image-wise reaction of one or more chromogenic
materials and a developer, said system comprising:
[0145] an imaging sheet comprising a first substrate,
[0146] a radiation curable composition which undergoes an increase
in viscosity upon exposure to actinic radiation,
[0147] a coating on one surface of said first substrate comprising
said chromogenic material and said radiation curable composition
optionally in the carrier of the invention,
[0148] said radiation curable composition being encapsulated in
rupturable capsules as an internal phase, and
[0149] a developer sheet comprising a second substrate having a
front and rear surface,
[0150] a developer material containing the carrier of the invention
on said second substrate, said developer capable of reacting with
said chromogenic material to form an image on the surface of said
second substrate,
[0151] wherein images are formed by image-wise exposing said
coating to actinic radiation, and rupturing capsules in the image
areas with said coating in facial contact with said developer sheet
such that said internal phase is image-wise released from said
ruptured capsules and there is image-wise transfer of said
chromogenic material to said developer sheet and a patterned
image-forming reaction occurs between said chromogenic material and
said developer material. The capsule may be a microcapsule having a
discrete capsule wall. The chromogenic material may be encapsulated
with said radiation curable composition.
[0152] Moreover, the invention is directed to the transfer imaging
system of U.S. Pat. No. 4,551,407 which further comprises the
carrier of the present invention. Thus, the present invention
relates to a transfer imaging system in which images are formed by
image-wise reaction of one or more chromogenic materials and a
developer, said system comprising:
[0153] an imaging sheet comprising a first substrate,
[0154] a chromogenic material,
[0155] a photodepolymerizable composition which undergoes a
decrease in viscosity upon exposure to actinic radiation,
[0156] a coating on one surface of said first substrate comprising
said chromogenic material and said photodepolymerizable composition
optionally dispersed in the carrier of the invention,
[0157] said photodepolymerizable composition being encapsulated in
rupturable capsules as an internal phase, and
[0158] a developer sheet comprising a second substrate having a
front and rear surface,
[0159] a developer material containing the carrier of the invention
on said second substrate, said developer capable of reacting with
said chromogenic material to form an image on the surface of said
second substrate,
[0160] wherein images are formed by image-wise exposing said
coating to actinic radiation, and rupturing said capsules in the
exposed areas with said coating in facial contact with said
developer sheet such that said internal phase is image-wise
released from said ruptured capsules and there is image-wise
transfer of said chromogenic material to said developer sheet and a
patterned image-forming reaction occurs between said chromogenic
material and said developer material. The capsule may be a
microcapsule having a discrete capsule wall. The chromogenic
material may be encapsulated with said photodepolymerizable
composition.
[0161] In addition, the present invention relates to the
photosensitive imaging system and self-contained imaging sheet of
U.S. Pat. No. 4,536,463, which further comprises the carrier of the
present invention. Thus, the present invention relates to a
photosensitive imaging system (or, self-contained sheet) in which
images are formed by image-wise reaction of one or more chromogenic
materials and a developer, said system (or sheet) comprising a
substrate having front and back surfaces,
[0162] a chromogenic material,
[0163] a composition which undergoes a decrease in viscosity upon
exposure to actinic radiation,
[0164] a coating containing said chromogenic material and the
carrier of the invention, and said composition on one of said front
and back surfaces, and
[0165] developer material capable of reacting with said chromogenic
material to form a visible image,
[0166] said composition being encapsulated in rupturable capsules
as an internal phase,
[0167] wherein images are formed by image-wise exposing said
coating to actinic radiation and rupturing said capsules in the
exposed areas and said chromogenic material and said developer
react pattern-wise to form an image. The internal phase may be
encapsulated in a microcapsule having a discrete capsule wall. The
chromogenic material may be encapsulated with said photosensitive
composition.
[0168] The invention is further directed to the imaging sheet of
U.S. Pat. No. 4,822,714, which further comprises the carrier of the
present invention. Accordingly, the present invention is directed
to an imaging sheet useful in forming images by
exposure-controlled, image-wise reaction of a chromogenic material
and a developer, said sheet comprising:
[0169] a support having a front and rear surface,
[0170] a layer of microcapsules and the carrier of the invention on
said transfer coating,
[0171] said microcapsules having discrete capsule walls which
encapsulate an internal phase,
[0172] said internal phase, including a photosensitive composition
which undergoes a change in viscosity sufficient to control the
release of the internal phase from said microcapsule,
[0173] a chromogenic material associated with said microcapsule
such that, upon image-wise exposing said layer of microcapsules to
actinic radiation and subjecting said layer of microcapsules to a
uniform rupturing force, said chromogenic material image-wise
becomes available for reaction with a developer to form an
image.
[0174] Furthermore, the invention is directed to the imaging system
of U.S. Pat. No. 4,416,966 which further comprises the carrier of
the present invention. Thus, the present invention is directed to
an imaging system comprising:
[0175] an imaging sheet and
[0176] a background dye or a combination of a dye precursor and a
dye developer which react to form a background dye,
[0177] said imaging sheet including:
[0178] a support having a front and rear surface,
[0179] a plurality of capsules and the carrier of the invention in
a layer on one surface of said support, and
[0180] an internal phase contained within said capsules comprising
a decolorizing agent and a photohardenable or photosoftenable
radiation sensitive composition,
[0181] wherein images can be formed by image-wise exposing said
sheet to actinic radiation and rupturing said capsules such that
said decolorizing agent is image-wise released from said capsules
and reacts with said associated background dye to decolorize it or
inhibits, prevents or reverses the color forming reaction of said
dye precursor and dye developer to produce a color difference in
the form of an image.
[0182] The invention is further directed to the imaging material of
U.S. Pat. No. 4,788,125 which further comprises the carrier of the
present invention.
[0183] The term "microparticle" is used herein to define a particle
formed from an admixture of an image-forming agent and a
photosensitive composition containing a depolymerizable polymer.
The term "microparticle" is to be distinguished from the term
"microcapsule" which is defined in U.S. Pat. Nos. 4,399,209 and
4,440,846 as a capsule having a discrete capsule wall or an
encapsulated dispersion of a photosensitive composition in a
binder.
[0184] Thus, the present invention is directed to an imaging
material comprising a support having a front and rear surface, and
a layer of photosensitive microparticles and carrier of the
invention on one surface of said support, said microparticles
including an image-forming agent and a photosensitive composition
containing a polymer which is capable of undergoing
cationically-initiated depolymerization and a photoinitiator
including a silver halide and an organo silver salt, wherein, after
exposing said microparticle to radiation, said microparticles,
directly or with additional processing, release said image-forming
agent or become permeable to a developer which reacts with said
image-forming agent to form a visible image.
[0185] The microparticles may comprise a first set of
microparticles containing a cyan image-forming material having a
first wavelength sensitivity, a second set of microparticles
containing a magenta image-forming material having a second
wavelength sensitivity, and a third set of microparticles
containing a yellow image-forming material having a third
wavelength sensitivity, said first, second, and third sensitivities
being sufficiently different that upon exposing said imaging
material to a first radiation, substantially only said first
microparticles release said image-forming material, upon exposing
said imaging material to a second radiation different than said
first radiation, substantially only said second set of
microparticles release said image-forming material, and upon
exposing said imaging material to a third radiation different than
said first and second radiations, substantially only said third set
of microparticles release said image-forming material.
[0186] The image-forming agent may be a colored dye or pigment.
[0187] The image-forming agent may be a chromogenic material and a
developer material associated with said imaging material may be
capable of reacting with said chromogenic material and forming a
visible image.
[0188] The first, second, and third radiation may be respectively
red, green and blue light.
[0189] Also, the present invention is directed to the color imaging
system of U.S. Pat. No. 4,842,976 which further comprises the
carrier of the present invention. Thus, the present invention is
directed to
[0190] a color imaging system comprising:
[0191] an imaging sheet having a front and rear surface, and dry
developer material dispersed in the carrier of the invention and
carried on said imaging sheet, or
[0192] an imaging sheet, a separate image receiving developer sheet
having a front and rear surface and a dry developer material
dispersed in the carrier of the invention on said front
surface,
[0193] said imaging sheet having on the front surface thereof a
coating comprising a cyan color precursor,
[0194] a radiation curable photosensitive composition associated
with said cyan color precursor,
[0195] a magenta color precursor,
[0196] a radiation curable photosensitive composition associated
with said magenta color precursor,
[0197] a yellow color precursor, and
[0198] a radiation curable photosensitive composition associated
with said yellow color precursor,
[0199] said radiation curable photosensitive compositions having
distinct sensitivities and being encapsulated in pressure
rupturable capsules as an internal phase,
[0200] said capsules having discrete capsule walls,
[0201] said cyan, magenta and yellow color precursors being soluble
in said associated photosensitive compositions or solvents for said
color precursors being encapsulated with said associated
photosensitive compositions and
[0202] said color precursors being present in said capsules with
said photosensitive compositions or in said discrete walls;
[0203] said imaging system being capable of forming images by
image-wise exposing said imaging sheet to radiation actinic with
respect to said photosensitive compositions, and rupturing at least
said capsules containing photosensitive compositions unexposed by
said actinic radiation in the presence of said developer material
to form an image by reaction of said color precursors with said
developer material.
[0204] The cyan, magenta and yellow color precursors may be
encapsulated in pressure rupturable capsules with their associated
radiation curable photosensitive compositions.
[0205] The invention is also applicable to "thermo-autochrome"
technology of Fuji Photo Film Co., Ltd., such as direct thermal
recording paper capable of full color imaging utilizing, for
example, a diazonium salt compound as a color forming material. As
a result of the present invention, the thermo-autochrome materials
will be capable of being transferred to a receptor element, thereby
opening new markets not previously contemplated. The
thermo-autochrome technology is well known in the art.
[0206] In the preferred embodiment of the invention involving
thermo-autochrome technology, a light-fixable thermal recording
material is prepared by coating a heat responsive microcapsule
containing a diazonium salt compound, a coupler, an a
reaction-accelerating organic base, along with the carrier of the
invention, optionally in one or more layers, on a substrate. Upon
heating, the coupler and organic base diffuse into the microcapsule
and a coupling reaction occurs to form an azo dye. Then, the entire
print is irradiated with light, the wave length of which
corresponds to the absorption of the diazonium salt compound.
Unused diazonium salt compound is photo-decomposed and the image is
fixed.
[0207] In another embodiment of the invention, a light-fixable
thermal recording material is prepared by coating a heat-responsive
microcapsule containing an oxidizable dye precursor in combination
with a photo-radical generator, and a reducing agent (radical
killer), plus carrier of the invention, on a substrate optionally
in one or more layers. Upon heating, reducing agent diffuses into
the microcapsule to form a latent image. The entire print is
irradiated with light wherein the wavelength thereof corresponds to
the absorption of the radical generator in each capsule, forming a
radical. The radical is deactivated in a heated microcapsule by the
reducing agent which diffused into the capsule, and no color
formation occurs. The oxidizable dye precursor is oxidized by the
radical (dehydrogenation) in an unheated microcapsule and a color
is obtained. Upon heating again, no color change occurs and the
print is fixed.
[0208] In another embodiment, a light-fixable thermal recording
material is prepared by coating a microcapsule containing an
organic cationic-dye borate anion salt compound (e.g. colored
compound) and an organic acid plus carrier of the invention
optionally in one or more layers on a substrate. Upon heating,
organic acid diffuses into the microcapsule and reacts with the
borate anion to form a latent image. The entire print is irradiated
with light wherein the wavelength thereof corresponds to the
absorption of the dye salt. In an unheated capsule, the dye salt is
activated and decolorizes (photobleaching). The borate anion is
decomposed beforehand in a heated capsule and the photobleaching
does not occur. Thus, photobleaching takes place in the unheated
portion. Because photobleaching is irreversible, no color change
occurs by successive heating or irradiation with light, and the
print is fixed.
[0209] In a further embodiment of the invention, a recording
material is prepared by coating a heat responsive microcapsule
containing a basic leuco dye (color former), a liquid vinyl monomer
and a photo radical generator, with a phenolic color developer and
the carrier of the invention, optionally in one or more layers, on
a substrate. Upon heating, the color developer diffused into the
microcapsule and reacts with the color former to form a dye. Then,
the entire print is irradiated with light wherein the wavelength
corresponds to the absorption of the photo-radical generator, and
the vinyl monomer in the microcapsule polymerized and
solidified.
[0210] In a still further embodiment of the invention, a recording
material is prepared by coating a heat responsive microcapsule
containing a basic leuco dye and a phenolic color developer having
a polymerizable vinyl group, along with the carrier of the
invention, optionally in multiple layers, on a substrate.
[0211] Of the above-mentioned methods, the diazonium salt compound
method is preferred. Usami et al., "The Development of Direct
Thermal Full Color Recording Material", J. Inf. Recording, 1996,
Vol. 22, pp. 347-357. To obtain a full color print, the imaging
material comprises a base support (e.g paper), a cyan color forming
layer, a magenta color forming layer, a yellow color forming layer
and an optional protective coating of the invention. The carrier of
the invention is incorporated into one or more of these color
forming layers. The innermost color forming layer is composed of a
basic leuco dye and a phenolic compound developer, which reacts to
form a cyan dye, plus carrier of the invention. The basic leuco dye
is encapsulated in a heat responsive microcapsule. The
magenta-color forming layer is composed of an encapsulated
diazonium salt compound which decomposes when exposed to 365 nm
ultraviolet light, an organic base, and a coupler, reacting to form
a magenta azo dye. The yellow-color forming layer is composed of an
encapsulated diazonium salt compound which decomposes when exposed
to 420 nm ultraviolet light, an organic base, and a coupler,
reacting to form a yellow azo dye.
[0212] The heat-responsive microcapsule in the yellow-color forming
layer has a high thermo sensitivity and therefore responds to low
thermal energy. The heat-responsive microcapsule in the
magenta-color forming layer has a mid-range thermo sensitivity, and
the heat-responsive microcapsule in the cyan color forming layer
has a low thermo sensitivity.
[0213] A full color print can be obtained in a five-step process.
First, the yellow color forming layer reacts to low levels of
thermal energy to generate the yellow portion of the image. Second,
the entire print is exposed with a 420 nm ultraviolet lamp which
decomposes the diazonium salt compound remaining in the
yellow-color forming layer. This exposure fixes the yellow-color
forming layer. Third, the magenta-color forming layer reacts to
mid-range levels of thermal energy to generate the magenta portion
of the image. Fourth, the entire print is exposed with a 365 nm
ultraviolet lamp, which decomposes the diazonium salt compound
remaining in the magenta-color forming layer. Finally, the
cyan-color forming layer reacts to high levels of thermal energy to
generate the cyan portion of the image.
[0214] The diazonium salt compound in the yellow color forming
layer has two photosensitivity peaks, at 355 nm and 420 nm. The
diazonium salt compound in the magenta color forming layer has a
photosensitivity peak at 365 nm. So, exposure with 420 nm
ultraviolet light can selectively decompose the diazonium salt
compound in the yellow color forming layer. A subsequent exposure
to 365 nm ultraviolet can decompose the diazonium salt compound in
the magenta color forming layer.
[0215] A diazonium salt compound gives both thermo sensitive and
light fixable properties to the yellow and magenta-color forming
layers. The diazonium salt compound is dissolved in core oil and
encapsulated in a microcapsule. The diazonium salt compound is thus
completely isolated from the coupler and the organic base, making
it stable over a long period of the time.
[0216] The coupler is used preferably in an amount of from 0.1 to
30 parts by weight per part by weight of the diazo compound. The
organic base is used preferably in an amount of from 0.1 to 30
parts by weight per part by weight of the diazo compound.
[0217] The microcapsule's wall is preferably poly(urea/urethane).
It is known that the poly(urea/urethane) wall membrane of a
microcapsule becomes permeable above its glass transition
temperature (Tg). When the color forming layer is heated above the
Tg of the capsule's wall, a coupler and an organic base instantly
permeate the wall and react with the diazonium salt compound in a
core oil to form dye.
[0218] All color forming materials must be water insoluble and oil
soluble. The diazonium salt compounds and the basic leuco dye are
dissolved in core oils and encapsulated. If the water solubility of
these materials is too high, excessive amounts of the materials
will escape to the outside of the capsule's wall. Leaking color
forming material causes color forming reactions and increases
background density. The couplers and the phenolic compound
developers are also dissolved in a hydrophobic solvent and
emulsified in the carrier of the invention or in said carrier of
the invention/gelatin mixture. Water soluble couplers and phenolic
compound developers tend to diffuse into the other color forming
layers and cause undesirable color forming reactions during
imaging.
[0219] To make diazonium salt compounds water insoluble, a counter
ion of the diazonium must be selected from hydrophobic groups such
as C.sub.8H.sub.17SO.sub.3.sup.-, PF.sub.6.sup.-, PF.sub.4.sup.- or
B (phenyl).sub.4.sup.-, and hydrophobic substituents must be
introduced to the structure.
[0220] The maximum wave length of a diazonium salt compound is
controlled by introducing a substituent group in an aromatic ring
of a benzenediazonium structure. It is known that the introduction
of an electron-donating substituent group increases the maximum
absorption wave length.
[0221] The color hues of the azo dyes, which are formed in the
yellow and magenta-color forming layers, depends on both the
diazonium salt compounds and the couplers. The color hue of the
basic dye; however, is almost completely dependent on the basic
leuco dye.
[0222] Additionally, if a silver salt is present in the imaging
material then the silver salt is preferably a non-organic silver
salt. Further, a dye donating substance is preferably not present
in the imaging material.
[0223] The image quality is evaluated with the FUJIX FOTOJOY
PRINTER NC-1.
[0224] In the thermal processing transfer systems of the present
invention, the melting point of the carrier material may be
selected as desired. For instance, if it is desired that the
carrier should not melt during the imaging of the thermal sensitive
microcapsules, then the material chosen for the carrier should have
a melting point which will survive the imaging of the material.
Then, the carrier will only melt during transfer of the image.
[0225] Heat sensitive recording materials are known in the art.
Thus, the invention is applicable to such materials and include,
for instance, materials disclosed in U.S. Pat. Nos. 5,494,772,
5,492,789, 5,304,452, 5,661,101, 5,593,938, 5,543,260, 5,525,571,
5,514,636, 5,486,446, 5,410,335, 5,409,880, 5,409,797, 5,407,777,
5,338,642, 5,328,796, 4,857,941, 4,760,048, 4,464,376, and
references cited therein.
[0226] The Thermo-Autochrome microcapsules according to the present
invention can be prepared as detailed in U.S. Pat. No. 5,492,789,
however, these procedures are merely illustrating and are not to be
considered as limiting.
[0227] In an embodiment of the present invention wherein
Thermo-Autochrome technology is employed the recording material may
be prepared by coating a support, such as paper, with at least one
coating comprising the carrier of the present invention,
Thermo-Autochrome (e.g. light-fixable heat-sensitive)
microcapsules, a coupler and an organic base. The coating procedure
according to the present invention may be accomplished by bar
coating, blade coating, air knife coating, gravure coating, roll
coating, spray coating, dip coating, curtain coating and the like.
Following each coating procedure, each layer is dried.
[0228] Recording on the (e.g. light-fixable) heat-sensitive
recording material of the present invention may be carried out as
follows. The recording material is imagewise heated with a thermal
head, etc. to soften the capsule wall whereby the coupler and the
organic base outside the capsules enter the inside of the capsules
to develop a color. After the color development, the recording
layer is exposed to light having the absorption wavelength of the
diazonium salt whereby the diazonium salt decomposes and loses its
reactivity with the coupler. As a result, the image is fixed.
[0229] Light sources for image fixation include various fluorescent
lamps, xenon lamps, and mercury lamps. It is desirable for
efficient fixation that the emission spectrum of the light source
substantially meets the absorption spectrum of the diazo compound
used.
[0230] A representative imaging sheet of the invention may be
formed as follows. A support is coated with a layer containing the
carrier of the present invention, Thermo-Autochrome microcapsules,
a coupler and an organic base. This layer is then dried. A
representative formulation of Thermo-Autochrome microcapsules,
lacking only in the carrier of the present invention, is described
in any one of Examples 3, 22, and 26 of U.S. Pat. No. 5,661,101,
and Examples 5 and 10 of U.S. Pat. No. 5,543,260.
[0231] Another embodiment concerning Thermo-Autochrome technology
and the present invention relates to an imaging system, which
comprises:
[0232] a support having a front and rear surface;
[0233] at least one thermal recording layer comprising the carrier
of the present invention and (e.g. light-fixable) thermal sensitive
microcapsules coated on said front surface of the support,
[0234] wherein said thermal recording layer is capable of
transferring and adhering an image formed by said microcapsules
from said front surface of said support upon the application of
heat energy to the rear surface of the support, said thermal
recording layer strips from said front surface of the support by
liquefying and releasing from said support when heated, said
liquefied thermal recording layer providing adherence to a receptor
element by flowing onto said receptor element and solidifying
thereon, said adherence does not require an external adhesive
layer, with the proviso that the carrier material is not capable of
reacting to form an image, and
[0235] wherein said thermal sensitive microcapsules are capable of
separating an inner phase within said microcapsules from an outer
phase contained outside said microcapsules, wherein said inner
phase is capable of reacting with said outer phase to create a
color forming element.
[0236] In the Thermo-Autochrome imaging system explained above, the
heat-responsive microcapsules have discrete capsular walls capable
of isolating said inner phase from said outer phase, wherein said
inner phase, for instance, comprises a diazonium salt compound and
said outer phase comprises a coupler and a reaction-accelerating
organic base. This outer phase also comprises the carrier of the
present invention.
[0237] In another embodiment concerning Thermo-Autochrome
technology and the present invention, the imaging system explained
above comprises an imaging sheet useful in forming images by
temperature controlled exposure of a said inner phase with said
outer phase, said sheet comprising:
[0238] a support having a front and rear surface;
[0239] a thermal transfer layer coated on said front surface of
said support, comprising the carrier of the present invention and
(e.g. light-fixable) thermal sensitive microcapsules, said
microcapsules having discrete capsule walls which encapsulate said
internal phase, said internal phase, including, for instance, a
diazonium salt compound, said outer phase comprising, for instance,
a coupler which upon an increase in temperature of said capsular
wall diffuses into said microcapsule and reacts with said inner
phase to form a color forming element.
[0240] According to the Thermo-Autochrome imaging system of the
present invention said (e.g. light-fixable) thermal recording layer
preferably comprises three separate layers, wherein each layer is
capable of generating a color selected from the group consisting of
yellow, cyan and magenta, with the proviso that each layer must
generate a different color. Said colors are generated in response
to heat. Specifically, said yellow color is generated in response
to a thermal energy level which is lower than the thermal energy
level sufficient to generate said cyan color. Additionally, said
magenta color is generated in response to a thermal energy level
which is lower than the thermal energy level sufficient to generate
said cyan color and which is higher than the thermal energy level
sufficient to generate said yellow color.
[0241] The yellow and cyan colors are fixed by exposure to
ultraviolet radiation. Specifically, the yellow color is fixed in
response to radiation having a 420 nm wavelength and the cyan color
is fixed in response to radiation having a 365 nm wavelength.
[0242] In another embodiment concerning Thermo-Autochrome
technology and the present invention, the imaging system also
relates to an imaging sheet useful in forming images onto a
receptor surface, said sheet comprising:
[0243] a support having a front and rear surface;
[0244] a transfer layer coated on said front surface of said
support, comprising the carrier of the present invention and (e.g.
light-fixable) thermal sensitive microcapsules, said microcapsules
having discrete capsule walls which encapsulate said internal
phase, said internal phase, including a diazonium salt compound,
said outer phase comprising a coupler which upon an increase in
temperature of said capsular wall diffuses into said microcapsule
and reacts with said inner phase to form a dye.
[0245] One preferred application of this invention with respect to
Thermo-Autochrome technology is directed to transfer elements
capable of producing multicolor dye images. Such a transfer element
comprises a support and a plurality of color forming layers coated
thereon. The color forming layers include at least one blue
recording yellow dye image forming layer, at least one green
recording magenta dye image forming layer, and at least one red
recording cyan dye image forming layer. Interlayers may be
positioned between the color forming layers. Each image forming
layer includes at least one microcapsule layer.
[0246] Accordingly, another embodiment concerning Thermo-Autochrome
technology and the present invention is directed to an imaging
system, which comprises
[0247] a support having a front and rear surface;
[0248] a transfer layer comprising the carrier of the present
invention and the (e.g. light-fixable) thermal sensitive
microcapsules; and
[0249] an optional layer of clear thermoplastic material.
[0250] The transfer layer of the present invention is applicable to
any imaging system based on thermal sensitive microencapsulates.
Said system comprises
[0251] a support;
[0252] at least one transfer layer coated on top of said support,
comprising the carrier of the invention and (e.g. light-fixable)
thermal sensitive microcapsules,
[0253] said carrier preferably having a melting point of
approximately 100.degree. C. to 180.degree. C., and which is
capable of transferring and adhering an image from said front
surface of said support upon the application of heat energy to the
rear surface of the support, said carrier strips from said front
surface of the support by liquefying and releasing from said
support when heated (and taking the formed image and non-image area
with it), said liquefied carrier providing adherence to a receptor
element by flowing onto said receptor element and solidifying
thereon, said adherence does not require an external (e.g. surface)
adhesive layer, and
[0254] an optional layer of clear thermoplastic material, wherein
the adherence of the transfer layer to the receptor element
preferably occurs in an area at least coextensive with the area of
said microcapsules, with the proviso that the carrier is not
capable of reacting (e.g. with a color precursor) to form an
image.
[0255] Another embodiment of the present invention relating to
Thermo-Autochrome technology is directed to an imaging sheet useful
in forming images onto a receptor surface, said sheet
comprising:
[0256] a support having a front and rear surface;
[0257] a transfer layer on said front surface of said support,
comprising the carrier of the present invention and (e.g.
light-fixable) thermal sensitive microcapsules.
[0258] The present invention further relates of a method of
transferring an image to a receptor element, which comprises the
steps of:
[0259] (a) forming the direct thermal recording image described
above, said image being formed on a front surface of a support
having a front and a back surface;
[0260] (b) positioning the front surface of said image against said
receptor element;
[0261] (c) applying heat to the rear surface of the support to
transfer the image to the receptor element.
[0262] The various layers of the imaging material are formed by
known coating techniques, such as by roll, blade, curtain coating
and air-knife coating procedures. The resulting material, then is
dried by means of, for example, steam-heated drums, air
impingement, radiant heating, or some combination thereof. Some
care must be exercised, however, to assure that drying temperatures
are sufficiently low so that the particles of thermoplastic polymer
present in the transfer layer do not melt during the drying
process.
[0263] The invention is illustrated in more detail by the following
non-limiting examples:
EXAMPLE 1
Coating solutions Formulation A
[0264] 62.8% Photosensitive Microcapsule at 31.2% solids
[0265] 18.8% HRJ4098 phenolic developer resin (Schnectady Chemical
Co.) at 53.7% solids
[0266] 3.0% Varion CAS surfactant at 10% solution
[0267] 15.4% H.sub.2O to make 30% total solids The carrier plus
Formulation A is blended together as follows:
1 Michem 58035 5 parts Michem 4983R 1 part Michelman Inc. 40-50%
Formulation A 50-30% Microthene FE532 or FN500 Quantum Ind.
10-20%
[0268] (Bead size 1-20 microns with a reported melting temperature
of 80 to 180C.) The preparation of the photosensitive microcapsules
is described in U.S. application Ser. No. 755,400 filed Jul. 16,
1985 (U.S. Pat. No. 4,904,645).
[0269] The coating solution and carrier is then coated onto a
polyester support with a #12 coating rod and air gun dried.
[0270] The coated sheet is then image-wise exposed through a mask
for 5.2 seconds using a fluorescent light source.
[0271] The exposed sheet is processed at high pressure with a
calendaring roll as described in Example 1 of U.S. Pat. No.
4,751,165.
EXAMPLE 2
[0272] Referring to FIG. 2, the method of applying the image and
non-image areas to a receptor element will be described.
[0273] The imaging sheet 50 is prepared, exposed and developed to
form an image as in Example 1. A receptor element (e.g., tee shirt
62) is laid flat as illustrated, on an appropriate support surface,
and the front surface of the imaging sheet 50 is positioned on the
tee shirt. An iron 64 is run and pressed across the back 52A of the
imaging sheet. The image and non-image areas are transferred to the
tee-shirt and the support is removed and discarded.
EXAMPLE 3
[0274] Considering % solids and color balance requirements,
photosensitive microcapsules with initiators responding to 350 nm,
390 nm, and 470 nm are blended together.
Coating Formulation B
[0275] 59.4% capsule blend @ 33% solids 18.8% HRJ4098 phenolic
developer resin @ 53.7 solids
[0276] 3.0% Varion CAS @ 10% solution
[0277] 18.8% H.sub.2O to make 30% solids coating solution
[0278] The carrier plus Formulation B is blended together as
follows:
2 Michem 58035 5 parts Michem 4983R 1 part Michelman Inc. 40-50%
Formulation B 50-30% Microthene FE532 or FN500 Quantum Ind.
10-20%
[0279] (Bead size 1-20 microns with a reported melting temperature
of 80 to 180C.)
[0280] For preparation of the microcapsules, reference can be made
to U.S. application Ser. No. 755,400 filed Jul. 16, 1985.
[0281] The coating solution is coated onto a polyester support
using a #12 coating rod and air gun to dry. The coated sheet is
then image-wise exposed through color separation masks for 24,6 and
3 seconds at 350 nm, 390 nm, and 470 nm, respectively. A 1000 watt
Xenon arc lamp is used with filters to modulate the wavelength.
[0282] The exposed sheet is processed at high pressure through a
calendar roller as described in Example 2 of U.S. Pat. No.
4,751,165.
EXAMPLE 4
[0283] A paper support which is not coated on both sides with
polyethylene is coated with a melt-transfer layer consisting of a
mixture of Michem.RTM. 58035R and Michem.RTM. Prime 4983R. Both
materials are available from Michelman, Inc., Cincinnati, Ohio. A
ratio of four or five to one of 58035R to 4983R is used. The basis
weight of the melt-transfer layer is 8 g/m.sup.2. Michem.RTM.
58035R is a 35 percent solids dispersion of Allied Chemical's AC
580, which is approximately 10 percent acrylic acid and 90 percent
ethylene The polymer reportedly has a softening point of
102.degree. C. and a Brookfield viscosity of 0.65 Pas (650
centipoise) at 140.degree. C. Michem.RTM. Prime 4983R is a 25
percent solids dispersion of Primacor.RTM.5985 made by Dow Chemical
Company. The polymer contains 20 percent acrylic acid and 80
percent ethylene. The copolymer has a Vicat softening point of
43.degree. C. and a ring and ball softening point of 108.degree. C.
The melt flow rate of the copolymer is 500 g/10 minutes.
[0284] The melt-transfer layer then is coated with a carrier
comprising particles of a thermoplastic polymer, a binder, and a
cationic polymer, said carrier containing microcapsules as formed
as in Example 1. When the thermoplastic binder and/or the binder
are the variables, the cationic polymer in every case is an
amide-epichlorohydrin copolymer, namely, either Kymene.RTM. 557H or
Reten.RTM. 204LS, both being supplied by Hercules Inc., Wilmington,
Del. The cationic polymer is included at a level of 5 weight
percent, based on the weight of the thermoplastic polymer. The
carrier is dried by heating at 80.degree.-95.degree. C. The basis
weight of the carrier layer is 15 g/m.sup.2.
[0285] In general, a minimum amount of binder is used. For example,
10 weight percent of a polyacrylate, Rhoplex.RTM. B-15J (Rohm and
Haas Company) may be used. Excess binder is expected to reduce the
porosity of the carrier layer and make it less absorbent. Another
binder which may be used at the 10 weight percent level is
Michem.RTM. 58035, described above. The binder must be compatible
with the cationic polymer. Two binders which are more compatible
with the cationic polymer and which yellow less than the
Michem.RTM. 58035 are Airflex.RTM. 124 and Airflex.RTM. 125, both
poly(vinyl alcohol) stabilized ethylene-vinyl acetate copolymers.
The materials are available from Air Products and Chemicals, Inc.,
Allentown, Pa.
[0286] Several thermoplastic polymers may be used including
Microthene.RTM. FE 532, an ethylene-vinyl acetate copolymer
supplied by Millenium Chemical Incorp., Cincinnati, Ohio. The
particle size is reported to average approximately 20 micrometers.
The Vicat softening point is 75.degree. C. The melt flow rate of
the copolymer is 9 g/10 minutes and it is reported to have a
density of 0.928 g/cm.sup.3. Another thermoplastic polymer is
Microthene.RTM. FN 500, a low density polyethylene powder also
supplied by USI Chemicals Co. The material has an average particle
size of 20 micrometers, a Vicat softening point of 83.degree. C., a
melt flow rate of 22 g/10 minutes, and a density of 0.915
g/cm.sup.3.
[0287] The material is exposed, developed and transferred as in
Example 2.
EXAMPLE 5
[0288] Example 1 is repeated, but using the following thermoplastic
polymers:
[0289] Thermoplastic Polymer A
[0290] This polymer is Microthene.RTM. FE 532, described in Example
15.
[0291] Thermoplastic Polymer B
[0292] This material is Microthene.RTM. FN-500, also described in
Example 15.
[0293] Thermoplastic Polymer C
[0294] Thermoplastic Polymer C is Corvel.RTM. 2093. It is a
polyester. The average particle size is 20 micrometers, the melting
point of the polymer is approximately 80.degree. C., and the melt
flow rate is reported to be "high". The material is supplied by
Powder Coatings Group of the Morton Chemical Division, Morton
Thiokol, Inc., Reading, Pa.
[0295] Thermoplastic Polymer D
[0296] This polymer is MP 22, described in Example 15.
[0297] Thermoplastic Polymer E
[0298] Thermoplastic Polymer E is MPP 611, also described in
Example 15.
[0299] Thermoplastic Polymer F
[0300] This material is MPP 635, also a polyethylene supplied by
Micro Powders, Inc. The average particle size of the polymer is 5
micrometers, the melting point is reported to be 124, and the melt
flow rate is "high".
[0301] Thermoplastic Polymer G
[0302] This polymer is Accumist.RTM. B6, supplied by Allied
Chemical Company, Morristown, N.J. The polymer is a polyethylene
having a melting point of 126.degree. C. The average particle size
of the polymer is 6 micrometers and the melt flow rate is
"high".
[0303] Thermoplastic Polymer H
[0304] Thermoplastic Polymer H is Accumist.RTM. B12, also supplied
by Allied Chemical Company. The polymer is a high density
polyethylene having a melting point of 126.degree. C. The average
particle size of the polymer is 12 micrometers.
[0305] Thermoplastic Polymer I
[0306] This polymer is DPP 714, a polystyrene dispersion supplied
by Dow Chemical Company, Midland, Mich.
[0307] Thermoplastic Polymer J
[0308] This material is Piccotex.RTM. LC55R, a styrene-methyl
styrene copolymer dispersion supplied by Hercules, Inc.
[0309] Thermoplastic K
[0310] Thermoplastic Polymer K is DL 256, a polystyrene dispersion
also supplied by Dow Chemical Company.
[0311] Thermoplastic L
[0312] This polymer is BN 4901X, a polystyrene dispersion available
from BASF Corporation, Sarnia, Ontario, Canada.
[0313] Thermoplastic M
[0314] This material is Ropaque.RTM., a polystyrene dispersion
supplied by Rohm and Haas Company, Philadelphia, Pa.
[0315] Four different binders are used:
[0316] Binder A
[0317] Binder A is Carboset.RTM. 514H, a polyacrylate binder
dispersed in water, supplied by B. F. Goodrich Company, Cleveland,
Ohio.
[0318] Binder B
[0319] This binder is Rhoplex.RTM. B15, described in Example
15.
[0320] Binder C
[0321] Binder C is Michem.RTM. 58035, also described in Example
15.
[0322] Binder D
[0323] This binder is Marklube.RTM. 542, a cationic low density
polyethylene emulsion from Ivax Industries, Inc., Rock Hill,
S.C.
[0324] The composition of the carrier layer is summarized in Table
1 below. In the Table, the "TP" column identifies the thermoplastic
polymer by letter, the "Type" column identifies the binder by
letter, and basis weights are given in g/m.sup.2.
3TABLE 1 Summary of Carrier Composition with Various Thermoplastic
Polymers Binder Basis TP Type Wt. % Weight A A 10 21 A B 10 23 A C
10 23 A C 20 23 B C 50 31 B C 10 23 C C 10 32 D C 10 30 E C 10 23 E
C 12.5 28 E C 12.5 8 E C 12.5 13 F C 10 23 F C 12.5 13 F C 18 11 F
C 20 13 F D 25 13 G C 18 13 H C 18 13 I C 10 17 J C 10 17 K C 10 8
L C 10 8 M C 10 8 M C 30 8 M C 40 8
EXAMPLE 6
[0325] Example 5 is repeated without the melt-transfer layer.
EXAMPLE 7
[0326] A base sheet of fiber based paper which is not coated with
polyethylene on both sides is coated with a low molecular weight
polymer film layer, referred to hereinafter as the first layer. The
next layer was a film based on a polymer having a higher molecular
weight, referred to hereinafter as the second layer. Finally, the
carrier (on top of the second layer) consisted mainly of low
molecular weight polyethylene wax particles, plus microcapsules as
described in Example 1.
[0327] A number of multi layered samples (including the base sheet)
are evaluated. In every case, the carrier layer consisted of 77
weight percent MPP 635 (Thermoplastic Polymer F), 8 weight percent
of BN 4901X (Thermoplastic Polymer L), 10 weight percent
Michem.RTM. 58035 (Binder C), 4 weight percent Reten.RTM. 204LS
(cationic polymer), and 1 weight percent Triton.RTM. X-100, a
surfactant, all based on the total weight of the layer (excluding
silver halide grains). These weights of binder, cationic polymer,
and surfactant are equivalent to 12, 5 and 1 weight percent,
respectively, based on the weight of thermoplastic polymer.
[0328] A preferred sample using this format contains the
following:
[0329] First layer: The layer consisted of 45 weight percent
Michem.RTM. 4983 and 55 weight percent Chemawax.RTM. 40. The layer
is applied as a mixed latex. The basis weight of the layer was 8
g/m.sup.2.
[0330] Second layer: The layer, located adjacent to the paper,
consisted of Epolene.RTM. C13 which is formed by melt extrusion at
a basis weight of 20 g/m.sup.2. The polymer is a 200 melt flow rate
low density polyethylene obtained from Eastman Chemical Products,
Inc., Kingsport, Tenn.
[0331] Another material which may be used as the second layer and
which can be extrusion coated on the paper base sheet is
Nucrel.RTM. RX 62, supplied by E. I. Du Pont de Nemours and
Company, Inc., Wilmington, Del. The polymer is an
ethylene-methacrylic acid copolymer having 10 weight percent
methacrylic acid and a melt flow rate of around 500 g/10 min.
[0332] The material is exposed, developed and transferred as in
Example 2.
EXAMPLE 8
[0333] This Example evaluates various cationic polymers. Two types
of carrier layers are employed, in which the cationic polymer is
included as a component. Type A consists of Microthene.RTM. FE 532
(Thermoplastic Polymer A), 13 weight percent of Michem.RTM. 58035
binder (Binder C), based on the weight of the thermoplastic
polymer, 1 weight percent Triton.RTM. X-100 surfactant, and the
cationic polymer. The basis weight of the layer is 15 g/m.sup.2.
The Type B layer consists of MPP 635 (Thermoplastic Polymer F), 18
weight percent of Michem.RTM. 58035 binder (Binder C), based on the
weight of the thermoplastic polymer, 1 weight percent Triton.RTM.
X-100 surfactant, and the cationic polymer. The basis weight of the
layer was 13 g/m.sup.2. When The Type B second layer is employed, a
third layer consisting of Michem.RTM. 58035 at a basis weight of 17
g/m.sup.2 is employed, adjacent to the paper support. The various
cationic polymers evaluated are as follows:
[0334] Cationic Polymer A
[0335] Cationic Polymer A is Kymene.RTM. 557, an
amide-epichlorohydrin copolymer available from Hercules, Inc.
[0336] Cationic Polymer B
[0337] This polymer is Calgan.RTM. 261LV, a quaternary polymer. It
is available from Calgon Corporation.
[0338] Cationic Polymer C
[0339] This material is Corcat.RTM. P145. It is a polyethyleneimine
supplied by Cordova Chemical Company.
[0340] Cationic Polymer D
[0341] Cationic Polymer D is Parez.RTM. 631NC, a polyacrylamide
available from American Cyanamide.
[0342] Cationic Polymer E
[0343] This material is Betz.RTM. 1260. It is obtained from Betz
Paperchem, Trevose, Pa.
[0344] Cationic Polymer F
[0345] This polymer is Reten.RTM. 204LS, an amide-epichlorohydrin
copolymer available from Hercules, Inc.
[0346] Cationic Polymer G
[0347] Verona.RTM. C-300 from Miles Inc., Pittsburgh, Pa.
[0348] Cationic Polymer H
[0349] Aquaprox.RTM. UP103 from Synthron, Morgantown, N.C.
[0350] Cationic Polymer I
[0351] Tinofix.RTM. EW from Ciba-Geigy Corporation, Hawthorn,
N.Y.
[0352] Cationic Polymer J
[0353] Reactofix.RTM. ES from Ivax Industries, Inc.
[0354] Cationic Polymer K
[0355] Protefix.RTM. TS, a cationic carbamide from Synthron.
[0356] In the table, the column "CP" Type" identifies the cationic
polymer, whereas the column "Type" identifies the type of carrier
employed, as described above.
4TABLE 4 Evaluation of Various Cationic Polymers CP Type Amount
Type A 2 A A 4 A A 6 A B 2 A B 4 A C 2 A C 4 A D 2 A D 4 A E 2 A F
5 A F 4 A F 8 A G 8 B H 8 B I 8 B J 8 B K 8 B
[0357] Microcapsules as described in Example 1 are incorporated
into the carrier layer, which is coated on (i) a fiber base paper
which is not coated on both sides with polyethylene and (ii)
transparent polyacetate film. The material is exposed, developed
and transferred as described in Example 2.
EXAMPLE 9
[0358] The formulations involving Cationic Polymer F as reported in
Example 8 are modified further since yellowing may be encountered
when images are heat transferred.
[0359] In the experiments, the paper base which is not coated on
both sides with polyethylene is extrusion coated with 44 g/m.sup.2
of Nucrel.RTM. RX62, an ethylene-methacrylic acid copolymer having
a melt flow rate of 600 g/10 minutes supplied by E. I. Du Pont de
Nemours and Co., Inc. The second layer had a basis weight of
approximately 13 g/m.sup.2.
[0360] The binder employed in the carrier layer (e.g. containing
microcapsules as described in Example 1) is either Airflex.RTM. 124
(Binder E) or Airflex 125.RTM. (Binder F). The binder is present at
a level of 26 weight percent, based on the weight of the
thermoplastic polymer. The cationic polymer used is Reten.RTM.
204LS, the humectant is Polyglycol.RTM. E200, a poly(ethylene
glycol) from Dow Chemical Company having a weight-average molecular
weight of about 200; the humectant level is 10 weight percent,
based on the weight of the thermoplastic polymer. The surfactant is
Triton.RTM. X-100 at a level of 3 weight percent, based on the
weight of thermoplastic polymer employed. The fluid viscosity
modifier is Polyox.RTM. N80 at a level of 3 weight percent, also
based on the weight of the thermoplastic polymer. The thermoplastic
polymers evaluated included micropowders MPP 635 and Accumist.RTM.
A-12, from Micropowders and Allied Chemical Company, respectively.
The material is exposed, developed and transferred as described in
Example 2.
[0361] The experiments are summarized in Table 5. In the table, the
"TP" column identifies the thermoplastic polymer by letter (see
Example 5), the "WT. -% CP" column identifies the amount of
Reten.RTM. 204LS employed in the second layer in weight percent,
based on the weight of the thermoplastic polymer, and the "WT. -%
Acid" column identifies the amount of citric acid included in the
carrier, in weight-percent based on the weight of the thermoplastic
polymer.
5TABLE 5 Summary of Cationic Polymer F Formulation Modifications
Sample Binder TP Parts CP Wt.-% Acid 1 F H 8 None 2 F H 8 4 3 E H 8
None 4 F F 8 None 5 F F 12 None 6 F F 16 None
EXAMPLE 10
[0362] As described above, the present invention also relates to
Thermo-Autochrome technology.
Coating solution Formulation Y
[0363] Coating solution formulation Y comprises the composition of
light-fixable thermal recording microcapsules according to Example
2 of U.S. Pat. No. 4,771,032.
[0364] The carrier plus Formulation Y is blended together as
follows:
6 Michem 58035 5 parts Michem 4983R 1 part Michelman Inc. 40-50%
Formulation Y 50-30% Microthene FE532 or FN500 Quantum Ind.
10-20%
[0365] (Bead size 1-20 microns with a reported melting temperature
of 80 to 180C.)
[0366] The coating solution and carrier is then coated onto a
polyester support with a #12 coating rod and air gun dried. The
recording material is then subjected to the procedure described in
the thermal recording Samples U.S. Pat. No. 5,486,446 as
follows.
[0367] Applied power to thermal head and pulse duration are set so
that the recording energy per area is 35 mJ/mm.sup.2. The writing
(I) of the heat-sensitive recording material is conducted using
Thermal head (KST type, a product of Kyocera K.K.)
[0368] Subsequently, the recording material is exposed to an
ultraviolet lamp (light emitting central wavelength: 420 nm; output
40 W) for 10 seconds. Applied power to the thermal head and pulse
duration are again set so that the recording energy per unit area
is 62 mJ/mm.sup.2, and writing (III) of the heat-sensitive
recording material is conducted under these temperatures.
[0369] Furthermore, the recording material is exposed to an
ultraviolet lamp (light emitting central wavelength: 365 nm;
output: 40 W) for 15 seconds. Applied power to the thermal head and
pulse duration are again set so that the recording energy per unit
area is 86 mJ/mm.sup.2, and writing (III) of the heat-sensitive
recording material is conducted under these conditions.
[0370] Next, referring to FIG. 2, the method of applying the image
to a receptor element will be described.
[0371] The imaging sheet 50 is prepared, exposed and developed to
form an image as described above. A receptor element (e.g., tee
shirt 62) is laid flat as illustrated, on an appropriate support
surface, and the front surface of the imaging sheet 50 is
positioned on the tee shirt. An iron 64 is run and pressed across
the back 52A of the imaging sheet. The image and non-image areas
are transferred to the tee-shirt and the support is removed and
discarded.
EXAMPLES 11-15
[0372] Example 10 is repeated but this time the light-fixable
thermal recording microcapsule formulation Y is substituted with
other light-fixable thermal recording microcapsule formulations as
follows:
7 Example Source of light-fixable thermal Number recording
microcapsule formulation 11 Ex. 5 of U.S. Pat. No. 5,543,260 12 Ex.
10 of U.S. Pat. No. 5,543,260 13 Ex. 3 of U.S. Pat. No. 5,661,101
14 Ex. 22 of U.S. Pat. No. 5,661,101 15 Ex. 26 of U.S. Pat. No.
5,661,101
[0373] All cited patents, copending applications, provisional
applications, and publications, referred to in this application are
herein incorporated by reference.
[0374] The invention being thus described, it will be obvious that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the present
invention, and all such modifications as would be obvious to one
skilled in the art are intended to be included within the scope of
the following claims.
* * * * *