Note: Descriptions are shown in the official language in which they were submitted.
CA 02537233 2006-03-10
HIGH MODULUS THERMOPLASTIC FILMS
AND THEIR USE AS CASH REGISTER TAPES
Field of the Invention
The present invention is generally directed to thermoplastic films of
sufficient
stiffness for use in high speed printing equipment. Specifically, the present
invention
describes an improved cash register receipt tape produced from a coated,
monolayer,
oriented, heat stabilized thermoplastic film.
BackEround of the Invention
Currently, point-of-sale cash register receipts are printed on a paper tape
using
inkjet, thermal image or ribbon printers. Numerous patents describe inventions
of
plastic films to replace these paper tape receipts. The primary focus for many
of these
inventions is to describe a plastic printer register receipt that is "co-
recyclable" with
existing plastic shopping bags.
For example, U. S. Patent 5,229,218 to Dobreski presents a general description
of plastic materials for use as a register receipt tape that is claimed to be
recyclable.
The concepts embodied in the Dobreski patent were continued in U. S. Patent
6,284,177 to Ewing, which similarly provides a somewhat general description of
a
recyclable plastic register tape. In the Background section, the `177 patent
notes that
the Dobreski patent, "does not provide sufficient details to select a specific
thermoplastic material which is economical, of sufficient strength and which
can be
reliably fabricated into a printable film."
U.S. Patent 6,407,034, also to Ewing, discloses a recyclable register tape in
which the base sheet materials and thermally printed media are combined prior
to
production of the film.
The above-described prior art laudably recognizes the benefit of providing a
thin, thermoplastic register tape as a replacement for prior paper tapes.
Specifically,
the current commonly used paper tape ranges in thickness from 2.1 to 2.5 mils.
A
cash register paper tape ro113-inches in diameter wound on a 7/8-in. diameter
core
contains 230 feet of paper register tape. A 3 inch diameter roll of a 0.5 mil
thick
thermoplastic tape wound on a 7/8 in. diameter core contains 1,077.9 feet of
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thermoplastic register tape or 4.7 times the length included in a similar
diameter paper
register tape roll. The thermoplastic tape therefore should provide numerous
economies to firms and individuals using cash register printers and receipt
printers
since the additional tape length available in the thermoplastic tape roll
should result in
less frequent roll changes at the cash register or receipt printer and less
storage space
for register tape roll inventory. However, the prior art to date has failed to
yield a
thermoplastic tape having adequate physical properties to serve as a drop-in
replacement for current paper register tapes.
Summary of the Invention
It is therefore one purpose of the present invention to provide a
thermoplastic
register or receipt tape having sufficient stiffness to run in current receipt
printers. It
is a further purpose of the present invention to provide such a thermoplastic
film with
adequate antistatic properties for printing. Specifically the film must have
sufficient
stiffness in the machine direction and it must also be capable of dissipating
static
electrical charges that accumulate on the film surface as a result of the film
encountering and separating from printer rollers as it moves through the
printer during
the printing process. Many of the commercial receipt printers are constructed
with
plastic cases that may develop high static electricity charges. If the
register film is not
relatively static free, it may be attracted to the case causing the film to
jam during the
printing process. Similarly a film with insufficient machine direction
stiffness will
jam during the printing process.
Accordingly, the present invention is directed to an oriented, thermoplastic
composite for use as a register or receipt tape, which is formed of a
monolayer film
having a first outer film surface and a second outer film surface, with an
anti-static
coating on the first outer film surface and a heat sensitive, thermal image
coating on
the second outer film surface, wherein the composite is essentially non-heat
shrinkable and has a 1% secant modulus in the machine direction of at least
150,000
psi. Preferably the overall composite has a thickness from about 0.35 to about
1.50
mils, more preferably from about 0.50 to about 0.75 mils. It is also preferred
that the
1% secant modulus in the machine direction is at least about 200,000 psi. The
monolayer film may be formed from a polymer such as polyethylene,
polypropylene,
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linear low density polyethylene, polystyrene, polyester or blends thereof,
although
polyester is preferred. Preferably, the monolayer film is biaxially oriented,
although it
is also within the scope of the present invention for the monolayer film to be
uniaxially oriented in the machine direction. Optionally, at least one
structural
component of the composite has a pigment blended therein. However, it has been
found in accordance with the present invention that an excellent final product
is
produced when none of the structural components contain a pigment.
Further, the present invention is directed to a method to make a thermoplastic
composite suitable for use as a register or receipt tape, which includes the
steps of:
a) extruding a monolayer film having a first outer film surface and
a second outer film surface;
b) orienting the film;
c) annealing the film;
d) surface treating each of the first and second outer film surfaces,
thereby preparing each surface for subsequent coating;
e) applying an anti-static coating to the first outer film surface;
and
f) applying a heat sensitive, thermal image coating to the second
outer film surface.
In a preferred embodiment the step of orienting involves biaxially orienting,
preferably such that the product of the machine direction and transverse
direction
stretch ratios is from about 2.OX to about 50.OX. Preferably the step of
surface
treating each of the first and second outer film surfaces involves corona
treating.
Additionally, the present invention is directed to an oriented, essentially
non-
heat shrinkable, thermoplastic composite for use as a register or receipt tape
which
includes a film having a first outer film surface and a second outer film
surface, the
film having at least a core layer, a heat sensitive, thermal image coating on
the first
outer film surface, and means for dissipating static electrical charges,
wherein none of
the composite components contain a pigment and wherein the composite has a 1%
secant modulus in the machine direction of at least 150,000 psi. In one
embodiment
the means for dissipating static electrical charges is an outer film layer,
which
includes an anti-static additive. In an alternative embodiment the means for
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dissipating static electrical charges is an anti-static coating on the second
outer film
surface. Preferably, the composite has a thickness of from about 0.35 mils to
about
1.5 mils, more preferably of from about 0.50 mils to about 0.75 mils. It is
also
preferred that the core film layer is a polymer such as polyethylene,
polypropylene,
linear low density polyethylene, polystyrene, polyester or blends thereof.
Polyester is
preferred. In one embodiment the film may include at least one outer layer
which is a
blend of polyester and a further polymer which is immiscible with polyester.
In accordance with another aspect of the invention, there is provided an
oriented, thermoplastic composite for use as a register or receipt tape,
comprising:
a) a monolayer film having a first outer film surface and a second
outer film surface;
b) an anti-static coating on the first outer film surface; and
c) a heat sensitive, thermal image coating on the second outer film
surface;
wherein the composite is essentially non-heat shrinkable and has a 1%
secant modulus in the machine direction of at least 150,000 psi.
In accordance with another aspect of the invention, there is provided a method
for making a thermoplastic composite suitable for use as a register or receipt
tape,
comprising the steps of:
a) extruding a monolayer film having a first outer film surface and
a second outer film surface;
b) orienting the film;
c) annealing the film;
d) surface treating each of the first and second outer film surfaces,
thereby preparing each surface for subsequent coating;
e) applying an anti-static coating to the first outer film surface;
and
f) applying a heat sensitive, thermal image coating to the second
outer film surface.
In accordance with another aspect of the invention, there is provided an
oriented, essentially non-heat shrinkable, thermoplastic composite for use as
a register
or receipt tape comprising:
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a film having a first outer film surface and a second outer film surface, the
film comprising at least a core layer;
a heat sensitive, thermal image coating on the first outer film surface; and
means for dissipating static electrical charges;
wherein none of the structural components have a pigment blended
therein and wherein the composite has a 1% secant modulus in the machine
direction of at least 150,000 psi.
In accordance with another aspect of the present invention, there is provided
an
oriented, thermoplastic composite for use as a register or receipt tape,
comprising:
a) a monolayer film having a first outer film surface and a second
outer film surface;
b) an anti-static coating on the first outer film surface; and
c) a heat sensitive, thermal image coating on the second outer film
surface;
wherein the composite is essentially non-heat shrinkable and has a 1%
secant modulus in the machine direction of at least 150,000 psi, and
wherein none of the structural component has a pigment blended therein.
In accordance with another aspect of the present invention, there is provided
a
method for making a thermoplastic composite suitable for use as a register or
receipt
tape, comprising the steps of:
a) extruding a monolayer film having a first outer film surface and
a second outer film surface;
b) orienting the film;
c) annealing the film;
d) surface treating each of the first and second outer film surfaces,
thereby preparing each surface for subsequent coating;
e) applying an anti-static coating to the first outer film surface;
and
f) applying a heat sensitive, thermal image coating to the second
outer film surface;
wherein none of the structural components has a pigment blended
therein.
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Brief Description of the Figure of the Drawint!
The present invention will be described with reference to the following
drawing:
Figure 1 is a schematic, cross-sectional view of a thermoplastic printing or
register tape in accordance with the present invention; and
Figure 2 is a schematic, cross-sectional view of an alternative thermoplastic
printing or register tape in accordance with the present invention.
Detailed Description of the Preferred Embodiments
Generally, the present invention is directed to an oriented, essentially non-
heat
shrinkable thermoplastic composite for use as a register or receipt tape.
Figure 1 of the
drawing illustrates an embodiment of the present invention, wherein the
composite 10 is
formed of a film 12 having at least one outer coating 20. As shown in the
embodiment
of Figure 1, film 12 includes a core layer 14, a first outer layer 16, and a
second outer
layer 18. First outer layer 16 has an outermost surface which is a first outer
film
surfacel7 and second outer layer 18 has an outermost surface which is a second
outer
film surface 19. In this embodiment, outer coating 20 has been applied to
second outer
film surface 19.
The overall composite preferably has a thickness in the range of from about
0.35
mils to about 1.5 mils, preferably from about 0.50 mils to about 0.75 mils.
Turning to the specific function of each component of composite 10, the core
layer of the
film provides the film stiffness, the first outer layer provides anti-static
properties, and
the outer coating 20 provides a printable surface. The second outer
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layer 18 of the film is preferred but optional. Outer coating 20 may be
applied
directly to an outer surface of the core layer. If outer layer 18 is present
it preferably
includes a pigment which renders the film opaque in order to enhance the
visibility of
the printing. If outer layer 18 is not present at least one of the remaining
film
components may include a pigment. A preferred pigment for use in accordance
with
the present invention is titanium dioxide.
The core layer may be formed of any of a number of thermoplastic polymers
or polymer blends. Preferred polymers for use in the core layer include
polyethylene
homopolymers and copolymers, including low density polyethylene and high
density
polyethylene, polypropylene homopolymers and copolymers, linear low density
polyethylene, polystyrene or polyester. However, any suitable thermoplastic
polymer
or polymers may be employed. Polyester is particularly preferred. The core
layer
preferably comprises from about 50% to about 85% of the overall film
thickiiess.
In one embodiment, core layer 14 preferably includes a cavitation promoting
additive such as AmpacetTM 110881, supplied by AmpacetTM Corp., Tarrytown, NY,
which is calcium carbonate and titanium dioxide in a high density polyethylene
carrier. With such an additive a relatively thick core layer may be formed
with a
reduced volume of polymer. However, a cavitation promoting additive only may
be
employed if both outer film layers are present. Otherwise, the additive would
render
the outer surface of the core layer, which would comprise an outer film
surface,
unsuitable for receiving a coating.
As noted above, optionally, the core layer may include a pigment. However, a
reduced amount of pigment may be employed if it is incorporated into one of
the
thinner layers or a thin coating. Thus, from an economic perspective, if the
core layer
is the thickest layer, it may be the least preferred composite component for
carrying
the pigment. Further, it unexpectedly has been found in accordance with the
present
invention that a high quality, legible, final product may be produced without
the
incorporation of a pigment into any of the structural composite components.
For
example, as is illustrated below in Examples 8 and 9, below, a commercially
available
multilayer film has been found which is a white matt film but which contains
no
pigment. Instead, a relatively thick core layer is flanked by at least one but
preferably
two outer layers which are composed of a major portion of the polymer of the
core
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CA 02537233 2006-10-20
layer blended with a minor portion of a polymer which is immiscible with the
polymer of the core layer. When this combination of polymer layers is
coextruded
and oriented, the immiscible component in the outer layer forms small globules
which
refract light thereby creating opacity. Further, even without employing such
matt
film, it has been found that the inherent opacity of most thermal image
coatings
renders the final composite sufficiently opaque to render the resultant
receipt legible.
Additionally, a thermal image coating which is essentially clear and would,
therefore,
permit the production of an essentially clear composite, is also within the
scope of the
present invention.
Continuing with a discussion of Figure 1, preferably first outer layer 16
provides anti-static properties to the film. Generally, there are two classes
of anti-
static agents, migratory and non-migratory, that can be used to dissipate
static
electricity charges that accumulate on the surfaces of plastic films. Each
class has
advantages and disadvantages. Migratory additives, either amine or non-amine,
are
inexpensive compared to non-migratory additives and work by diffusing to the
film
surface after the film is blown or cast. Once on the surface, they attract
atmospheric
moisture to the film surface to dissipate static electricity charges. This
type of
additive is not effective in very dry climates or in conditions where there is
insufficient moisture in the air. Accordingly, non-migratory additives, which
work by
forming a continuous matrix that is electrically conductive within the film
structure,
are preferred for use in accordance with the present embodiment. A preferred
non-
migratory anti-static additive for use in accordance with the present
invention is
AntistatTM PE MB 101710, a polyethylene-based antistatic additive supplied by
AmpacetTM Corp., Tarrytown, NY. In order for a non-migratory additive to be
economically viable, it becomes necessary to minimize the amount of additive
employed by limiting the inclusion of this additive to a thin surface layer.
Thus, it is
preferred that first outer layer 16 which carries the non-migratory additive
comprises
from about 7.5% to about 25% of the overall thickness of film 12.
Alternatively, the composite may include an anti-static coating. Such coating
may be applied to the outer film surface 17 or the first outer layer 16 may be
omitted
and the anti-static coating may be applied directly to an outermost surface of
the core
layer. Such alternative configuration is discussed in greater detail below
with respect
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to the composite of Figure 2.
In accordance with the present invention, outer coating 20, which provides a
printable surface to the composite, is opposite to the anti-static layer or
coating
because the "back," or non-printing, surface of the composite is subjected to
the
higher degree of friction as the tape passes through the printer. Coating 20
is a heat
sensitive, thermal image coating such as ProtecoatTM 8468, supplied by
NuCoatTM,
Inc., Plymouth, MN. The thermal image coating may be applied directly to an
outer
surface of the core layer. However, in one embodiment it is preferred that
film 12
includes second outer layer 18 and the coating is applied to outer film
surface 19. For
this embodiment, preferably second outer layer 18 comprises from about 7.5% to
about 25% of the overall film thickness. Further, second outer layer 18 may
include a
pigment in sufficient quantity to render the composite opaque. However, the
pigment
may be incorporated into the composite in any component including coating 20
or not
employed in any of the composite components. As noted above, most known
thermal
image coatings are sufficiently opaque to lend a desired degree of opacity of
the final
composite such that a pigment is not necessary.
Figure 2 of the drawing illustrates an alternative embodiment wherein the
composite 100 is formed of a monolayer film 112 having a first outer film
surface 117
and a second outer film surface 119. Outer coating 110 has been applied to
first outer
film surface 117 and outer coating 120 has been applied to second outer film
surface
119. Hereagain, the overall composite preferably has a thickness in the range
of from
about 0.35 mils to about 1.5 mils, preferably from about 0.50 mils to about
0.75 mils.
Turning to the specific function of each component of composite 100, the
monolayer film 112 provides the composite stiffness and other requisite
physical
properties, outer coating 110 provides anti-static properties, and outer
coating 120
provides a printable surface. Optionally, one of the composite components may
include a pigment. However, as noted above, it has been found unexpectedly in
accordance with the present invention that a pigment is not required for the
final,
printed composite register tape or receipt to be legible. Thus, in a preferred
embodiment none of the composite components contain a pigment.
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As with the core layer of composite 10, discussed above, the monolayer film
of composite 100 may be formed of any of a number of thermoplastic polymers or
polymer blends. Preferred polymers for use in the core layer include
polyethylene
homopolymers and copolymers, including low density polyethylene and high
density
polyethylene, polypropylene homopolymers and copolymers, linear low density
polyethylene, polystyrene, polyester or blends thereof. However, any suitable
thermoplastic polymer or polymers may be employed. Most preferred in
accordance
with the present embodiment is polyester. For the present embodiment, the
monolayer film preferably comprises at least about 85% of the overall
composite
thickness.
Outer coating 120 is a heat sensitive, thermal image coating as discussed
above with respect to outer coating 20. Outer coating 110 dissipates static
charges on
the opposite surface.
Turning to the present inventive method, the present composite is preferably
made by forming the film, orienting the film, applying the thermal image
coating and,
if one is employed, the anti-static coating. The film may be extruded or
coextruded
by any conventional means such as a blown film process or a cast film process.
Most
preferably, the film is extruded or coextruded through a flat die.
Thereafter, the film is oriented. Orientation is necessary to the present
invention in order to render the film sufficiently stiff to run through a
register or
printer. It should be noted that as the film thickness is decreased to a level
that is
commercially cost effective, the film stiffness decreases substantially. Thus,
although
a 1-mil thick static free film may have sufficient machine direction
stiffness, a
thermoplastic film with this thickness is not economically viable as a
register tape. It
is therefore necessary to reduce the film thickness to reach a film cost per
unit area
which is economically viable and which has sufficient machine direction
stiffness to
function in commercial register printers. Accordingly, the present film, which
most
preferably has a thickness of from about 0.50 mils to about 0.75 mils, must
have a 1%
secant modulus in the machine direction of at least about 150,000 psi,
preferably at
least about 200,000 psi, more preferably at least about 300,000 psi, more
preferably at
least about 400,000 psi, most preferably at least about 500,000 psi. In order
to
achieve this stiffness, the film may be uniaxially oriented in the machine
direction
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with a machine direction stretch ratio in the range of from about 1.5X to
about 10.OX.
This degree of orientation improves machine direction stiffness by 2 to 5
times as
compared to a non-oriented film. Alternatively, the film may be biaxially
oriented
such that the product of the machine direction and transverse direction
stretch ratios is
from about 2.OX to about 50X. In accordance with the present invention,
orientation
may take place in one step or in a series of stretching steps. Regardless of
the type of
orientation, thereafter the film must be thermally stabilized, i.e., annealed
or heat set,
in order to render it essentially non-heat shrinkable. Orientation and
annealing may
be performed either in-line or out-of-line with coextrusion.
Following orientation and heat stabilization, the outer film surface or
surfaces
which are to receive subsequent coating preferably are subjected to a surface
treatment such as, preferably, corona discharge, flame or chemical treatment,
prior to
the application of such coating. Such surface treatment is employed to ensure
adherence of the coating to the outer surface of the film.
Thereafter, the outer coating or coatings are applied in a conventional
manner.
Following extrusion, orientation, heat stabilization, surface adhesion
treatment
and coating, the film is slit and wound into roll sizes useful in commercial
register
printers. All process steps may be performed either in-line or out-of-line
with the
preceding step.
For those embodiments employing a multilayer film, the materials for each
film layer are preferably dry or melt blended prior to extrusion to improve
uniformity.
Although not required, intermediate layers, such as tie layers or other
structural
layers, may be included in the present multilayer film structure.
Thus, the present invention advantageously provides a thermoplastic register
or receipt tape of sufficiently reduced thickness to be commercially desirable
for
replacement of a conventional paper tape, which is of sufficient stiffness to
run
through a conventional printer and which has adequate anti-static properties
for
printing. However, it should be noted that if a non-migratory anti-static
additive is
included in a film layer such as first outer layer 16, discussed above with
respect to
Figure 1, one might expect that the subsequent orientation, which is necessary
to
improve stiffness and to reduce the film thickness, might disrupt the non-
migratory
anti-static additive matrix structure such that the anti-static properties of
the film
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would be lost. It has been unexpectedly found in accordance with the present
invention that this is not the case. For example, the 2.5-mil thick high
density
polyethylene film of Example 1, below, was produced with a non-migratory
antistatic
additive in the outer layer in a conventional blown film process. The layer
thickness
ratios for this structure were 10% for the first outer layer, 80% for the core
layer, and
10% for the second outer layer. The surface resistivity of the first outer
layer of this
film was 1010 ohms. The surface resistivity of the second outer layer that did
not
contain an anti-static additive was 1012 ohms. This film was stretched in the
machine
direction 5X to reach a final film thickness of 0.5 mils. There was no
transverse
direction stretch. The surface resistivity of the first outer layer after
stretching was
1010 ohms while the second outer layer remained at 10' 2 ohms. The machine
direction stretch therefore did not disrupt the anti-static additive matrix in
the first
outer layer and did not disturb the overall anti-static property of the film.
Further illustrations of the present invention are provided in the examples
cited below.
Example 1
A first outer layer, a core layer, and a second outer layer were coextruded
through a circular die and blown to form a three layer self-supporting film
having a
thickness of 2.5 mils. The layer percent thickness ratio was 10:80:10,
respectively.
The first outer layer was comprised of 58% high density polyethylene, 2%
titanium
dioxide and 40% non-migratory anti-static additive. The core layer was
comprised of
100% high density polyethylene. The second outer layer was comprised of 98%
high
density polyethylene and 2% titanium dioxide. The structure was coextruded on
a
conventional blown film line using a 4:1 blow up ratio.
Wound film from the above extrusion operation was then stretched in a
conventional roll-to-roll stretching unit where it was subjected to a 5:1
machine
direction stretch ratio. Following stretching, the second outer layer was
corona
treated prior to winding the now 0.5 mil thick machine direction oriented
film. There
was no transverse stretch employed. Corona treated wound film from the
stretching
operation was then coated with a heat sensitive, thermal image coating on the
corona
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treated second outer layer surface. Following coating, the film was then slit
into roll
sizes suitable for use in commercial register printers.
The resulting film structure had the following parameters and characteristics:
Nominal thickness: 0.5 mils
1% secant modulus in the machine direction:approx. 400,000 psi
Area factor: approx. 60,000 sq.
in./pound
Surface resistivity:
First outer layer: 1010 ohms
Second outer layer: >1012 ohms
A film produced according to this example was tested in an NCR point of sale
printer, Class 7193, Mode13205-9001, where it ran through repeated printing
cycles
without j amming. A non-oriented film, also having a 0.5 mil thickness and
produced
using the same materials and additives, was tested in the same printer. This
film,
which had a 1% machine direction secant modulus of approximately 200,000 psi
jammed repeatedly after less than five printing cycles.
Example 2
A 4.0 mil thick high density polyethylene film in accordance with the present
invention was produced with a non-migratory anti-static additive in the first
outer
layer in a conventional blown film process. The film had the same layer-by-
layer
composition and percent layer thicknesses as the film of Example 1. The
surface
resistivity of the first layer was 1010 ohms. The surface resistivity of the
second outer
layer that did not contain an anti-static additive was 1012 ohms. This film
was
stretched in the machine direction 8X to reach a final film thickness of 0.5
mils.
There was no transverse direction stretch. The surface resistivity of first
outer layer
after stretching was 1011 ohms while the second outer layer remained at 101 2
ohms.
Even at this higher level machine direction stretch, the anti-static additive
matrix in
the first outer layer was not disrupted to the point where the anti-static
property of the
film was lost.
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Example 3
A 0.48 mil, biaxially oriented, heat stabilized, monolayer opaque white PET
film was obtained from a film distributor, Transfilm Corp., Ltd, Shanghai,
China.
Both outer surfaces of the film had been corona treated by the manufacturer.
One
surface was coated with Protecoat 5977, a heat sensitive, thermal image
coating
supplied by NuCoat, Inc., Plymouth, MN. The dry coating weight of the thermal
image coating was about 3.0 to 4.01bs./3,000 sq. ft. The opposed surface was
coated
with MECOstat 3/112, an aqueous antistatic coating supplied by Energie-
Kollektoren,
GmbH, Allensbach, Germany. The wet coating weight for the antistatic coating
was
about 0.75 to 1.5 lbs./3,000 sq. ft.
The resulting composite had a nominal thickness of 0.7 mils and a 1% secant
modulus in the machine direction of approximately 550,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1011 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 109
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was good compared to the printed paper
receipt
of Comparative Example 10. The present receipt was clearly legible, although a
few
characters had faded areas.
Example 4
A 0.48 mil, biaxially oriented, heat stabilized, monolayer opaque white PET
film was obtained from a film distributor, Transfilm Corp., Ltd, Shanghai,
China.
Both outer surfaces of the film had been corona treated by the manufacturer.
One
surface was coated with Protecoat 5978, a heat sensitive, thermal image
coating
supplied by NuCoat, Inc., Plymouth, MN. The dry coating weight of the thermal
image coating was about 3.0 to 4.01bs./3,000 sq. ft. The opposed surface was
coated
with MECOstat 3/112, an aqueous antistatic coating supplied by Energie-
Kollektoren,
GmbH, Allensbach, Germany. The wet coating weight for the antistatic coating
was
about 0.75 to 1.5 lbs./3,000 sq. ft.
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The resulting composite had a nominal thickness of 0.6 mils and a 1% secant
modulus in the machine direction of approximately 550,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1011 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 109
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was excellent as compared to the
printed paper
receipt of Comparative Example 10, with very few characters having faded
areas.
Example 5
A 0.48 mil, biaxially oriented, heat stabilized, monolayer opaque white PET
film was obtained from a film distributor, Transfilm Corp., Ltd, Shanghai,
China.
Both outer surfaces of the film had been corona treated by the manufacturer.
One
surface was coated with Protecoat 8468, a heat sensitive, thermal image
coating
supplied by NuCoat, Inc., Plymouth, MN. The dry coating weight of the thermal
image coating was about 3.0 to 4.0 lbs./3,000 sq. ft. The opposed surface was
coated
with Baytron CPP 141D, an aqueous antistatic coating supplied by H.C. Starck,
Inc,
Newton, MA. The wet coating weight for the antistatic coating was about 0.75
to 1.5
lbs./3,000 sq. ft.
The resulting composite had a nominal thickness of 0.6 mils and a 1% secant
modulus in the machine direction of approximately 550,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1011 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 106
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was excellent as compared to the
printed paper
receipt of Comparative Example 10. All of the characters were clearly defined
with
no areas of fading.
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CA 02537233 2006-03-10
Example 6
A 0.48 mil, biaxially oriented, heat stabilized, monolayer clear PET film was
obtained from a film distributor, The Pilcher Hamilton Corp., Greer, SC. Both
outer
surfaces of the film had been corona treated by the manufacturer. One surface
was
coated with Protecoat 5983, a heat sensitive, thermal image coating supplied
by
NuCoat, Inc., Plymouth, MN. The dry coating weight of the thermal image
coating
was about 3.0 to 4.0 lbs./3,000 sq. ft. The opposed surface was coated with
MECOstat 3/112, an aqueous antistatic coating supplied by Energie-Kollektoren,
GmbH, Allensbach, Germany. The wet coating weight for the antistatic coating
was
about 0.75 to 1.5 lbs./3,000 sq. ft.
The resulting composite had a nominal thickness of 0.75 mils and a 1% secant
modulus in the machine direction of approximately 550,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1012 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 108
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was fair as compared to the printed
paper receipt
of Comparative Example 10. Printing failed in some areas.
Examule 7
A 0.48 mil, biaxially oriented, heat stabilized, monolayer clear PET film was
obtained from a film distributor, The Pilcher Hamilton Corp., Greer, SC. Both
outer
surfaces of the film had been corona treated by the manufacturer. One surface
was
coated with Protecoat 8468, a heat sensitive, thermal image coating supplied
by
NuCoat, Inc., Plymouth, MN. The dry coating weight of the thermal image
coating
was about 3.0 to 4.01bs./3,000 sq. ft. The opposed surface was coated with
Baytron
CPP 141D, an aqueous antistatic coating supplied by H.C. Starck, Inc, Newton,
MA.
The wet coating weight for the antistatic coating was about 0.75 to 1.5
lbs./3,000 sq.
ft.
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CA 02537233 2006-03-10
The resulting composite had a nominal thickness of 0.7 mils and a 1% secant
modulus in the machine direction of approximately 550,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1012 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 106
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was excellent as compared to the
printed paper
receipt. All characters were clear and well defined. However, there was not as
much
contrast between the printed characters and the receipt background as the
typical
printed paper receipt of Comparative Example 10.
Example 8
A 0.48 mil, biaxially oriented, heat stabilized, three layer white matt film
sold
under the tradename Type YGD was obtained from the manufacturer, Fuwei Films
Co. Ltd., China. Both outer surfaces of the film had been corona treated by
the
manufacturer. One surface was coated with Protecoat 8468, a heat sensitive,
thermal
image coating supplied by NuCoat, Inc., Plymouth, MN. The dry coating weight
of
the thermal image coating was about 3.0 to 4.01bs./3,000 sq. ft. The opposed
surface
was coated with Baytron CPP 141D, an aqueous antistatic coating supplied by
H.C.
Starck, Inc, Newton, MA. The wet coating weight for the antistatic coating was
about
0.75 to 1.5 lbs./3,000 sq. ft.
The resulting composite had a nominal thickness of 0.6 mils and a 1% secant
modulus in the machine direction of approximately 232,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1013 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 107
ohms.
The final composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was good as compared to printed paper
receipt
of Comparative Example 10, although a few characters had faded areas.
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CA 02537233 2006-03-10
Example 9
A 0.48 mil, biaxially oriented, heat stabilized, three layer white matt film
sold
under the tradename Type YGD was obtained from the manufacturer, Fuwei Films
Co. Ltd., China. Both outer surfaces of the film had been corona treated by
the
manufacturer. One surface was coated with Protecoat 5990, a heat sensitive,
thermal
image coating supplied by NuCoat, Inc., Plymouth, MN. The dry coating weight
of
the thermal image coating was about 3.0 to 4.0 lbs./3,000 sq. ft. The opposed
surface
was coated with MECOstat 3/112, an aqueous antistatic coating supplied by
Energie-
Kollektoren, GmbH, Allensbach, Germany. The wet coating weight for the
antistatic
coating was about 0.75 to 1.5 lbs./3,000 sq. ft.
The resulting composite had a nominal thickness of 0.65 mils and a 1% secant
modulus in the machine direction of approximately 232,000 psi. The surface
resistivity of the surface bearing the thermal image coating was 1013 ohms.
The
surface resistivity of the surface bearing the antistatic coating was 108
ohms.
The fmal composite was printed on the surface bearing the thermal image
coating on an Epson TM-T8811P Model M129B printer. Both the paper receipt of
Comparative Example 10 and the present plastic receipt were printed with a
print
density setting of 1. The print quality was excellent as compared to the
printed paper
receipt. All of the characters were clear and well defined. The contrast
between the
characters and the background was of similar quality to the printed paper
receipt of
Comparative Example 10.
Comparative Example 10
Epson Thermal Paper type SPE 1213 was obtained from a distributor, POS
World, Atlanta, GA. The paper had a nominal thickness of 2.2 mils and a
thermal
image coating on one surface.
The paper was printed on the surface bearing the thermal image coating on an
Epson TM-T8811P Model M129B printer with a print density setting of 1. The
print
quality was excellent. All of the characters were clear and well defined with
a good
contrast between the characters and the background.
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CA 02537233 2006-03-10
While the disclosed process has been described according to its preferred
embodiments, those of ordinary skill in the art will understand that numerous
other
embodiments have been enabled by the foregoing disclosure. Accordingly, the
foregoing embodiments are merely exemplary of the present invention.
Modifications, omissions, substitutions and rearrangements may be made to the
foregoing embodiments without departing from the invention as set forth in the
appended claims.
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