Note: Descriptions are shown in the official language in which they were submitted.
MAGNETIC T~RMAL TRA~SFlE:R_RIBBON
Back~round of the Inv tion
In the printing fieldr the impact type
printer has been the predominant apparatus for provid-
ing increased thr~ughput of printed information. The
impact printers have included the dot matrix type
wherein individual print wires are driven from a home
position to a printing position by individual and
separate drivers, and the full character type wherein
individual type elements are caused to be driven
ayainst a ribbon and paper or like record media adja-
cent and in contact with a platen.
The typical and well-known arrangement in a
printing operation provides for transfer of a portion
of the ink from the ribbon to result in a mark or
image on the paper. Another arranqement includes the
use of carbonless paper wherein the impact from a
print wire or a type element causes rupture of encap-
sulated material fvr marking the paper. Also known
are printing inks which contain magnetic particles
whPrein certain of the particles are transferred to
the record media for encoding characters in manner and
fashion so as to be machine readable in a subsequent
operationO One of the known encoding systems is ~ICR
(Magnetic Ink Character Recognition) utilizing the
manner of operation as just mentioned.
While the irnpact printing method has
dominated the industry, one disadvantage of this type
printing is the noise level which is atkained during
printing operation. Many efforts have been made to
reduce the high noise levels by use of sound absorbing
or cushioning materials or by isolating the printing
apparatus. More recently, the advent of thermal
printing which effectively and significantly reduces
the noise levels has brought about the requirement for
heating of extremely precise areas of the record media
3~'
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by use o relatively high currents. The intense
heating of the localized areas causes transer of ink
from a ribbon onto the paper or alternatively, the
paper may be of the thermal type which includes mate-
rials that are responsive to the generated heat.
Further~ it is seen that the use of thermal
printing is adaptable for MICR encoding of documents
wherein magnetic particles are caused to be trans-
ferred onto the documents for machine reading of the
characters. The thermal transfer printing approach
for use in MICR encoding of documents enables relia-
bility in operation at the lower noise levels,
Representative documentation in the area of
magnetic ink for use in nonimpact printing includes
United States Patent No. 3,042,616, issued to R~ J.
Brown on July 3, 1962, which discloses a process of
preparing magnetic ink by wetting powdered iron with a
resinous solution and adding an aqueous slurry of
carbonate to form droplets surrounded by solvent
liquidO The solven~ is separated by water and the
particles are then filtered and dried to produce
spheres of magnetic ink.
United States Patent No. 3,117,018, issued to
E~ Strauss on January 7, 1964, discloses a color
transfer medium and method of producing the same by
applying a coating consisting of a polycarbonate, a
solvent, a plastisizer and a pigment, and then drying
the coating to form a solid transfer layer.
United States Patent No. 3,284,360, issued to
J. V. Peshin on November 8, 1966, discloses a transfer
coating of magnetic pigment in a solution of a
stearamide binder or mixtures of stearamide and
oleamide and a solvent binder. A preferred solution
includes a major proportion o magnetic pigment and a
minor proportion of the binder consisting primarily of
stearamide or mixtures of stearamide and oleamide.
13 ~
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United States Patent No. 3,413,183, issued to
H. T. Findlay et al. on November 26, 1968, cliscloses a
transfer medium provided by a coating process wherein
the trans~er layer is a polycarbonate having voicls
which hold an imaging materialO
United States Patent No~ 3,4g6,015, issued to
D. A. Newman et al. on February 17, 1970, discloses
pressure-sensitive magnetic transfer elements for
placement of magnetically-sensible images under vari-
ous conditions of u~e. The imaging layer has a porous
resinous binder containing pressure-exudable liquid
ink. The ink comprises a liquid oil vehicle and
magnetic pigment having an oil absorption value below
twenty (20) and a tape density value above twenty
t20).
United States Patent No. 3,663,278, issued to
J. H. Blose et al. on May 16, 1972, discloses a
thermal transfer medium having a coating composition
of cellulosic polymer, thermoplastic resin, plastic~
izer and a sensible dye or oxide pigment material.
United States Patent No. 3~744,611, issued to
L. Montanari et al. on July 10, 1973, discloses an
electro~hermal printer for nonimpact printing on plain
paper that uses a ribbon made of a substrate having a
thermal transferable ink coated on one surface thereof
ancl a coating of electrically resistive material on
the other surface.
Unitecl States Patent No. 3,855,448, issued to
T. Hanagata et al~ on December 17, 1974, discloses a
print ribbon comprising a heat-resistant support sheet
with a heat-fusible material la~er of thermoplastic
resin, carbon black, pigment or oleic acid fats, ancl
wax, mineral oils or vegetable Oilsa
~ nited States Patent No. 4,022,936, issued to
R. E. Miller et al. on May 10~ 1977, discloses a
process for making a sensitized record sheet by pro-
viding a substrate, coating the substrate with an
aqueous compositionv and then drying the coating~
United States Patent No. 4,103~066, issued to
G. F. Brooks et alO on July 25, 1978~ discloses a
ribbon for nonimpact printing comprising a transfer
coating and a substrate which is a polycarbonate resin
containing a percentage b~ weight of electrically-
conductive carbon black.
United States Patent No. 4,251,276, issued to
W. I. Ferree et al. on February 17, 1981, discloses a
transfer ribbon having a substrate coated with a
thermally-activated ink composition comprising a
thermally-stable polymer, an oil-gelling agent, and an
oil-dissolving medi~ present in a percentage by
weight of the total nonvolatile components.
United States Patent No. 4,291,g94~ issued to
T. L. Smith et al. on September 29, 1981, discloses a
ribbon for nonimpact printing which comprises a trans-
fer coating and a substrate containing resin which is
a mixture of polycarbonate~ a block copolymer of
bisphenol carbonate and dimethyl siloxane7 and a
percenta~e b~ weight of electrically-conductive carbon
black.
United States Patent Mo. 4,309,117~ issued to
L. SO Chang et alO on January 5, 1982, discloses a
ribbon configuration for resistive ribbon thermal
transfer printing comprising a low resistive layer of
conductive car~on, a high resistive layer of a ceramic
metal mixture, a stainless steel conductive layer~ and
an ink transfer layer.
United States Patent No. 4,315,643, issued to
Y. Tokunaga et al. on February 16, 1982, discloses a
heat sensitive transfer element having a foundation, a
color developln~ layer on one surface and a hot melt
ink layer on the other surface of the foundation. The
ink layer has a heat conductiny material and a solid
wax.
Unlted States Patent No 4,3~0,170, issued to
. T~ Findlay on March 16, 1982, discloses a ribbon
3~
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for thermal printing which has a transfer coating and
a substrate which is a resin containing carbon black.
And~ United States Patent No. 4,463,0334,
issued to Y. Tokunaga et al. on July 31~ 19~,
discloses a heat-sensitive magnetic transfer element
for printing a magnetic image to be recognized by a
magnetic ink character reader (MICR) and which element
comprises a heat-resisting foundation and a heat-
sensitive transferring layer including a ferromagnetic
substance powder in a wax and/or plastic binder, and
having a melting point of 50 degrees to 120 degrees C
so that portions of the layer can be transferred onto
a receiving paper in the form of a magnetic image by a
thermal printer.
Summary of the Invention
The present invention relates to nonimpact
printing. More particularly, the invention provides a
formulation or composition for producing a thermal
magnetic ribbon or transfer medium for use in imaging
or encoding characters on paper or like record media
documents which enables machine reading of the imaged
or encoded characters. The thermal magnetic transfer
ribbon enables printing in quiet and efficient manner
and makes use of the advantages of thermal printing
while encoding documents with a magnetic signal
inducible ink.
In accordance with the present invention, there
is provided a magnetic thermal ribbon for use in
nonimpact printing comprising a substrate and a
transfer layer which is a mixture comprising the
combination of a wax emulsion essentially containing
about 25 to 50% amide wax, about 25 to 50% hydrocarbon
wax, about 5 to 20~ polyethylene, about 5 to 20%
styrene copolymer resin, and a dispersion essentially
containing about 25 to 60% magnetic pigment, about 1
to 5% wetting agent, and about 1 to ~% dye, all by dry
- 5~ -
weight, and about 60 to 80% solvent by wet weight for
solubilizing the mixture.
The ribbon comprises a thin, smooth substrate
such as tissue-type paper or polyester-type plastic on
which is applied a coating that generally includes a
magnetic pigment and a wax mixture dispersed in a
binder mix of polyethylene and resin to form the
emu]sion. The resin and the solids of the wax
emulsion are mixed into solution alony with a magnetic
filler and the wax emulsion is added aEter wetting the
pigment. The coating is put through a setting
procedure by drying the coating at an elevated
temperature
/
and the coating is then applied to the substrate by
well-known or conventional coating techniquesu
In view of the above discussion~ the
principal object of the present invention is to pro-
vide a ribbon including a thermal magnetic coating
thereon.
Another object of the present invention is to
provide a thermal magnetic transfer ribbon including a
coating thereon for use in encoding operations.
An additional object of the present invention
is to provide a maynetic coating on a ribbon having
ingredients in the coating which are responsive to
heat for transferring a portion of the coating to
paper or like record media.
A further object of the present invention is
to provide a coating on a ribbon substrate, which
coating includes a magnetic pigment and a wax emulsion
dispersed in a binder mix and which is responsive to
heat for transferring the coating in precise printing
manner to paper or like record media~
Still another object of the present invention
is to provide a thermally-activated coating on a
ribbon that is completely transferred from the base of
the ribbon onto the paper or document in an encoding
operation in printing manner at precise positions and
during the time when the thermal elements are activat-
ed to produce a well-def ined and precise or sharp
image.
Still a further object of the present
invention is to provide a two stage process which
includes the preparation of a specific wax emulsion
and the preparation of a transfer coating for use in
magnetic thermal printing~
Additional advantages and features of the
present invention will become apparent and ully
understood from a readin~ of the following description
taken together with the annexed drawing.
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Brief Description of the Drawing
Fig. 1 illustrates a thermal element
operating with a ribbon base having a transfer coating
thereon incorporating the ingredients as disclose~ in
the present invention; and
Fig. 2 shows the receiving paper with a
coating particle transferred thereto.
Description of the Preferred Embodiment
m e transfer ribbon 20, as illustrated in
Figs. 1 and 2, comprises a base or substrate 22 of
thin~ smooth tissue-type paper or polyester-type
plastic or like material having a coating 24 which is
thermally activated ancl includes magnetic particles 26
as an ingredient therein for use in encoding opera-
tions to anable machine reading of characters. Each
character that is imaged on a recei~ing paper 28 or
like record media produces a unique magnetic waveform
that is recognized and re~d by the reader.
As alluded to abovey it is noted that the use
of a thermal printer having a print head element, as
30, substantially reduces noise levels in the printiny
operation and provides reliability in MICR encoding of
paper or like documents 28. The thermal magnetic
transfer ribbon 20 enables the advantages of thermal
printing while encoding the document 28 with a magnet-
ic signal inducible ink. When the heating elements 30
of a thermal print head are activated, the encoding
operation requires that a portion of the magnetic
particles or like material 26 on the coated ribbon 20
be completely transferred from the ribbon to the
document ~8 in manner and form to produce precisely
defined characters 32 for recognition by the reader.
The thermal transfer ribbon of the present
invention is produced in a two stage process wherein
the first stage includes preparation of a specific wax
3~7
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:
emulsion or formulation and the second stage includes
preparation of the transfer coating or layer.
A preferred wax emulsion or formulation to
satisfy the first stage includes the ingredients in
appropriate amounts as set forth in the follo~7ing
table of Example I.
EXA~PLE I
TAB LE: 1
Wax_EmulsionPercent Dr~ Wet Ranqe
Ceramid*Wax39.5 39.5 20-60%
WB-5 h'ax 39.5 39.5 20-60%
AC-617
Polyethylene 11.7 11.7 0-20%
Piccotex*100
Resin 9.3 9.3 0-20%
100.0 100.0
Mineral Spirits 100.0
200.0
The nonvolatile materials in the above
formulation equate to 50%, and it is here noted that
Lacolene, or VM and P Naptha, can be substituted in
place of the mineral spirits.
The second stage of the process includes
preparation of the magnetic thermal transfer coating
wherein the followinq ingredients in appropriate
amounts, as set forth in Table 2 of Example I, are
placed into dispersion e~uipment such as a ball mill,
a shot mill, a sand mill, or an attritor and qround
for a period of approximately 20-40 minutes, or for a
sufficient period of time to provide a uniform fine (3
to 5 microns size) dispersion,
: * Trade mark
-- 3 --
TABLE 2
Material Percent Dry Wet Range
Iron Oxide 37.4 37.4 1-30%
Wax Emulsion 50.5 101.0 10-99%
tfrom Table 1
50% solids)
Melamine
Sulfonamid
. Resin 6,1 6.1 0-20%
Codispersion
31L62 1.0 1.7 0-40%
(in various
aliphatic solvents
at 56% solids)
: Slip-Ayd*425 1.0 5.0 0-10%
(in Xylene at
: 20% solids)
Soya Lecithin 1.0 1.0 0-10%
Flexo*Black X12 3.0 6.1 0-10%
(in N-Propanol
at 50~ solids)
:~'
100.0 158.3
Mineral Spirits 79.7
~ 238.0
':'
Example II provides slightly different
ingredients and amounts thereof, as set forth in
Tables 1 and 2, for preparation of the transfer
coating or layer.
:
'.
~ * Trade mark
'~
~2~3~
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EXAMPLE II
TABLE 1
Wax Emulsion Percent Dry Wet Range
Armid C 39.5 39O5 20-60
WB-5 39.5 39.5 20-60%
AC-617 11~7 11.7 0-2Q~
Piccotex-75 9.3 9.3 0-20%
100.O 100.O
Mineral Spirits 100.0
200.0
TABLE 2
Material Percent Dry Wet Range
Iron Oxide 37.4 37.4 1-80%
Wax Emulsion 50.5 101.0 10-99%
(from Table 1)
Melamine
Sulfonamid
Resin 6.1 6.1 0-20%
Codispersion
31L62 1.0 1.7 0-40%
Slip-Ayd 425 1,0 5.0 0-10%
Soya Lecithin 1.0 1.0 0-10%
Flexo Black X12 3.0 5.1 0-10%
100.0 15~.3
Mineral Spirits 79.7
238.0
A polyterpene, such as Wingtack 95, may be
substituted for the Piccotex 75 in Table 1.
Example III further provides slightly
different ingredients and amounts thereof, as set
Eorth in Tables 1 and 2, for preparation of the
transfer coating or layer.
EXAMPLE III
TABLÆ 1
Wax EmulsionPercent Dry Wet Range
Ceramid* 39.5 39.5 20-60%
WB-17 39.5 39.5 20-60%
AC-430 9.7 9.7 0-20%
~C-617 2.0 2.0 0-20%
Piccotex-100 9.3 9.3 0-20%
100.O 100.O
Mineral Spirits 100.0
200.0
TABLE 2
Material Percent Dry Wet Range
Iron Oxide 30.4 30.4 1-80%
Wax Emulsion 50.5 101.0 10-99%
(from Table 1)
Melamine
Sulfonamid
Resin 6.1 6.1 0-20%
Cupric Oxide 7O0 7O0 0-40%
Codispersion
31L62 1.0 1.7 0-40%
Slip-Ayd 425 1.0 5.0 0-10%
Soya Lecithin 1.0 1.0 0-10%
Flexo Black X123.0 6.1 0-10%
100.0 158.3
Mineral Spirits 79.7
238.0
Armid C is a fatty acid derived-multi carbon
chain lengths amide wax and Ceramid is a fatty acid
derived amide wax. WB-5 and WB-17 are oxidized,
isocyanated hydrocarbon waxes. AC-430 is an ethylene
vinyl acetate copolymer. AC-617 and AC-1702 are low
molecular weight polyethylenes. Piccotex-75 and
Piccotex-100 are hard, color stable, substituted
* Trade mark
- 12 -
styrene copolymer resins. Melamine Sulfonamid is an
amino resin of high moleculor weight made from
melamine and formaldehyde. Codispersion 31L62 is a
colloidal dispersion of carbon black suspended in an
aliphatic solvent. Slip-Ayd 425 is a 20% dispersion
of high melting point polymeric wax in xylene. Soya
Lecithin is a wetting agent, oil-like extract of
soybean. Flexo Black X12 is a 50% nigrosine
dispersion in alcohol. Wingtack 95 is a polyterpene
resin.
The nonvolatile materials are controlled at
25-50~ for proper viscosity. It should be noted that
all ingredients are carefully weighed and solubilized
in the mineral spirits using appropriate heat and
agitation. After the solution is complete, it is
slowly cooled to form a viscous wax dispersion to
prepare a thermally active, transfer coating.
The substrate or base 22, which may be 35-40
gauge capacitor tissue, manufactured by Schweitzer, or
25-35 gauge polyester film as manufactured by duPont
under the trademark Mylar, should have a high tensile
strength to provide for ease in handling and coating
of the substrate. Additionally, the substrate should
have properties of minimum thickness and low heat
resistance to prolong the life of the heating elements
30 of the thermal print head by reason of reduced
print head actuating voltage and the resultant
reduction in burn time.
The coating 24 is applied to the substrate 22
by means of conventional coating techniques such as a
Meyer rod or like wire-wound doctor bar set up on a
typical solvent coating machine to provide the coating
weight of between 3 and 13 grams per square meter.
The coating is made up of approximately 25-50%
nonvolatile material and may be maintained at a
desired temperature and viscosity throughout the
coating process. After the coating is applied to the
substrate, the web of ribbon is passed through a dryer
- 13 -
at an elevated temperature in the range between 93 and
150 degrees C for approximately 5-10 seconds to ensure
good drying and adherence of the coating 24 onto the
substrate 22 in making the transfer ribbon ~0. The
above-mentioned coating weight, as applied by the
Meyer rod onto a preferred 9-12 microns thick
capacitor grade tissue, translate to an overall total
thickness of 15-25 microns.
The availability of the various ingredients
used in the present invention is provided by the
follo~ing list of companies.
Material Supplier
Ceramid Wax Glyco Chemicals Inc.
Armid C Wax Armak Chemical
WB-5 Wax Petrolite Corp.
WB-17 Wax Petrolite Corp.
AC-430 Polyethylene Allied Chemical Corp.
AC-617 Polyethylene Allied Chemical CorpO
AC-1702 Polyethylene Allied Chemical Corp.
Piccotex 75 Resin Hercules Inc.
Piccotex-100 Resin Hercules Inc.
Mineral Spirits Ashland Chemical Co.
Iron Oxide BASF 345
Cupric Oxide American Chemet
Melamine Sulfonamid
Resin DayGlo
Codispersion 31L62 Borden Chemical Co.
Slip-Ayd ~25 Daniel Products
Soya Lecithin Capricorn Chemical
Flexo Black X12 BASF
Wingtack 95 Goodyear Chemical
Ceramid is a trademark of Glyco Chemicals
Inc. and Armid is a trademark of Armour Chemical. A-C
is a trademark of Allied Chemical. Piccotex is a
trademark of Pennsylvania Industrial. Codispersion is
a trademark of Binney and Smith. Slip-Ayd is a
trademark of Daniel Products. And, Wing-Tack is a
trademark of Goodyear.
It is thus seen that herein shown and
described is a magnetic thermal transfer ribbon for
use in thermal printing operations which includes a
thermal responsive magnetic coating on one surface
thereof. The coated ribbon enables transfer of
coating material onto documents or like record media
during the printing operation to form characters
thereon in an imaging or in an encoding nature,
permitting machine reading of the characters. The
present invention enables the accomplishment of the
objects and advantages mentioned above, and while a
preferred embodiment has been disclosed herein,
variations thereof may occur to those skilled in the
art. It is contemplated that all such variations and
modifications not departing from the spirit and scope
of the invention hereof are to be construed in
accordance with the following claims.
