Note: Descriptions are shown in the official language in which they were submitted.
~Vo 95116561 2 ~ 7 8 8 4 I PCTIUS94114501
INK ACCEPTOR MATERIAL
FIELD OF THE INV15NTION
This invention relates to an acceptor material for irlk printing and, more
particularly, to a coated acceptor material for forming water-resistant, light-stable ink
records with ink jet inks.
BACKGROUND OF THE INVENTION
Ink jet printing is a non-impact means of producing a pattern of ink droplets
which can be used to record digital information. To make a hard copy, the droplets are
deposited ontû a ~ a,u~ , fr~nel~ Pnf or opaque support such as film, vellum or
paper. Ink jet printers have been used for many years to make l~lullocluul~lc hard copy
from computers. A rapidly-growing use of ink jet printers is to generate subtractive
color images using a three- or four-color process. The resultant hard copy can be
viewed by Ll~ulallli~Cd light using an overhead projector (transparent film); bytransmitted light using a diffuse illuminator (translucent film); or by reflected light
(opaque support).
In subtractive continuous tone silver halide color ullutu~l~lly, color images are
produced by the aU,u~uOa;~iull of three primary continuous-tone color-intensity-graduated recording layers. In non-continuous tone ink jet color printing, use is made
of ~ ,lua~,uuic superposed color-separated dots (so-called halftone images) to create an
impression to the viewer of an intensity graduated image. The proper hue, size, and
degree of ~ and mixing of the primary color dots -- cyan, magenta, yellow
and black -- are necessary for the faithful reproduction of color on the recording
medium. Accurate ink jet color image recording thus requires a high degree of
coopPr:ltil-n between the ink jet color separation pulses, the ink dyestuffs, and the ink
acceptor material.
An irlk acceptor material should be capable of accepting the droplets readily amd
allowing them to coalesce, yet should achieve color isolation and separation with high
chroma and pure hue without image edge distortions due to poor registration, bleeding,
;
WO 95/16561 2 1 7 8 8 4 1 PCT/llS9~114501
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feathering, or other image quality defects. Acceptor materials for colored inks currently
available, however, suffer from rapid fading of one or more of the dyestuffs upon
exposure to light. Furthermore, currently available ink acceptor materials can be
degraded easily by repeated handling or contact with moist objects As a ~,UlI~ ,U~ ,t
5 of such contact, the moist object often becomes stained with the dyestuffs. Also,
because the usual aqueous ink jet inks have relatively low volatility, imaged acceptor
materials are typically still wet with the aqueous ink vehicle ~hen emergin~ from an
ink jet printer. Images are then most vulnerable and can be altered by smudging or
blocking as a c.".~ of print stacking.
PROBLEM TO BE SOLVED BY THE INVENTION
An object of this invention is to provide an ink acceptor material capable of
rendering ink jet images which dry rapidly, are water-resistant and light stable, can be
15 handled and stacked without damage to the printing or images, and have good layer
clarity and good sheet feeding properties in ink jet printers.
SUMMARY OF THE INVENTION
An acceptor material for inks that contain an ionic dye and an aqueous vehicle
comprises a support and an ink-accepting cullllJu ~;Liu~ coated on the support,
in that the ink-æcepting rr~nnrc~ rln comprises (a) a water-soluble
mordant which, when admixed in excess with the ionic dye in aqueous solution at room
~IIlAu~laLulc, forms a water-insoluble precipitate and a clear, ~ colorless
~u,u~ ai~ulL liquid, (b) a water-absorbing solid polymer, wherein the polymer has been
rendered insoluble in water at room t~ laiulc by chemical hardening of the polymer
at elevated i~.ll,u~ ulc in an aqueous coating solution prior to coating of the eoating
solution, and wherein the polymer is non-reactive with and permeable by the ionie dye,
and (c) non-porous, clear, substantially spherical, polymer beads dispersed in the
water-absorbing polymer in an uppermost layer of the ink-aecepting rrmror~itirn
O 95/16561 2 1 7 8 8 4 1 pf~T~S941l450l
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In another r~ O~ of the invention, an acceptor material for inks that
contain am ionic dye and an aqueous vehicle comprises a support and am ink-accepting
''' ''''I'f'`'l;'''' coated on the support, ~.1,-., ~, ;,. ~l in that the ink-accepting ~l.".l,o~:l;....
comprises (a) a water-soluble high molecular weight amino mordant or a water-soluble
5 ~ nl;l.;fl mordant which, when admrxed in excess with the ionic dye in aqueoussolution at room t~ ,u.,laLul~, forms a water-insoluble precipitate and a clear
~1.l.. -'-- ' Iiquid, and (b) a water-absorbing polymer which is non-reactive with and
permeable by the ionic dye.
ADVANTAGEOUS EFFECT OF THE INVENTION
The acceptor material of the present invention exhibits the ad~ uu~ effects
of high optical clarity, a rapid drying capability, and good sheet feeding properties.
Fu~ lulc~ it accepts aqueous inks to form images of high resolution and excellent
I S stability.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure I shows a cross-section of an ink acceptor sheet of the invention in
20 which the support is coated on one side with the ink accepting cnnnro~itinn and on the
other side with amtistatic, curl control, or other functional layer.
Figure 2 shows a cross-section of an ink acceptor sheet of the invention in
which the support is coated on two sides with ink accepting ~.... ,1...~, l ;....~
Figure 3 shows a cross-section of an acceptor sheet of the invention in which the
25 support is coated on one side with a dye lUUl~lLillg layer, a vehicle-absorbing layer,
and am overcoat layer.
Figure 4 shows a cross-section of another plural layer c..lbodl.~.L of the
acceptor sheet of the invention.
Figure 5 is a plot of light stability test results for dyes printed on an acceptor
30 material of the invention and on a cullllu~l~,;ally available material.
WO 95/16561 2 1 7 8 8 4 1 PCTIIJS94114!iOI
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DETAILED DESCRIPTION OF THE INVEN~AION
The acceptor materials of the present invention are useful as receivers for
thermal ink jet printing (bubble jet) or for non-thermal printing. In general, they are
i useful in any process for recording ;,.r...",-~i,." or images with inks comprising aqueous
vehicles and ionic, water-soluble, colored dyes, such as inks disclosed in U.S. Patents
Nos. 5,180,4ZS and 5,183,502, which are ;I.c~ ul~t~l herein by refe}ence. ~ith such
inks, of which the dyestuffs typically contain anionic groups such as carboxyl and/or
sulfonate groups, the acceptor materials of the invention can provide images of high
lO quality, which are resistant to smearing and have excellent light stability. The ink
acceptor materials of the invention are especially ~ d by rapid drying, a
quality of major importance in ink jet printing because of the high liquid content of the
ink 1~ and have excellent clarity and sheet feeding properties.
Acceptor materials of the invention function by ;~ 11 of the
lS ionic ink jet dyestuffs and the aqueous ink vehicle. A water-soluble mordant reacts
with and imml~hili7Pc the dyestuffs by forming a water-insoluble compoumd or
coacervate while a hydrophilic, water-absorbing, solid polymer ~;"...11....,,.~1~ wicks
away the ink vehicle from the surface of the acceptor material. The mordant thereby
controls the dye deposition and directs the dye movement (locus of dots) within the
20 acceptor material to provide dot separation and, ' -registration, thus
r the close-packing and ~. of the dyestuffs. The water-absorbent
polymer having spherical, non-porous polymer beads dispersed therein controls the large
volume of aqueous ink vehicle (for most aqueous inks, 70-90% of the ~..""l.,A,~,I;~,l,)
thus causing a rapid dry-to-the-touch response of the acceptor material with minimal dot
25 beading, spreading and no blocking or smudging of the image. The spherical, non-
porous polymer beads distributed at or near the irlk-accepting surface of the material
and protruding therefrom contribute to rapid drying amd good sheet feeding whileretaining optical clarity of the material. The result is a rapidly dried, fu~l color ink jet
image having excellent chroma amd image resolution and stability and desirable surface
30 properties.
O 95/16561 2 1 7 8 8 4 1 PCT/US94114501
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The present invention includes an acceptor material for inks that contain an
ionic dye and an aqueous vehicle, wherein the acceptor material includes a support and,
coated on the support, an ink-accepting c~mr~ til~n comprising (a) a water-soluble
mordant compound which, when admixed in excess with the ionic dye in aqueous
S solution at room l~ aLul~ forms a water-insoluble precipitate and a clear
~--h~tSmti~lly colorless s~ Iiquid; (b) a water-absorbing solid polymer, whereinthe polymer has been rendered insoluble in water at room t~ lUlUI~ by chemical
hardening at elevated ~tlll~ Lul~ in an aqueous coating . .,1..~ ;.,., prior to coating it
on the support, and wherein the polymer is non-reactive with and permeable by the
10 ionic dye; and (c) non-porous, clear, substantially spherical, polymer beads dispersed in
the water-absorbing polymer in an uppermost layer of the ink-accepting romro~iti/~n
Preferably the beads have a specific gravity no greater than that of the aqueous coating
and have diameters from about 3 to l'i ~m; the ~..,....,1.~l;..,. of the beads
in the uppermost layer is about 0.5 to 4 weight percent based on the amount of water-
l 'i absorbing polymer in the uppermost layer.
The invention also includes an acceptor material ~ ;a;llg a support and an
ink-accepting .. 1.~,~;l;.. " coated on the support, .1.,1,, ~ I in that the ink-æcepting
i..,,,,l.~.~;l;..,. comprises (a) a water-soluble high molecular weight amino mordant or a
water-soluble rl~ mordant which, when admixed in excess with the ionic dye0 in aqueous solution at room ~tlu~ ul~i, forms a water-insoluble precipitate and a clear
liquid, and (b) a water-absorbing polymer wnich is non-reactive with and
permeable by the ionic dye.
In acc~,llall.,c with the invention, a novel rnmr~itil~n for forming an ink
receiving layer on a support comprises water, a water-soluble mordant capable of25 forming a water-insoluble coacervate with ionic dyes, a hydrophilic hardenable polymer,
and a hardening agent in an amount sufficient to harden the polymer at elevated
t~ UI~ and render it water-insoluble but water-absorbent at room t~ UI~.
Also in accordance with the invention, a novel imaged ink jet acceptor sheet
comprises a support and, coated on the support, a layer containing hardened gelatin and,
30 dispersed therein, a water insoluble coacervate of a water-soluble mordant compound
WO 95/165G1 2 1 7 8 8 4 1 PCT/US94114501
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and a water-soluble dye compound. In a preferred rl"l,A.,I;",. .,1 suitable for outdoor
display, a transparent, water-absorbing layer of hardened gelatin is coated over the layer
containing the coacervate.
~urther in accordance with the invention, a method for making an acceptor sheet5 for inks containing an ionic dye comprises:
a) heating an aqueous soluti~m comprising a hardenable polymer,
water, and a chemical hardening agent;
b) I~ heating for a time sufficient to react the chemical
hardening agent with the hardenable polymer to form a coating
I 0 composition;
c) adding to the aqueous solution or to the coating ~ ." (i) a
water-soluble mordaAnt which, when admixed in excess with the
ionic dye in aqueous solution at room L.~ Lu c, forms a water-
insoluble precipitate and a clear, substantially colorless
~ Iiquid, and (ii) non-porous polymer beads of 3 to 15
m diameter and having a specific gravity not ~ h~tAntiAAIIy
greater than that of the coating cAmr~ iti~-n; and
d) coating the resulting aqueous I~VlllpVi~ iUl~ on a support.
The ink acceptor material of the invention provides diffusion II~ ....11 of the
20 deposited wet ink dots, the dyestuffs therein, and the liquid vehicle of the soluble dyes.
Surprisingly, the applicants have found that polymers, such as those mentioned
hereinafter, when subjected to chemical hardening prior to coating perform the role of
absorbing the ink droplets and providing a strong, durable, non-tacky, three-,l;,". ..~;III.AI
matrix for the dyestuff immA~hili7in~ component of the material, i.e., the water-soluble
25 mordant. The polymers employed are hydrophilic and easily swellable by the aqueous
vehicle of the inks to wick away quickly said vehicle from the surface of the material,
whereby the surface of the acceptor material dries rapidly. Said polymers are
transparent and can yield, if desired, a finished surface of high gloss. The solid
wicking or water-absorbing polymer is rendered insoluble in the ink vehicle below 50C
by chemical hardening of the polymer in an aqueous medium at elevated t~ UUC
~o 95/16561 2 1 7 8 8 4 1 PCTNSg4/14501
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prior to coating of the ~..,,.,l,..~;l;..,- on its support. The hardened polymer is, however,
soluble in the aqueous medium at elevated h~ LLul~ above 50C and the composition
therefore remains coatable.
The ink acceptor materials of the invention are prepared by coating and drying
5 on a transparent, translucent or opaque sheet or web a layer or layers of the a~plulJl;aL.,
f,""l,n~ In one . ..,l~ol~ an aqueous coating composition is formed which
contains the water-absorbing polymer, a hardening agent, the mordant and non-porous
polymeric beads. In addition, the ~ preferably contains a coating aid. The
coated layer is dried to form a thin layer in which the mordant is uniformly distributed
10 throughout the water-absorbing polymer matrix and the polymeric beads protrude from
the surface of the layer. The total thickness of the dried ink-accepting ~ .l. on
the support, whether coated as one or a plurality of layers, is preferably in the range
from about I to 25 ~Lm, (although greater Ll-i~,L.~ s can be used), and, most
preferably, is in the range from about 2 to 18 ~m. The polymeric beads improve sheet
15 handling and, with the water-absorbing polymer, contribute to rapid drying.
The water-absorbing polymers employed in the materials of the invention have
no affinity for the water-soluble ink jet dyes and therefore allow rapid diffusion of said
dyes into the ink acceptor material, wherein said dyes are very rapidly imm~bili7~d by
chemical reaction with a mordant to form a non-diffusing compound or coacervate.20 The mordant can be distributed uniformly tbroughout the water-absorbing polymeric
matrix or it can be mixed with a portion of the water-absorbing polymer and coated in
a separate layer above or below the water absorbing layer. When the mordant
compound is cationic it forms an ionic bond with water-soluble . u~ .t ;~ dye
~."..l.u...,.l~ such as those disclosed in U.S. Patents Nos. 5,180,425 amd 5,183,502 cited
25 above. The high optical density which ~ , . . ;, the images formed by the acceptor
materials of the invention appears to result from the high ~ ;.... of mordanted
dye or coacervate at the exposed surface of the mordant, regardless of its coated
placement relative to the support.
Although the ink jet inks with which the ink accepting materials of the invention
30 provide such . ' ~ results, are aqueous inks, it should be umderstood that, in
WO 951165C1 2 1 7 8 8 4 1 PCT/US94/14501
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addition to water, the ink vehicle can also include hydrophilic organic liquids. In
general, the water content of the aqueous vehicle of the inks is in the range from about
30 to 99 weight percent, and preferably 70 to 90 weight percent, the rest being
hydrophilic organic liquids such as glycols, glycol ethers, pyrrolidones and cllrfA~t~ntc
5 As is known, such hydrophilic liquids can aid in the delivery of the inks by ink jet
printers.
Referring to the drawings, Figure I shows a preferred c~ bud;l~ lL 10 of an
acceptor material of the invention comprising support 12 and, coated on it,
ink-accepting ~ 14. Support 12 is a sheet material which can be transparent,
10 trAnc~ rnt or opaque. Useful transparent or translucent materials include, for example,
poly(ethylene terephthalate), cellulose acetate, pOI~ bul.~ polyolefin, polyvinyl
chloride, polystyrene, polysulfone, styrene acrylonitrile (also known as SAN), glass amd
the like. Useful opaque sheet materials include paper, opaque filled polyester,
polyethylene-clad paper, white polypropylene film and the like. Support 12 can be
15 coated with a ~,ullv~llliollal tie or subbing layer (not shown) to enhance adhesion of
ink-accepting ~..",l,. ~,l;.." 14 to support 12, as well as one or more backing layers 16
to control conditions such as static, blocking, curl or color.
Ink-accepting rnmr~itinn 14 comprises a water-absorbing polymer, preferably a
hardened polymer such as hardened gelatin, wherein the gelatin may be hardened in
20 solution prior to coating by reaction with a hardening agent. Upon being coated and
dried, the polymer forms a matrix which is transparent to light, is insoluble in water at
room t,.ll~ L~ , and is resistant to abrasion. The polymer, however, retains itshydrophilic character, is easily swollen by water, is easily permeated by the aqueous ink
vehicle and by water soluble dyestuffs, and has no chemical affinity for said dyestuffs.
25 The hardened polymers used in the acceptor materials of the invention are water-
absorbing polymers that are so easily swollen by water that they are swellable by up to
400/~ when imrnersed in the aqueous ink vehicle. By this is meant that the volume of
the polymer increases by at least about 400% when soaked in water.
A highly preferred hardenable polymer is gelatin. Other preferred polymers
30 include chitosan (discussed more fully hereinafter) and 100 percent hydrolyzed
NO 9S/16561 2 1 7 8 8 4 1 PCTNS94/14501
9 _
poly(vinyl alcohol). Hardenable natural polymers other than gelatin and chitosan that
can be used in the materials of the invention include starch, agarose, albumen, casein,
and gum arabic. Il~d~lldlJlc synthetic materials include, for example, hydroxy propyl
cellulose (e.g., Klucel polymer of Hercules Corp.), ~,a~bu~yl~ yl~ . .IC
5 lattices, poly(acrylic acid), poly(lll.,ill.~lYillyl.,il..,l-co-maleic anhydride) e.g., Gamtrez
169 polymer, poly(vinyl alcohol) and poly(N-vinyl-4-pyrrolidone).
Still another ul~llald~ polymer which is useful as the water-absorbing
polymer in the ink-accepting materials of the invention is hardened chitosan. Chitosan
is partially dl,a~,~,iyl..~,d chitin. Commercially, chitin is extracted from shrimp and crab
10 shells and l..",~r.,l,.l~d to chitosan to obtain a water-soluble product. Chitosan is a
linear biopolymer, specifically a pOly~ac~llalidc which comprises two ".,,"..~ 1N-acetyl-D-~ and D-~ linked by ~(1~4) glycosidic bonds.
Commercial chitosans hâve degrees of ~,a~ ylaiivll between 75 and 95 percent. The
viscosity range of commercial chitosans is from lO to lO00 mPa s. A chitosan useful
lS in preparing the materials of the invention is available from Pronova Biopolymer a.s. of
Drammen, Norway. The chitosam is In~ all~llcd, by heating in aqueous solution with a
chemical hardening agent as disclosed herein, for use in the materials of the invention.
As discussed in more detail hereinafter, c- ,.,~ . 14 also has dispersed
therein, and ,ul.~L7.. ' .lly at the surface thereof, certain non-porous polymeric beads.
20 These beads provide valuable surface properties while cuilLIibuLillg to ink absorption,
but retain the desired clarity of the layers of the inlc-accepting material of the invention.
Ink-accepting c.. ~ . 14 further includes a water-soluble mordant or dye-
fixing agent, which is capable of bonding ionically or otherwise with the dyestuffs in
ink jet inlcs, to form a water-insoluble, immobile or "~uac~,l v " compound in the
25 acceptor matrix without any significant change in the chroma or hue of the original
dyestuffs. By water-soluble mordant is meant a Illul~allLi~lg compound capable of
dissolving in water at room t~ a~uL~, (20C) to at least a 10 gm/liter c..l.~...1.~;....
Preferably, the mordant is water-soluble to at least 30 gm/liter at room l~,lll,u~,laLuu~.
Different types of water soluble mordants are useful m the practice of the
30 invention. Certain ~ - "l J ~ l~ that are useful mordants in the materials of the invention
WO 95/165C1 2 1 7 8 8 4 1 PCT/US94/14501
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immobilize or anchor the anionic dyestuffs of ink jet aqueous inks by forming ionic
bonds with the dyes Others bond to the dyes by ~ ,,.."~",~ that are not fully
understood. They all have in common, however, the fact that, when tested in the
screening tests described hereinafter, they rapidly form insoluble l~c~ dLt;a with the
S dye when mixed therewith in aqueous solution at room h~ ul~. One useful type of
mordant that forms ionic bonds with the anionic dyes is a water-soluble, cationic
polymer having quaternary ~mm~nilmn side chains such as, for example,
Ll~yl.~ chloride llydlu~y~LIl~l cellulose (available as Celquat L-2û0 and
Celquat 11-100 from National Starch and Chemical Company). Both of the latter are
10 cationic cellulosic polymers; Celquat H-100 has a viscosity of .~ J 600
mPa-s (2% solids in wate~; RVF Brookfield Viscometer, #2 Spindle/20 RPM/21C) and
Celquat L-200 has a viscosity of ap~ L~ly 100 mPa s. Another useful mordant
that forms ionic bonds is a copolymer of dimethyldiallyl chloride (available
as FlocAid 19 from National Starch and Chemical Company).
Still another useful mordant in accordance with the invention comprises a metal
ion from the el~.L~v~ ;Liv~ side of the periodic table of elements, preferably, ions of
Group 11 metals such as divalent barium, strontium, or calcium. The metal ions are
il~C~lp~l.,t~ in the materials of the invention by mixing an aqueous solution of a salt of
the metal, e.g., BaCI2, SrBr2 or CaCI2, with the wicking material during formulation of
20 the coating ~.l"l..,~;li.",
Useful mordant ~.,.,.l).. ~ "I~ which pass the screening tests described hereinafter
and anchor the anionic dyestuffs by ,. ~ that are not umderstood include non-
ionic and high molecular weight (i.e., at least about 400 m.w.) amino UWllp~/Ull..b.
They cam be primary, secondary or tertiary amines. These include water-soluble, non-
25 ionic polymers containing amino groups, for example, poly(4-vi..yl~ylidill~) which is
available from Monomer Polymer Company. Other examples include the propylene
oxide based triamines of the Jeffamine T series which are available from Texaco, Inc.
They are prepared by the reaction of propylene oxide with an aliphatic triol initiator
having up to about 12 carbon atoms, such as trimethylolpropane or glycerine, ~ollowed
~WO 95/16S61 2 1 7 8 ~ 4 1 PCT/USg4/14501
11
by amination of the terminal hydroxyl groups. These tri-primary amines are
by the structure:
/ ( OCH2 CH ) Y--NH2
CH3
-(ocH2cH~y--NH2
CHa
\ (ocH2cH~ --NH2
0 CH3
wherein A is the initiator moiety. Molecular weights range from about 440 to about
5000, x, y and z are each positive integers, and x + y + z = 3 to about 85. Preferred
examples of such tri-primary amines of the Jeffamine T series include Jeffamine T-403,
in which the aliphatic triol is L~ ylol~ , the ClplJlU~ ., molecular weight is
440, and x+y+z is 5 or 6; Jeffamine T-3000, in which the aliphatic triol is glycerine,
the ~,IV~illl~.L~ molecular weight is 3000, and x+y+z is ~ t~.ly 50; and
Jeffamine T-5000, in which the aliphatic triol is glycerine, the ~ molecular
weight is ~000, and x+y+z is ~ IJlU~ ,ly 85.
Although tne above-noted water-soluble amino ~ .v , l~ are non-ionic, they
form water-insoluble reaction products with the anionic dyes of aqueous ink jet inks
and are useful as mordants in accordance with the present mvention.
Other ~ which pass the screening tests and are useful as water-soluble
mordants in the materials of the invention are high molecular weight rh..~rhnlirit~ such
as lecithin and also the phn~rhnliri~1 EFA, I,I,n~l.l,nl:l,:.l SV and l.~.n~l.l...l;l.;~l PTC,
25 which are available from Mona Industries, Inc. The latter l~ .l.nl;l: l~ have the
structure:
CH3
I ~
[R--N--CH2CHOH--CH20]~ P(ONa)y + xCle
CH3
WO 95/16561 2 1 7 8 8 4 1 PCT/US94/14501
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where x plus y = 3. In such pl~va,ullOlipid~ R is a saturated or ~ r(~ long chain
(e.g., of 14 to 22 carbon atoms) ~albuAcu~ido-alkyl (e.g., of 2 to 6 alkyl carbon atoms)
radical. In l.l.n~ ,f.l;l~ EFA, R is linnl~rniAorropyl; in rhncrhnliriA SV, R isctr~r~miAnrropyl; in ~ n~ A PTC, R is cul,aulli~v,ulv,uYI.
All ûf the described types ûf water-soluble mordants which pass the screerling
test A below are suitable for bonding to, and illullob;li~,ill~ in the matrix, the anionic
dyestuffs of ink jet inks. The selection of suitable mordants can be facilitated by the
simple screening test in which an aqueous solution ûf an anionic dyestuff which is
present in the aqueous ink jet ink is added at room i~lll,u~.aLu~ (20C) to an aqueous
solution of a molar excess of the mordant. The rapid formation of a coacervate or
precipitate, which can be an oil or a solid, and a clear, substantially colorless
~.. l.. ~l-.,l liquid indicates the suitability of the mordant for use in the ink acceptor
materials of the invention. The screening procedure is illustrated as follows:
15 Co ~ ' Screerlin~ Test A - Add dvestuff to mordant solution.
Polvmeric Oll~t~rn~rv Ammonium Salt Test:
1000 picoliters of 5% magenta dyestuff in water is added at room ~lll,u~la~uuc to
20 mg of FlocAid 19 polymeric quaternary ~mm~nil~m salt in water. A gelatinous red
precipitate forms. The ~ l Iiquid is clear and colorless.
~minn Com~ound Test
1000 picûliters of 5% magenta dyestuff in water is added at room tclll~,la~llc to
20 mg of poly(4-vill~l,uy~;l;ll~) in 2 ml of water. A gelatinous red precipitate forms.
The :~U,UC~ UI~ liquid is clear.
rl.f.~ nl;l.;A Test
1000 picoliters of 5% magenta dyestuff in water is added at room t~ u~"a~Ul~ to
20 mg of l,l,n~ l SV in 2 ml of water. A gelatinous red precipitate forms. The
~ 1... -~- .l liquid is clear.
~VO 9S116561 2 1 7 8 8 4 1 PCT/USg4/14~01
- 13 -
Poly(N-vinyl-4-DYrrolidone~ Test:
In the same manner the magenta dyestuff solution is added to an aqueous
solution of poly(N-vinyl-4-pyrrolidone). No precipitate forms and the liquid is colored.
As shown above, the quaternary ornmnnillnn polymer (FlocAid 19), the amino5 compound poly(4-vi..~lL,yl;.liule), and the ,ullu~,ulloli,u;:i compound all pass the screening
test A as useful mordants, but poly (N-vinyl-4-,uyl.ulidu.l~) does not.
Test A is the preferred method for selecting and defining the types of compound
that are useful as mordants in the acceptor materials of the invention. In this test, the
mordant candidate is in a molar excess. The suitability of the mordant is 1 "...,~
by the rapid formation of a precipitate and by the fact that the ~UU.,~IIa~lL liquid
remains clear and ellhr~oAtiAlly uncolored, thus showing that c~hstAntiAIly all of the dye
has been mordanted or converted to the insoluble precipate or coacervate.
Test B below is another screening test for mordants. In this test, an aqueous
solution of the candidate mordant is added to an aqueous solution of the ink jet anionic
dyestuff with which images are to be formed. Since the dyestuff is in excess, the
""I" 1 -'- ' liquid is colored. If the mordant candidate is suitable, it either forms a
precipitate; ' 'y or at least forms ~ a turbid suspension which can be
A~ntrifil~ d to obtain a precipitate. Thus, either Test A or Test B can be used, but
Test A is preferred as a method for defining the suitable mordants because Test A
shows that the dye reacts quickly with the mordant, and Cl~hstRntiAAIIy none remains in
solution in the ~ ¦ . Iiquid.
Coa,.... ~ ~A ' Test B - Add ~~~ ' ' to d~estuff solution.
Polvmeric Ouaternary Ammoniurn Salt Test:
To one ml of 5% magenta dyestuff aqueous solution is added 1000 picoliters of
a 5% aqueous solution of FlocAid 19 polymeric quaternary A ~- --- ;- ~ salt. A heavy
precipitate forms ;.. 1; ~. Iy
WO 95/16561 2 1 7 8 8 4 1 PCT/US94/14501
- 14 -
Amino Compound Test
To one ml of 5% magenta dyestuffaqueous solution is added 1000 picoliters of
a 5% aqueous solution ol: poly(4-villyll,.yl;di,le). A heavy precipitate forms
illllllC.~ y.
S PhosPholipid Test
To one ml of 5% magenta dyestuff aqueous solution is added IOOO picoliters of
a 5% aqueous solution of rhncrholiri~l SV. A heavy precipitate forms immediately.
PolY(N-vinYI-4-~,~1lulidulle) Test:
In the same manner an aqueous solution of poly(N-vinyl-4-pyrrolidone) is added
to the aqueous solution of dyestuff. No incnll~hili7sltinn reaction occurs.
Test B shows the rapid formation of a water-insoluble coacervate when a
polymeric quaternary ~mmnni.lm salt ( Floc-Aid 19), an amino compoumd
(poly-4-villyll,~lidill~), or a rhncrhnliri~l compound is mixed with the water-soluble,
anionic magenta dyestuff solution in excess, showing that these cnmrolln~c are-suitable
as mordants in the ink-acceptor materials of the invention. Poly(N-vinyl-4-pyrrolidone),
however, forms no insoluble coacerYate with the dyestuff and would not be selected as
a mordant component of the materials of the invention.
The ink-acceptor materials of the invention, in addition to the l~ d
water-absorbing polymer and water-soluble mordant, contain certain surface-modifying
polymeric particles which, in cnmhin~tinn with the ~ ud~".,.l polymer and the water-
soluble mordant, provide an ink-accepting rnmrnritinrl having a number of
11y superior properties. These properties include, not only rapid water-
absorption and dye retention, but also a desired degree of surface roughness, a low
coefficient of friction, and a porous surface that contributes to short drying time. These
desirable properties are achieved by ill~,ul~ulaLill~ in the coating ~.. I.~.~.I;nl) that forms
the surface of the irlk-accepting ~ J~ , clear, non-porous polymer beads,
preferably cllhct~ntiS-lly spherical beads, having diameters in the range from about 3 to
15 ,um, preferably 6 to 13 ~Lm. In addition, the beads have a specific gravity not
cl~hct~nti:~lly greater than that of the coating .. l,.. ~,l,.. ,. Especially preferred are
~WO 95116561 2 1 7 8 ~ 4 1 PCTIUS94/14501
- 15 -
beads of poly(methyl lL~tll~dcly' ) and poly(dimethylsiloxane) having specific gravities
in the range from about 0.4 to 1.2.
Examples of such beads include the clear transparent, spherical polymer beads of- 9-13 ~bm diameter which are available from Esprit Chemical Company as Soken MR13
S beads. The polymer is a crosslinked poly(methyl Ill~ a.,l~' ) of which the monomers
are 97 wt. % methyl lll~LLa~ly~ and 3 v~t. % ethylene glycol dilll~lla~ly~ Another
example is the GE SR346 bead product of General Electric Company. This product
consists of poly(dimethyl siloxane) spherical beads of 7 to 12 ~m diameter.
In accordance with the invention, the applicants have found that the addition of10 such polymer beads to the surface layer containing a IJlclla~ ,d water-absorbing
polymer improves the water-absorption of the acceptor material, reduces or eliminates
multifeed jams and other problems in the feeding of sheets of the acceptor material in
printing apparatus, and reduces or eliminates the blocking and image offset of stacked
sheets. Unexpectedly, the illcull~ul~lLiull of the described organic polymer beads in the
15 surface layer of the materials of the invention does not impair the l ~ l clarity
of the ink-accepting material. Thus, the materials of the invention are quick drying,
form water-resistant and light stable images, and have excellent lln~ clarity and
sheet feeding and handling properties.
Although applicants again do not wish to be bound by theoretical PYrlon~tinnc
20 it appears that the orgamic polymeric particles or beads of low specific gravity and of 3
to 15 ~m diameter are IJlclulllillalllly at or near the surface of the coated layer in which
they are ill~.ul~l ' Because of their low specific gravity, they do not settle to the
lowest level of the coated layer. Being at or near the top of the layer and being of
~,u~lul particle size, the beads, or a substantial portion thereof, protrude from the
25 surface of the layer. This results in the desired surface roughness. Since the particles
are c~h~onti:llly spherical, the surfæe also has a low coefficient of friction. In
addition, the beads contribute to excellent water àb~ul~Livi~y by the ink-accepting
material. Preferably, also the beads are formed of a polymer such as poly(methylIll~,illa~,ly' ) or poly(dimethyl siloxane) that has a refractive index close to that of the
WO 95/16561 2 1 7 8 8 4 1 PCT/US94114501
- 16 -
hardened water-absorbing polymer; thus the ~ ""~ clarity of the layer is
511het~nti~11y retained.
The surface roughness of the materials of the invention can be expressed in
terms of a BEKK cm~othnPee Ill~,~allLCIII~ . This well-known definition of ~
S is measured by means of a BEKK !~mf~othn~ ee and Porosity Tester ~hich is supplied by
Buchel-Vamder Korput Nederland BV of Veenendaal, Holland. The lll~aa~Cl~ are
expressed in reciprocal seconds. The BEKK em~othn~eC of the materials of the
invention is in the range from about S to 60 sec~~ amd, preferably, is in the range from
10 to 40 sec~l. The static coefficient of friction is less than about 0.45 and preferably
10 less than 0.35. The kinetic coeftlcient of friction is less than about 0.350 amd,
preferably, is less than about 0.300. ~oefficients of friction are measured with a TMI
coefficient of friction instrument. These levels of roughness and of coefficient of
friction can be achieved by ;,.~ in the coating ~OIIIy~a;~iOI~ for the uppermostor surface layer of the material of the invention ..yyl, ~ 'y 0.5 to 4 weight percent
15 on dry basis of sllhct~ntil~lly spherical polymer beads of 3 to 15 ~m diameter.
Preferably, the c~nl~ntr~tir~n of beads in the uppermost layer of the ink-accepting
cnmr..-;tinn is in the rarlge from àbout 1.5 to 4 weight percent based on the amount of
water-absorbing polymer in the layer.
In one ,".l.o,i;.,...,l of the invention, the BEKK ~ 11--... of the surface is 38
20 sec ~, as compared with > 1000 sec~~ for an otherwise identical control material
containing no polymer beads. For that same rll.llfl.1;....,1 the static amd kinetic
~,ucrrlci~,llL~ of friction are 0.328 and 0.282, Ic ~y~Li~ , for the control, these
coefficients are >1.0 and 0.560, I~,.y~,~,~i~.,ly.
The effect of the beads on 1 l . .~ . clarity of the materials of the invention,25 expressed as loss of ~ l density compared with an otherwise identical controlwhich contains no beads, is less than about 0.04 density units. Thus, although the non-
porous polymeric particles roughen the surface of the material and convert the normally
non-porous, smooth surface of the hardened polymer to a porous condition, they do not
cllhet~nti~lly impair the 1,,."~",;~;:.", clarity of the layer.
~WO 95/16561 2 1 7 8 8 4 1 PCT/US94114501
- 17 -
T,, .~.",~..". clarity of the materials of the invention can be measured by
laminating ten strips of the film with a coating of glycerine on each surface to match
the refractive index of the film at the air interfaces and measuring the ~
density. By this test the control having no beads in its surfæe layer measures 0.04
S ~ , density; the material of the invention is cllh~tsnti~lly as clear, i.e.,
measuring 0.06. Thus, the addition of the polymer beads to the surface layer does not
substantially reduce or impair its ~ clarity. As for drying time, the control
requires more than two minutes to dry a large area of black ink (I in.2), while the
material of the invention with the same area of black ink requires only 45 seconds.
Surface gloss of the acceptor materials of the invention can be controlled by
choice of mordant. Applicants have found that use of the polymeric quaternary
:lmnnrmil-nn mordant, Celquat L-200, with hardened gelatin as the water-absorbing
material, results in a matte surfæe material having low gloss and excellent tooth for
manual pencil or ink pen marking. In contrast, acceptor materials of the invention
15 having high gloss (which is desirable for image quality) are obtained when the mordant
is a non-ionic amino compound such as poly(4-v;~ ,y.;dil.~), or a ~
compound such as r~ l;l ;A EFA. Surprisingly, the addition of polymer beads to
the surface layer does not cllhct~ntislly reduce the gloss of such glossy materials.
The acceptor material of the invention accepts the ink dots cleanly and allows
20 sufficient ~ I time to achieve good dot ~ ,LI~LiU--, yet permits pPnPtr~til-n of
the inks to achieve proper hue and chroma without beading. At the moment of contact,
the ink vehicle begins to diffuse into the acceptor layer, increasing the ~ " ofdyestuff in the applied droplets on the acceptor material surface. The ionic colored
dyes also begin to diffuse into the material where they are captured and bound
25 irreversibly by the mordant as a coacervate which in the single layer ~.~ ' is
distributed uniformly throughout the coated layer. This coacervate formation causes
each colored dye dot to be fixed in l~tSi,L.~;u.i with good edge defmition onto the
mordant functional sites, and the image quality is thus preserved. Also, the high local
~""~ . . ,1".1;. " ~ of dyestuff results in a high chroma (or color saturation) and efficient
~0 packing density ~f the dye dots.
WO 95/16561 2 1 7 8 8 4 1 PCT/17S94114501
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The aqueous vehicle for the ink dyes is wicked away from the porous,
uppermost surface rapidly by the hydrophilic, water-absorbing polymer of the acceptor
material. In effect, the coated layer appears to perform a "I~ r separation of
the ink cnmro~itirln evidently retaining the dyes on the active mordant surface sites
5 while permitting the liquid vehicle to diffuse readily to the unswelled portion of the
polymer. This c...,.l.;"~;..,. of actions results in high chroma, good light stability, water
fastness, and short drying times. For all but a very large black image area, the inks are
dry to the touch as the print emerges from a thermal ink jet printer such as the "500 or
550 C Desk Jet" printer of the Hewlett-Packard Company and the BJC600 Color
10 Bubble Jet printer of Canon Company. Large black areas (50% page coverage)
become dry within 45 seconds.
The acceptor materials of the invention are capable of absorbing and wicking
away rapidly all the aqueous vehicle of the inks and dispersing the liquid throughout
the water-absorbing polymer, leaving the surface of the acceptor material dry to the
15 touch. The water-absorbing polymer swells by up to 400% in so doing, but thenremains water-insoluble at room t~ a~ because of the high degree of hardening
pre-treatment.
Figure 2 shows another ....I,i~ ~; ,....1 20 of the invention wherein support 12 is
coated on both sides with ink accepting ...",l,r.~ 14 and 15, which can be the same
20 or different and which can be coated to the same or different 11.~ The
~",1,~,1;",. .,l~ of Figures I and 2 can further include one or more protective overcoats in
which the polymer beads are dispersed (not shown) on top of ink-accepting
...llC 14 and 1,.
Figure 3 shows still another ~ ,o~ . ." 30 of the invention wherein an image-
25 forming layer 32 containing the mordant compoumd and a portion of the water-
absorbing polymer is coated on support 12. Coated over layer 32 is transparent water-
absorbing polymer layer 34 which is substantially free of said mordant, but contains
non-porous polymeric beads (not shown) that roughen the surface of the water-
absorbing polymer layer and render it semi-porous. The hardened, transparent polymer
30 of the water-absorbing wicking layer 34 has no affinity for the ionic dyestuffs of the
~Wo 95/16561 2 1 7 8 8 4 1 PCT/US94/14501
- 19 -
ink jet inks, which are captured completely and irreversibly by the mordant material in
layer 32. This .,lllVOdilll~.l.i is suitable for outdoor display and for other uses when a
high degree of protection for the image-forming layer is desired, since the image layer
is well below the upper surface of the film. If desired, the ,lllbvd;lll~lL of Figure 3 can
5 be further protected by a transparent polymeric overcoat 36, in which case the polymeric beads are dispersed in the overcoat 36.
Figure 4 shows still another, ~ ' 40 of the invention wherein an image-
forming, mordar~t layer 44 is coated over the water-absorbing polymer of wickinglayer 42. As in .. ,.l,o.l:.. ,l 30, a protective overcoat 46 may or may not be present.
10 F~ . ..l 40 can be useful when the maximum possible image definition is desired,
since the dyestuffs are captured near the upper surface of the acceptor material before
substantial diffusion of the imaging dots can occur.
An important aspect of the invention is the chemical hardening of the matrix-
forming polymer in the making kettle prior to coating. In this way, a higher level of
15 control of hardening is obtained than could be achieved by addition of hardening agent
to the coating machine delivery line as is UUIl~ .iUll~l in, for example, the l..^....rn. l.~ c
of ~ uy~ l products using gelatin. F~lllll.,l~llulc, no post-hardening or incubation
of the coated acceptor material is required.
Kettle l~lc~ll~.l~,ll;l.~ is A~.. l.l;~l.. ;I by adding the hardening agent to the
20 polymer solution at elevated r~ II G, e.g., 49C. (120F.), and then l~
that solution t~ la~ulc umtil all the agent is consumed in cross-linking of the
polymer. The reætion is ~ by a . ~ rapid increase in viscosity to
a ~lhst~lltiAlly higher but coatable viscosity. The reaction is deemed at ~-qllilihrillrn and
therefore complete when no further viscosity increase is seen after holding the
25 c-- .~ o.~ at the indicated elevated t llllJ~ lllC for 15 hours.
The particular hardening agent to be used can vary according to the ~..l.ll.c~
of the polymer to be hardened. For gelatin, a preferred hardener is dimethyl hydantoin.
Various aldehydes, e.g., rvlll. l;lc~yJc~ g' ' ' ' .~lc and ~ h~uu are also
useful. Other useful gelatin hardeners are disclosed, m "The Theory of the
30 Pl...l..~ .ll: Process," MæMillan Publishing Co., Inc., New York, Fourth Edition, T.
WO 95/16561 2 t 7 8 8 4 1 PCTIIJS9~114501
- 20 -
H. James, Editor; (see Chapter Ill, pages 77-87, by Burness and Pouradier, entitled
"The Hardening of Gelatin and Emulsions"), the disclosure of which is ill~UIIll ' 4
herein by reference. For 100 percent hydrolyzed poly(vinyl alcohol), preferred
hardeners are boric acid and urea-formaldehyde resins. Hardening agents for other
5 polymers include, for exarnple, the l,;r", 1;~ aziridine, trimethylolpropane tris(~-
aziridinyl) propionate, known as XAMA-7, which is available from Sanncor Co. Theamount of hardening agent in the ~ " of the invention can vary over a
f range. In general, however, the amount should be sufficient to render the
polymer insoluble in water at ~ lLulc:. below 50C while retaining water solubility
10 at L~ /.ldLUl~a above about 50C, so that the ink-accepting ~...,.I.n~,l;.." of the
invention can be coated on a support from an aqueous medium. In general, the desired
amount of hardening agent can be determined by the f fl lilihril-m viscosity achieved by
adding the agent. Sufficient hardening agent is added to increase the viscosity of the
aqueous polymer coating ...,..1.~.l;..,. from about 10 to 200% at a given solids15 ~ . f ~;"" but not so much as to render it uncoatable. Preferred weight ratios of
hardening agent to gelatin are in the range from about 1:1 to 1:10, although other ratios
are also suitable. Other hardenable polymers can be hardened with similar ratios of
hardening agent.
To prepare the irlk-accepting ,.. 1.. ~;l;.. , of the invention for coating as a single
20 layer on a support, preferably the hardenable water-absorbing polymer, the hardening
agent, the water soluble mordant, the polymer beads, and water are mixed together in a
vessel with stirring and moderate heating. If desired, the polymer and hardener can be
mixed before adding the mordant and beads, but it can be ddvallL~,~vu~ to add the
mordant before the polymer is hardened. This can have the effect of grafting the25 soluble mordant compound to the wicking polymer. Other desirable ~ of the
coating f--mro~ifi-~n such as a coating aid can be added before or after hardening the
matrix polymer.
Conventional coating techniques can be used for producing the coated ink
acceptor materials of the invention, including, for example, spray coating, bar coating,
30 extrusion die coating, air knife, knife over roll coating, reverse roll, curtain coating,
~'O YS/16561 2 1 7 8 8 4 ~ PCT~Sg4/1450l
- 21 -
blade coating, and gravure coating of a continuous web of the support material. The
coated web is dried in ~ u~ ll;ulldl manner, e.g., by contact with warm air while
passing through a drying chamber. The total thickness of the dried ink-acceptingcomposition on the support, whether coated as one or a plurality of layers, is preferably
in the range from about I to 25 ,um, (although greater Ll~;cLl~c~ can be used) and,
most preferably, is in the range from about 2 to 18 ILm. The dried coated web can be
wound on a take-up roll and later cut to desired sheet siæs.
The coated amount of water-absorbing polymer must be sufficient to absorb the
substantial volume of water that is present in the ink jet droplets. In general, an
amount of water-absorbing polymer of at least about 2.0 grams per square meter on the
support will adequately absorb the water in the ink jet droplets and will provide a
quick-drying material. Likewise, the ink accepting . v,.,~ , must contain a
sufficient amount of mordant to bind all of the dyestuff in the ink. In general, the
amount of mordant should be at least about O.S weight percent and, preferably, at least
IS S weight percent of the amount of dry water-absorbing polymer in the ink accepting
. ~""l,n~,l;.". The maximum mordant content should not be so high as to impair the
desired physical properties of the acceptor material. Preferably, the mordant
r~n~ ntr~tion does not exceed about 30 weight percent based on the weight of the~vater-absorbing polymer.
The examples which follow illustrate certain specific ~ ù~ of the
invention and describe ,ulllucu~lLive tests with commercially available ink jet acceptor
materials.
EYample I - l~ardened Gelatin and Polymeric 1~ .r A Mordant.
A batch of solution was prepared for coating in accordance with the invention.
A vessel fitted with a mixer and a heater was charged with 93 grams of 10%
suspension of gelatin in water (available as T7188 from K-~K Corp.) and S0 grams of
distilled water. The mixture was stirred and the t.,~ lu.c was raised to 49C
(120F). After S minutes of stirring, the viscosity was 23 mPa s. Then 1.72 grams of
a 55% aqueous solution of dimethyl hydantoin (Damtoin hardener, av~ilable from Lonza
wo 9~/16561 2 l 7 8 8 4 1 PCr/US9411450
- 22 -
Co ) was added with continued stirring. After 10 minutes, the viscosity had increased
to 35 mPa s, and no further increase was seen. Then was added as the mordant, 2.30
grams of aqueous solution of a polymeric quaternary ammonium compound (FlocAid
19 from National Starch and Chemical Co.) with stirring, followed by 0.23 grams of
5 cross-linked poly(methylmethacrylate) beads, 9-13 ~m in diameter (Soken MR-13Gbeads available from Esprit Chemical Co ) and 2.79 grams of 2% aqueous solution of
u~Lyllul~ u~yuolyethoxy-ethanol (Triton X-100 available from Union Carbide) as
coating aid. The ~ l,U~ .~Lul~ was reduced to 38C (100F), and the resulting thickened
solution was ready for coating.
The thickened solution was coated on transparent 98 ~m thick (3.85-mil)
poly(ethylene L~ ' ' ) film and dried to provide a dry coverage of 9 ~ UalC
meter of support, resulting in a dried ink-æcepting layer having a thickness of 9 ~m.
When this film was imaged on a Hewlett-Packard 500C DeskJet ink jet printer using a
cartridge of Hewlett-Packard ink containing ionic dyes, the individual ink images
15 emerged drv from the printer. Dot resolution was excellent.
To test water resistance of the printed dyes, a strip of the printed film was
immersed in water for two minutes, then removed and dried. Reflection dye densities
of immersed and non-immersed strips were measured with an X-Rite Ref~ection
D~ ",- " Model 408. The results of these ~ are listed in Table I and
20 .1~ . . " .. ,~ the water-fastness of the ink acceptor film of Example 1:
~WO 95/16561 2 1 7 8 8 4 1 PCTNS94/14501
- 23 -
TABLE I
Water-Fastness Test of E~ample 1 Film
S
Density Difference
Between Non-
Optical Density Optical Density Immersed and
Dye Before T After ~ Immersed Films
10 Cyan 1.42 1.54 +.12
Magenta 0.96 1.00 +.04
Yellow 0.86 0.89 +.03
Black 1.60 1.66 +.06
Tne results recorded in Table I show that immersion of the imaged film of the
invention in water caused no density loss, thus indicating that essentially none of the
mordanted dye was washed from the film. The increases in density shown for certain
of the dyes are believed to have resulted from swelling and possible dye l~- .~ lL,..,....
amd repacking. In f,..~ , a ..~ ll~.,;al ink jet acceptor film when printed and
25 subjected to the same water-immersion test showed a magenta dye density change of -
0.77.
LiPht ExPosure Testin~ of ExamPle I Film of the Invention and a Commercial Film .
Example 1 film of the invention and a ~,w~ .,;dlly available ink jet recording
30 film that were identically imaged in am ink jet printer were exposed to GE F400W
fluorescent bulbs at 5,000 lux intensity for 72 hours, at the end of which time they
were compared to otherwise identical unexposed strips (ASTM F767-82) of the same- imaged films. The reflection densities (indicating dye light stability) are shown in
Table II for the Example 1 film and for the commercial film.
WO 95116561 2 1 7 8 8 4 1 PCTIUS94114501
- 24 -
TABLE 11
Cl~ . of Light Exposure Results of Example 1
Film of the Invention and C~. .h.l Film
Density of Density of Density Difference Density Difference
Non- Exposed Between Non- Belween Non-
Exposed Film Exposed and Exposed and
Film of of Exposed Film of Exposed
10Dye Example I Example 1 Example 1 ('~ .; I Film
Cyan 1.42 1.27 -0.15 -0.89
Magenta 0.96 0.94 -0.02 -0.02
15Yellow 0.86 0.80 -0.06 -0.17
Black 1.60 1.50 -0.10 -0.38
Example 2 - Hardened Gelatin and Polymeric ~u ~ A Mordant.
In this example the mordant was the polymeric quaternary - ,..".,.,; ~ ..
compound Celquat H100. The mordant and wicking polymer, namely, ~Jl;,llald~
gelatin, were included in the same layer. The coating rnnnr- cition was prepared as in
Example I from the ~.. l.. ~ as follows:
20.0 grams 10% gelatin
0.37 grams 55% Dantoin hardening agent
6.0 grams 2.5% Celquat H100 mordant
0.06 grams 2% Triton TX-I00 coating aid
0.05 grams Soken MR-13G poly(metbyl ~ ,;ll~ly' ) beads (9-13 ~m)
73.52 grams Water
The solution was coated on a transparent polyester film support at a
~,~.... ,.l".l,"" of 9 ~I~UII:IS~lUa.lC meter and dried. After printing with colored aqueous
inks in an ink jet thermal printer the resulting image was tested and compared with a
CUIIUII~,IC;~ll film for water-immersion stability arld light stability of the dyes as
previously described. After water immersion for two minutes the Exa~nple 2 film of
~VO 95/16561 2 1 7 8 8 4 1 PCT/IJS94/14501
- 25 -
the invention had a nlagenla dye density loss of only -0.03, while the .,~JIIUII.II,;al film
decreased in ma~enta density by 0.77 units. The results of the light exposure test are
listed in Table Ill.
TABLE III
Comparison of Light Exposure Results of Example2
Film of the Invention and C~ .; I Film
Film of Film of Densit~ Difference Density Difference
Dye Example 2 Example 2 Between Unexposed Between Unexposed
Before After and Exposed Film and Exposed
Exposure Exposure of Example 2 Cl .;.. 1 Film
Cyan 1.36 1.08 -0.28 -0.59
Magenta 0.94 0.90 -0.04 -0.06
Yellow 0.53 0.51 -0.02 -0.11
Black 1.59 1.46 -0.13 -0.20
As in the other cwll~al~ivc tests, Table III shows superior dye fastness after
light exposure for the film of the invention containing the polymeric cationic mordant,
especially with regard to cyan dye stability.
20 E~ample 3 - Hardened Gelatin and Barium lon Mordant.
As in Example 1, a heated mixing vessel was charged with 20 g. of a 10%
aqueous suspension of gelatin and the t.l~ la~ul~ was raised to 49C (120F.). To the
gelatin suspension was then added 0.38 g of a 55% aqueous solution of dimethyl
hydantoin (Dantoin hardener). The mixture was stirred for 5 minutes to increase its
25 viscosity; then was added 0.6 g of a 2% aqueous Triton X-100 coating aid, 0.05 g of 9-
13 ~m cross-linked poly(methyl Ill~,~La~,ly;a~.) beads (Soken MR 13G beads) amd 2.0 g
of 10% aqueous solution of barium chloride. The resulting ink-acceptor ~
was coated on pol~(ethylene h~lC~ llUL~'C) film and dried to yield a.dried coating of
2 L~ Udl~; meter. The material was then printed with a magenta ink jet aqueous
30 ink and was subjected to the water imrnersion test as previously described. A control
WO 95/16561 2 l 7 8 8 41 PCT/US9-S/14501 ~
- 26 -
film material containing no barium chloride was printed and tested in the same manner.
The control showed a magenta dye density change of -0.27. The acceptor material of
the invention, containing barium ion as mordant, showed a magenta dye density change
of only -0.06, thus ~ g the superior water resistance of a dye printed on the
5 novel ink acceptor material of the invention.
E~ample 4 - Acceptor Material Containing Poly(4-~ ~lp~ ) Mordant.
A vessel fitted with a mixer and a heater was charged with 48.8 grams of 7.5%
suspension of gelatin in water (available as T7188 from K&K Corp.) and 36.6 grams of
10 distilled water. The mixture was stirred and the ~ laLul~; was raised to 49C(120=F). After 5 minutes of stirring, the viscosity was 23 mPa s. Then 4.88 grams of
a 55% aqueous solution of dimethyl hydantoin (Dantoin hardener, available from Lonza
Co.) was added with continued stirring. After 10 minutes, the viscosity had increased
to 35 mPa-s, and no further increase was seen. 8.0 grams of 10% poly(4-
15 viu,~l,uy,;.li"e) aqueous solution (available from Monomer-Polymer Corp.), pH adjusted
to 4.0 with acetic acid, was added with stirring, followed by 0.122 grams of particulate
Malogel starch (available from National Starch and Chemical Co.) as a lUU~ .lg
agent and 1.7 grams of 2% aqueous soluvion of o.,lyl~ll..lu,~yluol.~.l.v,.y-ethanol (Triton
X-100 available from Union Carbide) as coating aid. The batch was adjusted to pH 8.0
20 by addition of NH40H, the t~lll,U~ UlC was reduced to 38C (100F), and the resulting
thickened solution was ready for coating.
The thickened solution was coated on transparent 3.85-mil poly(ethylene
t~ ' ) film (Melanex 6093, available from ICI Ltd.) at a dry coverage of
3 ~lla~aulu~ meter of support, resulting in a glossy, dried ink accepting layer 3 ~Im
25 thick. When this film was imaged on a Hewlett-Packard 500C DesWet ink jet printer
with a cartridge of Hewlevt-Packard ink containing ionic dyes, the individual ink images
emerged dry from the printer. A large area black image did not transfer ink to a cotton
ball after 45 seconds of drying time. Dot resolution was excellent.
A strip of the imaged film was immersed in water for two minutes, then
30 removed and dried. Reflection dye densities of immersed and non-immersed strips
.
~wo 95116561 2 1 7 8 ~ 4 1 PCTIUSg4/1450
- 27 -
were measured with an X-Rite D~ ...,. , Model 408. The results of these
111~,~1~111~111.~11~ are listed in Table IV and .'- - the water-fastness of the ink
acceptor film of Example 1:
TABLE lV
Water-Fastness Test of Example 4 Film
Density Difference
Between Non-
10 Optical Density Optical Density Immersed and
Dye Before I After T Immersed Films
Cyan 1.50 1.52 +0.02
Magenta 0.87 0.87 0.00
Yellow 0.80 0.91 +0.11
Black 1.70 1.71 +0.01
The results recorded in Table IV show that immersion of the imaged film of the
invention in water caused no density loss, thus indicating that essentially none of the
mordanted dye was washed from the film. The increases in density shown for certain
25 of the dyes are believed to have resulted from swelling and dye .~- ., .~,..,....1 and
packing. In ~ . a C~ ;CII ink jet acceptor film when printed and subjected
to the same water-immersion test showed a magenta dye density loss of -0.77.
Although in Example 4 the pH of the batch was adjusted to 8.0 by adding
NHIOH, this adjustment was not required. The aqueous coating, ,..,l.c.~ , can be at
30 arl alkaline or acidic pH as .11 .,.. ~l-, .~.. 1 heremafter. The adjustment to an alkaline pH
simply .1---- that the poly(4-v;~ ) need not be protonated to its
quaternary ,...", ,......, form in order to function as a mordant for anionic dyestuffs.
wo 951165C1 2 1 7 8 8 4 1 PCT/Us94/l450
- 28 -
I.iQht Exoosure TestinQ of ExamnIe 4 Film of the Invention and a Commercial Film The non-immersed Example 4 film of the invention and a uu~ lly
available ink jet recording film which were identically imaged in an ink jet printer were
exposed to GE F400W fluorescent bulbs at 5,000 lux intensity for 72 hours, at the end
5 of which time they were compared to otherwise identical unexposed strips (ASTMF767-82) of the sarne imaged films. The reflection densities (indicating dye retention)
are shown in Table V for the Example 4 film and in Table VI for the commercial film.
TABLE V
Film of the Invention -- Optical Density Before and After Light Exposure
Density Difference
Film of Example 4 Film of Example 4 Between Unexposed
Dye Before EYposure After Exposure and Exposed Film
Cyan 1.50 1.35 -.15
Magenta 0.87 0.81 -.06
20Yellow 0.80 0.78 -.02
Black 1.70 1.56 -.14
TABLE Vl
C~ .;.. 1 Film -- Optical Density Before and After Light Exposure
30 C~. .;.d C~ .;.. 1 Density Difference
Film Before Filrn After Between Une~posed
DyeEYposure Exposure and Exposed Film
Cyam 1.50 0.91 -0.59
Magenta 0.99 0.93 -0.06
Yellow 0.88 0.77 . -0.11
Black 1.57 1.37 -0.20
~WO 95116S61 2 1 7 8 8 4 1 PCT/US94/14501
- 29 -
~ omr:lriqnn of the density differences in Tables V and VI shows that the light
stability of the imaged film of the invention was substantially improved over that of the
~,VIIIIII~ film, especially with regard to cyan dye stability.
Fig. 5 of the drawings also illustrates the superior light stability of the
S Example 4 film of the invention as compared with the ~UIIIII~ ;GI film. The cyan dye
densities of the two films are plotted in this figure over extended periods of time for
high intensity light exposure and for normal room light exposure. Curve A of Fig. 5
shows that the cyan dye density of the film of the invention remained s~lhrf~nti~ y
constant over a period of 110 hours of normal room light exposure. In contrast,
10 Curve B shows that the cyan dye density of the ~,vl~ l film decreased linearly
from 1.5 to about 1.1 after 110 hours. Curve C plots the cyan density for the film of
the invention after exposure and Curve D plots the cyarl density for the commercial
film after the same exposure. As Curves C and D illustrate, the Cvllllll~ film
decreased much more sharply in cyan density than did the film of the invention.
Example 5 - Acceptor Material Containing Triamine Mordant.
In the same manner as in Example 4, a coating ~ .v~:l;.,., having the
following rnmrnr;~inn was prepared:
20.00 g 10% gelatin
0.30 g 55% Darltoin hardener
2.50 g 10% high molecular weight amine (Jeffamine T-403)
0.05 g 20% Triton X-100 coating aid
0.04 g dimethylsiloxane particles (GE SR 346)
77.11 g water
This aqueous ~.,I.v :ll" was coated at c,l",ll ly 9.8 ~,I.IIII:J~ Ual~ meter
(2.0 Ib/1000 ft2) solids on a poly(ethylene terephthalate) film support and dried; the
dried layer had a thickness of about 9 ,um. The resulting ink acceptor material of the
invention was printed with colored ink in a thermal ink jet printer and produced image
densities as follows: cyan, 1.72; magenta, 1.48; yellow, 1.15; and black, 1.94. A strip
30 of the printed film was subjected to the 2 minute water immersion test. Magenta
density before the water test was 1.48 and after the test was 1.42. The density change
WO 95/16561 2 1 7 8 8 4 1 PCTIUS94/14501
- 30 -
of only - 0.06 indicates excellent water resistance and marked superiority over the
cU~ ,,;al film referred to in Example 4, which suffered a magenta density change of
-0.77 in the water-imme-rsion test.
S Example 6 - Acceptor Material Containing Another Triamine Mordant.
An ink acceptor material of the invention was prepared and tested as in
Example 5. The cnmrocition differed only in that the mordant compound was the high
molecular ~eight triamine, Jeffamine T-S000. Densities of dyes in a printed saml~le of
the film were: cyan, 1.74; magenta, 1.54; yellow, 1.21; and black 2.56. A sample10 subjected to the water dip test hâd a magenta density of 1.59 before immersion and
1.65 after immersion; The density difference of +0.06 shows that essentially no dye
was lost during water immersion.
Example 7 - Acceptor Material t~ O Poly(4-~ ' -) Mordant and
15 Polymer Beads.
Using the procedure of Example 4, a coating ~ of the following
"",l,.",. .,l~ was prepared:
20.0 g 10% gelatin
0.37 g 55% Dantoin hardening agent
200~ g 10% poly(4-vinyl pyridine) mordant
0.60 g 2~o Triton TX-I00 coating aid
0.05 g Soken MR-13G poly(lll~,Lll~yll-l~lll~,~,ly' ) beads, 9-13 ~m
diameter
78.73g Water
25 This cnmro~iti--n of the invention was coated on polyester film support and subjected to
high intensity fluorescent light exposure as in Example 4. Table VII provides a
of the dye densities of the film of the invention and of a ~,ullllll~.~;.d ink jet
acceptor film after ~"",p .~I,i,~ exposure.
~vo 95/16561 2 1 7 8 8 4 1 PCT/IJSg4/14501
- 31 -
TABLE VII
Light Fade C~ of Example 7 Film and 1'~ .;.. 1 Film
- 5 Film of Film of Density Difference Density Difference
Dye Example 7 Example 7 Between Unexposed Between Unexposed
Before After and Exposed Film and Exposed
E~posure Exposure of Example 7 C~ .;,.1 Film
Cyan 1.46 1.31 -0.15 -0.59
Magenta 0.92 0.86 -0.06 -0.06
Yellow 0.83 0.75 -0.08 -0.11
Black 131 1.22 -0.09 -0.20
The results recorded in Table Vll show markedly less density loss for cyan and
~,~"~ ly less density loss for yellow and black in the film of the invention than for
15 the ~,UI~IIII.,.I~;~I film after high intensity light exposure.
The Example 7 film of the invention and the commercial film were also
subjected to the 2-minute water immersion test as previously described. The magenta
density loss for the commercial film was 0.77, but only 0.02 for the film of theinvention. Thus, even with the lower mordant content, the film of the invention
20 provided superior light stability and water resistance.
Example 8 - Acceptor Material Containing Mordant and Water-Absorbing
Polymer in Separate Layers
In this example the mordant was poly(~vi~ ,yl;dillG) and the water absorbing
25 material was hardened gelatin. To prepare the ink acceptor material of the invention
the following solutions were formed in the manner described in Example 4:
WO 95/16561 2 1 7 8 ~ 4 1 PCTIUS9~14501
- 32 -
Solution A
40.0 grams 10% gelatin
40.0 grams 10% pOIy(4-Vill,~ l;d;.lc) solution
0.4 gram 55% Dantoin hardening agent
0.1 gram 2% Triton TX-I00 coating aid
19.5 grams Water
Solution B
98.77 grams 10% gelatin
0.99 grams 55% Dantoin hardening agent
0.15 grams poly(dimethyl siloxame) particles, 7-12 ~Lm diameter
(GE SR346 from General Electric)
Solution A was coated as a base coat at a solids nnnrl~ntr~tinn of 2.4 ~,IUII15/S~IU~C
15 meter (0.5 lb/1000 f2) on a polyester film support. After drying the base coat, solution
B was coated over it at a solids ~...,...,1.,.1;..,. of 4.9 L~ /a~ alc meter (1.0 Ib/1000
ft2) to form the top coat.
Tbe resulting two-layer film was imaged with ink jet colored ink in a thermal
ink jet printer and the resulting image was compared v~ith the c~ ,;l film for light
20 stability and water-immersion stability as previously described. For the film of tbe
invention, water stability was superior to that of the Cvlllll~ film as in the other
examples. Results of the light stability tests, in terms of reflection densities of the
mdividual dyes, are listed in Table VIII below.
~Wo 95/16561 2 1 7 8 8 4 1 PCr/US94rl4501
TABLE~
Light Stabilit~ of the Two-Layer Film
in Ct . ;~Uli ~ ith Commercial Film
Film ûf Film of Densit~ Difference Density Difference
Dye Example 8 Example 8 Bet~een Unexposed Betwe n Unexpûsed
Before After and Exposed Film and Expûsed
Expûsure Exposure of Example 8 (~ h~l Film
Cyan 1.87 1.67 -0.20 -0.59
Magenta 1.15 1.15 0 -0.06
10Yellow 1.08 0.98 -0.10 -0.11
Black 1.48 1.33 -0.15 -0.20
Example 9 - Acceptor Material Containing Pt . '-~ ' Mordant and
Pob(methyl '' .~lali) Beads.
A solution was prepared for coating in accordance with the invention A vessel
fitted with a mixer and a heater was charged with 93 grams of 10% suspension of
gelatin T7188 from (K&K Corp.), in water and 40 grams of distilled water. The
mixture was stirred and the t~ UIc was raised to 49C (120F). After S minutes
of stirring, the viscosity was 23 mPa s. Then 1.72 grams of a 55% aqueous solution of
dimethyl hydantoin (Dantoin hardener, available from Lonza Co.) was added with
continued stirring. After 10 minutes, t~le viscosity had increased to 35 mPas, and no
further increase was seen. Then waS added 3.0 grams of 30% aqueous solution of
rh~Crh~.liri-l EFA (Mona Industries, Inc.) with stirring, followed by 0.23 gram of
cross-linked poly(methyl lllcLila~,l.ylaLc) beads (Soken MR-13G, 9-13 ~m diameter,
available from Esprit Chemical Co.) and 2.79 grams of aqueous solution of
o~,~yl,ul.~ y~!olyethoxy-ethanol (Triton X-100 available from Union Carbide) as
coating aid. The ~ u~laL~ was reduced to 38C (100F), and the resulting thickened
solution was ready for coating.
The thickened solution was coated on transparent 3.85-mil poly(ethylene
~clc~ L'~ ) film (ICI 6138) at a dry coverage of 9 ~ /a~ meter of support,
WO 95/16561 2 1 7 8 ~ 4 1 PCT/US94114501
- 34 -
resulting in a glossy, dried ink-accepting layer 9 ILm thick. When this film was imaged
on a Hewlett-Packard 500C DeskJet ink jet printer using a cartridge of Hewlett-Packard
ink containing ionic dyes, the individual ink images emerged dry from the printer. Dot
resolution was excellent.
A strip of the imaged film was immersed in water for two minutes, then
removed and dried. Reflection magenta dye densities of imrnersed and non-immersed
strips were measured with an X-Rite D~ il.. , Model 408 and compared with those
of a similarly printed and water-immersed l,Ullllll~,lV;al ink jet acceptor film. The
magenta density change after water immersion for the film of the invention which10 contained the ~ i mordant was only -0.03 but was -0.77 for the ~vllll~ ;
film. This shows that essentially none of the dye was washed from the acceptor
material of the invention and ~l..,..."~ its superior water resistance in CUIIIIUCUi:~VII
with the uvlillll.,l.;dl film.
15 Lioht ExPosure Testin of Example 9 Film of the Invention and a Commercial Film
The non-immersed Example 9 film of the invention and a vulllll~ ,;dlly
available ink jet recording film which were identically printed in an ink jet printer were
exposed to GE F400W fluorescent bulbs at 5,00û lux intensity for 72 hours, at the end
of which time they were compared to otherwise identical umexposed strips (AST~I
20 F767-82) of the same imaged films. The reflection density differences (indicating dye
retention) are shown in Table IX for the Example 9 film and for the Cul~ ,;dl film.
~WO 95/16561 2 1 7 8 8 4 1 PCT/US94/14501
_
TABLE IX
C~ . of Light Exposure Results of Example 9
Film of the Invention and Commercial Film
S ._
Density of Density of Density Difference Density Difference
Dye Non- Exposed Betveen Non- Betwe~n Non-
Exposed Film of Exposed and Exposed and
Film of Example 9 Exposed Film of Exposed
Example 9 Example 9 C~ .;.. 1 Film
Cyan 1.42 1.30 -0.12 -0.59
Magenta 0.82 0.80 -0.02 -0.06
Yellow 0.76 0.73 -0.03 -0.11
Black 1.28 1.20 -0.08 -0.20
The optical density data in Table IX show al~;lfirl~ lly better dye light stability
15 for the film of the invention, especially for the cyan dye.
Example 10 - Acceptor Material 1~ J Mordant and
Poly(~ ) Beads
In this example the ink acceptor material was prepared c--hct ~l~t~ ly as in
Example 9, except that a different water-soluble ~ .l;l,;fi was used ac the mordant
compound and the ~ of the coating f...... llf~ ;.. were as followc
20.00 g 10% gelatin
0.37 g 55% Dantoin hardener
25 1.00 g 15.67% pl.~.~l,l.. i;l.. i PTC
0.60 g 2% Triton X-100 coating aid
0.05 g GE SR 346 poly(dimethyl siloxane) beads, 7 to 12 ~Lm diameter
(available from General Electric Company)
77.98 g Water
30 After coating on polyester f~lm and drying, the coated film was printed with colored ink
jet aqueous ink in a thermal ink jet printer. Dye densities measured for a sample of the
WO 95/16561 2 1 7 8 ~ 4 1 PCTIUS94114501
- 36 -
film were: cyan, 1.44; yellow, 0.85; magenta, 0.97; and black, 1.88. A sample of the
printed film had a magenta dye density before water immersion of 0.94. After the 2-
minute water dip test, its magenta density measured 1.04. The density change of +0.07
indicates essentially no dye loss and excellent water resistance.
S The invention has been described in detail with particular reference to preferred
)O.l~ thereof, but it will be understood tnat variations and m~rlifir~inn~ can be
effected within the spirit and scope of the invention.
