Note: Descriptions are shown in the official language in which they were submitted.
Background of the Invention
This invention relates to the labeling of objects by
the use of heat to transfer design prints from a carrier to the
objects being labeled.
In heat transfer labeling, a design print that is
affixed to a carrier by a release layer is brought into contact
with an object to be labeled. When heat is applied to the
carrier the release layer becomes molten and permits the design
print to become adhered to the object.
In the typical heat transfer label, as exemplified by
U.S. Patent 3,616,015, which issued October 26, 1971, the release
layer is a coating of wax on the carrier and the design print
is in a transfer layer that is printed on the wax coating. With
such a label, the application of heat during the transfer process
causes a film of wax to be deposited over the entire region where
the carrier is in contact with the object being labeled. The
deposited film is of random configuration and is frequently much
larger than the design print.
Although the wa~ film is transparent and generally not
noticeable by casual observation, under certain lighting con-
ditions the film is viewable and can present an objectionable
appearance. The resulting film can be regarded as an expanded,
irregular "halo" that surrounds the design print. Not only
can the irregular halo present an objectionable appearance, it
represents a wastage of material. Moreover, because of the
tendency of the wax to penetrate the carrier material usèd in
ordinary heat transfer labeling, a substantial amount of wax
material is needed to form the transfer coating.
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Accordingly it is an object of the invention to
expedite and facilitate the heat transfer labeling of objects.
Another object of the invention is to improve the
appearance of heat transfer labels. A related object is to
eliminate the enlarged, irregular halo often encountered in heat
transfer labeling.
A related object is to economi2e on the amount of
material needed for the release layer in the heat transfer labeling
of objects.
Summary of the Invention
In accomplishing the foregoing and related objects, the
invention provides for the use of a thermoplastic release layer
which is contoured in accordance with a prescribed pattern and
is in registration with a transfer layer.
Since the release layer is contoured, it does not present
an irregular appearance. Further the contoured pattern can be
made to closely approximate the contour of the transfer layer
and thereby significantly reduce the extent of the halo.
In accordance with one aspect of the invention the halo
20 can be completely eliminated by having the confines of the transfer
for layer exceed those o~ the release layer.
In accordance with a further aspect of the invention the
release layer is applied by printing, instead of coating the
carrier. This significantly reduces the amount of material needed.
In addition when the release material is a resin, as opposed to
a wax, there is less absorption by the carrier and less material
is needed.
Printing of the release layer also eliminates the need
for a coating operation in conjunction with the printing operation
3~ by which the transfer layer is applied to the carrier.
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Description of the Drawings
~ l~hou~h aspect~ o~the invention will become apparent
after considering several illustrative embodiments taken in
conjunction with the drawings in which:
FIGU~E lA is a plan view of heat transfer label carrier
of the prior art;
FIGURE lB is a sectional view of the carrier of FIGURE lA;
FIGURE lC is a perspective view of an okject that has
been labeled using the carrier of FIGURE lA;
FIGURE 2A is a plan view of a heat transfer label carrier
in accordance with the invention;
: FIGURE 2B is a sectional view of the carrier of FIGURE 2A;
FIGURE 2C is a perspective view of an object that has~
been labeledusing the carrier of FIGURE 2A; and
FIGURE 3 is a plan view of an alternative heat transfer
label in accordance with the invention.
Detailed Description
With reference to FIGURES lA through lC of the drawings,
a carrier 11 (FIGURES lA and lB) in accordance with the prior
art is provided with a coating 12 upon which is superimposed a
transfer layer 13 which includes a design print.
When the transfer layer 13 of the carrier 11 is brought
; into contact with an object to be labeled, such as the illus-
trative container 14 of FIGURE lC, and heat is applied, the
wax coating 12 melts and allows the contacting portion of the
transfer layer 13 to adhere to the container 14~ Simultaneo.usly
a wax film 15 is deposited on the container 14. This film is
of irregular configuration and considerably larger than the trans-
ferred design print 16. Under certain viewing conditions the
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film 15 presents an objectionable appearance.
To remedy the foregoing difficulties, the invention
provides the heat transfer labeling arrangement of FIGURE 2A
and 2B in which a contoured release layer 22 is applied to the
carrier 21 and a transfer layer 23 is superimposed on the re-
lease layer. As a result, when the transfer layer 23 is brought
into contact with an object to be labeled, such as the illus-
trative container 24 of FIGURE 2C, the transferred design print
25 has superimposed on it a release layer which provides a con-
toured halo 26 with a narrow margin.
If it is desired to eliminate even the narrow halo 26,this can be done, as shown in FIGURE 3, by forming the heat
transfer for label with a contoured release layer 32 that is
within the confines of a transfer layer 33. When this label is
applied to an object the design print from the transfer layer 33
is coextensive with the boundaries of release layer 32.
The release layers 22 and 32 are desirably applied to a
carrier by printing. For that purpose suitable materials are
resins such as polyamides, polystyrenes, resin derivatives,
phenol formaldehydes, terpene resins and ketone resins. A suit-
able material for the transfer layers 23 and 33 is the resin
isobutylmethacrylate desirably, which desirably has a low melt
viscosity in the range from 3.5 to 8.5 poises at 160 degrees
centigrade. They desirably have a s~ftening point in the range
from 95 to 106 degrees centigrade.
The practice o~ the invention is ~urther illustrated
with reference to the following non-limiting examples.
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EXAMPLE I
A polyamide resin sold and marketed under the trade
name EMEREZ* 1538 of Emery Industries was dissolved in 70 parts
isopropyl alcohol and 30 parts toluene to form a solution with
a concentration of 30 percent resin. The resulting solution was
then printed in a contoured pattern on a paper carrier of con-
ventional bodystock for heat transfer labeling using a roto-
gravure press. The print pattern was dried to remove the solvent
and overprinted with a transfer layer, formed by an ink lacquer
of isobutylmethacrylate, in a contoured pattern in registration
with the release pattern. The doubly imprinted carrier stock was
used to apply the design print of the ink lacquer to an object
and afforded good transfer with an insignificant release halo.
Other suitable polyamide resins of the EMEREZ* type are
sold and marketed under the trade names EMEREZ* 1536 and 1537.
EMEREZ* polyamide resins have the characteristics
illustrated in Table I, below.
TABLE I
CHARACTERISTIC EMEREZ* 1536 EMEREZ* 1538
Softening point range 95 - 105 98 - 106
(degrees centigrade)
Melt Viscosity 3~5 - 5.0 6.5 - 8.5
(poise at 160 degrees
centigrade)
Molten Color 12 10
(1963 Gardner)
Viscosity in 40% Mixed 66 82
Solvent O
` (cps at 25 C)
Viscosity in 40% n- 62 95
Propanol
(cps at 25C)
* Trade Marks
- 6 -
64'~
EXAMPLE II
Example I was repeated using a polyamide sold and
marketed under the trade name VERSAMID*g40 by General Mills~
Satisfactory release was achieved with an insigni~icant release
halo.
EXAMPLE III
Example I was repeated using a polyamide sold and
marketed under the trade name VERSAMID* 948. Satisfactory
release was again achieved.
EXAMPLE IV
Example I was repeated using a polystyrene resin sold
and marketed under the trade name LUSTPEX* 3 using toluene as
the solvent. Satisfactory release was achieved with an insig-
nificant release halo.
EXAMPLE V
Example IV was repeated with a similar result using a
resin derivative sold and marketed under the trade name PENTALYN* A.
EXAMPLE VI
Example IV was repeated with a similar result using a
modified phenol formaldehyde sold~and marketed under the trade
name AMBEROL* ~-7
EXAMPLE VII
Example IV was repeated with a similar result using a
terpene resin sold and marketed under the trade name PICCOLYTE*
S-100.
EXAMPLE VIII
Example IV was repeated with a similar result using a
ketone resin sold and marketed under the trade name ADVARESIN*
CXF.
* Trade Marks
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It will be understood that the foregoin~ examples
and description are illustrative only and that other examples
and equivalents within the spirit and scope of the invention will
; occur to those skilled in the art.
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