Note: Descriptions are shown in the official language in which they were submitted.
~N 9~ l t ~! 5 . _._
IMAE _ AN~s~ER F,LEMENT
This invention relates to a light-sensitive
; element which, after ima~ewise exposure and removal of
unexposed areas, can be utilized as a transfer element
whereby individual image areas can be transferred to
a receptor sur~ace.
Dry transfer sheets consist of a transparent
support carrying thereon indicia such as letters, numerals
or other symbols which can be individually transferred to
a receiving surface, such as a sheet of paper. Transfer
ld occurs by application of rubbing pressure to the rear
surface of the support while the image contained on the
support is in contact with the receptor followed by
peeling away the support whereupon the ima~e adheres
to the receptor surface.
A conventional technique for manufacturing
dry transfer sheets at the present time is to screen
print lndicia on a transparent support. Such manufacture
~' is costly and complex, generally being undertaken only
'~ by experts in the field. For each of the numerous indicia
-' 20 which might be required in practice, a separate screen
stencil is necessary thereby economically limiting the
manufacture to larger quantities of indicia having the
greatest utility in the field. The cost of providing
3 small numbers of special-purpose indicia for individual
1 25 uses is therefore prohibitive.
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~(313~73~ IL
Recently~ transfer elements utlllzing light~
sensitive systems have been disclosed. In U. S. patent
No. 3~671,236 a method for photo mechanically producin~
multicolored images on a single substrate is disclosed.
In that disclosure, the entire light-sensitive diazo
resln-based layer is transferred from a carrier sheet
to a receptor prior to imagewise exposure thereof.
Imaging and development is undertaken subsequent to
transfer. There is no disclosure of transferrin~
individual indicia comprising only the light exposed
areas of the transfer element. Additionally, the
llght-sensltive system therein is based on a diazo
resin as opposed ~o free radlcal photopolymerizable
materlals.
Free radlcal photopolymerizable materials
have been utilized in image transfer, generally based
on the fact that a differential degree of surface tack
exists between unexposed and exposed areas of a photo-
polymer system. Unexposed areas of the photopolymer
layer generally have a greater degree o~ tack than
exposed areas, thereby a~fording ability to selectively
transfer unexposed areas to a receptor. In U. S. patent
No. 3,342,593 this tack differential occurs upon heating
an imagewise exposed transfer element while in U. S.
patent No. 3,202,508 tack differential occurs in sltu
upon light exposure.
In U. S. patent No. 3,525,615 a thixotropic
gel is interspersed in the photopolymerizable layer.
After imagewise exposure~ unexposed areas are capable
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of liquifyin~ and trans~errlng when contacted with a
receptor sur~ace under hi~h pressure.
In all of these transfer processes utilizing
photopol~merizable materials, visual inspection of the
transferrable image areas is ~enerally unavailable because
the exposed and unexposed areas of the light-sensitive
layer are indistinguishable and remain as an integral
layer until the moment of transfer. Additionally,
selective transfer of individual indicia is generally
unavailable. ~urthermore, after light exposure, the
transferrable image portions remain light sensitive,
thereby necessitating storage and transfer under sub-
dued light.
It is of course known that a light exposed
photopolymerizable stratum can be imagewise developed
with a developing medium to thereby remove unexposed
areas of the stratum. See Light Sensitive Systems:
Chemistry and Application of Nonsilver Halide Photo-
graphic Processes, J. Kosar~ J. Wile~ and Sons tNew York,
1965). To our knowled~e, however, it has never been
disclosed that the exposed pol~merized image areas
remaining after development can be transferred to a
receptor.
British patent No. 1,336,065 discloses a
li~ht-sensitive transfer element which can be vi~ually
inspected prior to transfer. A component capable of
forming a gas upon light exposure is utilized in con-
~unction with a gas imperv~ous binder resin in the
transfer layer. The ~as causes the bond between the
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~L~373~1
transfer layer and the support ~o be weakened, thereby allowing removal of the
exposed portions ~rom the support with a developing medium, the unexpose~ por-
tions remaining. These remaining unexposed portions are then light exposed a
seco~d time to again weaken the bond between the support and image areas and
thereby provide indicia which are transferable to a receptor element by pres- ?
sure. ~lowever, this transfer system provides images with limited resolution
since the binder in the transfer layer must be able to retain the gas formed
upon exposure thereby limiting the sharpness of image boundaries. Similarly,
control of the release of the transfer layer from the support is difficult
10 to maintain. Additionally, this transfer element must be light exposed twice
before transfer can be effected.
According to one aspect of the present invention, there is provided
a presensiti7ed light-sensitive sheet structure suitable for producing a dry
transfer element comprising a thin, flexible~ transparent substrate having a
release coating thereon and overlying said release coating and releasably bond-
ed thereby to said transparent substrate a photosensitive layer comprising an
addition polymerisable, non-gaseous ethylenically-unsaturated compound con-
taining at least one terminal ethylenic group, a free-radical liberating pho~o-
initiator therefor and a binder, said photosensitive layer, after imagewise ex- `
20 posure thereof to actinic radiation and removal of unexposed portion of said
layer, having greater adhesion to a receptor surface when applied thereto under
pressure than ~he adhesion of said photosensitive layer to said transparent sub-strate under like pressure.
Another aspect of the inventlon provides a dry transfer element com- ;
prising a thin, flexible transparent substrate having a release coating thereon
and overlying said release coating and releasably bonded to said transparent
substrate, transferable indicia, said indicia comprising an actinic radiation-
exposed photopolymerisable compound which is an addition polymerisable, non-
gaseous ethylenically-unsaturated compound containing at least one terminal
30 e~hylenic group, an initiator therefor and a binder, and wherein said indiciahave greater adhesion to a receptor surface when applied thereto under pres-
sure than the adhesion of said indicia to said transparent substrate under like
~ -4-
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pressure.
Thus, in contrast to the aforementioned transfer systems, the inven-
tion provides a light-sensitive transfer element ~hich, upon a single image-
wise exposure and development, provides pressure transferable indicia having
excellent resolution which can be visually inspected prior ~o transfer. Since
the light exposed portions are transferable, indicia transfer can be undertaken
at normal room temperature and light conditions utilizing a simple stylus.
As mentioned, the basic components of the light-sensitive transfer
element of the invention include a thin, flexible, transparent substrate or
film support, a release coating on ~he support and a photopolymerizable over-
layer.
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The ril~ sup~)ort should be transparent slnce
exposure ls typicall~ undertaken through the backside
of the transfer element, i.e. through the support itself.
Also~ a transparent support is necessary to allow visual
positionin~ o~ individual indicia for transfer to a re-
ceptor. The support should also be surficiently thin
and flexible to allow transfer by stylus pressure.
Typical thin, flexible, transparent film supports in-
clude polyesters~ polypropylene~ polyethylene, polystyrene,
triacetate and transparent paper, e.g. ~lassine base, ~ -
coated with a non-porous material such as cellulose
acetate or polycarbonate.
The release layer acts essentially as a barrier
to prevent the light-sensitive overlayer from firmly
bonding to the transparent film support. Additionally,
the release layer must be capable of retaining the
exposed areas of the light-sensitive overlayer during
~mage development, yet allow release of these same areas
from the film support durin~ image transfer. The release ~.
layer is preferably substantially impenetrable to solvent
developers utilized during image development so as to
prevent undercutting of the exposed image areas desired
to be retained on the transfer element.
For image transfer to occur by proper- functioning
of the release layer~ the bond between the image layer
and the ~ilm support must fail during transfer by one of
the following mechanisms: (1) adhesive failure at the
release layer-film support interface; (2) adhesive failure
at the image layer-release layer interface; or (3) cohesive
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failure within the r-elease la~er.
~ echanism (1) results rrom release material.s which
have lower adhesion ~or the film support than ~or the
photopolymeri~ed image layer and have good lnternal
strength, i.e. they are ~ood film formers. An exe~plary
material is eth~1 cellulose. A filler such as colloidal
silica can typically be contained in the ethyl cellulose
to control adhesion thereof to the film support. In this
instance, the release material should be soluble in or
removable by the developing medium utilized during image
development.
Mechanism (2)~ adhesive railure at the ima~e
layer_release layer interface, results when the release
layer has greater adhesion for the film support than -
I5 for the ima~e layer. This result is generally attained
by utilizing release materials having low surface energies
thereby resulting in poorer wetting by the image layer,
and/or which are insoluble in the solvents utilized in
coating the image layer. An exemplary material exhibiting
such characteristics is a silicone resin.
Cohesive failure of the release layer, mechanism
~3), results when the release material has a low internal
strength, i.e. lower than either the photosensitive layer/
release layer bond or the release layer/substrate bond.
Commercially available mold release agents such as Vydax
AR, tradename for a telomer of tetrafluoroethylene and ~
Mold Wiz PS-9, tradename for a commercial mold release ~ ;
agent, believed to comprlse a silicone, hydrocarbon and
carboxylate s~lt blend, are exemplary.
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The preferre~ release mec~lanism is b~ cohe.~ive
failure o~ the release laver because variabl.e associated
with the ima~eable overlayer, such as solvent selection,
drying rates, etc. do not af~ect the release mechanlsm.
Release is dependent onl~ on the physical character:Lstics
or the release material which can be altered as desired
by inclusion of plasticizers, resins, flllers, etc.
The photosensitive material contained in the
imageable la~er of my transfer element comprises an
addition polymerizable, non-gaseous, i.e. having a
boiling point above about 100C at normal atmospheric
pressure, ethylenically-unsaturated compound containing
at least one terminal ethylenic group and bein~ capable
of forming a high polymer by free radical initiated~
chain propagating addition polymerization and a free
radical-liberating initiator therefor.
Typical polymerizable monomers include the
acrylates, e.g. methacrylate, methylmethacrylate, etc.
and the corresponding ethyl esters; polyhydric alcohol
esters of acrylates, e.g. tris-hydroxyethylisocyanurate-
trimethylacrylate~ pentaerythritoltetraacrylate and the
corresponding esters; vinyl aromatics, e.~. styrene,
1,4-divinylbenzene, naphthalene; unsaturated amides,
e.g. acrylamide, methacrylamide; vinyl esters, e.g.
vinyl acetate and vinyl butyrate; and the like.
Free-radical liberating photoinitiators include
any compound which liberates free radicals on stimulation
by actinic radiation. Exemplary photoinitiators include
the vicinal poly ketaldonyl compounds described in U.S.
:- : -: . ,., , . . - .......................................... .
: .- , . ,: . . - . :
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~373~
patcnt No. 2, 367, 660; t~le alpha-carbonyls described in
U. S. patent Nos. 2,~7,661 and 2,367,670; the acyloin
ethers described in U. S. patent No. 2,ll48,828; the
alpha-hydrocarbon-substituted aromatic acyloins described
in U. S. patent No. 2,722,512; the polynuclear quinones
described in U. S. patent Nos. 3"0l~6,127 and 2,951,758;
the triarylimidazolyl dimer/p-amino-phenyl ketone com-
bination described in U. S. patent No. 3,549,367; dye-
sensitized photolyzable organic halogen compounds described
in U. S. patent Nos. 3,6llo,718 and 3,617,228~ and the
vinyl-substituted halomethyl-s-triazines described in
U. S. patent No. 3,987,o37.
For the exposed photopolymerized image areas
of the transfer element to trans~er to a receptor, the
image area must be either tacky~ i.e. the image will
adhere to the receptor surface by adhesive foreces, or
soft, such that the image will conform to the receptor ~ -
surface and adhere thereto. Suitable receptor sur~aces
include paper, cardboard, metal sheets and foils, wood,
glass, nylon~ rubber, polyethylene polyesters, etc.
A tacky image can be attained by a variety of
methods including addition of plasticizers or plasticizing ;
. , .
resins, monomers, pressure-sensitive adhesives,~ree- ~ `
radical scavengers, soft binders, etc. to the photo-
polymerizable layer.
Soft image elements can be characterized as those
wherein the polymer will flow when sub~ected to the pressure
created by a stylus during transfer. This pressure is
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believed to be on the order of about 50 to about 1500
pounds per square inch. ~or example, ~ 0.030 inch
diameter pencil point~ llnder a 1 pound load creates
a pressure of about 1400 pounds per square lnch. The
same methods utilized to impart tack to a polymer can
be used to make a polymer soft.
Fillers are typically lncluded in the photo-
sensitive layer to provide color to the image areas and/
or to improve the characteristics thereof, e.g. by de-
creasing the tack, increasing the release, improving theimage development rate~ etc. Exemplary fillers include
carbon black, titanium dioxide, zinc o~ide and other
organic and lnorganic pigments. Dispersion of pigments
or other fillers in the coating composition can be
enhanced by utilizing conventional dispersants, sur-
factants, etc.
Fillers can generally be present in the light-
sensitive layer in an amount up to about 30 percent by
welght of the total solids. Decreasing concentrations
f pigment would correspondingly reduce the image color
density. At increasing filler concentrations, image
film strength decreases, correspondingly increasing image
loss during development. The preferred range of filler
concentration is from about 1 percent to about 20 percent
f the total sollds depending on the desired end properties
of the light-sensitive layer.
Image coloration is generally desirable ~or
registratlon o~ indicia prior to transfer. While this
can be undertaken by utilizing a pigment-filled light~
sensitive composition, it can also be accomplished
~0373~
subsequent to exposure and development by utilizinK con-
ventional dyes. For example, an aqueous solution o~ a
water soluble dye can be rubbed onto photopolymerized
ima~e areas after development until d,ye penetratlon and
corresponding coloration o~ the image areas occur. By
utilizing dyes, a variety of colors can be provided on
a single transfer sheet.
The light-sensitive layer can be considered to
contain three components--the photopolymerizable monomer~
an initiator therefor and a binder ~wherein the binder
is in actuallty a blend of the remaining materials such
as plasticizers, fillers~ etc.). The ratio of these
three components is important in determining the final
propertles of the transfer layer. For example, if` too
little photopolymerizable monomer or too much binder
is present~ image resolution and dif~erential solubility
o~ the image layer will be less than optimum. At the -
other extreme, the llght-sensitive layer may be too soft
and ~luid before exposure or the exposed image areas may
be too hard for e~icient trans~er. While the optimum
range will generally depend on the particular photopoly-
merizable monomer and binders, typically the llght-sensitive
layer contains ~rom about 25 percent to about 90 percent
monomer by weight based on total solids.
Initiator concentration is important in that at
very low concentrations the polymerizatlon process may -
be too slow or poor conversion o~ monomer to polymer can
occur (although this poor conversion can e~ectively add
to the tack of the exposed transfer areas). Too great
a concentration can cause extensive crosslinking
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thereby resultinF~ in loss of tack~ halation, etc., and
the added posslbility of po.st-development llght sensitivity.
Initiator concentration ~rom about 0.5 to about 5.0 percent
by weight based on the total sol:Lds ls generally satlsfactory,
depending on the particular init:lator and monomers chosen.
A protective layer can be applied over the
light-sensitive layer to prevent oxygen inhibition and
provide ease o~ handling the sheet structure if the photo-
polymer ls tacky.
Typical protectlve layers include polyvinyl
alcohol, gelatin, gum arabic, methyl vinyl ether/maleic
anhydride copolymers, polyvinyl pyrrolldones, etc. The
protective layer must be soluble in developer solutions
utilized in development of the imagewise exposed transfer
element.
Alternatively, a protective cover sheet having
a release coating, e.g. silicone, can be laminated to
the light~sensitive layer to provide protection thereto.
This cover sheet can be stripped from the photosensitive
layer after imagewise exposure. Imagewise exposure can
be undertaken by conventional exposure units such as
carbon arc, mercury vapor, pulsed xenon~ etc.
Developer solutions utilized should contaln a
solvent for the unexposed areas of the light-sensitive ~-
layer. Development action can occur by dissolving one
or more components comprising the light~sensitive layer.
For example, lf a water soluble component~ such as the
binder resin or the monomer ls utilized, the developer
can be an aqueous system.
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~L03~
When the preferred binder resin, namel~ a car-
boxylated vin~l resin~ is utilized, a dilute base is the
pre~erred developer, s~nce the binder resin is soluble
therein. Organic solvents such as ethyl alcohol, iso-
propanols, etc. can also be utilized in con~unction withwater if deslred.
The developer solution can be used as a bath
or in the f~orm of a spray. Removal of the unexposed
areas of the photopolymer layer can be generally improved
by brushing, rubbing with a wet sponge or other conventional
procedures.
My invention will be further illustrated by
the ~ollowing nonlimiting examples wherein all parts are
by welght unless otherwise indicated.
EXAMPLE 1
A release composition was prepared by mixing:
75 grams Mold Wiz PS-259 (a tradename for
a 10% dispersion believed to be
a blend of silicone, a hydrocarbon
and a carboxylate salt)
10 grams Vydax AR (tradename for a 20%
solids solution of a short chain
telomer ~of tetrafluoroethylene
in Freon TF)
.5 gram Polyethylene oxide
50 grams Trichloroethylene
The resulting disperslon was cascade coated onto a 3 mil ~ ~;
transparent polyester base and dried at 140F ~or 2 minutes
to provide a dry coatin~ weight of 120 milllgrams per square
~oot.
A photosensitive composition was prepared by first
milling on a sand or ball mill:
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.7 grams Telva C V 6 (tradename for
carboxy~a~ed polyvinyl acetate
copolymer)
1.62 grams Cabot Sterling R (tradename for
carbon black)
9.8 grams ethyl alcohol
17.4 grams methyl ethyl ketone
The milled material was added to a mlxture of the
following components followed by thorough agitation-
3.5 grams pentaerythritol tetraacrylate
11.9 gramæ triacrylate o~ (tris-2~hydroxyehtyl)
isocyanurate
2.g grams Daratak 74L (tradename for a 55
percent solids in water acrylate
copolymer adhesive emulsion)
1.9 gram Pycal 94 (tradename for a poly-
oxyethylene aryl ether flexi-
bilizer) ,~
- 0.24 gram FC-430 (tradename for a fluoro-
chemical surfactant)
1.4 gram Polyox N-10 (tradename for a
polyethylene oxide)
0.42 gram 2(p-methoxy styryl)-4~6-bis
(trichlormethyl)-s-triazine
31.0 grams methyl ethyl ketone
The photosensitive composition was knife coated
on the dry release layer and dried at 180F for 4 minutes
to provide a dry coating weight of 2.5 grams per square
foot.
A top coat solution was prepared by mixing:
7 grams ~elvatol 20-30 (tradename for
polyvinyl alcohol)
70 grams water
23 grams methyl alcohol
The resulting solution was knife coated over the photosensi- ,
tive layer and dried at 180F for 2 minutes to provide a dry
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coatlng weight Or ]50 milli~rams per square foot.
The sheet construction was exposed through the
polyester baclcing to a right-readlng negative for 2 minutes
in a NuArc pulsed Xenon exposure unit.
The exposed sheet was then placed in a development
sink wlth the coated side up. A developer solution of 1
percent sodium silicate in water was llberally poured on
the sheet. Development was accomplished by gently rubbing
the wet sheet with a so~t cotton pad whereupon the unexposed
areas were removed. After development, the sheet was
rin~ed with clear tap water and carefully blotted dry.
~ransfer occurred by placing the indicia, i.e.
the image areas on the sheet, in contact with the receptor
paper and rubbing the polyester backing with a dull pencil.
The polyester carrier sheet was then peeled away whereupon
the indicia adhered to the receptor paper.
In this instance, transfer occured due to cohesive
failure within the release layer.
EXAMPLE 2
A release composition was prepared by mixing the
following components:
68.1 grams rrE Sillcone No. 4191 (tradename
for a 30 percent solids silicone
resln solution in xylene)
2.7 grams GE Catalyst No. 4192 (tradename
~or a 50% solids silicone resin
curative solution in xylene)
27 grams ~E Accelerator No. 4193 (tradename
for a cure accelerator~
635 grams toluene
635 grams methyl ethyl ketone
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1'he mixture was cascade coated on a 3 mll trans-
parent polyester base, dried and cured for 4 minu~es at
190~ to provide a dry coatlng weight Or 25 milligram~
per square foot.
The photosensitive la!ler Or Example 1 was applied
over the dry release coating and dried as per Example 1.
A top coat solutlon was prepared by mlxln~: -
2 grams hydroxyethyl cellulose
.1 gram Triton X-100 (tradename for
alkylarylpolyether alcohol)
80 grams water
20 grams methyl alcohol
The resulting solution was knife coated over the photosen-
sitive layer and dried at 180F to provide a final coating -
weight of 200 milligrams per square foot.
The coated sheet was exposed~ developed and the . ~-
resulting indicia transferred as per Example 1.`
This sheet construction has properties very
similar to Example 1 except that upon trans~er, image :
release occurred at the interface of the photosensitive
and release layers.
EXAMPLE 3
A release compositlon was prepared by mixing the
following components:
2~ 100 grams Mold Wiz PS-259 (tradename for
a 10~ solids in toluene blend
of silicone, hydrocarbon and a
carboxylate salt)
100 grams Toluene
~ he composition was cascade coated onto a 3 mil
transparent polyester base and dried at 140F for 3
minutes providing a dry coating weight of 100 milligrams
~0;31~3~1
per square foot.
The p~otosensitive laver of Example 1 ~as applied
over the dry release coating and dried as per Example 1.
A plece of the 3 mil polyester coated ~rith the
release layer o~ Example 2 was u~ed as a liner and lami-
nated to the photosensitive laver. The resulting sandwich
was exposed as per Example 1, the liner peeled away and
the sheet developed as per Example 1. The resultin~ indicia
were transferred by placing the transfer e'ement on a paper
receptor and passing the sheets between heated nip rolls
operating at 210~. The polyester backing was separated
as it emerged from the rolls whereupon the indicia were
effectively transferred to the receptor. -
E Ar_PLE 4
A release composîtion was prepared by mixing the
following components:
7.5 grams Methocel 15 (tradename for methyl
cellulose)
22.5 grams normal propyl alcohol
120 grams water
20 grams Nalcoag 1050 (tradename ~or a
35 percent sollds aqueous col-
loidal silica dispersion)
1 gram Triton X-100 (tradename for
alkylaryl polyether alcohol)
The composition was knife coated onto a 3 mil
transparent polyester base and dried at 180F for 3 minutes
resulting in a dry coating weight of o.6 grams per square
foot.
The photosensitive layer and top coat of Example
1 was applied over the dry release layer. Exposure, de-
velopment and transfer were ~he same as in Example 1.
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~Excellent visible image release was noted.
EXA~P1E 5
The release layer of Exam~le 1 was overcoated
with a photoqensitive compositlon prepared by mixing:
3 grams trlmethylol propane trimethacr,ylate
2 grams trimethacrylate o~ (tris hydroxy-
ethyl) isocyanurate
2.5 grams ~elva C5V16 (tradename for a
carboxylated polyvinyl acetate
copolymer)
2.2 grams Daratak 74L (tradename for a
55 percent solids in water
acrylate copolymer adhesive
emulsion)
0.5 gram Polyox N-10 (tradename for poly-
ethylene oxide)
0.12 gram 2(p-methoxy styryl)-4,6-bis
(trlchloromethyl)-s-triazine
0.5 gram P~cal 94 ~tradename for a
flexibilizer) po~lyoxyethylene
aryl ether
1.1 gram Sudan Red 0 (tradename for a
red dye)
15 grams meth~l ethyl ketone
5 grams ethyl alcohol
The photopolymerizable coating was dried at 180F
for 3 minutes providing a dry coating weight of 1.5 grams
per square foot.
The top coat of Example 1 was applled over the
photosensitive layer.
The sheet was imaged through the transparent
polyester backing to a right reading negatlve for 1 minute
on a NuArc pulsed xenon exposure unit and developed with
a solution of 3.7 percent sodium acetate, 1.2 percent Triton
X-100 (tradename ~or alkylaryl polyether alcohol)~ 46.3 percent
., , . : ~
~l~373~
water and 48.8 percent eth,vl alcohol.
Transfer was arfected by placlng the red lndicia
in contact with a trans~arent po:L~ester receptor and
rubbing the polyester backing with a dull pencil.
EXAMPLE 6
.
The release layer of Example 1 was overcoated
with a photosensitive compositiorl prepared by mlxing:
3 grams trimeth,ylol propane trimethacry-
late
2 grams trimethacrylate of (tris h,ydrox,y-
ethyl) isocyanurate ~ -
2 grams VERR (tradename ror vinyl acetate/
vinyl chloride resin)
2 grams ~elva RA 788 (tradename for an
acrylate copolymer)
0.5 grams dibutyl phthalate ,;,~
0.2 grams Sudan ~reen (tradename for a
green dye)
0.15 gram 2-(p-methoxy styryl)-4,6-bis
(trichloromethyl)-s-trlazine
18.8 grams methyl ethyl ketone
11.3 grams ethyl alcohol
1.0 grams water ~-
The photopolymerizable coating was dried at 180F
for 4 minutes providing a dry coating weight of 1.8 grams
per square foot.
After overcoatlng as per Example ls the sheet was
exposed through the transparent polyester backing ~or 1
mlnute with a pulsed xenon light source at a distance of
18 inches.
Image development was undertaken utilizing a
solution of 40 percent by volume n-propyl alcohol and 60
percent by volume water.
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31~L
Indlcia were transrerred to a receptor utlllæing
a simple st~ylus.
EXAMPLE 7
The release layer o~ Example 1 was overcoated with
a photosensitlve composition prepared by mixlng: ~
1.5 grams pentaerythritol tetraacrylate
4.5 grams triacry:Late of ~trls 2-hydroxyethyl)
isocyanurate
3.0 grams Butvar 76 (tradename for a polyvlnyl
butyral resin)
5.0 grams Gelva RA 788 ~tradename for an
acrylate copolymer)
0.15 gram 2-(p-methoxy styryl)-4~6-bis
- (trlchloromethyl)-s-triazine
0.5 gram dlbut,yl phthalate
0.1 gram Sudan Red 0 (tradename ~or a red
dye)
27,0 grams methyl ethyl ketone
The photopolymerizable coating was dried at 180F
for 4 minutes to provide a dry coating weight of 1.5 grams
per square foot.
A silicone coated polyester sheet was laminated ~ -
to the photosensitive layer as per Example 3. Exposure was
undertaken through the transparent backing for 1.5 minutes
to a pulsed xenon light source at a distance of 18 inches
after which the sllicone-coated liner was peeled away.
Development of the imaged photosensitive layer
was undertaken utilizing a solution comprising 75 percent
isopropanol and 25 percent water by volume. -
Transfer of the red indicia was undertaken utilizing
a stylus. -
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~)~31~
F,X MPLE 8
The release layer o~ Example l was overcoated
wlth a photosensitlve composition prepared by mixing:
3.0 grams trimethylol propane trimethacrylate
2,0 grams tris methacrylate of (tris
hydroxy ethyl)isocyanurate
2.0 grams EAB500-1 (tradename for a
cellulose acetate butyrate
resin)
5.0 grams ~Telva RA-788 (tradename for an
acrylate copolymer) .:!:
0.5 gram Pycal 94 (tradename for a poly-
oxyethylene aryl ether flexi- -~
bilizer)
0.2 gram 2(p-methoxy styryl)-4,6-bis ~ .
trichloromethyl)-s-triazine ; : :
0.1 gram Sudan Red O (tradename for a
red dye)
18.0 grams methyl ethyl ketone
The photopolymerizable coating was dried at 180F
for 3 minutes providing a dry coating weight of 1.8 grams
per square foot.
After providing a top coat as per Example 1, the
element was exposed and developed as per Example 7 whereupon
indicia transferable by stylus pressure were obtained.
EXAMPLE 9
A release composition was prepared by mixing the
following:
75 grams Mold Wiz PS-259 ~tradename for
a lO percent solids in toluene
blend of silicone, wax and a
carboxylate salt)
lO grams Vydax AR (tradename for a 20%
solids solution of a short chain
telomer of tetrafluoroethylene
in Freon TF 3 a fluorocarbon sol-
vent)
-20-
,:, , .. - :: .: : , .~ . .
~al37~
25 ~rams Polvox N10 ttradename ~or poly
ethylene oxide) in trichloroethylene
The mixture was knife coated onto a transparent
polyester base and dried at 140:F ~or 2 minutes providing
a dr~ coating weight of 150 milligrams per square ~oot.
Over thls layer was coate~ a photopolymerlzable
composltlon prepared by mixing: :
1.0 gram pentraerythrito]. tetraacrylate
3.4 grams triacr~late o~ (tris 2-hydroxyethyl)
isocyanurate
1.9 grams Thiokol LP-31 (tradename for a
liquid polysulfide polymer)
4.0 grams 20 percent solids solution o~
dimethylaminoethyl methacrylate
homopolymer in methyl ethyl ketone
1.0 gram Santicizer 8 (tradename for N-
ethyl,O,p-toluenesulfonamide)
0.2 gram 2-methyl-4,6 bis(trichloromethyl)
s-triazine
0.1 gram 9,10-dimethoxyanthracene
0.7 gram 10% solids dispersion of FC-430
(tradename for a fluorocarbon
surfactant) in methyl ethyl ketone
0.15 gram Uvinul 400 (tradename ~or 2,4-
dihydroxy-benzophenone) : :
8.3 grams millbase from Example 9
8.o grams methyl ethyl ketone
3.0 grams methyl alcohol
The coating was drled at 180F for 4 minutes providing
a dry coating weight of 1. 8 grams per square ~oot.
A solution was prepared by mixing:
7 ~rams Gelvatol 20-30 (tradename for a
polyvinyl alcohol resin)
0.46 gram Triton X-100 (tradename ~or
alkylaryl polyether alcohol)
-21-
75 grams water
25 grams methyl alcohol
This solution was coated on a second polyester base and
dried at 190F for 2.5 minutes to a dry coatin~ weight
of 100 milllgrams per square ~oot. This la~er was lami-
nated to the tacky photopolymerlzable layer of the first
sheet and the polyester base pee:Led away from the polyvinyl
alcohol layer.
The transfer element was exposed through a negative
mask to ultra~iolet light through the polyester backing.
The imaged light-sensitive layer was developed
utilizing a l percent by weight aqueous ammonia developer
and slight rubbing action whereupon the unexposed portions
of the light-sensitive layer were removed.
The remaining indicia can be transferred to a
receptor by utilizing a simple stylus.
E MPLE 10
A millbase was prepared by ball milling a mixture
of: .
11.4 grams Gelva C5V16 (tradename for a
carboxylated polyvinyl acetate
copolymer)
2.2 grams carbon black
3.48 grams water
13.5 grams 95/5 parts by weight ethanol/
isopropanol
26.8 grams methyl ethyl ketone
This millbase was added to a mixture of:
2.7 grams polyethylene glycol diacrylate
8.9 grams pentaerythritol tetraacrylate
7.7 grams trlacrylate of (tris 2-hydroxyethyl)
isocyanurate
~22-
:~L03 ~31~
21.2 grams 10% solicls solution of poly-
ethylene oxlde in water
o.96 Pycal 9ll (tradename ~or a poly-
oxyethyLene aryl ether f'lexibilizer)
o.66 gram phenanthrenequinone
This light-sensitive composition was knife coated onto a
release layer prepared as per Example 1 on a 3 mil transparent
polyester base and dried at 180F for 3 minutes providing
a dry coating weight of 1.5 grams per square foot.
A second millbase was prepared by ball milling
a mixture of:
5.7 grams Gelva C5V16 (tradename for a
carboxylated polyvinyl acetate
copolymer)
1.0 gram carbon black
13.4 grams methyl ethyl ketone
6.7 grams ethanol
1.0 gram water
This was added to a mixture of:
2.9 grams polyethylene glycol diacrylate
9.4 grams pentaerythritol tetraacrylate
8.2 grams triacrylate of ~tris 2-hydroxyehtyl
isocyanurate
13.0 grams Daratak 74L (tradename for a 55
percent solids in water acrYlate
copolymer adhesive emulsion)
10.6 grams 10 percent solids solution of
polyethylene oxide in water
0.5 gram Pycal 94 (tradename ~or a poly-
oxyethylenje aryl ether ~lexibilizer)
o.66 gram phenanthrenequinone
25.9 grams methyl ethyl ketone
Thls composition was knife coated over the first light-sensi-
tive composition and dried at 180F for 4 minutes to provide
- -.; . . .
:, . : . . . . . .
~9373~
a dry coatin~ weight of 1.0 grams per square foot.
After ~op coating, exposin~ and developlng as
per Example 1~ a transfer element having black lndicia
capable of easy transfer to receptor sur~aces was
obtained.
, . ,~
-21~ - .
'' ' " ' '; ' ' ' ~ ` ' ' ' ~ ,. ! ~ .
