Note: Descriptions are shown in the official language in which they were submitted.
20~0052
RADIATION-SENSITIVE MIXTURE AND RADIATION-SENSITIVE
COPYING MATERIAL PREPARED THEREFROM
Backqround of the ~nvention
The present invention relates to a radiation-
or photo-sensitive mixture comprising
A) a 1,2-quinonediazide and/or a combination of
1. a compound forming a strong acid under
the action of actinic radiation and -
2. a compound having at least one cleavable
C-O-C bond, the solubility of which in:
liquid developer is increased by the
action of an acid,
B) a polymeric binder which is insoluble in water
and soluble in aqueous-alkaline solutions, and
15 C) a dye, :~.
and to a radiation-sensitive copying material
comprising a layer support coated with a layer
comprising said mixture. !~
., : ., .: ,, . . , .:, . ........ :: :.. ..... ; : . - . .:
,,. - . , . : ;' ,,, : . ~ : '. . , : ,.
20000S~
Radiation- or photosensitive mixtures
comprised of the above-mentioned components are
known, and many fields of application have been
described, such as, for example, the production of
photoresists or planographic printing plates.
The dyes contained in the known mixtures
generally have to satisfy two demands: one, a
clearly visible contrast between the exposed areas
and the unexposed areas of the layer prepared from
the mixture should be achieved upon exposure, and
two, the relief image obtained after development
should be of a color contrasting with the layer
support.
These two objectives are accomplished by
employing indicator dyes whose color changes as a
result of the pH change occurring when the layer is
irradiated, as described, for example, in German
Offenlegungsschrift 1,447,022 (equivalent to British
Patent 1,041,463). Cationic dyes, such as
triarylmethane dyes, acridine dyes, azine dyes,
oxazine dyes, thiazine dyes and cyanine dyes, have
found to be particularly advantageous dyes in this
connection. Even when being added in small amounts,
these dyes generally result in a good contrast upon
exposure.
It is a disadvantage of these dyes that to
cause a color change the pH must be shifted
relatively deep into the acidic range. Therefore,
these dyes are not very well suited for use in
mixtures where, due to the presence of relatively
high amounts of buffering substances, the pH does not
change significantly upon exposure.
.
' ~. '~ '` ~ ` .
20(~0052
With mixtures based on 1,2-quinonediazides
this is, for example, the case when they contain
amines or other components having a comparably strong
basic character in order to achieve a wide process
latitude for positive-negative conversion. In
mixtures 'based on compounds having acid-cleavable
C-O-C bonds it is often thè cleavable unit itself
which exerts a strong buffering effect, due to the
primary formation of oxonium ions occurring upon
irradiation. In these cases, azo dyes, as described,
for example, in German Offenlegungsschrift 31 44 480
(equivalent to U.S. Patent 4,458,000) or,
particularly for mixtures based on acid-cleavable
compounds, hemioxonol dyes, as mentioned in German
Offenlegungsschrift 36 41 534, have shown to be
suitable contrast formers.
The thermal stability of the contrast achieved
upon exposure is also unsatisfactory with the use of
the dyes described above, with the exception of the
hemioxonol dyes, - The hemioxonol dyes, however,
have an adverse effect on the shelf life of the
mixtures.
During the positive-negative conversion of
mixtures based on 1,2-quinonediazides temperatures up
to 150C are applied. Mixtures based on compounds
having acid-cleavable C-O-C bonds are preferably
heated to temperatures up to 100C during or after
irradiation in order to ensure completeness of the
cleaving reaction. A second exposure, which is
possible with this kind of mixtures, is frequently
performed following the heating step. To avoid the
risk of waste copies it is therefore essential that
- - - - , ~ .- - . ~ - - .
zoo~s~
the image contrast resulting after the first exposure
is not impaired by a subsequent heat treatment.
summary of the Invention
It is therefore an object of the present
invention to provide an improved radiation-sensitive
mixture.
Another object of this invention is to provide
a radiation-sensitive mixture which upon exposure
gives a good image contrast even when buffer
substances are contained in the mixture.
It is also an object of the invention to
provide a radiation-sensitive mixture wherein the
image contrast has a thermal stability satisfying
practical requirements, while at the same time other
properties of the mixture, such as shelf life, are
not adversely affected.
Another object of this invention is to provide
an improved radiation-sensitive copying material,
comprising a layer support and said mixture.
In accomplishing these objects, there has been
provided a radiation-sensitive mixture comprising a
1,2-quinonediazide and/or a combination of a compound
forming a strong acid under the action of actinic
radiation and a compound having at least one
cleavable C-0-C bond, the solubility of which in
liquid developer is increased by the action of an
acid; a polymeric binder which is insoluble in water
and soluble in aqueous-alkaline solutions; and a dye.
.... ..
:: ::~ . .: : . - ;, . :, : . ; , . , ~ .,
, . : . ~ . :. : : .: -
20000Sh
The dye comprises a spiro-indolino-benzopyran of the
general formula I
R
wherein
R denotes hydrogen or an alkyl
group having 1 to 16 carbon
atoms,
R1, R2, R3, and R4 are identical or different and
denote hydrogen or halogen,
alkyl or alkoxy groups having 1
to 4 carbon atoms, hydroxy
_ groups or nitro groups, and
R5, R6, R7, and R8 are identical or different and
denote hydrogen or halogen,
nitro groups, amino groups,
alkyl, alkoxy or hydroxyalkyl
groups having 1 to 5 carbon
atoms or aryl groups having 6
to 10 carbon atoms.
Further objects, features and advantages of
the present invention will become apparent from the
detailed description of preferred embodiments that
follows.
_
,. , . . . . . . , , . . . . , . . ... . ,.. ;.. , . .. . ~ ,.. . . ~ .
2000052
~.
Detailed Description of the_Preferred Embodiments
The spiro-[2H-1-benzopyran-2,2'-indolines] of
the formula I which can be used in the radiation-
sensitive mixtures according to this invention
include b~th derivatives which are substituted on the
benzopyran ring system and derivatives which are
substituted on the indoline system.
The following are preferred substituted
benzopyrans: 6-acetyl-, 5-bromo-8-methoxy-6-nitro-,
5-bromo-6-nitro-, 6-bromo-5-nitro-, 8-bromo-6-nitro-,
6-chloro-, 7-chloro-, 6-chloro-5,7-dimethyl-8-nitro-,
8-chloro-5,6-dinitro-, 5-chloro-6-ni-tro-,
5-chloro-8-nitro-, 6-cyano-, 5,7-dichloro-6-nitro-,
6,8-dichloro-5-nitro-, 5,7-dimethoxy-6-nitro-,
8-fluoro-, 6-fluoro-8-nitro-, 8-fluoro-6-nitro-,
7-hydroxy-, 6-iodo-8-nitro-, 8-iodo-6-nitro-,
7-methoxy-5-methyl-6-nitro-, 6-methoxy-5-nitro-,
8-methoxy-5-nitro-, 8-methoxy-6-nitro-, 5-nitro-,
6-nitro-, 7-nitro-, 8-nitro-, 6-nitro-
5,7,8-trimethyl-, 6-(~-nitrovinyl)- and 7-methyl-
benzopyran.
The following are preferred substituted
indolines: 1'-butyl-, 3'3'-diethyl-, 3',3'diphenyl-,
3',7'-diphenyl-, 3'-ethyl-, l'-hexadecyl-,
l'-isoamyl-, 5'-nitro-3'-phenyl-, 3'-phenyl-,
1',3',3'-trimethyl-, 4'-chloro-, 5'-chloro-,
6'-chloro-, 5',7'-dichloro-, 1',3',3'-
trimethyl-5'-chloro-, 4',6'-dimethoxy-,
4',7'-dimethyl-, 5',7'-dimethyl-,
- 4',6'-diphenyl-,
5',7'-diphenyl-, ~'-fluoro-, 5'-fluoro,
5'-(~-hydroxyethyl), 5'-methoxy-, 7'-methoxy-, 5'-
--6--
~0(~0052
methyl-, 6'-methyl-, 7'-methyl-, 5'-nitro-,
7' nitro-, 5'-phenyl-, 7'-phenyl- and
4',6',7'-triphenyl-indoline.
If one or several of the radicals R1 to R8 are
alkyl groups, these preferably have 1 to 2 carbon
atoms, ~èthyl groups are particularly preferred. R
preferably is an alkyl group which in particular has
1 to 5 carbon atoms, methyl groups are most
preferred. Advantageously, the mixture contains a
compound of formula I where three of the radicals R5,
R6, R7, and R8 are methyl groups.
Particularly strong color contrasts are
achieved with compounds of formula I which possess at
least one nitro group, preferably in the benzopyran
system. Therefore, the mixture according to the
invention preferably contains a compound of formula I
where at least one of the radicals R1, R2, R3 and R4
is a nitro group.
Among the suitable spiro-[2H-1-benzopyran-
2,2'-indolines] those are preferred which, in
accordance with the above-listed possible
substituents, are substituted in both ring systems.
Particular mention is made of those substituted
compounds which on the indoline system are
substituted by one methyl group in position 1' and by
two methyl groups in position 3', and which on the
benzopyran system are substituted by a nitro group in
position 6 and optionally also by an alkoxy group,
particularly a methoxy group, in position 8.
Spiro-indolino-benzopyrans are known and
described in detail in "Photochromism", by G. H.
Brown, Wiley Interscience, New York (1971), pp.
20~)0QS~
165-169, in particular p. 169. Further suitable
compounds can be found in that publication.
The amounts of compounds of the general
formula I contained in the radiation-sensitive
mixtures of this invention vary between about O.ol
and 10% b~ weight, relative to the solids contents of
the mixtures. If the admixture is only intended to
achieve a thermally stable contrast upon exposure,
rather small amounts are sufficient. If, however,
the admixture is also intended to achieve a wide
process latitude in image conversion processes r the
added amount will be in the upper region of the
indicated range.
In a preferred embodiment of this invention,
the mixture further comprises a second, cationic dye,
for example, a triarylmethane dye, an acridine dye,
an azine dye, an oxazine dye, a thiazine dye or a
cyanine dye. This second dye is also added in an
amount of about 0.01 to 10% by weight, relative to
the total solids content of the mixture.
Preferably, 1,2-naphthoquinone-2-diazide-4- or
-5-sulfonic acid esters or amides are used as
1,2-quinonediazides. Suitable compounds of this type
are known and are described, for example, in German
Patent 938,233, corresponding to GB Patent
Specification 739,654, and in German
Offenlegungsschrift 25 47 905, corresponding to GB
Patent Specification 1,561,438.
The quantity of 1,2-quinonediazide compounds
is in general about 3 to 50, preferably about 7 to 35
percent by weight, based on the nonvolatile
components of the mixture.
.~ , ~. ... .. .
200QC~52
The following should primarily be mentioned as
acid-cleavable compounds:
a) those containing at least one ortho-
carboxylic acid ester and/or carboxylic
acid amide acetal grouping, in which the
compounds may also have a polymeri--c nature
and the said groupings may occur as
linking elements in the main chain or as
lateral substituents,
b) oligomeric or polymeric compounds
containing repeating acetal and/or ketal
groupings in the main chain and
c) compounds containing at least one enol
ether or N-acylaminocarbonate grouping.
Acid-cleavable compounds of the type a) as
components of radiation-sensitive mixtures are
described in detail in EP-A 0,022,571, corresponding
to US Patent No. 4,311,782. Mixtures which contain
compounds of the type b) are described in German
Patent Specification 2,306,248, corresponding to US
Patent No. 3,779,778; compounds of the type c) are
described in EP-A 0,006,~27, corresponding to US
Patent No. 4,248,957.
Suitable radiation-sensitive components which
form strong acids on exposure to light are a large
number of known compounds and mixtures, such as
phosphonium, sulfonium and iodonium salts, halogen
compounds and organometal/organohalogen combinations.
The said phosphonium, sulfonium and iodonium
compounds are used in the form of their salts which
are soluble in organic solvents, generally as
_g_
20~Q05Z
precipitates with complex acids such as tetrafluoro-
boric acid, hexafluorophosphoric acid, hexafluoro-
antimonic acid and hexafluoroarsenic acid.
In principle, as halogen-containing,
radiation-sensitive compounds which form hydrohalic
acid, use may be made of all the organic halogen
compounds which are also known as photochemical
radical starters, for example those containing at
least one halogen atom on a carbon atom or on an
aromatic ring (US Patents No. 3,515,552, No.
3,536,489 and No. 3,779,778). Of these compounds,
the s-triazine derivatives containing halomethyl
groups, in particular trichloromethyl groups, and an
aromatic or unsaturated substituent in the triazine
nucleus, such as are described in German Patent
Specification 2,718,259, corresponding to US Patent
No. 4,1~9,323, and in German Patent 33 37 024,
corresponding to US Patent No. 4,619,998, are
preferred. Equally well-suited are 2-trichloro-
methyl-1,3,4-oxdiazoles (German Offenlegungsschrift
28 51 471, corresponding to US Patent No. 4,212,970).
The action of these halogen-containing compounds may
also be influenced spectrally and increased by known
sensitizers.
Examples of suitable photochemical acid donors
are 4-Methyl-6-trichloromethyl-2-pyrone,
4-(3,4,5-trimethoxystyryl)-6-trichloromethyl-
2-pyrone, 4-(4-methoxystyryl)-6-(3,3,3 trichloro-
propenyl)-2-pyrone, 2-trichloromethylbenz-imidazole,
2-tribromomethylquinoline, 2,4-dimethyl-
l-tribromoacetylbenzene, 3-nitro-1-tribromoacetyl-
benzene, 4-dibromoacetylbenzoic acid, 1,4-bis-
(dibromomethyl)-benzene, tris-dibromomethyl-s-
-10-
- : - . - . : . ~
ZO()OID52-`
t ri azine, 2 - (6-methoxynaphth-2-yl)-,
2-(naphth-1-yl)-, 2-(4-ethoxyethylnaphth-1-yl)-, 2-
(benzopyran-3-yl)-, 2-(4-methoxyanthrac-1-yl)-, 2-(4-
styrylphenyl)-, and 2-(phenanthr-9-yl)-4,6-
bis(trichloromethyl)-s-triazine and the compounds
cited in ~he examples.
The quantity of the photochemical acid donor
may also vary very considerably depending on its
chemical nature and the composition of the mixture.
Favorable results are obtained with about 0.5 to 20
percent by weight, based on the total solids content
of the mixtures. Preferred are about 0.1 to 12
percent by weight. Particularly for light-sensitive
layers having thicknesses exceeding 0.01 mm, it is
advisable to use relatively little acid donor.
The binders used are polycondensates or
polymers possessing free phenolic hydroxyl groups,
whereby the content of phenolic hydroxyl groups
preferably varies between about 2 and 9mmol/g of
binder. Examples of polycondensates include phenolic
resins of the novolak type or hydroxy-substituted
aramides. Examples of polymers include homo- and
copolymers of vinyl phenols (German Offenlegungs-
schrift 23 22 230, corresponding to US Patent No.
3,869,292; and German Offenlegungsschrift 34 06 927,
corresponding to US Patent No. 4,678,737), polymers
of the esters of acrylic acid and phenols (Japanese
Published Application 76/36129 and European Published
Application 0,212,439) or copolymers of hydroxyphenyl
maleimides (European Published Application
0,187,517). The glass transition temper~tures of
these binders vary in accordance with their
respective field of application. For dry resists
. ~ : ': : .`., ' .,
.. . . .
:.' . ' . ' '.............. '~' ', :
Z000()52
where good laminating properties are required, glass
transition temperatures of less than 100C are
advantageous. For the production of planographic
printing plates or microelectronic circuitry, glass
transition temperatures of more than lOO~C are
favorable~. The amount of binder generally is from
about 20 to 90~ by weight, preferably from about 50
to 85% by weight, relative to the non-volatile
constituents of the mixture.
Additionally, numerous other oligomers and
polymers may also be used at the same time, for
example, vinyl polymers such as polyvinyl acetals,
polymethacrylates, polyacrylates, polyvinyl ethers
and polyvinylpyrrolidones, which may themselves be
modified by comonomers.
The most favorable proportion of these
additives depends on the application-engineering
requirements and the effect on the development
conditions and is, in general, not more than about
20% by weight of the binder possessing lateral
phenolic groups. For special requirements such as
flexibility, adhesion, gloss etc., the radiation
sensitive mixture may, in addition, also contain
substances such as polyglycols, cellulose ethers,
for example ethylcellulose, wetting agents and finely
divided pigments in small quantities.
Furthermore, soluble or finely divided
dispersible dyes and also, depending on the purpose
of application, uv absorbers may also be added to the
radiation-sensitive mixture. Mixtures based on 1,2-
quinonediazides, which shall possess a wide process
latitude for positive-negative conversion,
furthermore contain a component which is capable of
-12-
- ,: . - - : . . , - , ,: , ., ,~ - - . - . . .".. , - :
2000052
forming a salt with the carboxylic acid set free upon
irradiation.
The invention also relates to a radiation-
sensitive copying material comprising a layer support
coated with the above-described radiation-sensitive
mixture.
To coat a suitable layer support, the mixtures
are, in general, dissolved in a solvent. The choice
of the solvents should be matched to the coating
method envisaged, the film thickness and the drying
conditions. Suitable solvents for the mixture
according to the invention are ketones such as methyl
ethyl ketone, chlorinated hydrocarbons such as
trichloroethylene and 1,1,1-trichloroethane, alcohols
such as n-propanol, ethers such as tetrahydrofuran,
alcohol ethers such as ethylene glycol monoethyl
ether, and esters such as butyl acetate. Mixtures
may also be used and these may contain, in addition,
solvents for specific purposes, such as acetonitrile,
dioxan or dimethylformamide. In principle, all
solvents may be used which do not react irreversibly
with the layer components. Partial ethers of
- glycols, in particular ethylene glycol monomethyl
ether and propylene glycol monomethyl ether, alone or
in a mixture, are particularly preferred.
For layer thicknesses below approx. 10 ~m,
metals are generally used as support materials. For
offset printing plates, the following may be used:
mill-finished, mechanically and/or electrochemically
grained and optionally anodically oxidized aluminum
which may, in addition, also be pretreated
chemically, for example with polyvinylphosphonic
-13-
. .
Z(~0005~
acid, silicates, phosphates, hexafluorozirconates or
with hydrolyzed tetraethyl orthosilicate.
The layer support is coated in a known manner
by spin-coating, spraying, immersing, by roller
application, by means of wide slit nozzles, doctor-
blading or curtain application.
For exposure to light, use may be made of the
standard light sources such as fluorescent lamps,
pulsed xenon lamps, metal-halide doped mercury-vapor
high-pressure lamps and carbon-arc lamps.
In this description, exposure to light or
irradiation is to bP understood as exposure to
actinic electromagnetic radiation in wavelength
ranges below about 500 nm. All radiation sources
emitting in this wavelength range are, in principle,
suitable.
Advantageously, use may also be made of laser
irradiation apparatuses, in particular, automatic
processing units which contain, for example, an ~
20 argon-ion or crypton --ion laser as radiation source. - `
The irradiation may also be carried out with
electron beams. X-rays may also be used for image
generation.
The layer exposed to light or irradiated in
imagewise configuration may be removed in a known
manner with virtually the same developers as are
known for commercial naphthoquinone diazide layers
and resists, or the novel materials may
advantageously be matched in their copying behavior
to the known aids such as developers and programmed
spray-development apparatuses. The aqueous developer
solutions may, for example, contain alkaliphosphates,
silicates or hydroxides and furthermore, wetting
.,; ,,
Z00005~
agents and also, optionally, relatively small
proportions of organic solvents. In particular
cases, solvent/water mixtures may be used as
developers. The choice of the most favorable
developer may he determined by experiments with the
layer used in a particular case. If required, the
development may be promoted mechanically.
If used as printing plates, the developed
plates may be heated for a short time to elevated
temperatures, as is known for diazo films from GB
Patent Specification 1,lS4,749, to increase the
mechanical strength during printing and also the
resistance to wash-out agents, deletion agents and
printing inks which can be cured with W light.
Examples of preferred embodiments are
specified below. In the examples, parts by weight
(pbw) and parts by volume (pbv) are in the ratio of g
to cm3, Unless otherwise speci~ied, percentage and
quantity ratios are to be understood as being in
weight units.
Exam~le 1
An aluminum plate which was grained in
hydrochloric acid, anodized in sulfuric acid and
hydrophilized with polyvinylphosphonic acid is
spin-coated with the following solution, which
according to EP-A 0,212,482 is suitable for
conversion processes:
1 6 pbw of an esterification product obtained
from 3 mol of 1,2-naphthoquinone-2-
- 30 diazide-4-sulfonyl chloride and 1 mol of
2,3,4-tri-hydroxybenzophenone,
-15-
- : ~ ' ~ ' ' .: : :
Z00005Z
8.0 pbw of a m-cresol/formaldehyde novolak having
a hydroxyl number of 320 and an average
molecular weight of 6,000,
0.8 pbw of 2,6-bis-hydroxymethyl-4-methylphenol,
0.05 pbw of 2-(4-styrylphenyl)-4,6-bis-trichloro-
methyl-s-triazine, and
0.1 pbw of dye (see Table 1), in
100 pbw of a solvent mixture of tetrahydrofuran
and propylene glycol monomethyl ether
(55:45).
Drying for 2 minutes at 100C results in layer
thicknesses of 2 ~m.
The printing plates are exposed to light under
a 5 kW metal halide lamp at a distance of 110 cm
through a continuous tone step wedge with 13 density
steps of 0.15 each (exposure wedge "BK 01"
manufactured by Hoechst AG), subsequently heated to
125C for 2 minutes, thereafter exposed without an
original for 40 seconds, and then developed for 60
seconds in the following developer composition:
8.5 pbw of Na2SiO3 9 H20
0.8 pbw of NaOH and
1.5 pbw of Na2B4O7 10 H20 i~
89.2 pbw of H2O.
':
In all cases, negative images of the original
are obtained. The individual results are compiled in
Table 2 below. The image contrast was evaluated
visually as follows:
~.
' "
;~000052
:
+ good contrast between exposed and unexposed
areas
o difference in contrast between exposed and
unexposed areas still recognizable visually
5 - visual contrast between exposed and unexposed
areas unsatisfactory for practical purposes.
Table 1
Dye No. Name of Dye
1 5'-chloro-1',3',3'-trimethyl-6-nitro-8-methoxy- I :.
spiro[2~-1-benzopyran-2,2'-indoline]
2 1',3'~3'-trimethyl-6-nitro-spiro[2H-l-benzo-
pyran-2,2'-indoline] ¦¦
3 1'.3',3'-trimethyl-6-nitro-8-methoxy-spiro-
[2H-1-benzopyran-2,2'-indoline]
4 Crystal Violet (C.I. 42555)
(Comparison)
Victoria Pure Blue (C.I. 42595)
(Comparison) l
.. Il
6 Astrazone Red Violet 3RN (C.I. 48013)
(Comparison)
. .. , __ 11
7 Sudan Yellow GG~ (C.I. 11021)
(Comparison)
. .
Table 2 below also indicates, which clean step
results on the test wedge when the imagewise exposure ~-
10 for 60 seconds is immediately followed by '
development, i.e., when processing is performed
positively.
-17-
ZOU0052 ~
Table 2
_
Ex- Dye Color Change Image Contrast Fully Clean
ample No. before after covered step
No. heating heating step (pos.
(neg. proc.)
proc.)
. .:
1/1 1 blue-violet-~ + + 3 3
yellow-green
1/2 2 blue-violet~ + + 3 3
yellow-green :
_
1/3 3 blue-violet~ + + 3 3
yellow-green
__
1/4 4 blue-violet~ + - -- 3 3
(Comp.) yellow-green
1/5 5 green ~~ + - 3 3
(Comp.) yellow-green
.. ..
1/6 6 red~ + 3 3
(Comp.) light red
/7 7 yellow ~ + o 2 1
(Comp.) brown
.
These results show that excellent image contrasts of
outstanding thermal stability are achieved with the
spiro-indolino-benzopyrans according to this
invention.
Example 2 -
Coating solutions are prepared from:
5.0 pbw of binder (see Table 3)
1.4 pbw of an oligomeric acetal obtained by :
polycondensation of triethylene glycol
and 2-ethylbutyraldehyde, hydroxyl number .:
140,
:
I, j . . .
-18-
., . .. ... 1' . , .. . .. ~ -,
'. " - '. " ' ' , . ' ' ' ' ' . '' ' ' " " . " ' I" ' .. ' .. ' .. ' . . '
Z000052
.
0.2 pbw of 2-(4-styrylphenyl)-4,6-bis-trichloro-
methyl-s-triazine, and
X pbw of dye (amount and name see Table 4), in .
100 pbw of the solvent mixture of Example 1.
The solutions are spun onto aluminum plates
which were pretreated as described in Example 1.
After drying at 100C for 2 minutes layer thicknesses
of 2.5 ~m result. Thi~ copying layer is overcoated
with a 0.2 ~m thick, non-photosensitive cover layer
comprised of an aqueous solution of polyvinyl alcohol
(X-value 4; content of residual acetyl groups 12%),
in accordance with DE-A 37 15 790.
Table 3
~ ~ _
~inder Composition Hydroxyl Weight average
No. number value (GPC)
1 m-Cresol-formaldehyde- 320 6,000
. . ` I
2 copolymer (45:55) of 230 20,000 l :.
4-hydroxystyrene and
methylmethacrylate
3 copol~e. t7^ 30) Oc 240 20,000
2-hydroxyphenylmeth-
I acrylate and styrene
_ 11 : - '
3,5-dimethyl-4- 225 15,000
l hydroxybenzylmeth- l
I acrylamide and styrene l -~:
_ _ .
--19--
:: , :
. : -: , . ~.
2000052
Table 4
:
Dye Amount Name
3 0.03 1',3',3'-trimethyl-6-nltro-8-methoxy-
spiro-[2~-1-benzopyran-2,2'-indoline]
8 0.05 Acid Violet 520 PINAR, anti-halo dye, ¦
¦(Comp.) from Riedel de Haen, art.-No. 28587
9 O.OS Acid Violet 520 T PINAR, art.-No. 28579
(Comp.)
O.OZ Crystal Violet Base
Comp.)
Dyes Nos. 8 and 9 belong to the class of hemioxonol
dyes described in DE-A 35 41 534.
The printing plates are exposed for 20 seconds
through an original as described in Example 1, then
heated to 80C for 1 minute to complete the acetal
hydrolysis and thereafter developed for 1 minute in
the developer of Example 1. The results are shown in
Table 5 below. The exposure contrast was judged and
evaluated as in Example 1. To test the shelf life of
the plates, they were stored at 100C over a
prolonged time, and the development behavior was ~ -
examined in intervals of 1 hour. After 6 hours, the
test was stopped.
15The results show that the contrast stability
which can be achieved with the hemioxonol dyes is
comparable to the stability achieved using the
spiro-indolino-benzopyrans of this invention.
However, the shelf life of the layers is considerably
reduced.
-20-
200UOS2
Table 5
_ I
1~- r~ ~ C~QE~ ~3e ~ cl~ ~f
~e ~. ~. b~ a~ s~p (~
I ~. ~ ~ ~ oc
I
12-1 3 1 ~Lev~ + + 3 >6
I _ . ~ .. _ _ .~
2-2 8 ~ + + 4 < 1 I :
~ t red l
I _~
12-3 9 1 ~k~ + + 4 1 I
I (~P ) li~ r~ l
12-4 10 1 bll~ ~ + - 3 > 6 I .
(C~P ) ~ _ .. _ 11 '"
1 2-5 3 3 ~11E~ ~ + + 3 > 6 I .
~ -- - --I
1 2-6 8 3 ~ + + 4 C 1 I
(a:~Zp. ) ~k ~ I
I
1 2-7 9 3 ~ + + 4 1 1
(~p. ) li~ l
.... ___ 11
1 2-~3 10 3 k~ + - 3 > 6 1 ~ -
(~P~) ~ :~
1 2-9 3 2 ~ + + 3 > 6 1
~ l - .
._ - I
2-10 3 4 ~ + + 3 > 6
~e~ I
-- -- , -- - --- , __ . _- ~ .
Example 3
Coating solutions are prepared from:
. . .
8.0 pbw of the binder of Example 1, --
1.6 pbw of an esterification product obtained
from 1 mol of 1,2-naphthoquinonediazide- -
4-sulfonyl chloride and 1 mol of
p-cumylphenol,
. .
' . ' ' ' . .
'` ' ' ' ' : ` ` ,. ` ' ,.' ' ' ` ,, ',, ', .. ~ .;:. :. ':
'Z0~5Z
X1) pbw of 2, 4-diethoxy-6-diethylamino-
s-triazine, according to DE-A-37 11 263,
as a base,
X1) pbw of 2 - (4-styrylphenyl ) -4, 6-bis-
trichloromethyl-s-triazine, as an acid
f ormer, and
Xl ) pbw of dye, in
loO pbw of the solvent mixture of Example 1
1) amounts indicated in Table 6 below
These solutions are spin-coated onto aluminum
plates which were pretreated as described in Example
1. After drying at 100 C for 2 minutes, layers
having thicknesses of 2 ,um are obtained. -
The printing plates are exposed for 60 seconds
15 through an original, as desc ribed in Example 1,
stored for 2 minutes at various temperatures (Table !'
6), then exposed for 40 seconds without original and
developed as in Example 1.
The results are compiled in Table 6. Contrast
20 stability was evaluated as in Example 1. The term
"temperature latitude" defines the temperature range
where a positive-negative conversion is possible
within a conversion period of 2 minutes. -
Examples 3-2 and 3-3 show that a wide -
25 temperature latitude for the conversion can also be
achieved when spiro-indolino-benzopyrans are added in
quantities which have found to be advantageous for
the base additives for achieving a favorable
conversion behavior.
--22--
., .. ,. ,, . . .:.:: . , .. : ~ . .. . , . , ,, ~
Z00~)052
Ta~le b
~) ~ ~. ~ ~ af~ la~b~ l
~) ~ ~ (C) I
..
~1 ~ ~145 I
(Cblp.) ~ I . .
I
3-2 - _ 2 (0.4) vi~ gr~ + + 95 145
3-3 - - 3 (0.4) ~finlet~ + + 95 145
. _ ._. .
3-4 0.4 - 3 (0.1) ~lL~vi~et~ + + 50 145 l
Y~
3~5 0.40.05 3 (0.1) ~ + + S5 145 I
Y~ I '
3~ 0.4 - 5 (0.1) gre~n~ - - 90 145 l
(~P ) I
3-7 0.40.05 5 (0.1) ~n-~ - - 95 145 I .
((h~p.)
3~3 0.4 - 3 (0,05) hll~ ~ + + 90 145 l
S (O.~i) ~ I
_ _
3~ 0.4 - 7 (0.05) g~n ~ + o 90 145
(C~P ) 5 (0.05) ~ I
.
Example 4
~oating solutions are prepared from: ;
5.0 pbw of a 1:1 mixture of the polymeric binders
No. 1 and No. 3 of Table 3,
0.5 pbw of an esterification product obtained
from 3 mol of 1,2-naphthoquinone-
2-diazide-4-sulfonyl chloride and 1 mol
of 2,3,4-trihydroxylbenzophenone,-
1.2 pbw of the oligomeric acetal of Example 2,
0.15 pbw of 2-(4-styrylphenyl)-4,6-bis- ~ '
trichloromethyl-s-triazine, and
-23-
- ,. . ....... .
., ; , ~ - : . :, , . ' ' , . ': ~: . ,
Z~00()52
'~
X pbw of dye (type ancl amount see Table 7), in
100 pbw of the solvent mixture of Example 1.
The solutions are coated onto aluminum plates
which were pretreated as described in Example 1, such
that layer thicknesses of 2 ~m resulted after drying
periods of 2 minutes at 100C. The copying layers
are provided with polyvinyl alcohol cover layers, as
described in Example 2. '
The plates were exposed through a continuous
tone step wedge and a screened original (60 lines/cm)
- for 30 seconds, as described in Example 1,
subsequently heated for 1 minute to 80C and then
developed for 1 minute in the developer of Example 1.
":
The results are compiled in Table 7 below.
:
' ,
Table 7
,. .
. .
E~ n 5l~ ~n t~t
a ple N: . ~ ~ b~e a~r a~ im
N~ t~ s~p (2 96 ~)
~je ., ,~: .
~1 3 (0.06) bl~ ~ + + 4 al~t
~ ~ebe ,:
4-2 10 (0.04) ~vi~ ~ l - 4 ally - : :
Earbally ..
_ - : .. ....
The baking behavior of the plates is tested by
heating them to 230C for 5 minutes and then testing
their resistance to chemicals and the print run. The
results are summarized in Table 8 below. -(`
. ~ .~
~ .:
-24-
-!., ,
',
Z000052
Table 8
d~ ~s~En~ n~ ~ a~
to d~l ~ E~
. b~ ~o~g~b~
4-1 h~e~ + ~.o~
4-2 h~v~ + ~.~ .
. ._ ._.
The above Examples show that the reproduction
properties are favorably influenced by the
spiro-indolino-benzopyrans according to this
invention, and that these dyes indicate a baking
treatment by a color change.
