Radiation-sensitive composition, radiation-sensitive recording material produced therewith and process for the production of relief records.

0001The invention relates to a radiation-sensitive mixture, a recording material produced therewith and a method for producing heat and chemical-resistant relief recordings by means of this recording material. The invention is based on a positive working radiation or light-sensitive mixture, which are essential components<ul id="ul0001" list-style="none"><li>a) a water-insoluble, polymeric binder soluble in aqueous alkaline solutions and</li><li>b) a 1,2-quinonediazide and / or a combination of</li><li>1. a compound that forms a strong acid under the action of actinic radiation</li></ul> and<ul id="ul0002" list-style="none"><li>2nd a compound with at least one cleavable COC bond</li></ul> contains.

0002Positive-working light-sensitive mixtures, that is to say mixtures of the constituents mentioned, the copying layer of which becomes soluble in the exposed areas, are known and are known for a variety of possible uses, such as described for the production of planographic printing plates or photoresists.

0003A substantial part of the properties of these copying layers is determined by the main quantitative component of the radiation or light-sensitive mixture, the binder. Phenol or cresol-formaldehyde condensation products of the novolak type are used almost exclusively as binders for positive copying layers. For some applications of positive copying layers, however, the resulting properties are not yet optimal. This applies in particular to the heat resistance in the case of photoresist applications and the amount of print runs when used as planographic printing plates.

0004It has been shown that the novolaks are suspended by binders with a higher glass transition temperature, resulting in a generally better property profile. A whole series of alkali-soluble binders for positive copying layers have been described, such as, for example, naphthol-based phenolic resins (US Pat. No. 4,551,409), homopolymers and copolymers of vinylphenols (DE-A-23 22 230 corresponding to US Pat. No. 3,869,292 and DE-A-34 06 927 corresponding to US-A 4 678 737), polymers of the esters of acrylic acids with phenols (JP-OS 76/36 129, EP-A 0 212 440 and EP-A-0 212 439) or copolymers of Hydroxyphenyl maleimides (EP-A-0 187 517).

0005However, binders of the type mentioned have not yet been able to be used in practice. One reason for this is that these polymers do not satisfactorily meet an essential requirement that is placed on binders of positive copying layers, namely the possibility of thermal self-crosslinking. This property, which is given with novolaks, is important if the copy layer is to withstand aggressive chemicals.

0006DE-A-38 20 699 describes polymers based on hydroxybenzyl acrylamides which meet the requirement for crosslinkable, alkali-soluble monomer units. However, it is disadvantageous that these monomers can only be present in the polymer in a limited amount, since otherwise photosensitivity and development behavior are adversely affected.

0007Furthermore, it is also known to incorporate units into the polymers which are not soluble in alkali, but which enable thermal crosslinking, such as the polymers described in EP-A-0 184 044, corresponding to US Pat. No. 4,699,867, with crosslinking -CH₂ -OR units, where R is hydrogen, alkyl or acyl groups. However, these units in the polymers also impair the development behavior if they are present in the amounts necessary for reliable thermal post-curing.

0008It was therefore an object of the invention to provide a positive-working radiation-sensitive mixture for a corresponding recording material, with which planographic printing plates with a higher print run performance or photoresists with improved heat resistance can be provided, and which can be thermally crosslinked without impairing its photosensitivity and development behavior.

0009The solution to this problem is based on a positive-working radiation-sensitive mixture of the type mentioned at the outset and is characterized in that in the mixture as a polymeric binder, a polymer having a molecular weight between 5000 and 100000 and a phenolic hydroxyl group content of approximately 1 to 15 mmol / g of polymer and a content of -CH_3-nX_n Units of at least 0.1 mmol / g polymer, where X is halogen and n is 1, 2 or 3, is present.

0010The polymer according to the invention preferably has a content of about 2 to 10 mmol / g of phenolic hydroxyl groups and a content of about 0.5 to 2 mmol / g of -CH_3-nX_n Units.

0011Are the phenolic hydroxyl groups and the cross-linkable -CH_3-nX_n Units not within the same monomer unit, the polymeric binder is preferably a copolymer which a) units of formula I.<chemistry id="chem0001" num="0001"><img file="EP0440086A2_D0001.tif" /></chemistry> wherein<ul id="ul0003" list-style="none"><li>R₁ is hydrogen or (C₁-C₄) alkyl,</li><li>A a single bond or a configuration A₁ from the series</li></ul><chemistry id="chem0002" num="0002"><img file="EP0440086A2_D0002.tif" /></chemistry><ul id="ul0004" list-style="none"><li>with K for -O-, -S- or -NR₂- and R₂ hydrogen or (C₁-C₄) alkyl or (C₁-C₄) alkylene,</li><li>B is a mono- or dinuclear carbocyclic aromatic ring system which is optionally substituted by alkyl, alkoxy, halogen or aryl and</li><li>m 1 or 2</li></ul> mean and

b) units of the general formula II

0012<chemistry id="chem0003" num="0003"><img file="EP0440086A2_D0003.tif" /></chemistry> wherein<ul id="ul0005" list-style="none"><li>R₃ is hydrogen or (C₁-C₄) alkyl,</li><li>D is a single bond, (C₁-C₄) alkylene or the configuration A₁,</li><li>E is a single bond, (C₁-C₄) alkylene, (C₁-C₄) hydroxyalkylene or B,</li><li>X halogen and</li><li>n 1, 2 or 3</li></ul> mean contains.

0013In particular, the copolymer contains units of the general formula I in which<ul id="ul0006" list-style="none"><li>R₁ is hydrogen or methyl,</li><li>A the configuration A₁<chemistry id="chem0004" num="0004"><img file="EP0440086A2_D0004.tif" /></chemistry></li><li>with K for -O-, or -NR₂- and R₂ hydrogen,</li><li>B phenyl and</li><li>m 1 or 2</li></ul> and units of the general formula II in which<ul id="ul0007" list-style="none"><li>R₃ is hydrogen or methyl,</li><li>D a single bond or configuration<chemistry id="chem0005" num="0005"><img file="EP0440086A2_D0005.tif" /></chemistry></li><li>with K for -O- or -NR₂- and R₂ hydrogen,</li><li>E is a single bond, (C₁-C₂) alkylene, (C₁-C₂) hydroxyalkylene or phenyl,</li><li>X chlorine or bromine and</li><li>n 1, 2 or 3</li></ul> mean.

0014Are the phenolic hydroxyl groups and crosslinking -CH_3-nX_n Units within the same monomer unit, the binder according to the invention has units of the formula III as homo- or copolymer:<chemistry id="chem0006" num="0006"><img file="EP0440086A2_D0006.tif" /></chemistry> wherein<ul id="ul0008" list-style="none"><li>R₄ is hydrogen or (C₁-C₄) alkyl,</li><li>G is a single bond or (C₁-C₄) alkylene or a configuration G₁ from the series<chemistry id="chem0007" num="0007"><img file="EP0440086A2_D0007.tif" /></chemistry></li><li>with F for -O-, -S- or -NR₅- and R₅ hydrogen, (C₁-C₄) alkyl or (C₁-C₄) alkylene,</li><li>H is a mono- or dinuclear carbocyclic aromatic ring system which is optionally substituted by alkyl, alkoxy, halogen or aryl,</li><li>X halogen,</li><li>m 1 or 2 and</li><li>n 1, 2 or 3</li></ul> mean. In particular, the homo- or copolymer contains units of the general formula III in which<ul id="ul0009" list-style="none"><li>R₄ is hydrogen or methyl,</li><li>G a single bond or configuration</li><li>G₁<chemistry id="chem0008" num="0008"><img file="EP0440086A2_D0008.tif" /></chemistry> with F for -O-,</li><li>H phenyl,</li><li>X chlorine,</li><li>m 1 or 2 and</li><li>n 1</li></ul> mean.

0015It can be advantageous if the polymeric binder is a copolymer which contains units of the formulas I, II and III.

0016Radiation-sensitive mixtures are preferred in which a copolymer is present as a polymeric binder which contains or consists of units of the general formulas I and II and / or III.

0017Homopolymers or copolymers corresponding to formulas I, II or III contain chlorine, bromine or iodine, in particular chlorine, for X as halogen. It has been shown that m and n are preferably equal to 1.

0018A benzene or naphthalene nucleus may be mentioned as a mono- or dinuclear carbocyclic aromatic ring system, of which the benzene nucleus is preferred.

0019Preferred monomer units corresponding to formula I are, for example: N- (4-hydroxyphenyl) methacrylamide, N- (4-hydroxyphenyl) acrylamide, o-, m- and p-hydroxyphenyl acrylate or methacrylate and o-, m- and p-hydroxystyrene, 4-hydroxy-3-methylstyrene, 4 -Hydroxy-3,5-dimethylbenzyl methacrylate or methacrylamide and N- (4-hydroxyphenyl) maleimide.

0020Preferred examples of monomer units corresponding to formula II are: 2-, 3-, 4-chloromethylstyrene, vinyl chloroacetate, vinyl trichloroacetate, chloromethyl acrylate or methacrylate, 1- or 2-chloroethyl acrylate or methacrylate, N- (2,2,2-trichloro-2-hydroxyethyl) acrylamide or methacrylamide, chloromethyl vinyl ketone , 3-chloro-2-hydroxypropyl acrylate or methacrylate.

0021Preferred monomer units of the formula III are in particular the chloromethylated derivatives of the monomers corresponding to formula I.

0022In addition to the monomer units described, the polymers can also contain units which serve to adjust or adapt the polymer properties to specific applications. In the case of dry resist applications, rather low glass transition temperatures of the polymers are advantageous, which can be set, for example, by copolymerization with acrylic or methacrylic acid alkyl esters or alkyl vinyl ethers, the alkyl groups having 4 to 12 carbon atoms. Rather high glass transition temperatures are advantageous for use in printing plate copying layers. This, a good oleophilicity of the copying layer film and the content of phenolic hydroxyl groups, which is important for alkali solubility, are achieved by copolymerization with styrene, α-methylstyrene, vinyl toluene, phenyl, benzyl, furfuryl or methyl methacrylate, acrylonitrile or methacrylonitrile. It is also possible to polymerize small amounts of bifunctional monomers or monomers which lead to a thermal crosslinking reaction in the presence of acid, for example those with pendant --CH₂OR groups, in accordance with EP 0 184 044, or monomers with epoxy units, into the binder.

0023It has been shown that the presence of -CH_3-nX_n-Units of at least 0.1 mmol / g polymer is sufficient. A content of about 0.5 to 2, in particular of about 1 mmol / g of polymer has proven to be favorable in order to achieve favorable curing. If necessary, higher levels can also be present without adversely affecting other properties.

0024The polymers according to the invention are prepared by homo- or copolymerization of monomers which are crosslinkable -CH_3-nX_n Units included and / or through the subsequent introduction of the -CH_3-nX_n Units in the polymers. In the case of the chloromethyl groups in particular, this is achieved in a simple and known manner by reaction with chloromethyl alkyl ethers in the presence of acid.

0025The homopolymerization of the monomers with units of the formulas I to III or their copolymerization with other monomers can be carried out by conventional methods, for example in the presence of a polymerization initiator such as azo-bis-isobutyronitrile in organic solvents such as methyl ethyl ketone or tetrahydrofuran at elevated temperatures for a period of 1 up to 20 hours. In addition, however, a suspension, emulsion or bulk polymerization is also possible, which can also be triggered by radiation, heat or ionic initiators.

0026To prepare the mixtures according to the invention, the binder described, which is present in amounts in the range from 10 to 95 percent by weight, based on nonvolatile constituents of the mixture, is combined with photosensitive compounds or mixtures, the solubility of which in an aqueous alkaline developer solution is increased with the exposure becomes. These include 1,2-quinonediazides and mixtures of photolytic acid donors with acid-cleavable compounds.

0027Naphthoquinone-1,2-diazide- (2) -4- or -5-sulfonic acid esters or amides are preferably used as 1,2-quinonediazides. Of these, the esters, especially those of 5-sulfonic acids, are preferred. Suitable compounds of this type are known and are described, for example, in DE-A 938 233, corresponding to GB-B 739,654.

0028The amount of o-quinonediazide compounds is generally 3 to 50, preferably 7 to 35 percent by weight, based on the nonvolatile components of the mixture.

0029It is also possible to use the 1,2-quinonediazide compounds in the form of their esters with the polymers according to the invention.

0030The esterification of the corresponding 1,2-quinonediazide chlorides with the hydroxyl groups of the polymers on which they are based is carried out by the processes known in the literature (DE-A 25 07 548, corresponding to US Pat. No. 4,139,384).

0031Materials based on acid-cleavable compounds can also be used with good effect in the mixture according to the invention. The following can be mentioned as acid-cleavable compounds:<ul id="ul0010" list-style="none"><li>a) those with at least one orthocarboxylic acid ester and / or carboxamide amide acetal group, the compounds also being polymeric in nature and the said groups may appear as linking elements in the main chain or as pendant substituents,</li><li>b) oligomer or polymer compounds with recurring acetal and / or ketal groups in the main chain and</li><li>c) Compounds with at least one enol ether or N-acylaminocarbonate grouping.</li></ul>

0032Acid-cleavable compounds of type a) as components of radiation-sensitive mixtures are described in detail in EP-A 0 022 571, corresponding to US Pat. No. 4,311,782; Mixtures containing compounds of type b) are described in DE-C 23 06 248, corresponding to US-A 3 779 778, and in DE-C 27 18 254 and US-A 4 189 323; Compounds of type c) are disclosed in EP-A 0 006 627, corresponding to US-A 4 248 957.

0033The type and amount of the cleavable compound can vary depending on the type of application. Portions between 5 and 70 percent by weight, in particular 5-40 percent by weight, based on the non-volatile portions of the mixture, are preferably used.

0034A large number of known compounds and mixtures, such as phosphonium, sulfonium and iodonium salts, halogen compounds and organometal-organohalogen combinations are suitable as radiation-sensitive components which form strong acids on exposure.

0035The phosphonium, sulfonium and iodonium compounds mentioned are generally used in the form of their salts, which are soluble in organic solvents, mostly as a deposition product with complex acids such as borofluorohydric acid, hexafluorophosphoric acid, hexafluoroantimonic acid and arsenic acid.

0036In principle, all organic halogen compounds also known as photochemical starters, for example those having at least one halogen atom on a carbon atom or on an aromatic ring, can be used as halogen-containing radiation-sensitive and hydrohalic acid-forming compounds (US Pat. No. 3,515,552). Of these compounds, the s-triazine derivatives with halomethyl groups, in particular trichloromethyl groups and an aromatic or unsaturated substituents in the triazine nucleus, as described in DE-C 27 18 259, corresponding to US Pat. No. 4,189,323, are preferred. 2-Trihalomethyl-1,3,4-oxdiazoles are also suitable. The effect of these halogen-containing compounds can also be spectrally influenced and increased by known sensitizers.

0037Examples of suitable photochemical acid donors are: 4-methyl-6-trichloromethyl-2-pyrone, 4- (3,4,5-trimethoxy-styryl) -6-trichloromethyl-2-pyrone, 4- (4-methoxy-styryl) -6- (3.3 , 3-trichloropropenyl) -2-pyrone, 2-trichloromethyl-benzimidazole, 2-tribromomethylquinoline, 2,4-dimethyl-1-tribromoacetyl-benzoic acid, 1,4-bis-dibromomethyl-benzene, tris-dibromomethyl-s-triazine, 2- (6-methoxy-naphth-2-yl) -, 2- (naphth-1-yl) -, 2- (4-ethoxyethylnaphth-1-yl) -, 2- (benzopyran-3-yl) -, 2- (4-methoxyanthrac-1-yl) -, 2- (4-styrylphenyl) -, 2- (phenanthr-9-yl) -4,6-bis-trichloromethyl-s-triazine and the compounds listed in the examples.

0038The amount of the photochemical acid donor can also be very different depending on its chemical nature and the composition of the layer. Favorable results are obtained with about 0.5 to 20 percent by weight, based on the total solids. Especially for light-sensitive layers with a thickness of more than 0.01 mm, it is advisable to use relatively little acid donor.

0039In addition, numerous other oligomers and polymers can also be used, for example phenol resins of the novolak type or vinyl polymers such as polyvinyl acetals, polymethacrylates, polyacrylates, polyvinyl ethers and polyvinyl pyrrolidones, which can themselves be modified by comonomers.

0040The cheapest proportion of these additives depends on the application requirements and the influence on the development conditions and is generally not more than 20 percent by weight of the polymer used according to the invention. In small amounts, the radiation-sensitive layer can also be used for special requirements such as flexibility, adhesion, gloss, etc., and also substances such as polyglycols, cellulose ethers, for example Contain ethyl cellulose, wetting agents and finely divided pigments.

0041Furthermore, soluble or even finely divided dispersible dyes and, depending on the application, UV absorbers can also be added to the radiation-sensitive mixture. The triphenylmethane dyes, in particular in the form of their carbinol bases, have proven particularly useful as dyes. The most favorable proportions of the components can easily be determined in individual cases by preliminary tests.

0042The invention also relates to a radiation-sensitive recording material comprising a layer support and an applied radiation-sensitive layer which contains a mixture according to the claims.

0043To coat a suitable support, the mixtures are generally dissolved in a solvent. The choice of solvent must be matched to the intended coating process, the layer 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 trichlorethylene 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 can also be used, which can also contain solvents such as acetonitrile, dioxane or dimethylformamide for special purposes. In principle, all solvents can be used that do not react irreversibly with the layer components. Partial ethers of glycols, especially ethylene glycol monomethyl ether and propylene glycol monomethyl ether, alone or in a mixture, are particularly preferred.

0044Metals are mostly used as a layer support for layer thicknesses below approx. 10 µm. The following can be used for offset printing plates: bright rolled, mechanically and / or electrochemically roughened and optionally anodized aluminum, which can also be chemically pretreated, for example with polyvinylphosphonic acid, silicates, phosphates, hexafluorozirconates or with hydrolyzed tetraethyl orthosilicate.

0045The coating of the substrate is carried out in a known manner by spinning, spraying, dipping, rolling, by means of wide-slot nozzles, doctor blades or by application by a caster.

0046The usual light sources such as tube lamps, xenon pulse lamps, metal halide-doped high-pressure mercury lamps and carbon arc lamps can be used for exposure.

0047In this description, exposure or irradiation means the action of actinic electromagnetic radiation in wavelength ranges below about 500 nm. All radiation sources emitting in this wavelength range are suitable in principle.

0048It is also advantageous to use laser radiation devices, in particular automatic processing systems, which contain, for example, an argon or krypton ion laser as the radiation source.

0049The irradiation can also be carried out with electron beams. In this case, compounds which do not form photosensitive acids in the customary sense can also be used as initiators of the solubilization reaction, for example halogenated aromatic compounds or halogenated polymeric hydrocarbons. X-rays can also be used for image generation.

0050The imagewise exposed or irradiated layer can be removed in a known manner using practically the same developers as are known for commercially available naphthoquinonediazide layers and copying lacquers, or the materials according to the invention can advantageously be copied to known auxiliaries such as developers and programmed spray development devices in their copying behavior be coordinated. The aqueous developer solutions can contain, for example, alkali phosphates, silicates or hydroxides and also wetting agents and optionally smaller proportions of organic solvents. In certain cases, solvent-water mixtures can also be used as developers. The choice of the cheapest developer can be determined by experiments with the layer used in each case. If necessary, the development can be supported mechanically.

0051In particular, the recording material according to the invention can be used in a process for the production of chemical and heat-resistant relief recordings, in which a radiation-sensitive recording material comprising a substrate and a radiation-sensitive layer is exposed imagewise, developed with an aqueous alkaline developer solution and the relief image obtained - optionally coated with a hydrophilic protective film - heated to elevated temperature.

0052The method is characterized in that a radiation-sensitive recording material according to claim 14 is used and the developed layer is heated to a temperature in the range from 150 to 280 ° C for 0.5 to 60 minutes.

0053In the case of planographic printing plates, a heating time in the lower range, approximately from 0.5 to 6 minutes, and in the case of photoresists, a heating time in the upper range, approximately from 10 to 60 minutes, is preferably used.

0054The invention ensures that radiation-sensitive mixtures and recording materials are now available which have good photosensitivity and flawless development behavior, with which it is possible to print in large quantities and which have excellent heat resistance when used as photoresist, which in particular can be post-cured thermally and, after post-curing, have better chemical resistance than known materials.

0055Examples of preferred embodiments are given below. In the examples, parts by weight (Gt) and parts by volume (Vt) are in a ratio of g to ccm. Unless otherwise stated, percentage and quantity ratios are to be understood in weight units.<tables id="tabl0001" num="0001"><img file="EP0440086A2_D0009.tif" /></tables><tables id="tabl0002" num="0002"><img file="EP0440086A2_D0010.tif" /></tables><tables id="tabl0003" num="0003"><img file="EP0440086A2_D0011.tif" /></tables>

example 1

0056An aluminum plate electrolytically roughened in hydrochloric acid, anodized in sulfuric acid and hydrophilized with polyvinylphosphonic acid is spin-coated with the following solution:<dl id="dl0001"><dt>7.0 pbw </dt><dd>(Parts by weight) binder (see Table 3),</dd><dt>1.5 pbw</dt><dd> an esterification product of 3 mol of 1,2-naphthoquinone (2) diazide-5-sulfonyl chloride and 1 mol of 2,3,4-trihydroxybenzophenone,</dd><dt>0.2 pbw</dt><dd> 1,2-naphthoquinone- (2) -diazide-4-sulfonyl chloride,</dd><dt>0.08 pbw</dt><dd> Victoriareinblau (CI 44 045),</dd><dt>100 Gt</dt><dd> a solvent mixture of tetrahydrofuran and propylene glycol monomethyl ether (55:45).</dd></dl>

0057After drying for 2 minutes at 100 ° C, a layer thickness of 2 µm results.

0058Light sensitivity test: The respective printing plates are exposed under a 5 kW metal halide lamp at a distance of 110 cm through a halftone step wedge with 13 density steps of 0.15 (exposure wedge "BK 01" from Hoechst AG) for 60 seconds (s) and for 60 seconds in one of the following developers:<tables id="tabl0004" num="0004"><img file="EP0440086A2_D0012.tif" /></tables>

0059The light sensitivity is assessed using level 3 of the halftone step wedge: open = already free of copy layer, not open = copy layer remnants still present.

0060Testing the thermal crosslinking behavior: The plates are then exposed on one side and baked in a lacquer drying cabinet at 230 ° C. for 5 minutes. Dimethylformamide is used to test the chemical resistance of the burned-in plates in the unexposed and exposed areas (+ = no attack; - = attack). exposed areas checked (+ = no attack; - = attack).

0061Examination of residence behavior: The exposed plates are developed for 15 seconds and then colored with commercially available black offset ink. The appearance of sound in the non-image areas is assessed.

0062A number of these plates were subjected to printing tests in a sheetfed offset press in the non-thermally hardened state. Table 4 shows the results.<tables id="tabl0005" num="0005"><img file="EP0440086A2_D0013.tif" /></tables><tables id="tabl0006" num="0006"><img file="EP0440086A2_D0014.tif" /></tables>

0063The results show that printing plate copying layers produced with polymers according to the invention have a higher print run than conventional positive copying layers with novolaks as binders, that they become resistant to aggressive chemicals even in pre-exposed areas by thermal post-curing, and that they have no disadvantages in terms of photosensitivity and winding.

Example 2

0064An aluminum plate electrolytically roughened in hydrochloric acid, anodized in sulfuric acid and hydrophilized with polyvinylphosphonic acid is spin-coated with the following solution:<dl id="dl0002"><dt>7.0 pbw</dt><dd> Binder (see Table 5),</dd><dt>1.5 pbw</dt><dd> an esterification product of 3 mol of 1,2-naphthoquinone (2) diazide-4-sulfonyl chloride and 1 mol of 2,3,4-trihydroxybenzophenone,</dd><dt>0.2 pbw</dt><dd> 1,2-naphthoquinone- (2) -diazide-4-sulfonyl chloride,</dd><dt>0.08 pbw</dt><dd> Victoriareinblau (CI 44 045),</dd><dt>100 Gt</dt><dd> a solvent mixture of tetrahydrofuran and propylene glycol monomethyl ether (55:45).</dd></dl>

0065After drying for 2 minutes at 100 ° C, a layer thickness of 2 µm results.

0066The photosensitivity, the thermal crosslinking behavior and the winding behavior were tested as described in Example 1.

0067Table 5 shows the results.

0068The examples show 1) the suitability of polymers according to the invention which are composed of different units corresponding to formula II and 2) that polymers with a molecular weight of> 100,000 can no longer be developed sufficiently quickly.<tables id="tabl0007" num="0007"><img file="EP0440086A2_D0015.tif" /></tables>

Example 3

0069An aluminum plate electrolytically roughened in hydrochloric acid and anodized in sulfuric acid and hydrophilized with polyvinylphosphonic acid is spin-coated with the following solution:<dl id="dl0003"><dt>5.0 pbw</dt><dd> Binder (see Table 6),</dd><dt>0.5 pbw</dt><dd> an esterification product of 3 mol of 1,2-naphthoquinone (2) diazide-4-sulfonyl chloride and 1 mol of 2,3,4-trihydroxybenzophenone,</dd><dt>1.4 pbw</dt><dd> an oligomeric acetal which was obtained by polycondensation of triethylene glycol and 2-ethylbutyraldehyde, hydroxyl number 140,</dd><dt>0.2 pbw</dt><dd> 2- (4-styrylphenyl) -4,6-bistrichloromethyl-s-triazine,</dd><dt>0.03 pbw</dt><dd> Crystal violet base (CI 42 555: 1),</dd><dt>100 Gt</dt><dd> a solvent mixture of tetrahydrofuran and propylene glycol monomethyl ether (55:45).</dd></dl>

0070After drying for 2 minutes at 100 ° C, a layer thickness of 2 µm results.

0071A non-photosensitive cover layer made of polyvinyl alcohol (K value 4, residual acetyl group content 12%) according to DE-A 37 15 790 made of water with a thickness of 0.2 μm is then applied to this copying layer.

0072The plates are exposed under a template as in Example 1 for 25 seconds, heated to 80 ° C for 1 minute and then developed. Photosensitivity, development and thermal crosslinking behavior are tested as in Example 1. The cover layer is washed off with H₂O before thermal curing.<tables id="tabl0008" num="0008"><img file="EP0440086A2_D0016.tif" /></tables>

0073The results show that the content of crosslinking -CH_3-nX_n Units in the polymer must be above 0.1 mmol / g polymer in order to ensure chemical resistance of the crosslinked film.

Example 4

0074To produce a positive dry resist, coating solutions are made from:<dl id="dl0004"><dt>40.0 pbw</dt><dd> Binder (see Table 3),</dd><dt>10.0 pbw</dt><dd> a compound with acid-cleavable COC units (Table 7),</dd><dt>0.5 pbw</dt><dd> a photochemical acid generator (Table 7),</dd><dt>6.0 pbw</dt><dd> Polyacrylate,</dd><dt>0.01 pbw </dt><dd>Crystal violet base (CI 42 555: 1),</dd><dt>100 Gt</dt><dd> Butanone.</dd></dl>

0075The solutions are in each case spun onto 26 μm thick, biaxially stretched and heat-set polyethylene terephthalate films and then dried in a forced-air drying cabinet at 100 ° C. for 10 minutes. The number of revolutions of the centrifuge is regulated so that a layer thickness of 25 µm results. To protect against dust and scratches, a polyethylene film is laminated onto it as a cover film.

0076For the production of printed circuit boards, the dry resists are laminated in a commercially available laminator on a cleaned, preheated carrier, which consists of an insulating material with one or both sides, 35 µm thick copper layer, after removing the cover film. After the backing film has been peeled off and possibly dried, exposure is carried out under a template with a 5 kW metal halide lamp at a distance of 110 cm for 30 seconds and, after a waiting time of 15 minutes, developed in 1% sodium hydroxide solution for 90 seconds.

0077The resulting resist stencils were annealed at 150 ° C for 30 minutes and then subjected to the following tests:<ul id="ul0011" list-style="none"><li>1. Galvanoresistance (build-up of Pb / Sn alloy),</li><li>2nd Etching resistance (ammoniacal Cu (II) chloride solution),</li><li>3rd Resistance to solvents (eight hours immersion in isopropanol).</li></ul>

0078The results are shown in Table 7. The following compounds with acid-cleavable COC units were used:<dl id="dl0005"><dt>Number 1:</dt><dd> polymeric orthoester produced by condensation of trimethyl orthoformate with 4-oxa-6,6-bis-hydroxymethyloctan-1-ol,</dd><dt>No. 2:</dt><dd> Polyacetal, made from triethylene glycol and 2-ethylbutyraldehyde, hydroxyl number 140.</dd></dl> The following photochemical acid generators were used:<dl id="dl0006"><dt>Number 1:</dt><dd> 2- (4-ethoxy-naphth-1-yl) -4,6-bis-trichloromethyl-s-triazine,</dd><dt>No. 2:</dt><dd> 2- (4-styrylphenyl) -4,6-bis-trichloromethyl-s-triazine.</dd></dl><tables id="tabl0009" num="0009"><img file="EP0440086A2_D0017.tif" /></tables>

Example 5

0079To test the influence of baking rubber on the thermal crosslinking behavior, the following test is carried out with the printing plates from Example 1:

0080After exposure and development of the printing plates, as described in Example 1, they are gummed manually with a commercially available stoving gum (RC 99 from HOECHST AG) and then baked in a drying cabinet at 230 ° C. for 5 minutes. After rinsing off the rubber coating with water, the chemical resistance is checked in the usual way with dimethylformamide.

0081Table 8 below shows the results.<tables id="tabl0010" num="0010"><img file="EP0440086A2_D0018.tif" /></tables>

0082There is no impairment of the thermal crosslinking behavior of the polymers according to the invention by baking rubber.