Anti-blocking, water soluble top coat for color proofing films

A photosensitive, resist-imageable color element comprises a transparent support laser, colored photosensitive resist layer, and a water-removable polymeric layer with water-insoluble polymeric particles in the water-removable polymeric layer.

FIELD OF THE INVENTION 
The present invention relates to the incorporation of a non-permanent water 
soluble protective top coat for overlay color proofing films. The 
protective top coat prevents blocking of the films and improves vacuum 
drawdown without optical interference, reduction in image transparency, 
gloss or quality. The resulting overlay color films are used to form 
multicolored images for proofing color separation negatives or positives 
in preparation for multicolor lithographic reproduction. 
BACKGROUND OF THE INVENTION 
In color reproduction, it is often necessary to verify the color accuracy 
of separation negatives or positives used in the printing process. The use 
of overlay and surprint proofing systems for this application is well 
known in the literature. Even though surprint proofing systems have by far 
received the most acceptance for application where color assessment is 
critical, overlay proofing systems provide a more economical and more 
productive method for non-critical color prepress applications. Some 
examples of different types of overlay proofing films which are wet 
processed are described in U.S. Pat. Nos. 3,136,637; 4,299,906; 4,469,772; 
4,482,625; 4,487,823; 4,748,102; 4,952,482; 5,001,037; and DE 37 20 724 
A1; DE 38 13 322 A1; EP 338,786 A2; EP 404,507 patent applications. The 
technologies used to image these films are photosensitive systems well 
known in the art. Overlay color proofing films which are based on dry peel 
apart processes provide another method of generating multicolored proofs. 
Some examples of these can be found in U.S. Pat. Nos. 4,174,216; 
4,334,006; 4,396,700; and EP 385,466 A2 patent application. Even though 
the dry process peel apart systems provide a convenient method of 
generating images without the use of wet developers, the image quality of 
these system are generally not as good as those generated by wet 
processes. 
Other improvements to overlay systems, as described in U.S. Pat. Nos. 
4,634,652 and 4,748,101, have included treatment of the polyester support 
for increased transparency and clarity. The intent of these permanent 
treatments are to reduce the internal reflections within the composite 
proof to provide a better match to the printed sheet. Particulate layers 
are positioned either on the opposite side of the carrier from the 
photosensitive color layer is coated or lie below the photosensitive color 
layer between it and the carrier. 
The use of protective layers for preventing blocking or protecting the 
image have been described in U.S. Pat. Nos. 4,719,169; 4,902,594; and 
4,999,266. In each of these patents, the protective layer is a permanent 
layer that is applied after the image is formed. The layer provides no 
protection for the film prior to image formation and subsequent 
lamination. The layer consists of a non-water soluble thermoplastic resin 
which may or may not contain particulate matter. 
The use of particulate matter in adhesives for anti-blocking 
characteristics is well known. A specific example of using organic 
polymeric beads with a narrow molecular weight distribution in the 
adhesive layer of a surprint color proof is described in U.S. Pat. No. 
4,885,225. The narrow distribution of beads allows one to incorporate a 
low concentration of beads into the adhesive layer without introducing 
optical interference or reduction in adhesive performance. 
In an overlay construction, unlike a surprint type film, an adhesive layer 
is not the top layer in the construction. The exposed coated surface on an 
overlay film prior to development is either a photosensitive layer, which 
may or may not contain a colorant, or an oxygen barrier layer. An oxygen 
barrier layer is necessary when photopolymers or monomers are used which 
are quenched by triplet oxygen during the photoimaging process, typically 
acryloyl and methacryloyl polymerizable systems. The surface of these 
layer is typically very smooth, making it difficult to achieve uniform and 
intimate contact with separation negatives or positives during vacuum 
drawdown prior to the imaging process. The oxygen barrier layers are 
comprised of water soluble polymers which may block when subjected to 
moisture if the smooth top layer is allowed to come into contact with a 
second smooth surface. When photopolymers or monomers are used as the 
photosensitive element in the construction, the photosensitive layer and 
oxygen barrier layer are often soft and easily embossed during the 
photoimaging process. When non-uniform contact between the separation and 
photosensitive element occurs, a pattern results in the final image. 
SUMMARY OF THE INVENTION 
The present invention provides a color proofing element comprising , in 
order (a) a permanent transparent carrier or support layer, (b) a 
photosensitive color layer and (c) a non-permanent water soluble 
protective layer containing particulate organic polymeric beads. 
A negative-acting photosensitive system can be used to produce a 
multicolored composite image can be obtained by performing the following 
procedure using the aforesaid photosensitive element; 
(i) exposing said presensitized sheet to actinic radiation through a color 
separation negative corresponding to the pigment of said color coating 
thereby crosslinking the exposed areas of the photosensitive element and 
rendering said color coating insoluble in an aqueous alkaline developing 
medium (creating a latent image); 
(ii) developing said image with an aqueous alkaline developing medium 
whereby the protective layer is totally removed, the unexposed color 
coating is removed and the exposed color coating remains; 
(iii) repeating steps (i)-(ii) with additional presensitized elements as 
described above, each of said presensitized elements being of a different 
color. 
(iv) registering each color imaged film on a substrate to form a 
multicolored composite image. 
DETAILED DESCRIPTION OF THE INVENTION 
The construction according to the present invention would typically 
comprise a transparent carrier (generally having an adhesion promoted or 
roughened surface); a colored photopolymerizable layer; and a water 
soluble protective layer containing a narrow distribution of organic 
polymeric beads. 
In a preferred embodiment, the carrier is composed of a dimensionally and 
chemically stable base material. In particular the carrier is polyethylene 
terephthalate having a thickness of 1 to 10 mils (0.025 to 0.25 nm) and 
more preferably a thickness of 2 to 3 mils (0.05 to 0.076 nm). The carrier 
must be capable of holding the image during and after development which 
may require some treatment of the polyester surface. Adhesion promotion 
can be achieved through chemically treated films, such as Melinex.TM. 505 
from ICI, and/or treatment with corona discharge flame treatment, or 
irradiation (as in U.S. Pat. No. 4,879,176) to promote adhesion of the 
image without interference in development of the non-imaged areas. 
Coated onto the carrier surface is a photosensitive color layer which 
typically comprises a photopolymerizable oligomer, colorant, initiator 
system, binders and other optional components such as wetting agents, 
surfactants, coating rheology modifiers, optical brighteners, 
plasticizers, residual solvents, fillers etc. The photosensitive color 
layer is coated onto the adhesion promoted surface of the carrier using a 
mixture of solvents which give rise to the best coating quality and 
solution stability. Representative solvents include ketones, alkyl ethers 
or acetates of propylene glycol, alkyl ethers or acetates of ethylene 
glycol, dioxalane, butyrolactone, and alcohols. 
The photopolymerizable oligomer comprises a multifunctional acrylate whose 
function is to form a high molecular weight polymer upon initiation by 
radiation (e.g., ultraviolet radiation or visible light) generated 
radicals. The molecular weight of the acrylated oligomer influences 
several performance characteristics of the final coated films such as the 
tack, of the coated film, the strength of the developer necessary to 
develop the image and the quality of the image attained. If the film 
imparts too much tack then it is difficult to manufacture the material in 
a production coating process without disruption of the film, in turn, 
giving rise to poor coating quality. The strength of the developer 
required to develop the image is generally directly proportional to the 
molecular weight of the oligomer and the acid content of the oligomer. 
Oligomers with lower molecular weights and high acid content are easier to 
develop and therefore do not need very aggressive developers. However, too 
much acid content or too high a molecular weight can cause destabilization 
of the pigment dispersions when acidic binders are used to disperse the 
pigments. Some examples of oligomers non-exclusively include and 
multiacrylated urethane oligomers, as described in U.S. Pat. No. 
4,304,923. The photo-oligomer is present in the composition in the amount 
of 45-70% by weight and has a mean molecular weight range of 2500 to 5500. 
In the preferred embodiment, the photoinitiator(s) used must not generate a 
visible color change in the image after exposure. Examples of 
photoinitiators non-exclusively include; triazines, acetophenones, 
benzophenones, and thioxanthones. The preferred photoinitiators include 
Irgacure.TM. 
907(2-methyl-1-(4-(methylthio)phenyl)-2-(4-morpholinyl)-1-propane) from 
Ciba Geigy, Irgacure.TM. 369 from Ciba Geigy, Quantacure.TM. ITX 
(isopropylthioxanthone) from Biddle Sawyer and triazines tethered to 
alkylarylpolyether alcohols U.S. application Ser. No. 07/752,775 with the 
title "Light-Sensitive Article Containing Non-Migrating 
Halomethyl-1,3,5-Triazines.") and are present in the composition in the 
amount of 1.0-15% by weight. The optimum amount of initiator will be 
dependent upon the oligomer type used and the light filtering effect of 
the pigment used. 
Pigments or dyes may be used as colorants in the photosensitive color 
layer; however, pigments are preferred since they provide more light 
stable colored images. The pigments are generally introduced into the 
photosensitive formulation in the form of a millbase comprising the 
pigment dispersed with a binder and suspended into a solvent or mixture of 
solvents. Many different pigments are available and are well known in the 
art. The pigment type and color are choosen so that the coated colored 
element is matched to a preset color target or specification set by the 
industry. The type of dispersing resin and the pigment to resin 
composition ratio choosen are dependent upon the pigment type, surface 
treatment on the pigment, dispersing solvent and milling process. Some 
examples of resins suitable for generating millbases which are compatible 
with the aforementioned photo-oligomers non-exclusively include; Polyvinyl 
acetate/crotonic acid copolymers, styrene maleic anhydride half esters 
resins, acrylic and methacrylic polymers and copolymers, polyvinyl 
acetals, polyvinyl acetals modified with anhydrides and amines, hydroxy 
alkyl cellulose resins and styrene acrylic resins. The primary composition 
of the dispersing resin is an acidic resin, however, some non-acidic 
resins may be present. In some combinations, a dispersing agent may be 
necessary to achieve optimum dispersion quality. Some examples of 
dispersing agents non-exclusively include; polyester/polyamine copolymers, 
Disperse Aids.TM. from Daniels, PKE 1370 polyester resin from Biddle 
Sawyer, alkylarylpolyether alcohols, and acrylic resins. Other components 
may also be included in the millbase such as surfactants to improve 
solution stability, fluorescent materials, optical brighteners, UV 
absorbers, fillers, etc. The preferred composition of the millbase 
comprises 30-71% by weight pigment, 15-30% by weight acidic resin, 0-25% 
non-acidic resin, 0-20 %, more preferably 0-10% dispersing agents. 
Additional binders may also be included in the photosensitive color 
formulation to balance developability and tack. Some examples of 
additional binders which are compatible with the aforementioned 
photo-oligomers and millbases non-exclusively include; Polyvinyl 
acetate/crotonic acid copolymers, styrene maleic anhydride half esters 
resins, acrylic and methacrylic polymers and copolymers, polyvinyl 
acetals, polyvinyl acetals modified with anhydrides and amines, and 
styrene acrylic resins. In the preferred composition of the photosensitive 
color layer, the pigment is present in the amount of 5-20% by weight, the 
acidic resin in the amount of 10-20% by weight and non-acidic resin in the 
amount of 0-5% by weight. 
Overlying the light sensitive color layer is a continuous developer soluble 
resinous protective layer which may also function as an oxygen barrier 
containing a narrow distribution of organic polymeric beads. If the 
photosensitive color layer is sensitive to oxygen quenching during the 
exposure process, then an oxygen barrier layer is necessary. In such a 
case, the protective layer can function as both a barrier for oxygen and 
as a protection layer for the underlying photosensitive color layer. The 
protective layer is coated onto the photosensitive color layer using an 
aqueous solution of water soluble resins. Preferred water soluble resins 
non-exclusively include alkyl ethers of cellulose, polyvinyl alcohols and 
polyvinyl pyrrolidone. The organic polymeric beads are added to the water 
soluble resinous layer to provide an uneven surface of the protective 
coating. The disruption of the smooth surface of the coating gives rise to 
several advantages, such as anti-blocking characteristics of the films, 
especially under humid conditions (as seen in example 2); easier handling 
of the films, such as the sliding of the graphic arts separation film over 
the surface of the photosensitive element or pulling sheets out of a 
package due to less friction and tack (as seen in example 3); and a more 
productive proof making process due to the decrease in drawdown time 
required to achieve acceptable contact in the contact frame with the 
graphic arts separation film (as demonstrated in example 4). If the 
particle size distribution of the organic polymeric beads is too broad, 
the smaller particles may be too small to be of any use and may cause 
unacceptable haze in the coating (as demonstrated in example 5); and the 
larger particles may cause disruption of the colored image (matte surface 
or deglossing effect) and may also interfere with the uniform contact 
between the surface of the photosensitive element and the graphic arts 
separation film during the exposure process. Using a narrow distribution 
of beads allows one to more effectively use beads with the desired average 
diameter required to achieve the desired effect and avoid disadvantages 
such as haze and poor contact in the exposure frame. In the preferred 
embodiment, the organic polymeric beads have a mean average diameter from 
4-10 microns and are present in the protective layer in an amount of 
0.05-2.0%, more preferably 0.5-2.0%. The protective layer thickness is 
coated between 0.3 to 1.7 g/m.sup.2. Other ingredients may be added such 
as mold inhibitors, anti-halation dyes, filter dyes, solvents, wetting 
agents, etc. 
These and other aspects of the invention will now be illustrated in the 
following non-limiting examples:

EXAMPLES 
EXAMPLE 1 
The following protective coating solution was coated at 0.8 g/m.sup.2 onto 
either a photosensitive color layer (as described in example 6) or onto a 
2 mil biaxially oriented polyethylene terephthalate polyester film. The 
formulations described below were used for evaluating the effect of the 
size and distribution of organic polymeric beads and their concentration 
in the practice of the present invention (see examples 2 through 5). 
Included below is also a table listing the mean diameter distribution of 
the bead lots used; 
______________________________________ 
EXPERIMENTAL CONDITIONS VARYING PMMA 
BEAD CONCENTRATIONS (by Weight %) 
Control 
high (+) center (0) 
low (-) 
______________________________________ 
Vinol .RTM. 205 
5.6 5.6 5.6 5.6 
Polyvinyl alcohol* 
Vinol .RTM. 107 
2.4 2.4 2.4 2.4 
Polyvinyl alcohol* 
MA-6 PMMA 0.0 16.0 4.0 0.4 
Beads* (1% T.S.) 
KATHON .RTM. 
0.1 0.1 0.1 0.1 
CG-ICP 
Preservative* 
D.I. Water 91.9 75.9 87.9 91.5 
______________________________________ 
*Vinol .RTM. 205 and Vinol .RTM. 107 are available from Air Products MA6 
PMMA Beads composition described in U.S. Pat. No. 4,885,225 
Kathon .RTM. CG/ICP is available from Rohm and Hass 
______________________________________ 
PMMA BEAD DISTRIBUTION (% Frequency by Number) 
Mean Diameter 
PMMA Bead Lot Number 
in Microns D-113 D-148 D-153 D-179 
______________________________________ 
&gt;15.0 0.5 
14.0-15.0 0.4 
13.0-14.0 0.1 0.6 
12.0-13.0 0.8 1.0 
11.0-12.0 1.0 1.0 
10.0-11.0 3.7 3.1 
9.0-10.0 7.8 8.3 
8.0-9.0 13.7 55.4 
7.0-8.0 28.1 29.6 
6.0-7.0 2.6 
5.0-6.0 
4.0-5.0 0.5 
3.0-4.0 0.9 
2.0-3.0 0.6 83.8 
1.0-2.0 1.3 1.9 13.9 
0.0-1.0 98.7 39.2 0.1 1.4 
______________________________________ 
PMMA (Polymethylmethacrylate) Beads were supplied by 3M Fine Chemical Mfg 
Division, Rochester, NY 
The mean diameter distribution by Number was measured on a Horiba CA00 
Particle Analyzer 
EXAMPLE 2 
Protective coating solutions for each of the PMMA Bead lots were coated 
onto a polyethylene terephthalate polyester film upon which had been 
coated and dried the black photosensitive color solution as described in 
example 6 at the three different concentrations levels. Each of these 
samples were then subjected to a blocking test under the following 
conditions: four sheets of material to be tested were cut to dimensions of 
30.5 cm by 13 cm and stacked with the coated side of one sheet in contact 
with the back (uncoated) side of the next sheet. A flat, smooth aluminum 
plate of the same dimensions was placed over the material. The aluminum 
plate was of uniform thickness and weighed 526 grams; this resulted in a 
pressure of 1.35 g/cm.sup.2 on the material during the test. (This 
pressure was chosen to correspond with the pressure at the bottom of a 
stack of 160 sheets of boxed proofing material.) Two sets of material were 
then exposed to 60.degree. C. for 24 hours at 6% relative humidity and 80% 
relative humidity. On cooling, the material sheets were separated. Any 
tendency to cling together or disrupt any coating layer was regarded as 
blocking and was graded visually from 0 to 6, with 0 being the case with 
no blocking and 6 being completely blocked such that the layers are 
disrupted on separation. The table below summarizes the results from this 
test. 
______________________________________ 
BLOCKING TEST (KRAL Grade*) 
Bead Experimental 6% Relative 
80% Relative 
Distribution 
Condition Humidity Humidity 
______________________________________ 
D-153 high (+) 0.0 0.8 
D-153 Center (0) 0.0 0.8 
D-153 low (-) 0.2 0.8 
D-113 high (+) 0.0 2.5 
D-113 Center (0) 0.0 4.0 
D-113 low (-) 0.2 4.8 
D-148 high (+) 0.0 0.3 
D-148 Center (0) 0.2 0.2 
D-148 low (-) 0.2 0.8 
D-179 high (+) 0.0 1.2 
D-179 Center (0) 0.2 1.0 
D-179 low (-) 0.0 1.0 
no beads Control 0.2 3.8 
No Protective Coat 
6.0 6.0 
______________________________________ 
*The KRAL Grades are based on &lt;3.0 is acceptable, 3.0 is marginal and &gt;3. 
is unacceptable 
When no protective coat was present on the element severe blocking was 
observed under both relative humidity conditions. Without the PMMA beads 
present or present with the mean distribution of particle sizes less than 
4 microns in diameter, in particular at low concentrations levels, the 
resistance to blocking under humid condition was not acceptable. 
EXAMPLE 3 
Protective coating solutions for each of the PMMA Bead lots were coated 
onto a polyethylene terephthalate polyester film upon which had been 
coated and dried the black photosensitive color solution as described in 
example b 6 at the three different concentrations levels. The samples were 
then tested for their ease of slip between the front of the top sheet and 
the back of the second sheet. The test was intended to simulate the ease 
of withdrawing an element from a package of material. The lower the number 
indicated the easier it was to slide materials on top of each other. The 
elements were tested on a 3M-90 Slip/Peel Tester in accordance with test 
procedure ASTM Spec. D-1894. 
______________________________________ 
SLIP TEST 
Experimental Coefficient 
Bead Distribution 
Condition of Friction 
______________________________________ 
D-153 high (+) 0.20 
D-153 Center (0) 0.22 
D-153 low (-) 0.23 
D-113 high (+) 0.25 
D-113 Center (0) 0.25 
D-113 low (-) 0.27 
D-148 high (+) 0.20 
D-148 Center (0) 0.19 
D-148 low (-) 0.20 
D-179 high (+) 0.22 
D-179 Center (0) 0.24 
D-179 low (-) 0.24 
no beads Control 0.30 
No Protective Coat 
0.34 
______________________________________ 
When no PMMA Beads were present in the protective layer or no protective 
layer is present, the elements have the least resistance to slip. As the 
concentration of the beads was decreased, proportionally the resistance to 
slip increased. The resistance to slip also increased as the percentage of 
mean diameter beads increases below 2 microns. 
EXAMPLE 4 
Protective coating solutions for each of the PMMA Bead lots were coated 
onto a polyethylene terphthalate polyester film upon which had been coated 
and dried the black photosensitive color solution described in example 6 
at the three different concentrations levels. A draw down test was 
performed on the samples to simulate the efficiency of bringing the 
photosensitive elements into intimate contact with a graphic arts 
separation film. The faster the draw down time the more productive the 
proof making process. A Bekk smoothness/porosity tester Model 131-ED was 
used for the test. The values in the following Table are expressed as time 
in seconds for passing 10 cm.sup.3 of air at an underpressure of 38 mm Hg 
between the sample and a polished surface with an area of 19 cm.sup.2 with 
a dead weight load of 1 Kg/cm.sup.2. 
______________________________________ 
DRAW DOWN TEST 
Experimental 
Average of 3 
Bead Disribution 
Condition Samples in seconds 
______________________________________ 
D-153 high (+) 762 
D-153 Center (0) 3,710 
D-153 low (-) &gt;10,000 
D-113 high (+) 7,025 
D-113 Center (0) &gt;15,000 
D-113 low (-) &gt;15,000 
D-148 high (+) 172 
D-148 Center (0) 2,653 
D-148 low (-) &gt;6,000 
D-179 high (+) 2,108 
D-179 Center (0) &gt;11,821 
D-179 low (-) &gt;10,000 
no beads Control &gt;10,000 
______________________________________ 
The test results clearly showed that at low concentrations and distribution 
of beads containing no beads with diameters greater than 4 microns the 
efficiency of drawdown is poor. The higher number of seconds to achieve 
efficient drawdown would translate to longer vacuum drawdown times in the 
exposure frame prior to exposure to insure intimate contact between the 
photosensitive element and the graphic arts separation film. This would 
extend the process time for producing a proof. If intimate contact between 
the element and graphic arts separation film is not achieved, poor image 
quality may result. 
EXAMPLE 5 
Protective coating solutions for each of the PMMA Bead lots were coated 
onto a 2 mil (0.051 mm) polyethylene terephthalate polyester film. In 
order to evaluate the optical clarity of the protective layer as a 
function of PMMA bead distribution and concentration, samples were 
prepared and measured on a Gardner/Neotec Haze Meter Model #XL-211 in the 
transmission mode. Acceptable haze values range from 0.79 to 1.50. 
______________________________________ 
HAZE TEST 
Experimental 
Average of 3 
Bead Distribution 
Condition % Haze 
______________________________________ 
D-153 high (+) 1.82 
D-153 Center (0) 1.01 
D-153 low (-) 0.78 
D-113 high (+) 3.83 
D-113 Center (0) 1.49 
D-113 low (-) 0.85 
D-148 high (+) 1.74 
D-148 Center (0) 1.06 
D-148 low (-) 0.76 
D-179 high (+) 2.62 
D-179 Center (0) 1.41 
D-179 low (-) 0.78 
no beads Control 0.76 
______________________________________ 
The clarity of the layer decreases as the concentration of PMMA beads 
increases and as the percentage of mean diameter beads less than 2 microns 
increases. 
EXAMPLE 6 
The following example demonstrates the use of a protective layer in an 
overlay construction to generate a multicolored proof. 
A 2.65 mil (0.067 mm) adhesion promoted biaxially oriented polyethylene 
terephthalate polyester film is first primed by corona discharge treatment 
. Then the following photosensitive color coating solutions were coated 
and dried to a reflection optical density representative of the color 
specifications for each industry color target; 
The following pigment millbases were prepared first for incorporation into 
the photosensitive color coating solution; 
______________________________________ 
Millbase Compositions 
(% by weight) 
______________________________________ 
Green Red Red Blue 
Shade Shade Shade Shade 
Yellow 
Yellow Magenta Magenta 
______________________________________ 
Mobay Pigment 11.6 
YB-5785 
Sun Yellow Pigment 11.6 
275-0005 
Sun Magenta Pigment 11.2 
234-0071 
Mobay Magenta 6.8 
Pigment RV-6803 
Butvar .RTM. B-98* 
2.7 2.7 1.5 2.3 
Joncryl .RTM. 67* 
5.0 2.7 6.0 2.3 
Disperbyk .RTM. 161* 
0.6 0.6 1.1 0.7 
FC-430 0.04 0.04 0.2 0.02 
Methyl ethyl ketone 
56.0 56.0 56.0 61.4 
Propylene glycol 
24.0 24.0 24.0 26.6 
mono methyl ether 
______________________________________ 
Green Red 
Shade Shade 
Cyan Cyan Black 
______________________________________ 
Sun Cyan Pigment 
11.6 
249-0592 
Sun Cyan Pigment 11.6 
248-0615 
Columbia Black 16.6 
Pigment Ravent .RTM. 760 
Butvar .RTM. B-98* 
3.9 4.0 3.0 
Joncryl .RTM. 67* 
3.9 4.0 3.0 
Disperbyk .RTM. 161* 
0.6 0.6 1.5 
FC-430* 0.04 0.04 0.05 
Methyl ethyl ketone 
56.0 56.0 50.0 
Propylene glycol 
24.0 24.0 20.0 
mono methyl ether 
______________________________________ 
*Butvar .RTM. B-98 (Polyvinyl butyral) available from Monsanto 
Joncryl .RTM. 67 (Styrene acrylic resin) available from Johnson Wax 
Disperbyk .RTM. 161 available from Byk Chemie (dispersing agent) 
FC-430 (fluorinated nonionic surfactant CAS# 111140173) available from 3M 
______________________________________ 
PHOTOSENSITIVE COLOR SOLUTIONS 
(% by Weight) 
% YEL- MA- 
Solids 
LOW GENTA CYAN BLACK 
______________________________________ 
Green Shade Yel- 
20 16.1 
low Millbase 
Red Shade Yel- 
20 3.5 
low Millbase 
Red Shade Ma- 
20 17.0 
genta Millbase 
Blue Shade Ma- 
12 7.5 2.0 
genta Millbase 
Green Shade 
20 13.6 
Cyan Millbase 
Red Shade Cyan 
20 4.0 2.6 
Millbase 
Black Millbase 
30 0.08 0.4 0.2 18.1 
Acrylated Ure- 
64 11.5 16.7 25.8 15.3 
thane Oligomer 
P-11* 
Acidified 21 5.7 3.6 3.8 7.2 
Butvar .RTM. B-98* 
Triazine Initiator* 
50.6 2.9 1.3 1.6 4.1 
Joncryl .RTM. 67* 4.0 5.0 0.9 
Methyl ethyl 43.2 34.8 46.0 38.9 
ketone 
Propylene glycol 17.0 14.7 10.9 
mono methyl 
ether 
______________________________________ 
*Synthesis described in U.S. Pat. No. 4,304,923 
Triazine Initiator = mMOST-ol tethered to lgepal CO520 (as described in U 
S. Pat. application S.N. 07/752775 
Acidified Butvar .RTM. B98 = Butvar .RTM. B98 modified with succinic 
anhydride and triethyl amine (as described in U.S. Pat. application S.N. 
07/716,316 filed on June 17, 1991) 
Joncryl .RTM. 67 (available from Johnson Wax) = Styrene acrylic resin 
The following water soluble protective coating solution was coated and 
dried to a dry coating weight of 0.8 g/m.sup.2 onto the previously coated 
photosensitive color layer; 
______________________________________ 
PROTECTIVE COATING SOLUTION 
(% Solids) 
(% by Weight) 
______________________________________ 
Vinol .RTM. 205 Polyvinyl alcohol 
5.6 
Vinol .RTM. 107 Polyvinyl alcohol 
2.4 
MA-6 PMMA Beads* 1.0 8.0 
Kathon .RTM. CG/ICP 0.09 
D.I. Water 83.9 
______________________________________ 
*Vinol .RTM. 205 and Vinol .RTM. 107 are available from Air Products 
PMMA Beads composition described in U.S. Pat. No. 4,885,225 
Kathon .RTM. CG/ICP is available from Rohm and Haas 
A multicolored proof using the four process color films was imaged and 
developed as described in the summary. The following developer composition 
was used to develop the image. 
______________________________________ 
DEVELOPER SOLUTION 
(% by Weight) 
______________________________________ 
Postassium Carbonate 
1.0 
Postassium Bicarbonate 
1.0 
Surfynol .RTM. 465 
0.1 
Water 97.9 
______________________________________ 
*Surfynol .RTM. 465 (Ethoxylated tetramethyldecynediol) available from Ai 
Products. 
A commercially available sample of Igepal.TM. CO-520 was obtained 
commercially which had approximately 5% water present as an impurity. This 
water was removed by a vacuum azeotropic distillation of a solution 
containing 1.0 kg of the Igelpal CO-520.TM. in 1.0 L of toluene until the 
concentration of the solution was approximately 70-80%. Analysis by Karl 
Fischer indicated water to be present in &lt;100 ppm. The final concentration 
was determined to be 79.2%. The structure of polyoxyethylene compounds of 
this type usually only show the mole ratio of ethylene oxide used in their 
preparation. For Igepal.TM. CO-520, this mole ratio is 5. Analysis by mass 
spectrometry and nmr, however, showed the Igepal.TM. CO-520 to be a 
mixture of the structures shown. 
##STR1## 
To a slurry of 13.04 g (0.02 mole) of para-MOSTROL/TDI in 70 mL of toluene 
was added 11.34 g of a dry, solution of Igepal-CO-520 (8.98 g, 0.02 mole) 
in toluene followed by 0.030 g of dibutyltin dilaurate. The reaction 
mixture was heated for 3 hours at 60.degree. C. GPC and infrared analysis 
indicated that the reaction was complete. A clear yellow-brown viscous 
syrup was isolated by removal of the toluene solvent on a vacuum rotary 
evaporator. The product para-MOSTOL/TDI/Igepal.TM. CO-520 has the 
structure shown. 
##STR2## 
PREATIONS 
The following preparatory examples illustrate methods for synthesizing 
photopolymerization initiators (photoinitiators) that are useful in this 
invention. All percentages are percentages by weight, unless indicated 
otherwise. 
PREATION I 
This preparation illustrates the synthesis of 
2,4-bis(trichloromethyl)-6-[3-(2-hydroxyethoxy)styryl]-1,3,5-triazine, 
referred to hereinafter as meta-MOSTOL. 
A stirred solution of 2,4-bis(trichloromethyl)-6-methyl-1,3,5-triazine (103 
g, 0.31 mole), 3-(2-hydroxyethoxy)benzaldehyde (47 g, 0.28 mole), and 
ammonium acetate (10.5 g) in 270 mL of methanol was refluxed for 12 hours. 
After the mixture had cooled, an additional 80 mL of methanol was added, 
followed by 112 mL of water. The product precipitated from the reaction 
solution, was filtered and dried to yield 74 g of meta-MOSTOL, mp 
127.degree.-128.degree. C. 
PREATION II 
This preparation illustrates a simple, two-step, one-batch reaction of 
2,4-bis(trichloromethyl)-6-[3-(2-hydroxyethoxy)styryl]-1,3,5-triazine 
(meta-MOSTOL), 2,4-tolylene diisocyanate (TDI), and polyoxyethylene 
nonylphenol ("IGE CO-520") to prepare a mixture containing 80% 
meta-MOSTOL/TDI/POENP5, 15% [meta-MOSTOL].sub.2 /TDI, and 5% 
[POENP5].sub.2 /TDI, which mixture can function as a photoinitiator. 
(POENP5 is a commercially available polyoxyethylene nonylphenol having a 
mole ratio of 5 polyoxyethylene units to nonylphenyl units.) 
To a stirred dispersion containing 
2,4-bis(trichloromethyl)-6-[3-(2-hydroxyethoxy)styryl]-1,3,5-triazine 
(55.00 g, 0.1151 mole) and 2,4-tolylene diisocyanate (18.2 g, 0.102 mole) 
in 200 mL of toluene at a temperature of 16.degree. C. was added 
dibutyltin dilaurate (0.150 g). A slight exotherm raised the temperature 
of the reaction mixture to 19.degree. C. and the reaction mixture became 
clear after approximately 20 minutes. The meta-MOSTOL had completely 
reacted in 5 hours and the resulting mixture was analyzed by GPC and found 
to contain the following materials: meta-MOSTOL/TDI (54.5 g, 0.0837 mole), 
(meta-MOSTOL).sub.2 /TDI (17.7 g, 0.0314 mole), and 2,4-tolylene 
diisocyanate (0.9 g, 0.0052 mole). 
To this mixture was added a 79.2% solution of polyoxyethylene nonylphenol 
("IGE CO-520") (58.92 g, 0.0941 mole) in toluene and the solution was 
heated to a temperature of 60.degree. C. and maintained at that 
temperature for 4 hours. Infrared analysis indicated that all of the 
isocyanate had reacted. The reaction mixture was determined by high 
performance liquid chromatography (HPLC) analysis to contain approximately 
80% (96.0 g) meta-MOSTOL/TDI/POENP5, 15% (17.8 g) [meta-MOSTOL].sub.2 
/TDI, and 5% (6.0 g)[POENP5].sub.2 /TDI. Removal of the toluene under 
vacuum by means of a rotary evaporator provided a slightly brown viscous 
syrup. For ease of handling, this material was redissolved in sufficient 
methyl ethyl ketone to produce a solution having a concentration of 
approximately 50%.