Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ Wo ss/13195 2 1 7 5 ~ 8 8 PCT/US94/1134S
-- 1 --
'I'RAN.CF~R ~KTl~L I Nr. M~nIl~N
Background of the Invention
This invention relates to laser-induced transfer
5 printing.
In laser-induced transfer printing, irradiation of
an ink-bearing carrier with laser light causes the ink to
transfer from the carrier to a 6urface, e.g., the surface
of a microelectronic device, audio cassette, computer
10 A;~'Ptte, or syringe body. By r-nir~ ting the 8C:~nn~n~
parameters of the laser beam, the ink can be deposited in
a ~L~yL ' pattern.
~c of the Invention
In a first a6pect, the invention features a
15 transfer printing medium that includes a carrier to which
is applied a curable laser-transferrable ink having one
or more layers. The transfer medium is capable of
converting laser energy to heat. The ink inrlll~3D~ (a) at
least one colorant; (b) at least one polymerization
20 initiator; and (c) at least one curable prepolymer. By
"colorant" it is meant any additive that imparts color to
the ink, ;nf~ ;n~ the colors white and black. Colorants
include both dyes and pigments, as well as met~ l l; 70d
coatings. By "prepolymer" it i8 meant any species
25 capable of being polymerized following either thermal or
pl~o~o~ ...ir~l initiation to form a polymer.
In preferred ~ s, the ink transfers to a
surface of interest and cures in one step upon
application of laser energy. In one preferred
30: ' ; , at least one of the polymerization initiators
is a thermal polymerization initiator and at least one of
the prepolymers is th~rr- 1 1 y curable . In another
preferred ~ L, at least one of the polymerization
initiators is a photoinitiator and at least one of the
35 prepolymers is photochemically curable.
Wo95/l3l9s PCTIUS94/11345
2175~88
-- 2 --
One example of a preferred prepolymer i8 an epoxy-
functinn~ Dd prepolymer. A second example i5 an epoxy-
fl1nr~ inn~l; 7Dd prepolymer, ;n^~ with a vinyl ether-
fllnn~ inr~li7D~ prepolymer. A third example i8 an epoxy-
S funct; nn51 l; 7e~ prepolymer , - i nD-l with an acrylate-
functinnAl;~ed prepolymer. A fourth example lnr-lll~C the
acrylate-functinnAl; ~tl prepolymers themselves. A fifth
example i5 a blocked isocyanate-function~l; 7Dd prepolymer
and a sixth example is a blend of a vinyl ether-
10 functionalized prepolymer and a maleate- or r~ n;dD-
funct; nn~ ed prepolymer.
At least one of the ink layers may be a curable
size coat that includes a polymerization initiator and a
curable prepolymer. The size coat is used in combination
15 with a color coat layer. In one preferred ~n~horli L,
the color coat is non-curable and; nrlll~ C a colorant and
a thermoplastic film-forming resin. In another preferred
, the color coat is curable and includQs a
colorant, a polymerization initiator, and a curable
20 prepolymer. In the case of curable color coats used with
curable size coats, the poly![~erization initiators and
prepolymers f ound in the respective layers may be the
same as, or different from, each other.
In a second aspect, the invention f eatures a
25 laser-induced transfer printing method using the above-
described transfer printing medium. The method ;n~ Dc
the steps of irradiating the particular transfer printing
medium with laser light of a predet~rm;nDd wavelength to
transfer the ink from the carrier to a surface of
30 interest, and curing the ink to adhere thQ ink to the
6urface of interest. The transfer and cure of the ink
may be effected in a single step through irradiation with
said laser light. Cure may also be e~fected in a
6eparate step subsequent to transfer.
~ Wo 95113195 217 ~ 5 8 8 PCTNS94111345
,
-- 3 --
The invention provides transfer printing media
featuring curable inks that adhere well to the surface on
which they are deposited following la6er irradiation.
The inks transfer cleanly from the supporting carrier and
5 cure rapidly; in some cases, transfer and cure are
effected in a single step. It is not n--r~ to add a
separate self-oxidizing material such as nitrore~ l nce
in order to effect transfer. In addition, the ability to
use nu.. cu~able layers (e.g., non-curable color coats) in
l0 combination with curable layers (e.g., curable size
coats~ expands the types of materials that can be used
for the inks, enabling the properties of the inks to be
adjusted as needed for a particular application.
Other f eatures and advantages of the invention
15 will be ay~a~e-lL from the following description of the
preferred ~mhQ~i- Ls thereof, and from the claims.
DescriPtion of the Preferred E'---i- c
The invention features a transfer printing medium
capable of converting laser energy to heat in which a
20 curable laser-transferrable ink having one or more layers
i5 deposited on a carrier. The carrier must have
sufficiently low surface energy to permit transfer of the
ink. It also must not melt or otherwise deform upon
laser irradiation. Examples of suitable carriers include
25 flexible plastic films such as polyethylene,
polypropylene, and polyester.
The transfer medium is capable of converting laser
energy to heat to promote transfer of the ink from the
carrier to the surface of interest. To this end, one or
30 more thermal convertors are incul~vLated into the
carrier, the ink, or both. The thermal convertors may be
separate additives or may be part of the prepolymer.
In the case of separately added Cv~ Lu1 2~
inrll-~l~cl in the ink, the amount of convertor ranges from
35 about o . 25 to about 30% by weight (ba23ed upon the total
~ro 9S/13195 ; PCr/US94/1134~ ~
2~
-- 4 --
solids content of the ink) . The particular C~IIV~L L~. is
selected based upon the particular laser energy used f or
irradiation. In the case of Co2 lasers, the preferred
convertors are carbon black, polyethylene glycol te.g.,
5 PEG 3000 commercially available from Union Carbide), talc
(e.g~, Nytal 400 commercially available from R.T.
Vanderbilt), and PPZ, a phosphotriazine ~ ._i~lly
available from Idemitsu Petrorh~ cAl s Co. Ltd; PPZ may
also function as a prepolymer. In the case of Nd:YAG
10 lasers, the preferred convertors are IR99, IRA 980, and
IRl65, all of which are proprietary dyes ~:ially
available from Glendale Protective Technologies, IR dye
14, 617 (a proprietary dye commercially available from
Eastman Kodak), and Pro~et gooNP (a proprietary dye
15 _ ~ially available from ICI). In the case of diode
lasers, the preferred convertors are IR dye 14,617 and
IRA 980.
The inks may have one or more layers, with
particular ingredients (e.g., prepolymer, polymerization
20 initiator, etc. ) being present in any of the layers. One
example of ink is a one layer ink (referred to here as a
"one-pass" coating) having a curable color coat that
;nrl-lrloc, in a single layer, a curable prepolymer, a
polymerization initiator, and a colorant. Another
25 example i8 a two layer ink (referred to here as a "two-
pass" coa'cing) having a color coat (which may be curable
or n~ uL~lble) in combination with an overlying curable
size coat that includes a curable prepolymer and a
polymerization initiator.
Because the inks are curable, ;~rlhoc; nn upon
transfer to a surface of interest is; ~ved. The
&lvc...Lc.ge of the size coat (which is transferred with the
color coat upon laser irradiation) is that A~ho~cion is
further o~h:-nrod, thereby making it rOcc; hlo to use even
35 a non-curable color coat.
~ ~VO 95113195 2 1 7 ~ ~ 8 8 Pcrluss4lll34s
-- 5 --
The inks contain one or more curable prepolymers,
with the total amount of curable prepolymer ranging from
25 to 95~ by weight (based upon the total solids content
of the ink). Curable prepolymers useful in the invention
5 have two or more functional groups available for
croEG~ ;nkin~ (which occurs either simult InPollGly with
transfer upon application of laser radiation or following
laser irradiation in a separate thermal or photo~-
cure step).
One class of suLtable curable prepolymers i nrlll~Dc
epoYy-functio"~li70d prepolymers such as hiGrhPnol A
diglycidyl ether (commercially available from Shell Oil
under the designation Epon 1001) and epoxy-function~l i 7Pd
novolac resins (e.g., Epon 164 ~ . ially available
15 from Shell Oil). Lower molecular Pr.,Y;.lPc such as
UVR6110 (a liquid ~iipp~y;rle commercially available from
Union Carbide) may be added as well.
A second class of suitable curable prepolymers
1PG these epoxy-funct~ 70d prepolymers in
20 combination with one or more vinyl ether-functionalized
prepolymers which co-cure with the epoxy-function~ sd
prepolymers. Examples of suitable vinyl ether-
functionalized prepolymers include bisphenol A-divinyl
ether adduct; 2,4-toluene diisocyanate/l,y-l-."cy~-.Lyl vinyl
25 ether adduct; cyclohexyl divinyl ether ~;ially
available from GAF or ISI Products; vinyl ethyl ether,
vinyl isobutyl ether, vinyl octadecyl ether, polyethylene
glycol divinyl ether, polytetrahydrofuran/350/divinyl
ether, and trimethylol propane trivinyl ether, all of
30 which are commercially available from BASF; Rapi/cure
divinyl ether/3, Rapi/cure cyclohexyl vinyl ether,
Rapi/cure PEPC, and Rapi/cure hydroxy butyl vinyl ether,
all of which are commercially available from ISP; and
V~Pct~ ~- 2010, 2031, 2032, 4010, 4020, and 4030, all of
35 which are commercially available from Allied-Signal.
~IVO 95/131sS PCT/US94/11345
2175~
A third class of suitable cura41e prepolymers
~nr1~ Pc the above-described epoxy-functit~n~l ;7ed
prepolymers in combination with one or more acrylate-
fl~n~ nAl; 7ed prepolymers~ 1P~: of acrylate-
5 fllnt~tioni~li7Pcl prepolymers include RDX 29522 and Ebecryl639 tboth of which are commercially available from
Radcure); Sartomer 351 (commercially available from
Sartomer); and NR440 (commercially available from Zeneca
Re6ins) .
A fourth class of s~;t~l~1e curable prepolymers
inrl-lrlPq the acrylate-funct;nn~l;rPd prepolymers
themselves without the epoxy-f-~nrt; r~nA l; ~qd prepolymers .
A fifth class of suitable curable prepolymers
; nr~ blocked isocyanate-functionalized prepolymers .
15 Exa_ples include B1299 (commercially available from Ku18)
and BL4165A (commercially available from Miles).
A sixth class of suitable curable prepolymers
includes the above-described vinyl ether-functi~-n~1;7~
prepolymers in combination with maleate- or r-lP;mltlP-
20 func~ n~l; 7P(~ prepolymers. Examples of maleate-
functi~n~ prepolymers include 89-8902 (- ~lally
available ~rom Cargil Products); and Astrocure 78HV and
A:~Ll~-,uLe: 78LV (both of which are ~- ~ially availa~le
from Zircon). Examples of r-lP;m;~p-functio~ zed
25 prepolyners include BMI/S/M/20/TDA (~ ~;lally
~vailable from Mitsui Toatsu Ohpm;c~l, Inc.
one or more non-curable layers may be used in
combination with one or more curable layers. For
example, a nu-. _uLable color coat may be ~ ' lned with an
30 overlying curable size coat. Suitable ~ uLable re8ins
are ~h ~ tic film-forming resins. Examples include
acrylic resins such as Rhoplex B85 (an acrylic dispersion
commercially available ~rom Rohm & Kaas) and Amsco 3011
(an acrylic dispersion available from Rohm & Kaas);
35 urethane resins such as QW-16 (a urethane dispersion
~ WO 95/13195 2 1 7 5 ~ ~ 8 PCr/US94111345
useful as a film-former that i5 commercially available
from K.J. Quinn); phenoxy resins such as PKHW 35
(~ ~;ially available from Union Carbide); and
combinations thereof. The amount of nol- _uL~.ble
5 prepolymer in the ink ranges from about 15 to about 35
by weight (based upon the total solids content o~ the
ink ) .
The inks also contain a polymerization initiator
in an amount ranging from about 0.1 to 596 by weight
10 (based upon the total solids content of the ink). The
initiator (which typically is a free radical or cationic
initiator) may be a photochemical initiator or a thermal
initiator; in some cases, the same initiator can act as
both a thermal and a photo~h-~mic~l initiator. In the
15 case of multi-layer inks containing multiple curable
layers, layers containing photochemical initiators may be
;nc~cl with layers ccntaining thermal initiators. In
addition, some initiators may be used in conjunction with
accelerators such as benzpinacole, copper II salts (e.g.,
20 copper benzoate), and hFYArh ~nylethane.
In the case of thermal initiators, the initiator
must exhibit good stability at ambient t~ c~Lu.~ to
prevent ~L~ Lule curing of the prepolymer. In addition,
the initiation temperature must be within the range
25 achievable by laser irradiation. Examples of suitable
thermal initiators for cationic initiation include aryl
~ulfonium salts (e.g., the salts described in W090/11303,
hereby incu.y~. lLed by reference); aryl ~ ni~lm salts
(e.g., UVE 9310 and U 479, both of which are ~ .:ially
30 available from General Electric); and i.lm salts
(e.g., FC520, commercially available from 3M). Examples
of suitable thermal initiators for free radical
initiation include the class of compounds leading to
peroxy radicals, e.g., hydroperoxides, peLc,..y~Lers, and
35 peroxyketals; representative ~ __ '~ are commercially
Wo 95113195 PCTiUS94/11345
~ 1 7~
-- 8 --
~vailable from Elf-Atochem. Also suitable for free
radical initiation are azo polymerization initiators
.;ially available from Wako.
In the case of photnl h-mi~l initiators, the
5 initiator must also exhibit good stability st ambient
t~ ~LUL.~ to prevent pr ~ur~: curing of the
prepolymer. In addition, it must exhibit absorption
maxima ln regions of the ele.:~L, -_ Atic :jUe~ -Lu.,.
different from the regions in which the colorant e~chibits
10 absorption maxima. Examples of suitable photn~ hAm;cAl
initiators for cationic initiation include aryl sulfonium
salts (e.g., WI 6974 commercially available from Union
Carbide) and aryl iodonium salts (e.g., UVE 9310 and U
479, both of which are commercially available from
15 General Electric). Another example of a suitable
initiator for cationic initiation i8 hydroxy naphthyl
imide sulfonate ester. Examples of suitable
photoAh-m~AAl initiators for ~ree radical initiation
include CPTX and ITX (both ~ ~ially available from
20 Ciba-Geigy), each of which is ~i nAfl with methyl
diethanolamine (commercially available from Aldrich
lA-h_mi~AAl CO~; lucerin TP0 ( ~.lally available from
BASF) ' ;n_,fl, with methyl fl;~fhAnnlamine; Darcure 4265
(commercially available from Ciba Geigy), and Irgacure
25 369 '-;ne~fl, with ITX.
The ink contains one or more colorants, which may
be dyes, ri~_ ~L, or me~;~ll;7-d coatings (e.g., an
Al1~m~n~79d coating). In the case of dyes and pigments,
the colorant is present in an amount ranging from a~out
30 35 to 65~ by weight (based upon the total solids content
of the ink). The particular colorant is chosen based
upon the color desired on the final printed surfacQ.
Examples of suitable colorants include pigments such as
talc, Tio2 (white), phthalogreen (GT-674-D), chrome green
35 oxide (6099), ultramarine blue (R5-9), black oxide (BR-
~VO 95113195 2 1 7 5 S 8 8 PCrlUS94/11345
, , ' . . 1 ,. ,..
_ g _
5099D), Kroma red (7097), and rl~vclp~:LIIl yellow (HR-70),
and dyes such as dynonicidine (2915) and Dianell orange,
as well as the aforementioned - ~ 11 i 7arl coatings.
In the case of inks containing photocurable
5 prepolymers, a 6ensitizer may be added in an amount
ranging from about 0 . 5 to 8% by weight (based upon the
total solids content of the ink) to extend the
irradiating wavelength for photoinitiation into the
visible region. Such sensitizers are useful, for
10 example, where the formulation contains large amounts of
Tio2 pigment which absorbs light below 400 nm and thus
competes with the initiator. Examples of suitable
sensitizers, all of which are commercially available from
Aldrich Chemical Co., include perylene, rubrene,
15 phenothiazine, anthracene derivatives, and thioxanthones,
as well as lucerin TPO (commercially available from
BASF) .
Other ingredients which may be added to the inks
to improve the coatability, printability, print
20 performance, and durability of the inks include various
~iurfactants, dispersing agents, and polymer dispersions.
The amount of each ingredient is selected based upon the
desired properties. Examples of suitable surfactants
(which may be anionic, cationic, or nnn;oni~-) include
25 Triton X-100 (an aryl ethoxylate _ ~:ially available
from Rohm & E~aas) and Fc 430 (a fluoroaliphatic polymeric
ester available from 3M). Examples of suitable
dispersing agents include polyacrylate salts such as
Daxad 30, a 30% aqueous solution of polyso~ rylate
30 commercially available from W. R. Grace . r la~: of
suitable dispersions include Shamrock 375 and Aquacer
355, both of which are polyethylene wax dispersions
commercially available from Diamond Shamrock.
The transf er medium according to the invention is
35 yL~=~a~ d by combining the ink ingredients in an aqueous
Wo 95/~3195 PCr/USs4/11345
217SS~3 ~
-- 10 --
or organic solvent (with aqueous solvents being
preferred), and then applying the resulting composition
to the carrier. If a size coat is used, it is applied on
top of the color coat. To facilitate coating, the total
5 sollds content of the ink is adjusted to be between lO
and 50% by weight of the ink. The coated carrier is then
irradiated with laser light le.g., as described in the
commonly ~e~cl~n~ et al. application, U.S.
Serial No. 08/_, filed CU1IUUL1e~ 1Y with this
10 application and hereby in~uL~uuLated by reference) to
transfer the ink from the carrier to a desired surface,
e.g., the surface of a semiconductor device. Suitable
lasers include Cû2 lasers (irradiation wavelength equals
10.6ILm), Nd:YAG lasers (irradiation wavelength equals
15 1.06~m), and diode lasers (irradiation wavelength equals,
e.g., 0 . 9~m) . The particular irradiation wavelength,
power, ~nd time of application parameters are selected to
ensure clean transfer.
In the case of some inks, laser irradiation both
20 transfers and cures the ink simultaneously. With other
inks, a separate thermal or photo~-h~ c~l cure is
effected following transfer. The cure conditions are
selected based upon the particular prepolymers and
initiators used in the f ormulation .
The invention will now be further described by way
of the following examples.
r le l
This example describes the ~)L ~ar,ltion of a
transfer medium having one-pass, thermally curable,
3 0 ca~ i ~n i C:~ 1 1 y initiated, ink .
The following ingredients were combined to form a
lase~ sferrable ink (all amounts in weight percent):
Tio2 55 . 0
Ri ~rh~nnl A-DVE adduct 13 . 0
21~5588
~ WO95/13195 PcrluS94111345
", . t .,
-- 11 --
352011 24.8
PEG 30002 5 . 0
Aryl sulfonium salt3 2 . 0
Triton X-1004 0 . 2
5 1 Agueous dispersion of hi ~rh~ l A-epichl~L~ ydLin
adduct formerly available from Rhone-Poulenc.
2 pOlyethylene glycol (Mn = 3000) ~ially available
from Union Carbide.
3 Aryl sulfonium salt thermal initiator of the type
10 described in W090/11303.
4 Surfactant ~ lally available from Rohm & Haas.
Water was added to adjust the total solids content
to 3596 by weight, after which the resulting ink was
coated onto a 1. 2 mil thick polypropylene carrier f ilm
15 using a #15 mayer rod. The coated surface of the film
was then placed in intimate contact with the surface of a
molded s~ n~ otor device. Next, a C02 laser was
directed through the uncoated side of the carrier film to
transfer the ink to the surface of the semiconductor
20 device. The laser dwelled on each addressed piYel for
16 ~sec. The power output of the laser at the point of
contact with the coated film was 14 . 5 W. The device
bearing the transferred image was then placed in a forced
hot air oven for 30 min. at 175C to cure the ink. After
25 curing, the transferred image was found to be resistant
to L,c:at L with 1,1,1-trichloroethane (3 min. soak, 10
brush strokes, cycled 3 times).
r le 2
This example describes the ~L-:paLe.tion of a
30 transfer medium having a two-pass, cat;-~n;~lly initiated
ink in which both the color coat and the size coat are
pho~o~-hF~n; c~ l 1 y curable .
The following ingredients were inod to form a
photochemically curable color coat (all amounts in weight
35 percent):
WO 95/13195 ' PCr~S94111345 ~
21~ S
-- 12 --
TiO2 55 . 0
2, 4-toluene diisocyanate/HBVE adductl 35 . 8
QW-16 (urethane dispersion) 2 2 . 0
ppz3 5 . 0
5Triton X-1004 0 . 2
WI 69745 2.0
l Hydroxy butyl divinyl ether adduct.
2 Pre-made urethane dispersion commercially available
from X.J. Quinn.
10 3 Commercially available from Idemitsu P~LLV~ CO.
Ltd .
4 Surfactant commercially available from Rohm & Naas.
5 Triaryl sulfonium salt-based initiator commercially
available from Union Carbide.
Water was added to adjust the total solids content
to 35% by weight, after which the resulting color coat
was applied to a l . 2 mil thick polypropylene carrier f ilm
using a ~13 mayer rod.
The following ingredients were combined to form a
20 photn~h~ l ly curable size coat (all amounts in wlaight
percent):
EPON l00ll 89. l
WI 6ll02 5. 45
FC-4303 2 . 47
WI 69744 1.68
Perylene5 o . 3
ppz6 l . 0
1 R~ ~:phPnrll A diglycidyl ether commercially available
from Shell Oil Co.
30 2 Liquid ~ier~Yicl~ commercially available from Union
Carbide .
3 Fluoroaliphatic polymeric ester surfactant commercially
available from 3~ Co.
4 Triaryl sulfonium salt-based initiator commercially
35 available from Union Carbide.
I wo 95/13195 217 5 5 8 8 PCT/US94/113J5
5 Photosensitizer commercially available from Aldrich
rh~.m; ~ 1 CO .
6 C ;ially available from Idemitsu Pt:L-U- 1 ;c~ Co.
Ltd .
Methyl ethyl ketone was added to adjust the total
solids content of the 6ize coat to 2596 by weight, after
which the resulting size coat was applied on top of the
color coat using a #5 mayer rod.
The coated surface of the film was then placed in
lO intimate contact with the surface of a molded
semicon~ t tor device. Next, a C02 laser was directed
through the uncoated side of the carrier film to transfer
the ink (color coat plus size coat) to the surface of the
semicnn~ rtor device. The laser dwelled on each
15 all.~ssed pixel for 20 ~sec. The power output of the
laser at the point of contact with the coated film was
14 . 5 W. The device bearing the transferred image was
then cured (5 min. at a 150C preheat, followed by a 3.6
gec ~O~UL~ to W radiation). The resulting cured
20 printed image was found to be resistant to ~.~a, with
l, l, l-trichloroethane (3 min. soak, lO brush strokes,
cycled 3 times ) .
r le 3
This example describes the yL~ Lion of a
25 transfer medium having a wu ~ass, cat;nn;n~lly curable
ink in which the color coat is non-cura~le and the size
coat is thc.rr- 11 y curable .
The following ingredients were ;n~d to form a
non ~_u--ble color coat (all amounts in weight percent):
Water 54. 0
Daxad 30l 0 5
Tio2 38 . 4
Triton X-lOo2 o . 5
CUULu~k 3753 6.2
Rhoplex B854 l . 4
WOss/l3lss v PCT/US94/113~5
2175~8~
-- 14 --
Amsco 30115 7.7
1 Polyacrylate dispersing agent ~ ially available
f rom W . R . Grace .
2 Surfactant commercially available from Rohm & Haas.
5 3 Polyethylene wax dispersion commercially available from
Diamond Shamrock.
4 Acrylic dispersion commercially available from Rohm &
Haas .
5 Acrylic dispersion ~ .;ially available from Rohm &
l0 Haas.
Enough ammonium hydroxide was added to adjust the
pH to 8.5, after which the resulting color coat was
applied to a 1.2 mil thick polypropylene carrier film at
a coat weight of 69 mg/m2.
The following ingredients were ;nPd to form a
photonhP~ Al ly curable size coat (all amounts in weight
percent):
EPON l00ll 88 . 2
WR 6llo2 ll . 6
20FC-4303 3.0
W 4794 l. 6
IR 995 0 . 5
Benzpinacole6 o . 47
1 R; ~rhPnnl A diglycidyl ether cially available
25 from Shell Oil Co.
2 Liguid ~i;Prn~ P commercially available from Union
Carbide .
3 Fluoroaliphatic polymeric ester surfactant ~;iall
available from 3N co~
30 4 Io~nn;l-~ salt thermal initiator commercially available
from General Electric .
5 Dye ~ ~ially available from Glendale Protective
~echnologies .
6 Accelerator commercially available from Aldrich
35 ~'hP~n;cAl Co.
~ ~0 95/13195 2 1 7 ~ ~ 8 8 PCr/US94/11345
~ ~"f ~
-- 15 --
Methyl ethyl ketone was added to adjust the total
solids content of the size coat to 259~ by weight, after
which the resulting size coat was applied on top of the
color coat using a ~5 mayer rod.
The coated surface of the film was then placed in
intimate contact with the surface of a molded
8~micon~ tor device. Next, a Nd:YAG laser was directed
through the uncoated side of the carrier ~ilm to transfer
the ink (color coat plu5 size coat) to the surface of the
10 s~i cnn~ tor device. The laser dwelled on each
~ dLe~ed pixel for 18 ~Lsec. The power output of the
laser at the point of contact with the coated f ilm was
4.5 W. The device bearing the transferred image was then
cured (4 min. at 175C). The resulting cured printed
15 image was found to be resistant to LLe:al L with 1,1,1-
trichloroethane (3 min. soak, 10 brush strokes, cycled 3
times) .
r le 4
This example describes the ~r~paL~tion of a
20 transfer medium having a one-pass, fhF-~-lly curable,
ca~inniAlly initiated ink in which transfer and cure
takes place in a single step upon laser irradiation.
The following ingredients were _ 'in~ld to form a
laser-transferrable ink (all amounts in weight percent):
Talcl 30.0
UVE 93102 7.0
Copper benzoate3 0.14
Epon 1644 51. 43
CHVE54 11. 43
30 1 Nytal 400 commercially available from R.T. Vanderbilt.
2 Photo and thermal initiator _ ~cially available rrom
General Electric.
3 ~-c~] ~ator commercially available from Aldrich
'h ~-m i A 1 Co .
35 4 Epoxy novolac resin having an epoxy equivalent of 200-
240 commercially available from Shell Oil.
WO 95~13195 PCrlUS94/11345
21~ ~588
-- 16 --
5 Cyclohexyl divinyl ether commercially available from
GAF or ISI Products.
Methyl ethyl ketone was added to adjust the total
801ids content to 50% by weight, after which the
5 resulting ink was coated onto a 1. 2 mil thick
polypropylene carrier film using a ~10 mayer rod. The
coated surface of the film was then placed in intimate
contact with a glass slide. Next, a C02 laser was
directed through the uncoated side of the carrier ~ilm to
10 trnnsfer the ink to the surface of the glass slide. The
laser dwelled on each addressed pixel for 80 ~sec. After
addressing, the transferred coating was removQd form the
glass slide and analyzed by differential S~Anninq
calorimetry. There was no evidence of residual heat of
15 reaction, indicating that the tranar~aLLt:d coating had
cured during the transfer step.
r le 5
This example describes the ~ ~a~a~ion of a
transf er medium having a two-pass, f ree radical-initiated
20 ink in which both the color coat and the ~iize coat are
pho~Ir h.o~; CAl ly curable.
The following ingredients were combined to form a
photochemically curable color coat (all amounts in weight
percent):
25Tio2 65 . 0
Aquacer 3551 11. 0
NR 4402 18.8
ppz3 3 . 0
Triton X-1004 0 . 2
30Daracure 42655 2 . 0
1 Polyethylene wax dispersion commercially available from
Diamond Shamrock.
2 Acrylate-funct;~nAl; ~ed prepolymer ~:iall
available from Zeneca Resins.
35 3 Commercially available from Idemitsu P~l,L~ 1R CO.
Ltd .
~ WO95113195 ~17~588 PCT/US9~11rl45 ~
-- 17 --
4 Surfactant _ . lally available from Rohm & Haas.
5 photnrhPm~r~l free radical initiator ~;ially
available from Ciba Geigy.
Water was added to adjust the total solids content
5 to 4096 by weight, after which the resulting color coat
was applied to a 1.2 mil thick polypropylene carrier film
using a J~13 mayer rod.
The following ingredients were ~ined to form a
photorhPm;r~lly curable size coat (all amounts in weight
10 percent):
NR 4401 78 . 0
Ebecryl 6392 20 . 0
Daracure 42653 2. 0
1 Acrylate-f-lnrtinn~l ized prepolymer ~ ially
15 available from Zeneca Resins.
2 Acrylate-functinn;~li7Pcl prepolymer commercially
available from Radcure.
3 Photorhpmi r;~-l free radical initiator commercially
available from Ciba Geigy.
Water was added to adjust the total solids content
of the size coat to 40% by weight, after which the
resulting size coat was applied on top of the color coat
using a ~5 mayer rod.
The coated surface of the film was then placed in
25 intimate contact with the surface of a molded
8Pm i rnn~ rtor device . Next, a CO2 laser was directed
through the uncoated side of the carrier film to transfer
the ink (color coat plus size coat) to the surface of the
Somi rnn-ll-rtnr device. The laser dwelled on each
30 add~ asOed pixel for 20 ~sec. The power output of the
laser at the point of contact with the coated f ilm was
14 . 5 W. The device bearing the transferred image was
then cured (5 min. at a 100C preheat, followed-by
passage through a W fusion oven equipped with an H bulb
35 at a speed of 100 in. /min. ) . The resulting cured printed
W095113195 , PCrlUS94111345
21~55~
-- 18 --
image was found to be re6istant to treatment with 1,1,1-
trichloroethane (3 min. soak, lo brush strokes, cycled 3
times ) .
other ~mho~l;~ Ls are within the following claims.
What is claimed is:
