Field of the Invention
[0001] This invention relates to a photographic imbibition dye transfer process and imbibition
printing materials. It relates particularly to improved dye imbibition printing blanks
with improved antistatic properties and reduced haze, improved imbibition printing
matrix films, and use of such materials in forming an imbibition print.
Background of the Invention
[0002] The imbibition printing dye transfer process is well known. According to common procedures,
a tanned colloid relief image is formed by imagewise exposure of a suitable light
sensitive layer on a support, differentially hardening the colloid layer in accordance
with the imagewise exposure, and removing the colloid from the support in inverse
proportion to the amount of imagewise light exposure. The differential colloid hardening
and removal is conventionally performed with a pyrogallol hardening developer as described,
e.g., in U.S. Patent 2,837,430. For full color prints, three separate relief images
corresponding to the blue, green, and red color records of the image being reproduced
may be formed in separate blue, green, and red light sensitive matrix films by three
separate exposures though a color negative film. The resultant colloid relief images
are then dyed with yellow, magenta and cyan dyes, and the dye images transferred to
an imbibition printing blank receiver film. In this manner imbibition printed colored
dye images may be obtained which faithfully reproduce a colored subject. Imbibition
printing blanks typically comprise a dye receiving layer on a support. Where the resulting
image is intended to be viewed by light projection, such as in a motion picture film,
a transparent film support is generally used.
[0003] The photographic industry has long recognized the need to provide photographic film
and paper with antistatic protection to prevent the accumulation of static charges
during manufacture and use. Such protection is advantageous in photographic elements
as static charges can cause irregular fog patterns in photographic silver halide imaging
emulsions. To prevent the problems arising from an accumulation of static charges,
it is conventional practice to provide an antistatic layer (i.e., a conductive layer)
in a photographic element.
[0004] A wide variety of antistatic layers are known for use in photographic elements. Such
layers, however, have not previously been used with dye imbibibition printing blanks.
As the visual dye image is transfered to an imbibition printing element blank rather
than being formed directly in a silver halide emulsion imaging layer of the element,
and as the back side of an imbibition printing element support bearing a dye receiving
layer will be in contact with such dye receiving layer when the element is rolled
up, such printing elements have different requirements as to antistatic protection
needs. While image fog problems due to static charge buildup are generally not a problem
with imbibition printing elements, such charges may attract dirt and dust to the printing
element surface under high manufacturing and processing speeds which may result in
the formation of "pinholes" in the processed imbibition printing blanks as well as
a variety of handling and conveyance problems.
[0005] U.S. Patents 3,625,694; 3,958,995; and 3,898,088 disclose cationic (basic) mordants
which may be used in dye imbibition printing blanks. Such mordants are suitable for
use with anionic (acid) printing dyes. When using blanks containing a dye receiving
layer comprising a cationic mordant and a hydrophilic colloid such as gelatin as a
binder, there is a tendency for the blank to be brittle resulting in cracking and
degradation of the transferred dye image.
[0006] The necessity for maintaining flexibility in film is obvious in view of the handling
to which it is subjected in manufacturing and use. For example, films are flexed and
bent during use in cameras, printers, projectors, and processing equipment. The brittleness
of film is affected by both temperature and relative humidity, the latter being generally
of greater practical importance. Below approximately 25 percent relative humidity,
a significant change in film brittleness may occur with only a small change in relative
humidity. The failures in film as a result of lack of flexibility may be of different
types, depending upon the nature of the stress.
[0007] It has been suggested to include plasticizers in imbibition printing blanks and photographic
elements to reduce brittleness. U.S. Patents 2,882,156 and 3,709,690 disclose blanks
containing mordants and polymer latices as plasticizers. U.S. Patent 5,135,835 relates
to heat developable photographic elements which contain a mordant, oil droplets and
a polymer latex having a glass transition temperature (Tg) of 40°C or less for improving
brittleness.
[0008] The imbibition process normally results in a sensitometric Density vs. Log-Exposure
curve shape with a relatively sharp (high contrast) "toe", or lower scale, region
for the developed matrix films and resulting imbibition prints. The toe region is
generally regarded as the curved region below the straight, or mid-scale, region of
a D-LogE sensitometric curve. Reducing the toe area contrast, or "softening" the toe,
is often desirable to extend the latitude of the matrix film. One process which has
been used to control the toe contrast is "flashing". Flashing is the non-selective
low level exposure of a photographic material with the intent of softening the toe
region of the sensitometric curve. While flashing of photographic materials to control
contrast is a well known procedure, imbibition printing matrix films are unique in
that the light sensitive layer of the matrix film generally has a large portion of
a visible light absorbing non-photosensitive material, such as carbon particles, coated
along with silver halide and colloid materials. The carbon absorbs light as it passes
through the matrix film, thus concentrating the exposure towards the base (the exposure
in this process is conventionally made through the base). A normal flash exposure
with this type of material accordingly will not control the curve shape in the desired
manner to the desired extent.
[0009] In years past, green and red matrix films having sufficient native blue sensitivity
have been flashed with blue light in order to control the lower-scale sensitometry.
A yellow dye was added to the matrix film which had the effect of lowering the contrast
of the flash exposure. This allowed good control of the curve shape for the green
and red matrix films. The blue matrix film, however, could not use the yellow dye
for the flash exposure control since the main image exposure is also made with blue
light which would be absorbed by the yellow dye. In years past, however, relatively
coarse (larger grain size) emulsions were used which had inherently relatively low
toe contrasts. The blue matrix film (very coarse grain emulsion) was low enough in
contrast that a minimal blue flash was required to control toe contrast. Thus, the
blue matrix film was flashed with blue light without the presence of a yellow dye.
[0010] For blue matrix films made with modern fine grained emulsions, however, which are
inherently relatively higher in contrast, blue flash toe contrast control is not effective.
Additionally, when using green and red matrix films containing excess yellow absorber
dye, there is a tendency for the film to become very brittle resulting in cracking
and degradation of the dye image, as well as dirt generation in manufacture and use
of the film. While the lower inherent contrast of previously used coarser emulsions
required only relatively low levels of yellow absorber dye in the green and red matrix
films for sufficient toe contrast control, modern fine grain emulsions used in green
and red matrix films are also inherently relatively higher in contrast and much larger
quantities of the yellow absorber dye is needed to control the toe contrast. This
can lead to physical problems such as tackiness, brittleness and film fracturing in
manufacture of the film.
Problems to be Solved
[0011] It would be desirable to improve the manufacturability of dye imbibition printing
material and the image quality of imbibition prints.
[0012] Accordingly, it would be desireable to provide cationic mordanted imbibition printing
element blanks with sufficient antistatic properties which enable high manufacturing
and processing speeds without adversely affecting printed image qualities.
[0013] Additionally, often when polymer latices are added to a mordant layer containing
a cationic mordant the layer becomes hazy due to incompatibility between the latex
and the mordant. It would accordingly be further desirable to provide a polymeric
plasticizer for use with cationic mordants which would not result in increased haze.
[0014] It would also be desirable to provide effective toe contrast control for each of
the blue, green and red imbibition printing matrix films without physical problems
such as tackiness, brittleness and film fracturing in manufacture of the film, and
especially to provide such control in a consistent manner.
Summary of the Invention
[0015] In one embodiment, this invention provides an improved dye imbibition printing blank
comprising a support bearing on one side thereof a dye-receiving layer comprising
a cationic mordant, and further comprising an antistatic layer substantially free
of cationic polymers. In a preferred embodiment of the invention, the antistatic layer
is provided on the opposite side of the support relative to the dye-receiving layer.
Such antistatic layer provides improved antistatic properties which enable high manufacturing
and processing speeds without adversely affecting printed image qualities.
[0016] In a further embodiment of the invention, printing blanks are provided wherein the
dye-receiving layer comprises a cationic mordant, a hydrophilic colloid and a plasticizer
polymer, wherein the plasticizer polymer is a latex polymer having a glass transition
temperature below about 30°C comprising from about 2 to 20 wt% of units having a quaternary
ammonium group. In a preferred embodiment, the latex polymer comprises a vinyl co-polymer
addition product of from about 50 to 98 weight percent of acrylic or methacrylic ester
units, 0 to 48 weight percent of vinyl benzene units and 2 to 20 weight percent of
the quaternary ammonium group containing unit. Use of such latex provides a dye imbibition
printing blank substantially free of haze and brittleness.
[0017] In another embodiment of the invention, a UV (Ultra Violet) absorber dye is incorporated
in a dye imbibition printing matrix film, and preferably in each of the blue, green
and red matrix films, to attenuate light in the UV region, which for the purposes
of this invention is defined as less than 400 nm. Preferably, the spectral characteristics
of the UV absorber do not interfere with the main imagewise exposure of the matrix
films. In accordance with such embodiment of the invention, a process for exposing
dye imbibition printing matrix films is disclosed comprising imagewise exposing a
matrix film comprising a visible light sensitive silver halide emulsion containing
colloid layer on a support to blue, green or red light, wherein the visible light
sensitive emulsion is also sensitive to UV light and the toe contrast of the imaged
matrix film is controlled by (i) incorporating a UV absorber in the colloid layer
of the matrix film, and (ii) flash exposing the matrix film with UV light in the substantial
absence of light having a wavelength above 410 nm, wherein the UV absorber provides
sufficiently low absorption above 410 nm such that it does not substantially alter
the effective photographic speed of the matrix film during the imagewise exposure
or the mid scale contrast of the imaged matrix film, and sufficiently high absorption
to the UV light to decrease the resulting toe contrast of the imaged matrix film.
In accordance with preferred embodiments of the invention, the above contrast control
process is performed for each of the blue, green and red matrix films to be used in
an imbibition printing process, wherein each matrix comprises a blue, green or red
light sensitive silver halide emulsion which is additionally sensitive to UV light.
[0018] In accordance with another embodiment of the invention, a matrix film for use in
imbibition printing is disclosed comprising a support bearing a colloid layer comprising
(i) a visible light sensitive silver halide emulsion which is also sensitive to UV
light, (ii) visible light absorbing non-photosensitive particles, (iii) a hydrophilic
colloid, and (iv) a UV absorber having a peak absorbance between 360 and 410 nm. Use
of matrix films in accordance with the invention achieves desired toe contrast control
of all three matrix films in the same manner. The blue matrix film no longer requires
to be treated differently. This allows use of identical matrix films having blue,
green and red sensitivity (e.g., a panchromatic sensitive film) in forming the separate
blue, green and red exposed relief images if desired. The invention also allows greater
control over matching the sensitometric contrast curves of the three matrix films.
Additionally, preferred UV absorber dyes absorb UV light more efficiently than the
yellow dye previously used in green and red matrix films absorbed blue light such
that much less dye is needed to attain a specific density, which results in good physical
characteristics of the matrix films.
[0019] In further embodiments of the invention, imbibition prints are formed by registration
printing yellow, magenta and cyan dye images formed in matrix films exposed as described
above onto printing blanks as described above.
Brief Description of the Drawings
[0020] Figure 1 depicts the absorption spectrum of a preferred UV absorbing dye.
[0021] Figure 2 depicts the spectral characteristics of a HOYA U-340 filter.
[0022] Figure 3 is a graph depicting the Matrix Exposure Profile for matrix films having
various UV dye optical densities.
[0023] Figure 4 depicts the sensitometric curves for matrix films having varying levels
of UV absorber dye exposed to UV light resulting from Example 4.
[0024] Figure 5 is a graph depicting the Best Fit Contrasts of the curves of Figure 4 vs.
UV dye concentration.
[0025] Figure 6 depicts the absorption spectra of the UV absorbing dyes used in Example
5.
[0026] Figure 7 depicts the sensitometric curves for the matrix films exposed to UV light
resulting from Example 5.
Detailed Description of the Invention
[0027] Dye imbibition printing blanks within the scope of one embodiment of this invention
comprise a support bearing on one side thereof a dye receiving layer containing a
cationic mordant, and further comprise an antistatic layer. In a preferred embodiment,
in addition to the cationic mordant, the dye image receiving layer also comprises
a hydrophilic colloid, and a plasticizer polymer.
[0028] Any antistatic conductive materials, excluding cationic polymers, such as those previously
suggested for use with photographic elements may be used in the printing element antistatic
layer in accordance with the invention. Such materials include, e.g., anionic polymers,
electronic conducting non-ionic polymers, and electrically-conductive metal-containing
particles such as metal halides or metal oxides in polymer binders. While antistatic
compositions comprising a cationic polymer are also applicable for use with conventional
photographic elements, such as the highly crosslinked vinylbenzyl quaternary ammonium
polymer disclosed in U.S. Patent 4,070,189, such antistatic materials are excluded
from the scope of the instant invention. Dyes intended for printing on the cationic
mordant containing printing blanks of the invention are anionic and will transfer
from the front dye-receiving side of the film to the antistat backing when such sides
come into contact (such as in a rolled film) if the backing contains a catonic polymeric
material such as quaternary ammonium polymer, resulting in dye stain. For the purposes
of this invention, "substantially free of cationic polymers" is intended to apply
to the absence of cationic polymers above trace or impurity levels.
[0029] Examples of suitable antistatic materials and layers include the following. U.S.
Patent 3,033,679 discloses an antistatic layer comprised of an alkali metal salt of
a copolymer of styrene and styrylundecanoic acid. Films having a metal halide, such
a sodium chloride or potassium chloride, as the conducting material in a hardened
polyvinyl alcohol binder are described in U.S. Patent 3,437,484. In U.S. Patent 3,525,621,
the antistatic layer is comprised of colloidal silica and an organic antistatic agent
such as an alkali metal salt of an alkylaryl polyether sulfonate, an alkali metal
salt of an arylsulfonic acid, or an alkali metal salt of a polymeric carboxylic acid.
An antistatic layer comprised of an anionic film forming polyelectrolyte, colloidal
silica, and a polyalkylene oxide is disclosed in U.S. Patent 3,630,740 while U.S.
Patent 3,681,070 describes a copolymer of styrene and styrene sulfonic acid as an
antistatic agent. U.S. Patent 4,542,095 describes antistatic compositions comprising
a binder, a nonionic surface-active polymer having polymerized alkylene oxide monomers,
and an alkali metal salt. In U.S. Patent 4,916,011, an antistatic layer comprising
a styrene sulfonate-maleic acid copolymer, a latex binder, and an alkyl-substituted
trifunctional aziridine crosslinking agent are disclosed. Antistat layers comprising
a polythiophene with conjugated polymer backbone in the presence of a polymeric polyanion
compound are described in EP 554,588; EP 553,502; EP 564,911; DE 4,138,628.
[0030] Any of the wide diversity of electrically-conductive metal-containing particles proposed
for use heretofore in imaging elements can be used in the electrically-conductive
antistatic layer of this invention. Examples of useful electrically-conductive metal-containing
particles include donor-doped metal oxides, metal oxides containing oxygen deficiencies,
and conductive nitrates, carbides or borides. Specific examples of particularly useful
particles include conductive TiO
2, SnO
2, Al
2O
3, ZrO
2, In
2O
3, ZnO, TiB
2, ZrB
2, NbB
3, CrB
2, MoB, Wb, LaB
6, ZrN, TiN, TiC, WC, HfN, and ZrC.
[0031] Metal oxides, and particularly vanadium pentoxide as described, for example, in Guestaux,
U.S. Patent 4,203,769, are preferred for use in the dye imbibition printing elements
of the invention. Antistatic layers containing vanadium pentoxide provide excellent
protection against static and are highly advantageous in that they have excellent
transparency and their performance is not significantly affected by changes in humidity.
The use of metal oxide materials is further advantageous, as their antistatic properties
allow the use of a protective overcoat layer such as a layer of cellulosic material
to provide abrasion protection and/or enhance frictional characteristics while still
providing acceptable antistatic performance.
[0032] Conductive fine particles of crystalline metal oxides dispersed with a polymeric
binder have been used to prepare optically transparent, humidity insensitive, antistatic
layers for various imaging applications. Many different metal oxides, such as AnO,
TiO
2, ZrO
2, Al
2O
3, SiO
2, MgO, BaO, MoO
3, and V
2O
5, are disclosed as useful as antistatic agents in photographic elements or as conductive
agents in electrostatographic elements in such patents as U.S. Patents 4,275,103;
4,394,441; 4,416,963; 4,418,141; 4,431,764; 4,495,276; 4,571,361; 4,999,276; and 5,122,445,
the disclosures of which are hereby incorporated by reference. Preferred metal oxides
are antimony doped tin oxide, aluminum doped zinc oxide, and niobium doped titanium
oxide, as these oxides have been found to provide acceptable performance characteristics
in demanding environments.
[0033] Particular preferred metal oxides are antimony-doped tin oxide and vanadium pentoxide
having good resistance to static discharge and no dye stain resulting from transfer
of dye from front side to the back of the film. For high dye imbibition printing blank
manufacturing and processing speeds (e.g., transport speeds above about 60 m/s), a
surface resistivity of less than 10
9 ohms per square is desired for the printing blanks to prevent static discharges during
unwinding of the film and the buildup of static dirt during handling of the film.
[0034] Preferred binders which may be included in the antistatic layer of the printing blanks
of the invention include vinylidene chloride-containing latexes and polyesterionomer
dispersions, which can improve the integrety of the layer and the adhesion of the
layer to the support. Polyesterionomer refers to polyesters that contain at least
one ionic moiety. Such ionic moieties function to make the polymer water dispersable.
These polymers are prepared by reacting one or more dicarboxylic acids or their functional
equivalents such as anhydrides, diesters, or diacid halides with one or more diols
in melt-phase polycondensation reactions well known in the art as shown in U.S. Patents
3,018,272, 3,929,489, 4,307,174 and 4,419,437. Examples of this class of polymers
include, for example, Eastman AQ polyesterionomers manufactured by Eastman Chemical
Company.
[0035] To provide protection of the antistatic layer, a protective overcoat may be applied
thereon. The protective layer can chemically isolate the antistatic layer and also
serve to provide scratch and abrasion resistance. The protective overcoat layers may
be, e.g., cellulose esters, cellulose nitrate, polyesters, acrylic and methacrylic
copolymers and homopolymers, polycarbonates, polyvinyl formal polymethyl methacrylate,
polysilicic acid, polyvinyl alcohol, and polyurethanes. Such layers may be aqueous
coated or organic solvent coated as appropriate.
[0036] The chemical resistance of the antistatic layer or an overcoat can be improved by
incorporating a polymer cross-linking agent into the antistatic layer or those overcoats
that have functionally crosslinkable groups. Cross-linking agents such as aziridines,
carbodiimide, epoxys, and the like are suitable for this purpose.
[0037] A suitable lubricant may also be included in the antistatic layer or protective overcoat
in order to provide desired friction performance to assure good transport characteristics
during manufacturing and handling of the elements of the invention. Many lubricating
agents can be used including higher alcohol esters of fatty acids, higher fatty acid
calcium salts, metal stearates, silicone compounds, paraffins and the like. Aqueous
dispersed lubricants are preferred as they may be directly incorporated into an aqueous
antistatis or overcoat layer, thus avoiding the need for a separately applied lubricant
layer. The aqueous dispersed lubricants of carnauba wax and stearates are preferred
for their effectiveness in controlling friction at low lubricant levels and their
excellent compatibility with aqueous overcoat polymer solutions.
[0038] Matting agents may also be included in the antistatic layer or overcoat thereon in
order to improve transport properties of the elements of the invention on manufacturing,
printing, processing, and projecting equipment. Such matting agents can also help
prevent sticking between the front and back sides of the elements in a tightly wound
roll. Matting agents may be silica, calcium carbonate, other mineral oxides, glass
speres, ground polymers and high melting point waxes, and polymeric matte beads.
[0039] The antistatic layer may also contain a coating aid to improve coatability, including
anionic or nonionic coating aids such as para-isononylphenoxyglycidol ethers, octylphenoxy
polyethoxy ethanol, sodium salt of alkylaryl polyether sulfonate, and dioctyl esters
of sodium sulfossuccinic acid, which coating aids are typically used at from 0.01
to 0.30 weight percent based on the total coating solution weight.
[0040] Cationic mordants for use in the dye receiving layer of the printing blanks in accordance
with the invention are preferably quaternary ammonium and phosphonium mordants of
the type described in U.S. Pats. 3,898,088 and 3,958,995. The cross-linked mordants
of U.S. Pat. 3,958,995 are particularly preferred. Such mordants are generally of
the formula:

wherein A' represents units of an addition polymerizable monomer containing at least
two ethylenically unsaturated groups; B' represents units of a copolymerizable α,β-ethylenically
unsaturated monomer; Q is N or P; R', R", and R"' are independently carbocyclic or
alkyl groups; M
- is an anion; a is from about 0.25 to 5 mole percent, preferably from about 1 to 10
mole percent; b is from about 0 to 90 mole percent, preferably from about 0 to 60
mole percent; and c is from about 10 to 99 mole percent, preferably from about 40
to 99 mole percent, for effective dye mordanting.
[0041] It is understood throughout this specification that any reference to a substituent
by the identification of a group containing a substitutable hydrogen (e.g. alkyl,
amine, aryl, alkoxy, heterocyclic, etc.), unless otherwise specifically stated, shall
encompass not only the substituent's unsubstituted form, but also its form substituted
with any other photographically useful substituents. Typical examples of photographic
substituents include alkyl, aryl, anilino, carbonamido, sulfonamido, alkylthio, arylthio,
alkenyl, cycloalkyl, and further to these exemplified are halogen, cycloalkenyl, alkinyl,
heterocyclyl, sulfonyl, sulfinyl, phosphonyl, acyl, carbamoyl, sulfamoyl, cyano, alkoxy,
aryloxy, heterocyclyloxy, siloxy, acyloxy, carbamoyloxy, amino, alkylamino, imido,
ureido, sulfamoylamino, alkoxycarbonylamino, aryloxycarbonylamino, alkoxycarbonyl,
aryloxycarbonyl, heterocyclylthio, spiro compound residues and bridged hydrocarbon
compound residues. Usually the substituent will have less than 30 carbon atoms and
typically less than 20 carbon atoms.
[0042] The hydrophilic colloid may be any of those generally employed in the photographic
field, including, for example, gelatin, colloidal albumin, polysaccharides, cellulose
derivatives, water-soluble polymer or copolymer including, but not limited to polyvinyl
compounds, including polyvinyl alcohol and derivatives thereof, partially hydrolyzed
poly(vinylacetate-co-vinylalcohol), hydroxyethyl cellulose, poly(acrylic acid), poly(1-vinylpyrrolidone),
poly(sodium styrene sulfonate), poly(2-acrylamido-2-methane sulfonic acid), polyacrylamides.
Copolymers of these polymers with hydrophobic monomers may also be used. Gelatin is
a preferred hydrophilic colloid. This may be gelatin per se or a modified gelatin
such as acetylated gelatin, phthalated gelatin, oxidized gelatin, etc. Gelatin may
be base-processed, such as lime-processed gelatin, or may be acid-processed, such
as acid processed ossein gelatin.
[0043] In a preferred embodiment of the invention, the dye-receiving layer of the printing
blanks are hardened with a cross-linking agent. Various types of hardeners are useful
in conjunction with elements of the invention. In particular, bis(vinylsulfonyl) methane,
bis(vinylsulfonyl) methyl ether, 1,2-bis(vinylsulfonylacetamido) ethane, 2,4-dichloro-6-hydroxy-s-triazine,
triacryloyltriazine, and pyridinium, 1-(4-morpholinylcarbonyl)-4-(2-sulfoethyl)-,
inner salt are particularly useful. Also useful are so-called fast acting hardeners
as disclosed in U.S. Patents 4,418,142; 4,618,573; 4,673,632; 4,863,841; 4,877,724;
5,009,990; 5,236,822.
[0044] In a preferred embodiment, the dye receiving layer of the imbibition printing blanks
of the invention include a plasticizer polymer latex. Such latex polymer are preferably
water insoluble vinyl copolymers derived from any copolymerizable monomers, such as
α,β-ethylenically unsaturated monomer (including two, three, or more repeating units)
such as ethylene, propylene, 1-butene, isobutene, 2-methylpentene, 2-methylbutene,
1,1,4,4-tetramethylbutadiene, styrene, α-methylstyrene; monoethylenically unsaturated
esters of aliphatic acids such as vinyl acetate, isopropenyl acetate, allyl acetate,
etc.; esters of ethyleneically unsaturated mono- or dicarboxylic acids such as methyl
methacrylate, ethyl acrylate, diethyl methylenemalonate, etc.; monoethylenically unsaturated
compounds such as acrylonitrile, allyl cyanide, and dienes such as butadiene and isoprene.
The particular monomer units and their proportions may be selected to achieve a desired
glass transition temperature for the resulting polymer as is well known in the art.
[0045] For effective plasticizing, and as a distinguishing factor from cationic dye mordants,
the plasticizer polymers of the invention have a glass transition temperature of about
30°C or lower, more preferably about 20°C or lower. The latex polymers comprise from
about 2 to 20 wt%, more preferably 2 to 10 wt%, of units having a quaternary ammonium
group. Such units are preferably acrylic or methacrylic esters or amides to which
the quaternary ammonium group is appended. A preferred class of ethylenically unsaturated
monomers which may be used to form the remaining 80 to 98 wt% portion of the preferred
vinyl polymers of this invention includes acrylic or methacrylic esters and vinyl
benzenes.
[0046] In preferred embodiments of the invention, the units of the plasticizer latex polymer
having a quaternary ammonium group are as defined in Formula I below, and in particularly
preferred embodiments of the invention the plasticizer latex is of the Formula I.

wherein A represents units derived from an acrylic or methacrylic ester monomer;
B represents units derived from a vinyl benzene monomer; R
1 is H or methyl; L is -C(O)O-, -C(O)NH-, or an aromatic linking group such as phenyl;
M is a C
1 to C
12 alkenyl linking group, which may be straight, branched, or cyclic; R
2, R
3, and R
4 are C
1 to C
6 alkyl groups; X
- is an anionic counterion such as CH
3SO
4-, Cl
-, Br
-, or I
-; w is 50 to 98 weight percent; y is 0 to 48 weight percent; and z is 2 to 20 weight
percent.
[0047] Representative plasticizer polymers in accordance with one embodiment of the invention
include the following:
- PP-1
- poly(ethylacrylate-co-styrene-co-2-(N,N,N-trimethylammonium)ethyl methacrylate methosulfate)
71/19/10 wt
- PP-2
- poly(ethylacrylate-co-2-(N,N,N-trimethylammonium)ethyl methacrylate methosulfate)
90/10
- PP-3
- poly(butyl acrylate-co-styrene-co-2-(N,N,N-trimethylammonium)ethyl methacrylate methosulfate)
71/19/10 wt
- PP-4
- poly(methyl acrylate-co-2-(N,N,N-trimethylammonium)ethyl methacrylate methosulfate)
95/5 wt
- PP-5
- poly(ethyl acrylate-co-styrene-co-2-(N,N,N-trimethylammonium)ethyl methacrylate methosulfate)
75/20/5 wt
- PP-6
- poly(butyl acrylate-co-3-(N,N,N-trimethylammonium)propyl methacrylamide methosulfate)
90/10 wt
- PP-7
- poly(butyl acrylate-co-4-vinyl-N-methylpyridinium methylsulfate) 90/10 wt
- PP-8
- poly(butyl acrylate-co-p-N-(vinylbenzyl)-N,N,N-trimethylammonium chloride) 90/10 wt
[0048] The plasticizer polymers may be synthesized as set forth in the representative synthesis
example described below or by using other well known vinyl polymer synthesis procedures.
[0049] The plasticizer polymer in accordance with the preferred embodiment of the invention
must contain a quaternary ammonium group to give acceptable haze and coating solution
stability. Plasticizer latices which contain anionic groups cannot be coated because
the mordant layer coating composition coagulates upon the addition of latices containing
an anionic group.
[0050] Matrix films for use with printing blanks in imbibition printing dye transfer processes
of the invention typically comprise a support bearing a light sensitive layer containing
a hydrophilic colloid (typically gelatin), visible light absorbing particles (typically
carbon), a silver halide light sensitive emulsion, plus various photographic addenda
to provide satisfactory stability, as well as coating aids necessary for suitable
manufacture. Sensitizing dyes may be used in the matrix films to provide blue, green,
and red light sensitivity for recording the blue, green, and red color record imagewise
exposures. Separate matrix films designed to optimize sensitivity for particular color
record exposures may be used, or alternatively identical pan-sensitive matrix films
may be used for each of the blue, green and red exposures.
[0051] In the following discussion of suitable materials for use in the matrix film and
printing blank elements of the invention, reference will be made to
Research Disclosure, September 1994, Item 36544, available as described above, which will be identified
hereafter by the term
"Research Disclosure." The Sections hereafter referred to are Sections of the
Research Disclosure, Item 36544.
[0052] Suitable silver halide emulsions and their preparation as well as methods of chemical
and spectral sensitization are described in Sections I, and III-IV. Preferred matrix
film silver halide emulsions are AgBrI cubic emulsions (e.g., 1-6 mole % iodide),
and have an average cubic edge length of less than 0.5 microns, more preferably less
than 0.3 microns, and most preferably less than 0.25 microns. Silver halide emulsions
of all types generally exhibit native sensitivity to UV light. The native UV sensitivity
of the silver halide emulsion is preferably used to record the toe contrast controlling
UV flash. Alternatively or additionally, sensitizing dyes and/or other components
may also contribute to emulsion sensitization in the UV region.
[0053] Matrix films in accordance with the invention comprise a hydrophilic colloid or mixture
of such colloids generally employed in the photographic field as described above,
preferably gelatin. Vehicles and vehicle related addenda are described in Section
II. Various other additives such as UV dyes, brighteners, luminescent dyes, antifoggants,
stabilizers, light absorbing and scattering materials, coating aids, plasticizers,
lubricants, antistats and matting agents may be included, as described, for example,
in Sections VI-IX. Dye image formers and modifiers are described in Section X. Layers
and layer arrangements, color negative and color positive features, scan facilitating
features, supports, exposure and processing can be found in Sections XI-XX.
[0054] In accordance with one embodiment of the invention, a UV (Ultra Violet) absorber
is used in the blue matrix film, and more preferably in each of the red, green and
blue matrix films, used in dye imbibition printing to attenuate the light in the UV
region. A flash exposure is performed on the matrix film with UV light in the substantial
absence of light having a wavelength above 410 nm. In accordance with conventional
photographic flashing techniques, the flash exposure may be performed either before
or after the imagewise exposure. UV absorbing dyes having the required absorption
properties which may be used in the matrix films of the invention may be selected
from UV absorber dyes described by Besio et al U.S. Patent 4,849,326 (cyano substituted
butamines), Logan U.S. Patent 4,839,274 (acetylenic compounds), Pruett et al U.S.
Patent 5,215,876 (substituted styrenes), Nishijima et al EPO 0 451 813, Schofield
et al EPO 0 190 003, and Umemoto U.S. Patent 5,084,375 (hydroxyphenyl benzotriazoles),
Leppard et al EPO 0 531 258 (triazines), Oliver U.S. Patent 3,723,154 (cyanomethyl
sulfone-derived merocyanines), Sawdey U.S. Patents 2,739,888, 3,253,921 and 3,250,617
(thiazolidones, benzotriazoles and thiazolothiazoles), Sawdey et al U.S. Patent 2,739,971,
Hirose et al U.S. Patent 4,783,394, Takahashi U.S. patent 5,200,307, Tanji et al U.S.
Patent 5,112,728, and Leppard et al EPO 0 323 408, Liebe et al EPO 0 363 820, Roth
East German DD 288 249, Heller et al U.S. Patent 3,004,896 (triazoles), Wahl et al
U.S. Patent 3,125,597 and Weber et al U.S. Patent 4,045,229 (hemioxonols), Diehl et
al EPO 0 246 553 (acidic substituted methine oxonols), Leppard et al EPO 0 520 938
and EPO 0 530 135 (triazines), and Liebe et al EPO 0 345 514. Specific examples of
UV absorbers are shown below.

[0055] The UV absorber is selected according to its spectral characteristics, so as to provide
sufficiently high absorption to the UV light flash exposure to decrease the resulting
contrast of the matrix film, and sufficiently low absorption above 410 nm such that
it does not significantly interfere with the imagewise exposure of the matrix film.
A preferred UV absorber absorption spectrum is depicted in Figure 1, which is the
absorption spectrum of UV absorber dye UV-1 illustrated above.
[0056] In accordance with a preferred embodiment of the invention, the UV flash exposure
may be conveniently made, e.g., with a conventional tungsten or tungsten-halogen lamp
printer fitted with a filter that transmits UV light and absorbs substantially all
visible light above 410 nm. An example of such a filter is a HOYA U-340 filter, the
spectral characteristics of which are shown in Figure 2. As such conventional printing
lamps do not provide high levels of energy below about 360 nm, the UV absorber preferably
has a peak absorbance from 360 to 410 nm, and more preferably from 360 to 390 nm of
the absorption spectrum. Of course, the peak absorbance may be at less than 360 nm
as long as there is sufficient absorbance between 360 and 410 nm, but this would generally
require the use of greater amounts of the UV absorber, which is less preferred. For
printing lamps having significant energy below 360 nm, however, the UV absorber may
be advantageously selected to provide a corresponding peak absorbance below 360 nm.
[0057] In the matrix film light sensitive colloid layer, there are significant levels of
light absorbing particles, typically carbon particles, dispersed throughout the layer.
In accordance with one embodiment of the invention, a UV dye is also distributed in
the colloid layer. The level of contrast control depends on the concentration of the
UV dye in the matrix film. As the concentration is increased, the exposure profile
of the flash is biased towards the base of the matrix film, where the exposing light
is incident. The total silver halide that is available for a sensitometric exposure
can be represented as a straight line on a graph of relative exposure vs relative
distance from the film base, as in the top line in Figure 3. As the distance from
the base is increased, more of the exposure light is absorbed, and therefore the majority
of the silver halide at the top of the matrix film layer never receives exposure.
[0058] The horizontal axis in Figure 3 is the relative distance from the base of the matrix
material, 0.0 is at the base and 1.0 is on the top of the film. The vertical axis
is the relative intensity of an exposure through the base. Five levels of UV dye are
shown in Figure 3. The levels are such that the optical density of the specific concentration
of UV dye in the spectral region used in the exposure correspond to values of 1.0,
2.0, 3.0, 4.0, and 5.0. It is easily seen that as the dye density increases, the bulk
of the exposure will reside nearer to the base. In an ideal system, the actual sensitometric
contrast which results from filtration will be the original contrast without any filtration
reduced by the ratio of the integral of the dyed curves in Figure 3 to the integral
of the undyed curve. This technique allows the contrast control of any silver halide
grain size in the imbibition matrix film with the proper choice of the UV dye concentration,
filter and light source.
[0059] The imbibition printing blanks and matrix films described above may contain further
features and layers as are known in the art. Preferred supports for such blanks and
matrix films comprise transparent polymeric films, such as cellulose nitrate and cellulose
esters (such as cellulose triacetate and diacetate), polycarbonate, and polyesters
of dibasic aromatic carboxylic acids with divalent alcohols such as poly(ethylene
terephthalate).
[0060] Photographic silver halide emulsion layers may also be included in the printing blanks
of the invention. In a motion picture film blank, such a layer may be included between
the support and the dye receiving layer as is known in the art in order to enable
recording a sound track for the film in accordance with conventional motion picture
sound track recording, exposing, and processing procedures. Alternatively, a sound
track may be printed on the blank receiver as part of the imbibition printing process.
[0061] If desired, the printing blank and matrix films of the invention can be used in conjunction
with an applied magnetic layer, such as those described in
Research Disclosure, November 1992, Item 34390 published by Kenneth Mason Publications, Ltd., Dudley House,
12 North Street, Emsworth, Hampshire P010 7DQ, ENGLAND.
[0062] As described above, after imagewise exposure, the colloid layers of such matrix films
are typically differentially hardened and removed with a pyrogallol hardening developer
as described in U.S. Patent 2,837,430. After formation of colloid relief images in
blue, green and red matrix films, the matrix films are dyed with yellow, magenta and
cyan dyes, and the dye images are transferred to the mordant-containing receiver film.
Exemplary yellow, magenta and cyan dyes which may be used in the imbibition printing
process include Y-1, Y-2, M-1, and C-1 illustrated below.

[0063] While the plasticizer polymers of one embodiment of the invention have been particularly
described in connection with their use in a dye imbibition printing blank receiver,
it will be understood that such plasticizers may also be used in other elements which
employ a cationic mordant, such as photographic thermal dye transfer receiving layers
or antihalation layers, where it is desired to use a plasticizer which does not generate
haze in combination with such mordants. The plasticizers of the invention are most
advantageous, however, in elements containing printed dye images which are viewed
by light projection, such as motion picture films printed by dye imbibition, as it
is most desirable to minimize haze in such embodiments.
Plasticizer Polymer Synthesis Example
[0064] A latex copolymer having the composition 75 wt % ethylacrylate, 20 wt % styrene,
and 5 wt % 2-(N,N,N-trimethylammonium) ethylmethacrylate methosulfate is prepared
as follows: to a 500 ml addition flask was added 100 ml of distilled degased water,
1 ml of Igepal CO 730, 1 ml Ethoquad 0/12, 75 g of ethyl acrylate, 20 g of styrene,
6.3 g of 80 % aqueous solution of 2-(N,N,N-trimethylammonium)ethyl methacrylate, and
0.5 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride. The mixture was stirred
under nitrogen. To a 1 L reaction flask was added 300 ml of degased distilled water,
1 ml of Igepal CO 730, 1 ml of Ethoquad 0/12 and 0.5 g of 2,2'-azobis(2-methylpropionamidine)dihydrochloride.
The reaction flask was placed in an 80°C bath with stirring and the contents of the
addition flask was added over a period of 30 minutes. The contents was stirred at
80°C under nitrogen for 3 hours. The condenser was then removed and the flask was
heated to 90°C with a nitrogen purge for 1 hour to remove residual monomer. The flask
was then cooled to give a translucent latex containing 24 % solids.
Example 1
[0065] Coated dye imbibition printing blank supports were prepared as follows:
Support 1
[0066] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing a copolymer of styrene sulfonic acid sodium salt and 2-hydroxyethyl
methacrylate 70/30 wt (182 mg/m
2), a polymer latex of methyl acrylate, vinylidene chloride, and itaconic acid (15/83/02
wt%) (60 mg/m
2) and Cymel 300 (melamine-formaldehyde resin crosslinking agent from American Cyanamide
Co.) (18 mg/m
2) and on the front side with a gel subbing layer containing poly(acrylonitrile-co-vinylidene
chloride-co-acrylic acid) (14/80/6 wt%).
Support 2
[0067] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing Nalco 1115 (colloidal silica from Nalco Chemical) (404 mg/m
2), a polymer latex of methylacrylate, vinylidene chloride, and itaconic acid 15/83/02
wt (135 mg/m
2) and on the front side with a gel subbing layer.
Support 3
[0068] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing antimony-doped tin oxide (370 mg/m
2) and Witcobond 232 (polyurethane from Witco Corp.) (125 mg/m
2) and on the front side with a gel subbing layer.
Support 4
[0069] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing antimony-doped tin oxide (226 mg/m
2) and a polymer latex of methyl acrylate, vinylidene chloride, and itaconic acid 15/83/02
wt (75 mg/m
2) followed by a layer containing Witcobond 232 (899 mg/m
2) and on the front side with a gel subbing layer.
Support 5
[0070] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing Witcobond 232 (899 mg/m
2) and on the front side a gel subbing layer followed by a layer containing antimony-doped
tin dioxide (296 mg/m
2) and gelatin (52 mg/m
2).
Support 6
[0071] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing Witcobond 232 and a polyaniline imine (1:1 ratio) (108 mg/m
2) followed by a layer containing Elvacite 2041 (polymethylmethacrylate from DuPont)
(1076 mg/m
2) and on the front side a gel subbing layer.
Support 7
[0072] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing a polymer of N-vinylbenzyl-N,N,N-trimethylammonium chloride and
ethyleneglycol dimethacrylate 93/7 wt (129 mg/m
2) and a polymer of acrylonitrile, vinylidene chloride and N,N-dimethylaminoethyl methacrylate
methosulfate 25.1/73.4/1.5 wt (194 mg/m
2) and on the front side a gel subbing layer.
Support 8
[0073] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing a polymer of N-vinylbenzyl-N,N,N-trimethylammonium chloride and
ethyleneglycol dimethacrylate 93/7 wt (129 mg/m
2) and a polymer of acrylonitrile, vinylidene chloride and N,N-dimethylaminoethyl methacrylate
methosulfate 25.1/73.4/1.5 wt (194 mg/m
2) followed by a layer containing cellulose diacetate (2690 mg/m
2). The front side was coated with a gel subbing layer.
Support 9
[0074] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing vanadium pentoxide (3.2 mg/m
2) and Eastman AQ55D (polyesterionomer from Eastman Chemical Co.) (32 mg/m
2). The front side of the support was coated with a gel subbing layer.
Support 10
[0075] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing vanadium pentoxide (296 mg/m
2) and Eastman AQ29D (polyesterionomer from Eastman Chemical Co.) (3.2 mg/m
2) followed by a layer containing Witcobond 232 (899 mg/m
2) and the front side was coated with a layer containing a gel sub well known in the
art.
Support 11
[0076] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing Elvanol 71-30 (polyvinylalcohol from DuPont) (54 mg/m
2), Volan (methacrylato chromic chloride from DuPont) (1.9 mg/m
2) and potassium nitrate (5.4 mg/m
2). The front side of the support was coated with a gel subbing layer.
Support 12
[0077] A 5 mil polyethylene terphthalate film support was coated on the backside with a
layer containing vanadium pentoxide (3.2 mg/m
2) and a polymer latex of acrylonitrile, vinylidene chloride and acrylic acid 15/9/76
wt (2.4 mg/m
2) followed by a layer containing Elvacite 2041 (1064 mg/m
2). The front side of the support was coated with a gel subbing layer.
Control Support
[0078] A 4.7 mil polyethylene terphthalate film support was coated on the backside with
a layer containing Witcobond 232 (899 mg/m
2) and on the front side with a gel subbing layer.
[0079] Dye imbibition printing blank Samples 1-12 and a Control Sample were made using corresponding
Supports 1-12 and the Control Support as follows. Each support was coated on the front
side with a layer containing silver bromoiodide emulsion (1940 mg/m
2 Ag), EDTA sodium salt (83.2 mg/m
2), methylbensothiazolium chloride (10.1 mg/m
2), gelatin (3500 mg/m
2) and bisvinylsulfonylmethyl ether (75.6 mg/m
2) followed by a layer containing polymer of copoly (N-vinylbenzyl-N,N,N-trimethylammonium
chloride-co-ethyleneglycol dimethacrylate) 93/7 mole (861 mg/m
2), Olin 10G surfactant (97.3 mg/m
2), potassium nitrate (39.7 mg/m
2), gelatin (2800 mg/m
2), and a polymer methacrylate methosulfate 75/25/5 wt (280 mg/m
2).
[0080] The surface electrical resistivity and the water electrode resistivity for certain
of the above coatings were measured. The results are indicated in Table I below.
Table I
Sample |
Surface Electrical resistivity (ohm/square, 20% RH) |
Water Electrode resistivity (ohm/square, 20% RH) |
1 |
2 X 1010 |
|
2 |
6 X 1011 |
|
3 |
5 X 108 |
|
5 |
|
1 X 109 |
6 |
|
1 X 109 |
7 |
5 X 109 |
|
8 |
|
4 X 109 |
9 |
1 X 109 |
|
10 |
|
1 X 108 |
11 |
>3 X 1014 |
|
12 |
|
1 X 107 |
Control |
>3 X 1014 |
4 X 1011 |
[0081] Desired resistivity values for surface electrical resistivity are less than about
10
9 and for water electrode resistivity are less than about 10
9, and especially less than about 10
8 ohm/square. While all antistatic materials will improve resistivity levels to some
extent, the metal oxide containing antistatic layers of Samples 3, 5, 9, 10, and 12
demonstrate especially preferable results. It is also noted the antistat in Sample
1 is not photographic development process surviving, and therefore not preferred.
[0082] An unwinding electrification test is used to determine if there is a "discharge"
or "glow" in the unwinding nip of a roll of light sensitive film during production
or handling. During this test a roll of film is unwound at a high speed. If there
is a large separation charge, due to the fact that two dissimilar materials are being
separated, the electric field in the unwind nip will be large. It can be large enough
such that the air can no longer sustain the intense field and air breakdown will occur
resulting in a static discharge. Such discharge can potentially be harmful to a light
sensitive emulsion which may be used for recording a sound track in an imbibition
printing blank. Table II shows the results of such an unwinding electrification test
which was performed on Samples 7, 8, 11 and 12.
Table II
Sample |
Glow observed |
11 |
yes |
7 |
yes |
8 |
yes |
12 |
no |
[0083] Retransfer of dye from the printed front side of a dye imbibition print to the backside
during storage in the roll can be a problem especially at high humidity and temperature.
An antistatic backing layer can play an important part in this retransfer. To check
for dye retransfer, the front sides of imbibition prints dyed with magenta dye M-1
were placed in contact with the backsides of each of Samples 1-12 and the Control
Sample between two glass plates, and the assemblage was then placed in a chamber at
80 percent relative humidity and 38°C for four days. The backs of the undyed imbibition
prints were then observed for the presence of transfered dye. The results are shown
in Table III.
Table III
Sample number |
Dye present |
1 |
no |
2 |
no |
3 |
no |
4 |
no |
5 |
no |
6 |
no |
7 |
yes |
8 |
no |
9 |
no |
10 |
no |
11 |
no |
12 |
no |
control |
no |
[0084] Antistatic backings that contain a cationic polymeric material as in Sample 7 can
result in dye retransfer as indicated above. Overcoating this antistat layer with
a polymer as in Sample 8 may solve this retransfer problem, but poorer antistatic
properties result.
[0085] In accordance with the most preferred embodiments of the invention, Samples 3, 5,
9, 10, and 12 meet the desired attributes of desired resistivity, no glow discharge
and no dye retransfer. These examples all contain metal oxide antistats.
Example 2
[0086] Dye imbibition printing blanks were prepared as follows:
Component |
Coverage |
Top layer: |
|
Mordant: copoly(N-vinylbenzyl-N,N,N-trimethylammoniumchloride co-ethyleneglycol dimethacrylate) |
861 mg/m2 |
93/7 mole ratio |
|
Olin 10G surfactant |
97.3 mg/m2 |
KNO3 antistatic agent |
39.7 mg/m2 |
gelatin |
2799 mg/m2 |
plasticizer polymer PP-1 |
280 mg/m2 |
|
Bottom layer: |
|
EDTA sodium salt |
83.2 mg/m2 |
Methylbenzothiazolium chloride |
10.1 mg/m2 |
Gelatin |
3498 mg/m2 |
Bisvinysulfonylmethyl ether |
75.6 mg/m2 |
Support:
[0087] A 4.7 mil polyethylene terphthalate film support coated on the backside with a layer
containing Elvanol 71-30 (polyvinylalcohol from DuPont) (54 mg/m
2), Volan (methacrylato chromic chloride from DuPont) (1.9 mg/m
2) and potassium nitrate (5.4 mg/m
2).
[0088] Additional blanks were prepared substituting plasticizer polymers PP-2, PP-3 and
PP-4 and comparative plasticizer polymers C-1, C-2 and C-3 for PP-1 at equal weights.
C-1 poly(methyl acrylate)
C-2 poly(ethyl acrylate)
C-3 poly(ethyl acrylate-co-styrene) 80/20 wt
[0089] The haze of each coating was measured after drying using a XL-211 Hazegard system
manufactured by BYK-gardner which measures the transmitted light passed through a
sample. The results are presented in Table IV below:
Table IV
Plasticizer Polymer |
%Haze |
None |
1.5 |
PP-1 |
1.4 |
PP-2 |
1.4 |
PP-3 |
1.4 |
PP-4 |
1.2 |
|
C-1 |
7.5 |
C-2 |
2.9 |
C-3 |
4.1 |
[0090] As demonstrated above, plasticizer polymers other than those in accordance with the
preferred embodiments of the invention in the presence of the mordant in the coating
composition can cause hazy coatings to occur upon drying. This difficulty is overcome
by using the plasticizer latex of the preferred embodiments of the invention.
Example 3
[0091] The effectiveness of plasticizer latex in accordance with the preferred embodiments
of the invention at reducing brittleness was also demonstrated. A dye imbibition printing
blank was made as described in Example 2, with PP-5 in place of PP-1 at the indicated
coverages. The brittleness test performed provides for quantitatively measuring the
brittleness of film by subjecting it to bending. By means of a wedge, the diameter
of a film loop was constantly changed through gradually decreasing openings until
a failure of the film resulted. The opening of the wedge at which the film failed
is the measure of its brittleness. The film was conditioned at 15 percent relative
humidity and 21°C before running the test. The smaller wedge opening before the onset
of failure the more flexible the film.
Table V
Example |
Polymer level mg/m2 |
Brittleness (relative wedge opening at failure) |
2.1 (comparison) |
0 |
0.20 |
2.2 (invention) |
215 |
0.11 |
2.3 (invention) |
430 |
0.08 |
[0092] Table V shows the effectiveness of the plasticizer latex of the invention to give
acceptable coatings with reduced brittleness.
Example 4
[0093] Blue light sensitive matrix films were coated with different levels of the UV absorber
dye UV-1 (0.0, 135, 269, and 538 mg/m
2). The format below was used for the experiments of this example:

Support
[0094] 5 mil clear polyester film support coated on the backside with a layer containing
vanadium pentoxide (3.2 mg/m
2) and a polymer latex of acrylonitrile, vinylidene chloride and acrylic acid 15/9/76
wt (2.4 mg/m
2) followed by a layer containing Elvacite 2041 (1064 mg/m
2). The front side of the support was coated with a gel subbing layer.

[0095] The Top Layer described above was provided to improve uniformity of the coating,
processing, and antistatic performance of the matrix films, but is not necessarily
required for the matrix films in accordance with the invention.
[0096] The matrix films were exposed through a 21 step tablet on a sensitometer with a conventional
tungsten lamp printer fitted with a HOYA U-340 filter (the spectral characteristics
of which are shown in Figure 2) and processed with a pyrogallol hardening developer
as described in U.S. Pat. no. 2,837,430 to form a relief record. The resulting sensitometric
curves for the matrix films are shown in Figure 4. As is evident from Figure 4, the
contrast of the matrix films decreased as the UV dye concentration increased. The
Best Fit Contrast (the slope of the best straight line which fits the contrast of
the sensitometric curve) of the four levels of UV dye are plotted in Figure 5. Within
this range, any contrast can be attained for a flash exposure with the proper dye
concentration, which in combination with an imagewise exposure enables effective and
selective toe contrast control for the resulting relief image.
Example 5
[0097] Not all UV absorbers will work effectively with conventional tungsten or tungsten-halogen
lamp printers fitted with a filter that transmits UV light and absorbs substantially
all visible light above 410 nm. The peak wavelength of the UV absorber selected for
use with such printers is preferably above 360 nm (but still below 410 nm), as tungsten
lamps typically have minimal energy below 360 nm. The native blue sensitivity of the
silver halide is active within this 360-410 nm wavelength range. If the UV dye absorption
peak is relatively short (such as 350 nm), it may not have the ability to attenuate
light in the range where a tungsten or tungsten-halogen lamp produces energy and the
matrix film senses the energy.
[0098] Example 4 was essentially repeated, except for substituting a mixture of UV absorber
dyes UV-2 and W-3 for dye UV-1. A comparison of the UV absorbers is shown in Figure
6, where the absorbance spectrum on the right in Figure 6 with the longer wavelength
peak is that of dye UV-1, while absorbance spectrum on the left in Figure 6 with the
shorter wavelength peak is that of the mixture of dyes UV-2 and UV-3. Figure 7 shows
the sensitometry of the experimental results. The three curves plotted are three similar
blue matrix films with 0.0 mg UV dye, 269 mg/m
2 of UV-1 and 269 mg/m
2 of UV-2/UV-3. The sensitometry of the matrix film without dye and the matrix film
with 269 mg/m
2 of the shorter peaked absorber dyes (UV-2/UV-3) are similar in contrast. Thus, the
shorter peaked UV absorber did not work in this case in combination with a tungsten
lamp UV flash to reduce contrast, while the matrix film with 269 mg/m
2 of UV-1 did exhibit a large contrast change.
Example 6
[0099] Red and green light sensitive matrix films of the following formats were coated with
different levels of the UV absorber dye UV-1 and exposed and processed similarly as
described in Example 4.
Component |
Coverage |
|
(Red Matrix) |
(Green Matrix) |
Silver Halide Layer |
|
|
Gelatin |
10764 mg/m2 |
9688 mg/m2 |
Carbon |
431 mg/m2 |
538 mg/m2 |
Sensitized emulsion |
1938 mg/m2 |
1722 mg/m2 |
|
(cubic Ir-doped AgBrI with 3.4 mole% iodide and 0.13 cubic edge length, spectrally
sensitized with red sensitizing dye RSD-1) |
(cubic Ir-doped AgBrI with 3.4 mole% iodide and 0.09 cubic edge length, spectrally
sensitized with green sensitizing dyes GSD-I and GSD-2) |
|
Yellow dye YD-1 |
2368 mg/m2 |
2799 mg/m2 |
UV absorber dye UV-1 |
various mg/m2 |
various mg/m2 |
Support
[0100] 5 mil clear polyester film support coated on the backside with a layer containing
vanadium pentoxide (3.2 mg/m
2) and a polymer latex of acrylonitrile, vinylidene chloride and acrylic acid 15/9/76
wt (2.4 mg/m
2) followed by a layer containing Elvacite 2041 (1064 mg/m
2). The front side of the support was coated with a gel subbing layer.

[0101] The matrix films contained further conventional photographic coating addenda well
known in the art. Similar contrast reduction for the red and green matrix films was
observed dependent upon the UV absorber concentration as was observed for the blue
matrix films of Example 1.