Note: Descriptions are shown in the official language in which they were submitted.
~8f~357
- 1 - LFM-7035
DECORATIVE SHEETS AND COVERINGS COMPRISING POLYVINYL
CHLORIDE AND CATIONIC DYESTUFFS
The present invention relates to decorative
sheets and coverings and more particularly to decorative
sheets and coverings comprising polyvinyl chloride and
cationic dyestuffs.
Background of the Invention
Substrates comprising polyvinyl chloride have
come into wide use as decorative coverings and
partic~larly as decorative floor coverings. In order
for such materials to be aesthetically acceptable, they
must be provided with a colored pattern or designO Two
general types of colorants have traditionally been
available to provide such patterns; namely, dyes and
pigments. The Encyclopedia of PVC defines dyes to be
colorants that are soluble in vinyl formulations,
whereas pigments are colorants that are insoluble in
vinyl formulations. Dyes have primarily comprised
disperse and solvent dyes; however, such dyes have been
shown to have definite drawbacks which precl~de their
use in polyvinyl chloride systemsO Thus, although they
may be conveniently used in polyvinyl chloride-
containing formulations to give products that have good
transparency and color strength, problems associated
with color bleeding, poor light fastness, lack of heat
stability and the like have mitigated against their use
and have resulted in the general adoption of ~igments to
8.~
- 2 ~ 7035
provide color to polyvïnyl chloride compositions.
Pigments are conventionally applied by means
of printing inks, or by stencil deposition of pigmented
particles. Nevertheless, pigmented produets are not
entirely satisfactor~ because, for example, the color
selection is limited and through-color images cannot be
obtained. Accordingly, industrial producers of products
containing polyvinyl chloride have long sought ways to
improve the color characteristics of such products.
The Prior Art
Recently, Stetson et al., in U.S. Patent No.
4,23~,076, disclosed processes for obtaining through-
color penetration of plasticized polyvinyl chloride
substrates by transfer printing using sublimable
disperse dyes. These processes comprised the steps of
applying a transfer paper ~r other release surface
coated with a pattern or design comprising a sublimable
disperse dye to the surface of a polyvinyl chloride
substrate. When the composite was heated, the dye
sublimed into the substrate. rrhe transfer paper was
then removed leaving a substrate with a sharp~
through-color image.
One stated advantage of flooring structures
prepared in this fashion was the distinctiveness of
detail which allegedly remained during the service life
of the floor covering. It has been found, however, that
when vinyl floor structures comprising a sublimable
disperse dye are subjected to heat, migration of color
and loss of pattern definition can be accelerated.
Accordingly, one objective of the present
invention is to provide processes for preparing
substrates comprising polyvinyl chloride whereby said
substrates have a through-color image ~hich will not
fade or bleed with time or when exposed to high
temperatures.
Yet another objective of the present invention
is to provide decorative sheets and coverings having
through color images, said sheets arld coverings being
~8~S~
- 3 - ~ 7035
usable as flooring rnaterials, wall coverings, and the
like.
Still yet another objective of the present
invention is to provide transfer sheets and ink
compositions comprising cationic dyestuffs which will be
useful to prepare decorative surfaces comprising poly-
vinyl chloride.
These and other objectives of the present
invention will become apparent from the detailed0 description of preferred embodiments which follows.
Summary of the Invention
The present invention concerns our discovery
that decorative sheets and coverings comprising
polyvinyl chloride and having substantially
non-migratable through-color images may be prepared
using cationic dyestuffs. These coverings may be
prepared by providing a variety of polyvinyl
chloride-containing substrates with image compositions
comprising cationic dyestuffs and a suitable binder, and
then treating these materials such that the cationic
dyestuffs migrate into the substrate. Through-color
images are obt~ained which are substantially
non-migrating~ even under severe conditions.
Detailed Description o Preferred Embodiments
2~ In one embodiment the presen~ invention
comprises a process for preparing a decorative sheet
comprising polyvinyl chloride and a substantially
non-migratable image, said process comprising the steps
of selecting a substrate comprising polyvinyl chloride;
interfacing an image composition with said substrate,
said image composition comprising at least one cationic
dyestuff and a binder; and heating said interfaced
substrate and image composition to migrate said dyestuff
into said substrate, said binder being of a type which
will not substantially impede migra~ion of said
dyestuff.
In a second embodiment the present invention
comprises a decorative sheet comprising pol~vinyl
~88~
- 9 - L~"-7035
chloride and a substantially non-migratable image
comprising at least one cationic dyestuff.
In a third embodiment the present invention
comprises a decorative floor covering comprising a
backing and a substrate comprising polyvinyl chloride
adhered to said backing, said s~bstrate comprising a
substantially non--migratable image comprising at least
one cationic dyestuff.
In a ~ourth embodiment the present invention
comprises an image composition adaptable to provide a
substantially non-migratable through-color image for a
substrate comprising polyvinyl chloride when interfaced
with said substrate and heated, said image composition
comprising at least one cationic dyestuff and a binder
which will not substantially impede migration of said
dyestuff.
Basic dyes have long been of interest for
dyeing various substrates, particularly fibrous textile
substrates. Conventionally, these dyes were employed in
dye baths in which the substrates were immersed.
However, with the advent of transfer printing as a
useful application technique for~ disperse dyes, many
attempts were made to apply the same techno~ogy to basic
dyestuffs. Basic dyes differ from disperse ~yes
because, as a general rule, they do not sublime at
atmospheric pressure and, even under re~uced pressure,
they sublime only slightly. Therefore, difficulties
were encountered relating to the proclivity to thermal
degradation shown by many basic dyes. These problems,
combined with the generally lower melting points of
basic dyes, virtually precluded their use for transfer
printing. Therefore, substantial effort was expended to
find ways to overcome these problems.
As a result of these efforts, numerous
additives or dye treatments were proposed which
purported to overcome the relative non-transferahility
of the basic dyes, thereby making them useful to print
fibrous materials. For example, U.S. Patent No.
- 5 ~ ~ 7035
3,922,~45, which is one of a series of patents that
iss~ed to ~izl~no et al., disclosed that the
incorporation of oxidizing agents into transfer printing
inks enabled otherwise poorly transferable basic
dyestuffs to be transfer printed. A similar result was
reported in U.S. Patent No. 3,969,071 in which a
material that chemically altered the dyestuff was
included in the printing ink. In U.S. Patent No.
3,992,140, carbinol bases of basic dyestuffs were used,
as they were in U.S. Patent Nos. 3,999,939 and
4,040,779. Other approaches were also disclosed in U.S.
Patent Nos. 3,995,992; 4,057,388; 4,137,042; 4,253,838;
and 4,306,875.
The aformentioned transfer printing
techniques, which are applicable to basic and disperse
dyes, are essentially directed to the printing of
synthetic fibers, .uch as polyesters, acrylics, nylons
and acetates. These materials readily permit the
migration of dyes through the fiber matrix, presumably
due to the high surface-area-to-volume ratio of the
fibers. Conversely, sheet products present a different
situation because they have a low surface-area-to-volume
ratio, which tends to impede migration. The usual way
to improve migration in such circumstances is by raising
the temperature settings; however, this can lead to
destruction of the dyes and can also damage the sheet
material itself. Accordingly, it was surprising and
unexpected to fina that basic dyes in their cationic
~orm could be induced to migrate into substrates
comprising polyvinyl chloride without the use of
migration enhancers, and that the resulting dyed
substrates retained sharp images over long periods of
time and when subjected to strong heating. These
results are especially surprising in view of our finding
that the process of the present invention gives poor
results with polyesters, acrylics, urethanes, nylons and
epoxy materials.
The term "cationic dye" as used herein to
5~
- 6 - ;.~-7~35
define the present invention comprises basic dyes which
are in their cationic form, and we have found that
; virtually any such dye may be used in conjunction wi~h
the present invention. Hundreds of these dyes are in
existence, many of which are found in The Colour Index
published by The Society of Dyers and Colourists in
association with the ~merican ~ssociation of Textile
Chemists and Colorists~ We have discovered, however,
that superior résults may be obtained if the ionic
charge on the cationic dye is delocalized. Thus,
methine dyes, triphenylmethane dyes, xanthene dyes,
cyanine dyes and the like give more vivid colors than do
simple cationic dyes having localized ionic charges.
The present invention is applicable to a wide
variety of fibrous or sheet substrates derived from
vinyl chloride. Homopolymeric vinyl chloride substrates
are preferred, although copolymers with vinylidene
chloride, vinyl acetate, acrylic acid or other
polymerizable materials also give good results. Most
vinyl chloride-containing copolymers that are in use
today contain at least 70% vinyl chloride. For con-
venience, the term~polyvinyl chloriden as used herein
to define various applicable substrates will be deemed
to include copolymers of vinyl chloride with other
monomers.
Polymeric materials derived rom vinyl
chloride monomer are essential because, as noted above,
poor results are obtained with non-vinyl chloride-
containing materials that are known to be transfer
printable with cationic dyestuffs in the presence of
migration-encouraging compounds, such as the oxidizing
agents of Mizuno et al. While applicants do not wish to
be bound by any particular theory of operability, it
appears that cationic dyes have a particular affinity
for ~olyvinyl chloride such that, ~hen the dyes migrate
by sublimation or otherwise into a substrate comprising
polyvinyl chloride, they interact with the polyvinyl
chloride and become essentially non-migratable. Thus,
~3~ 57'
- 7 ~ 703
even w}-,en subjected to solvents or prolonged, severe
heat conditions, patterns prepared according to the
present invention remain sharp and clear.
The physical character of,the polyvinyl
chloride-containing substrate does not appear to be
particularly significant. Suitable through-color images
have been obtained by interfacing an image composition
with gelled and ungelled plastisols (with or without
chemical blowing agents), sintered dryblend resins, fused
plastisols, and plasticized or unplasticized polyvinyl
chloride film. In addition, it has been found that
saran film, or like films ~hich are copolymers of
polyvinyl chloride, can be similarly treated. The
substrates may also comprise other common additives such
as heat and light stabilizers, blowing agents, fire
retardants, and the like, which are compatible with the
objectives of the present i~vention.
When heated, the~cationic dyes in the image
composition migrate into these substrates to give
substantially non-migratable through-color images. Of
importance, however, is the fact that cationic dyes
treated as des~ribed herein will maintain a colo~ shade~
which remains essentially true throughout the dyein~
process. Thus, the present invention is decidedly
superior to those prior art processes employing cationic
dyest~ffs in which the dyestuffs are treated such that
they temporarily change or lose color.
Despite these advantages, care must be taken
in selecting the substrates which will be dyed according
to the present invention. It has been observed that the
inclusion in a substrate of certain materials that have
an affinity for cationic dyes, such as limestone or
silica fillers, may impede migration. Therefore, use of
such materials should be avoided where good depth of
penetration is desired.
The cationic dyestuffs of the present
invention will be applied in combination with a binder
that does not interfere with the subsequent migration of
r371
- & - 1,.~ 1n-~5
the dycst~If into the s~lbstrate~ Certain bindels, such
as polyvinyl a~cohol or polyvin~vl acetate will cause
this interference or impedence. Accordingly, a bin~er
should be selected which does not cause this effect.
Examples of binders which have given superior results
are polyvinyl acetals, such as polyvinyl butyral;
cellulose ethers, such as ethyl cellulose ~nd methyl
cellulose; and mixtures thereof. Compositions
comprising the cationic dyes and binders of the present
invention will be referred to herein as "image
compositi~ns. Il
Image compositions may be applied to or
interfaced with various surfaces by virtually an~
- technique, such as transfer printing, conventional
printing using rotogravure, flexographic, lithographic,
screen, ink jet and other printing processes, hand
application techniques such as th~se used by an artist,
powder dispersion techniques and the like. For
convenience, the method of applying an image composition
will be referred to herein as "imaging," and the
exposure of a substrate to an image composition will be
referred to as "interfacing."
An especially preferred method of migrating an
image into polyvinyl chloride-containiny substrates is
by transfer printing. Transfer printing basically
comprises the steps of imaging a transfer sheet, inter-
facing the sheet with the substrate such that the image
is in contact, but preferably in intimate contact, with
the substrate, and then applying heat to transfer the
image.
A variety of transfer sheets are commercially
availablel and many of these are suitable to practice
the present invention. Care must be taken in selecting
an appropriate sheet, however, because certain sheets
will become strongly adhered to the surface of the
substrate during the transfer printing process.
Con~equently, even though a suitable image transfer may
occur, adhesion of the transfer paper to the s~bstrate
1~9~ 5~
_ g _ LF~ 35
may prevent a oesirable product from being prepared.
Especially good results have heen obtained using foil or
polyester transfer sheets; however, the most satisfactory
results have been obtained using clay-coated kraft paper
S comprising a coating material between the clay coating
and the image ~o ~acilitate release of the transfer
~ sheet from the hot substrate~ An exa~ple of such a
coated transfer sheet is Frankote* Cover Bristol, a com-
mercially available kaolin clay-coated white kraft
1~ paper, which has been coated with a 1-3 mil layer of
polyvinyl alcohol, ethyl cellulose or methyl cellulose
prior to use. Tllese coated transfer papers also provide
an exceptionally smooth surface for the image, as well
as excellent contact of the image with the substrate.
lS Furthermore, they have shown a remarkable ability to
give immediate release from a hot (about 300 F) vinvl
substrate without ~ausing picking, pitting or other
damage to the substrate.
Once the paper has been prepared, it is imaged
20 by virtually any technique, such as those set forth
above. With transfer printing, it is preferable that
the binder cause the image composition to remain adhered
to the transfer sheet when the latter is separated from
the substrate. Although image compositions which
adhere, in whole or in part, to the surface of the
substrate may also have utility, they are not preferred
because they usually must either be removed at a later
stage in the process, or be protected with a wear layerO
It has been found that image compositions comprising the
preferred binders set forth a~ove also possess this
desired attribute.
When a dry powder is imaged to a transfer
sheet, it will usually be applied as a pattern ~hich
preferably is then warmed to cause the binder to adhere
to the sheet. Transfe~ sheets may be prepared in which
the image composition is not ~dhered; ho~ever, they
often lead to products having smeared images and, thusv
are not preferred.
* Trademark
,r~
- 10 - IF~'-703S
l~hen the image compositions are applied as
inks, the inks will usually comprise one or more
solvents for the dye and binder. A wide variety of
solvents have ~tility when incorporated into printable
cationic dye systems. Examples of these may ~e found in
U.S. Patent No. 4,272,292, another of the Mizuno et al.
references. It is noted, however, that this reference
places certain restrictions on the proportions of
solvents which may be used due to stability problems
assoc;ated with the car~inol bases disclosed therein.
No such restrictions apply to the present invention and
virtually any desired solvent may be used. Preferably,
but not necessarily, the solvent or solvents that are
selected will be suitable to solubilize essentially all
of the binder and dyestuff in order to obtain a uniform
printing composition. These compositions may also con-
tain other compatible components, such as drying agents,
hardening agents, emulsifiers, dispersants, thickeners,
fillers and the like, all of which are well known in the
art and which will be soluble or dispersable in the
selected solvent systemO
It~has been observed that ink compositions of
the present invention may be used without difficulty
when they are freshly prepared. Upon standing for
several hours, however, a gelling reaction occurs which
interferes with the applicability of the ink. The
reason for the gelling is not apparent although it is
believed to be due to an interaction of the dyestuff
with the binder; nevertheless, gelling normally does not
affect dye color.
Me have found that the ink may be stabilized
against gellation by including an appropriate basic
stabilizer in the ink, provided that the basic material
does not substantially change the color of the dye,
either immediately, or on long standing. Aminesl and
particularly tertiary amines, have provided good
results~ One such tertiary amine is N,N,N'/N'-tetra-
methylethylene diamine. This compound has given
~ J ':-7035
especially good results when included in the ink at
levels of about 1 to about 5 percent of the total weight
of the ink. The amount of amine used is not critical,
although if too much is used, precipitation of the
binder may occur.
Amines and bases have been used by others in
formulating various cationic dye-containing compositions;
however, the purposes for including these bases were
entirely different. For example, Mizuno et al., in U.S.
Patent No. 4,272,292, used strong bases to prevent
long-term decomposition of the carbinol bases of the
cationic dyes disclosed therein. As another example,
Deago et al., in ~.S. Patent No. 4,042,545, disclosed a
system in which organic or inorganic acid acceptors were
used to free the cationic dyes from their salt form.
These acid acceptors, which included amines, caused a
color change or a loss of color, and the invention
disclosed by Defago et al. taught the addition of an
indicator dye so that this drawback could be
circumvented. Thus, the bases disclosed by Mizuno et
a and Defago et al. were required for the operability_
of their respective~inventions.
The use of the stabilizing bases disclosed
herein is purely optional. The cationic dyes maintain
essentially a true color throughout the processes of the
present invention and these colors remain constant in
the presence or absence of a stabilizer. Therefore,
virtually any basic stabilizer may be used to practice
the present invention, provided that it stabilizes the
3~ ink composition without causing a significant change in
color. Nevertheless, amines, and particularly tertiary
amines, are the preferred stabilizers.
Three major factors appear to contribute to
the depth of color penetration into substrates suitable
to practice the present invention. These are the nature
of the ionic charge on the cationic dyestuff, the
temperature during migration of the image into the
8~5~7
1;-`'`'-7035
substrate, and the length of time during which the
temperature is applied. In addition, three other
factors may be considered, these being the pressure that
is applied, the amount of dyestuff available to migrate
and the color type of the dyestu~f.
Appropriate inks may be applied to the
transfer paper by any of the techniques referred to
above. The ink is allowed to dry and the transfer sheet
is interfaced with the substrate such that -the image is
in contact with the substrate. The interfaced materials
are then subjected to heat and perhaps pressure for a
period of time. The temperature and the residence time
of the interfaced materials at that temperature are
probably the two most important variables, the pressure
being needed primarily to maintain good contact between
the substrate and the image to be transferred. Suitable
temperatures and residence times range from about 180
to about 380 F for from about 1 to about 300 seconds.
Preferred ranges are from about 270 to about 350 F for
from about 1 to about 100 seconds, whereas most
preferred ranges are from about 290 to about 320 F for
from about 30 to about 90 sec~onds. Pressures of from 0
to about 50Q po~lnds per square inch may be used although
pressures of ~rom about 10 to about 50 pounds per square
inch are preferred.
The best penetration is obtained using
transfer printing. For example, when a fused polyvinyl
chloride plastisol sheet is subjected to moderate
conditions, such as 310 F for 30 seconds, penetrations
of about 3 to 5 mils are usually obtained, whereas,
under more severe conditions~ penetrations of about 8 to
10 mils can be obtained. Furthermore, if increased
amounts of cationic dyes are used, penetrations of as
much as perhaps 20 mils may be obtained. Nevertheless,
increased levels of dyestuff cause loss of pattern
definition and should be avoided.
It is generally known that dye penetration may
also depend to a certain extent on dye color. For
t;~
- 13 - 1r~:_7035
example, experiments conducted using red, black, blue
and yellow dyestuffs at different temperatures for
various times on a fused 30-mil thick plastisol showed
varied results. When different samples comprising these
dyes were heated for 60 seconds at 260 F and at 310~ F,
the red, black and blue dyes penetrated to a certain
depth and stopped, whereas the yellow dye continued to
penetrate until heating was stopped. At 350~ F, the red
and black dyestuffs showed deeper penetration when the
time of exposure was increased from 60 to 120 seconds,
whereas the blue dyestuff showed no further penetration.
As before, the yellow dyestuff showed continued
penetration with continued heating, although it, too,
eventually ceased migrating. For these reasons t the
migration characteristics of each individual dye should
be considered by the artisan when practicing the present
invention.
Aside from the good depth of penetration
available through the use of transfer printing as
opposed to direct printing, another advantage is the
sharp pattern definition and clarity of color w~ich may
be obtained. The reason for this appears to be due to
the manner in which migration occurs. Presumably the
dyestuff migrates as individual molecules from the
transfer sheet into the matrix of the substrate where it
becomes essentially non-migratable. The process occurs
in conformity with the pattern that has been selected;
thus, through-color images having very sharp definition
are possible. Furthermore, as discussed in more detail
below, the apparent molecular migration and attachment
process may also account for the stability of these
products even when exposed to prolonged heating or
solvents.
The color fastness of the various through
color transfer-printed products was evaluated in a
number of ways. One method involved the subjection of
samples~ such as fused polyvinyl chloride sheets which
had been transfer printed with a wood grain patternJ to
35~
~ 7()35
thermal stability tests at 158 F and 180 F for six
weeks. ~o color migration or color change was observed
during this time period and the dye colors also remained
bright and unfaded.
A second method of testing stability involved
the subjection of samples of several substrates ~yed
with different colors to various solvents, such as
isopropyl alcohol, 5~ acetic acid, 5~ sodium hydroxide,
5% sulfuric acid, beef tallow, ASTM $1 oil, or
- 10 cottonseed oil. No extraction of color was observed,
even after 46 hours of testing. Furthermore, no
crocking was observed when ethyl alcohol or water laden
cloths were rubbed over the surfaces of the samples.
A third test involved the subjection of
several samples to a xenon fadeometer test, a severe
test which measures the fading of the color when a
sample is exposed to a xenon lamp for at least 100
hours~ The test indic`ated that samples-of transfer
printed polyvinyl chloride containing a plastisol had
reasonably good color stability even after 100 hours.
As a basis for comparison, cationic dyes in hydrophilic
polymer systems such as cotton or nylon are known to
have relatively poor color stability under these
conditions.
In addition to transfer printing, imaging may
also be achieved by interfacing the image composition
with the substrate by applying the irnage composition
directly on the surface of the substrate. Alternatively,
a support surface may be imaged and then interfaced with
a later-applied substrate into which the dye will
migrate. Any of the application techniques previously
described may be used. If prihting inks are used, the
solvent is evaporated and the substrate bearing the
design is heated as previously described. Nevertheless,
although through-color images may be obtained by such
direct application techniquesr product quality is often
not as satisfactory because the images normally are not
as sharp or as deep as those obtained by transfer
~9~
- lS - LF~-7035
printing. This may be illustrated as follo~s.
When directly printed samples were heated at
temperatures ranging from 270 to 370 F for 30 seconds
to 2 minutes, and then subjected to wet and dry crocking
tests, variable results were obtained~ Under the less
stringent conditions, severe crocking and poor
penetration were observed whereas generally good to very
good results were observed after heating for the full
two-minute period at 370~ F. Nevertheless, pattern
definition was not as good for these samples as it was
for transfer printed samples. While applicants herein
again do not wish to be bound by any theory of
operability, it is believed that this is due to the
presence of microscopic particles of dye in the image
composition residing on the surface of the substrate or
- the underlying support. Each of these particles can
serve as a source ~rom which the individual dye
molecules can migrate in all directions when heated.
Thus, because the image composition remains in contact
with the substrate during heat aging, dye molecules can
continue to migrate from ~hese particles, causing a
fuzziness of pattern. Eventually these~ molecules also
interact with the polyvinyl chloride, as suggested
earlier, and become essentially ixed in place.
A variety o~ uses are envisaged for the
products and processes of the present invention.
Accordingly, products such as wall coverings, floor
coverings, decorative films and windows, picture frames,
toys, or virtually any substance comprising a polyvinyl
chloride substrate in its structure or as a component
may be provided with a sharp, long-lasting image
according to this invention. Furthermore~ 2 wide range
of applications is envisaged within each area of
application. Floor coverings prvvide a particularly
good illustration of this diversity. Thus, floor
structures comprising a backing coated with a fused or
gelled polyvinyl chloride-c~ntaining plastisol can be
transfer printed or directly printed and treated to give
~9~^57
- 16 - L.~ 7035
a through-color image; Alternatively, the flooring can
be constructed by sequentially applying to a backing a
plurality of individ~ally dyed polyvinyl chloride-
containing layers, thereby giving a three-dimensional
color effect. As yet another alternative, a trarlsfer
sheet of the present invention can hav~ a polyvinyl
chloride-containing substrate applied to it in order to
provide the substrate with a transferred, through-color
image. This substrate could then be used as a wear
layer which is subsequently adhered to a floor
structure.
A further advantage resides in the
light-stability of these cationic dye-containing
products. As an example, it is possible to apply a UV
or visible light-curable wear layer to a through-color
composition because the curing process will normally
have essentially no effect on the color of the cationic
dyes contained in the composition.
The foregoing are provided merely to
illustrate, but not to limit, the scope of the present
invention. However, to provide further insight into the
advantages and utilities of the present invention the
following additional examples are presented.
EXP~IPLES
The plastisol used in the following examples
was comprised of the following components:
Ingredient Parts by Weight
: Dispersion grade PVC resin 100
Dioctyl phthalate plasticizer 25
2,2,4-~rimethyl-1,3-pentanediol
diisobutyrate ester plasticizer15
Stabilizer 2
Where indicated, the plastisol was coated at
various thicknesses on a standard permanent floor
backing and fused at about 375 F for 3-5 minutes.
Plastisols of this type are referred to herein as
"backed Eused plastisols." Samples were also prepared
5~ .
~ 7035
by drawing down coatings of the plastisol on a glass
plate, similarly fusing them, and removing the resulting
film from the plate. Plastisols of this type are
referred to herein as l'clear fused plastisols."
Examples I--IV
Examples I-IV illustrate the transfer printing
of clear f~sed plastisols with various dyes at various
temperatures to measure dye penetration. Transfer
printing was achieved using a Frankote Cover Bristol
transfer sheet that had previously been coated with
12-15% aqueous poly~inyl alcohol ~o give a 1-3 mil dry
coating. Two ink bases were prepared as foll~ws:
Parts by Weight
Ingre~ient Ink Base A InX Base B
15 Polyvinyl butyral binder 9.1 4.4
Ethyl cellulose binder -- 4.4
Xylene 66.9 68.3
l-Butanol 22.S 22.9
~,N,N',N`-Tetramethylethylene 1.~ -~
diamine
E~ample I comprised 6 parts ~f Basic Yellow 13 dye for
every 100 parts of InX Base A; Example II comprised 6
parts of Basic Blue 26 dye for every 100 par~s of InX
Base A; Example III comprised 6.2 parts of Basic Red 12
~5 dye for every 100 parts of Ink Base B; and Example IV
comprised 6~2 parts of Maxilon Super Black OLN dye for
every 100 parts of InX Base B~ ~he inks of Examples I
and II were found to be stable for weeks, whereas the
inks of Examples III and IV, which contained no
stabilizer, gelled after a few hours.
Each o the abo~e i~ks was rotogravure-printed
onto the transfer paper described above, which was then
used to transfer print pieces of clear fused plastisol
under the conditions listed below. The depth o~
3~ penetration was measured microscopically~ The pressure
applied to each sample was about 10-20 pounds per square
inch~
* Trademark
- 18 - LFJ,-7035
Dye Penetration in Mils
Example Time(seconds) 260F 310~F 350F
(Basic Yellow 13~ 10 1.0 2.0 2.0
1.4 2.6 2.0
1.4 3.3 2.6
1.4 3.6 4.0
1.7 4.0 5.3
120 2.3 8.0 7.0
II (BasicBlue 26~10 t).5 1.3 1.0
0.7 1.3 1.5
1.0 2.6 2.0
1.3 2.6 3.3
1.3 3.3 5,0
120 2.4 4.0 5.0
15 III (Basic T~ed12) 10 0.7 2.0 1.3
0.7 2.5 1~3
1~0 2.5 2.7,
1.0 2.5 2.7
~ 2.0 2.5 4.0
120 2.0 3,3 6.0
IV (Maxilon Black OLN) 10 0.7 1.3 1.3
0.7 2.0 1.3
1.0 3.3 2.0
1.4 3.3 2 D 7
1.4 3.3 4O~
120 2.0 ~.0 6.6
For comparative purposes, samples of Mylar~'
polyester film were transfer printed with the same imaye
compositions. Virtually no coloration of the film
30 occurred, other than a faint coloration of the surface.
This coloration was readily removed by wiping with a dry
cloth.
~6?~ j7
- 19 -- L. '!,_70~5
Exa~ples V-VIII
These examples illustrate the types of results
that may be obtained if substrates are directly printed
with compositionS comprising a cationic dye, and then
S heated to migrate the dye. In Examples V through VIII,
backed f~sed plastisol pieces having a plastisol layer
about 30 mils thick ~ere directly printed with the ink
compositions of Examples I, II, III and IVt respectively.
The samples were placed in a forced air oven at tempera-
tures of 270~ or 370F for times ranging from 30 to 120seconds. After each sample had cooled, it was checked
for wet a~d dry crocking and the depth of penetration
was measured. Dry crocking was measured by using a
white cloth and rubbing vigorously; wet crocking was
measured by similarly rubbing with room temperature
solutions of water or a laboratory cleaning solution
containing ammonia and an anionic surfactant. The cloth
in each case was examined for any color which might have
been removed, and the sample was examined for any change
in appearance. The following results were obtained.
Depth of Penetration (mils)
&~Crockin~ !
270~F 370F
ExampleTime Crocking Mils Crocking Mils
25 ~seconds) Wet ~ Wet Dry
V(Basic Yellow 13) 30 s s <0.5 p p 1.0
s s0.5 g p2.0
p s0.5 vg p2.5
120 s s1.5 vg 96.0
30 VI(Basic Bl~e 26) 30 s s <0.5 vg p <0.5
s s<0.5 vg p1.5
_
p s0.5 vg p2.0
120 9 s0.5 vg g3.0
VII(Basic Red 12) 30 s s <0.5 s p 0.5
s s<0.5 s p0.5
~ s s~ 0.5vg 92.0
120 s s0.5 vg g3.0
s~
- 20 - LFM-7035
Depth of Penetration (mils)
& Crocking
Example 270F 370F
Time Crocking Mils Crocking Mils
s (seconds) Wet ~ J
VIII(Maxilon Black
OLN) 30 s s <0.5 p p <0.5
s s <0.5 s p 1.0
s p 0.5 p g 2.0
120 s p 0.5 vg g 2.0
KEY: vg -- very good = trace of color removed; no
difference in sample appearance.
g = good = signific~ant color removed, slight
difference in sample appearance.
p = poor = much color removed; sample appeared
light where rubbed.
s -- severe = ink totally removed; sample appeared
pale where rubbed.
Example IX
This example illustrates the heat stability of
color patterns produced according to the present
invention. These samples were prepared utiliæing three
ink compositions containing about 100 parts of Ink Base
B and about 6 parts of Basic Blue 26, Basic Red l~ or
Basic Yellow 11, respectively. The respective inks were
rotogravure printed onto transfer sheets, as described
for Examples I-IV; which were then used to individually
transfer print different samples of backed fused
plastisol at 300F for 60 seconds under a pressure of 10
psi. The individual samples were placed in an oven at
158F for six weeks, during which time they were
examined for color fastness. Essentially no loss of
pattern definition or color fading was detected.
A comparative sample of a backed fused
plastisol transfer printed with a disperse dye pattern
was prepared as follows. A commercially available
857
- 21 - LF.'.-7035
transfer paper printed w;th a geometric design was
obtained from S~blistatic Corporation of America. ~his
paper was interfaced with a sample of backed fused
plastisol which was then transfer printed to give a
through-color pattern comprising several colors,
including yellow, red, orange, green and p~rple.
The printed sample was placed in an oven at
158F and changes were apparent after fo~r days. ~'hese
changes included blurring of the pattern edges and
merging of the colors into one another to give new color
combinations. After six weeks the pattern had markedly
degraded and several of the colors had faded significantly.
- Examples X-XIV
These examples illustrate the stability of
through-color images obtained when backed fused
plastisol samples comprising such images and prepared
according to the present invention were treated with
various solvents according to Paragraph 4.4.1 of Federal
Specification L-F-001641 (GSA-FSS) dated September 8,
1971, which pertains to the chemical and oil resistance
vinyl floor coverings with backing. Five separate
samples were transfer printed as decribed in Examples
I-IV using a transfer paper imprinted with about 6 parts
of dye for every 100 parts of Ink Base Bo As
illustrated, the various solvents had no effect (NE) on
any of the samples after 46 hours at room temperat~reO
SolventExample No. and Colour Inde~ Designation
X_ _XI XII XIII XIV
Basic Basic Basic Basic Basic
Red 1 Red 12 Red 46 Green 4 Yellow 11
Isopropyl Alcohol NE NENE NE NE
5~ Acetic Acid NE NENE NE NE
5% Sodium Hydroxide NE NE NE NE NE
5% S~lf~ric Acid NE NENE NE NE
35 Beef Tallow - NE - - -
ASTM ~1 Mineral Oil - NE
Cottonseed Oi~l - NE - - -
- ~2 - lF:~-7035
Example XV
This example illustrates the preparation of a
sample having a la~ered or three-dimensional image. A
standard permanent backing material of a type
conventionally used in flooring structures was directly
imprinted with a design according to the procedure
described in Examples V-VIII. An ink was used which
contained about 6 parts by weight of Basic Yellow 13 dye
for every 100 parts of Ink Base Bo After the solvent
had evaporated, the backing was coated with a 10-mil
layer of plastisol which was fused at 375~F for 3
minutes in the absence of pressure. This caused the dye
to migrate upwardly into the plastisol. When the
plastisol had cooled, it was transfer printed at 300~F
for 60 seconds under a pressure of 10 psi using a
transfer paper imprinted with an image composition
containing about 6 parts of Basic ~lue 26 dye for every
100 parts of Ink Base B. The resulting structure had an
upper blue layer and a lower yellow layer, thus giving a
three-dimensional effect.
Example XVI
Ex~mple XVI illustrates the application of a
transfer printed design to a polyvinyl chloride-containing
tile base. A tile base comprising 37 parts of a vinyl
chloride-vinyl acetate copolymer resin, 5 parts of a
hydrocarbon resin, 14.5 parts of plasticizer, 2.4 parts
of stabilizer, 235.1 parts of limestone and 6 parts of
fiber was prepared and transfer printed using the
Frankote paper described for Examples I-IV. The
transfer sheet had been rotogravure printed with a Basic
Yellow 13 ink as set forth in Example I. Even under
severe conditions, such as 380F for 10 minutes at 1,000
psi, very poor penetration of the color into the tile
was observed. Unfortunately! the transfer paper was
difficult to release from the tile. A preferred method
of providing a tile substrate with a through-color image
according to the present invention is illustrated in the
following t~o examples.
. '
- 23 - IF;~,-7035
Example XVII
Example XVII illustrates the simultaneous
application and transfer printing of a polyvinyl chlori~e
wear layer to the tile base of Example XYI. A 4-mil
plastisol layer was applied to the transfer sheet which
had been rotogravure printed with a Basic Yellow 13 ink
composition as set forth in Example XV. The plastisol
was gelled at 250~F for 3 minutes and then interfaced
with a tile substrate as set forth in Example XVI. The
interfaced composite materials were then subjected to 10
psi pressure at 320F for 60 seconds, after which the
transfer paper was separated from the plastisol. A tile
having a through-color fused wear layer was produced.
Example XVIII
This example illustrates the interfacing of a
tile base, a vinyl film and a transfer paper printed
with a design to produce a tile having a through-color
wear layer. A tile base as set forth in Exa~ple XVI was
interfaced with a 4-mil, commercially available vinyl
film containing about 20% but~l benzyl phthalate
plasticizer. The exposed surface of the vinyl film was
then interfaced ~with an image carried by a transfer
paper prepared as descri~ed in Examples I-IV, the image
on the transfer paper having been rotogravure printed
using an ink composition as set forth in Example XV.
The interfaced materials were subjected to a temperature
of 300~F and a pressure of 10 psi for 1 minute. After
separating the transfer paper, the tile had a fused,
through-color vinyl wear layer.
Example XIX
This example illustrates the use of a powder
dispersion technique to image a transfer sheet, after
which the dye is migrated into a substrateO A powdered
image composition comprising 46~ polyvinyl butyral
35 binder, 3% Basic Blue 25 dye and 51% inorganic material
was randomly sprinkled on the surface of a piece of
Frankote paper prepared as described in ~xamples I-IV.
The transfer sheet was warmed to 300~F to tack the image
~9~5~7
- 24 - LF~-7035
composition to the surface of the sheet. The imaged
transfer sheet was then interfaced with a backed fused
plastisol and heated under about 10 pounds pressure for
30 seconds at 300~F. The transfer sheet was separated
and ~lie image composition was removed with the transfer
sheet. The resulting dyed substrate had a through-color
image corresponding to the random distribution of the
image composition.
The present invention is not limited solely to
the descriptions and illustrations provided above, but
encompasses all modifications encompassed by the
following claims.
