CA2000052A1 - Radiation-sensitive mixture and radiation-sensitive copying material prepared therefrom - Google Patents

Abstract

Abstract of the Disclosure The invention relates to a radiation- or photosensitive mixture and to a radiation-sensitive copying material produced from said 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 acid-cleavable C-O-C bond;
B) a binder which is insoluble in water and soluble in aqueous-alkaline solutions; and C) a spiro-indolino-benzopyran of the general formula I

in which R denotes hydrogen or an alkyl radical having 1 to 6 carbon atoms, R1, R2, R3, R4 are identical to or different from one another and denote hydrogen or halogen, alkyl groups or alkoxy groups having 1 to 4 carbon atoms or hydroxy groups or nitro groups; and R5, R6, R7, and R8 are identical to or different from one another and denote hydrogen or halogen, nitro groups or amino groups, alkyl groups, alkoxy groups or hydroxyalkyl groups having 1 to 5 carbon atoms or aryl groups having 6 to 10 carbon atoms.

Upon exposure, the mixture results in a very pronounced color contrast which is maintained even at elevated temperatures.

Description

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. !~

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,,. - . , . : ;' ,,, : . ~ : '. . , : ,.

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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.

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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 - - - - , ~ .- - . ~ - - .

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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.

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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'-~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.

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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-- : - . - . : . ~

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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 - ,: . - - : . . , - , ,: , ., ,~ - - . - . . .".. , - :

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 . .

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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, - : ~ ' ~ ' ' .: : :

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:

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;~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.

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, :
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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 -~:
_ _ .

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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.

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, . .

' . ' ' ' . .

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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.

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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 - ,. . ....... .

., ; , ~ - : . :, , . ' ' , . ': ~: . , 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. -(`
. ~ .~
~ .:

-!., , ', 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.

Claims (10)

1. A radiation-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 C) a dye, comprising a spiro-indolino-benzopyran of the general formula I

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.

2. A mixture as recited in claim 1, said dye comprising a compound of the formula I wherein at least one of the radicals R1, R2, R3, and R4 is a nitro group.

3. A mixture as recited in claim 1, said dye comprising a compound of the formula I wherein three of the radicals R, R5, R6, R7, and R8 are methyl groups.

4. A mixture as recited in claim 1, wherein said mixture contains between about 0.01 to 10% by weight said dye, relative to total solids.

5. A mixture as recited in claim 1, further comprising a cationic dye.

6. A mixture as recited in claim 5, wherein said cationic dye comprises a triarylmethane, acridine, azine, oxazine, thiazine or cyanine dye.

7. A mixture as recited in claim 5, wherein said mixture contains between about 0.01 to 10% by weight said cationic dye, relative to the total solids content.

8. A mixture as recited in claim 1, wherein said 1,2-quinonediazide compound is an ester or amide of 1,2-naphthoquinone-2-diazide-4- or -5-sulfonic acid.

9. A radiation-sensitive mixture as recited in claim 1, wherein said compound having at least one acid-cleavable C-O-C bond is an oligomeric or polymeric compound possessing recurring acetal groupings and/or ketal groupings in the main chain.

10. A radiation-sensitive copying material, comprising layer support and a mixture as recited in claim 1.