MXPA96005443A - Engraving material, sensitive to radiation, for the production of places of printing planograf - Google Patents

Abstract

The present invention relates to a radiation-sensitive etching material, which works in a positive manner, for the production of planographic printing plates, consisting of an aluminum support and a layer sensitive to the radiation applied thereon, characterized in that the support of aluminum has been grained in nitric acid, then cleaned in sulfuric acid, anodized in sulfuric acid and, subsequently, hydrophilized with a compound comprising at least one unit with a phosphonic acid or a phosphonate group, and the radiation sensitive layer comprises: a radiation-sensitive ester, 1,2-naphthoquinone-2-diazide-2-α-5-sulfonic acid and a polycondensate having phenolic hydroxy groups, said polycondensate being obtained by reacting a phenolic compound with an aldehyde or a ketone; novolac or a polycondensation product obtained by reacting a polyphenol with an aldehyde or a ketone, as a soluble resin in cali; c) a polymer of the vinyl type, comprising at least one unit having a lateral hydroxyphenyl group, d) a clathrate-forming compound, e) a low molecular weight compound, comprising at least one hydrogen atom; and in silica gel particles that have a maximum diameter of 15

Description

ENGRAVING MATERIAL, RADIATION SENSITIVE, FOR THE PRODUCTION OF PLAQUE PLATFORMS The present invention refers to a radiation-sensitive engraving material, working in positive, for the production of planographic printing plates; said material comprising an aluminum support and a radiation sensitive layer. The radiation-sensitive etching materials for the production of plano-printing plates (presensib printed printing plates or "PS plates") are generally known. The layer weight of the radiation-sensitive layer is generally less than 3 g / rn2. Usually the engraving material is brought into direct contact with the original film by evacuation, it is irradiated in image form, preferably with UV radiation, and subsequently it is revealed. It is generally used water-alkaline developers. A printing plate obtained in this way can be baked and / or gummed, if appropriate. A positive work plate P is described in ; iP-fl 06-067 419 (equivalent to DE-A 41 26 836). It comprises an aluminum support film that: (i) has been electrically grained in hydrochloric acid; di) has been cleaned in sulfuric acid; (in) has been anodized in sulfuric acid and (iv) has become hydrophilic with polyvinyl or phonic acid. This support is coated with a radiation-sensitive layer comprising a compound of 1,2-naphthoquone-2-d-azide as the main radiation-sensitive component and a polymecop binder, for example, a ream novolak. In order to be able to distinguish between irradiated and unirradiated areas from the etching material, minimal amounts of other radiation-sensitive components may be present which, when exposed, generate or release a strong acid and, in a secondary reaction with a suitable dye, cause a change of color in the radiation sensitive layer. In order to reduce the evacuation time in the vacuum contact frame, and to induce uniform contact, the surface of the etching material may be roughened, for example, by suitable particles. In the cited reference, these particles are silica particles that are partially embedded in the radiation sensitive layer. The continuous and discontinuous matte layers, applied on top of the radiation sensitive layer, are also known in the prior art. In order to improve the latitude of the development process and to enable the use of weakly alkaline developers, the use of specific polyrneric binders has been proposed. In accordance with the teachings of JP-fl 61-006 647 (equivalent to DE-A 35 21 555), the binder comprises at least two different novolak reams. They are obtained by means of copolycondensation from 5 to 75 mol% of phenol, 20 to 70 mol% of rn-cresol (and / or o-cresol) and from 5 to 75 mol% of p-cresol with fopnaldehyde. In 3P-A 61 205 933 (equivalent to DE-A 36 07 S98) a novolak resin is used which has a weight average molecular weight (Mw) of 6,000 to 20,000 and a ratio of Hw: Mn (that is, polydispersity). ) from 2 to 14. JP-A 07-114 178 (equivalent EP-A 639 97) is directed to the problem of correcting film edge portions in lithographic printing plates. This problem occurs particularly when a light-sensitive composition is provided, which works in positive, on a support subjected to grain formation treatment and anodization treatment. It occurs additionally when a polar ortho-quinone-azide compound is used. The problem is solved by providing a light-sensitive composition comprising a high molecular weight, da-treatment-forming compound. The high molecular weight compound provides internal channels or other cavities within which low molecular weight compounds fit. The preferred clathrate-forming compounds are the cyclic D-glucans, cyclopnes and, in particular, cyclodext squabbles. Another problem is that photosensitive lithographic printing plates, working in positive, are usually easily attacked by various processing chemicals, used during printing, for example, isopropyl alcohol contained in soaking solutions and, consequently, have a career short print According to JP-A 01-302 349, 02-001 855 and 02-029 750 (equivalent to EP-A 345 016) the problem is solved by means of a photosensitive composition comprising 0..2 to 20% by weight of an activating compound, in addition to the o-naphthoquinone compound and the soluble resin in lcali. The activator is an ester or an ester of a polyoxyalkyl lensorbitol fatty acid, and an adduct with alkylene oxide, castor oil, lanolin, lanolin alcohol, beeswax, phytosterol or phytostanol or is an alkyl-alkyl ether, an alkyl ether or an alkyl ester of pol oxypropylene. According to 3P- C 63-223 637, 63-276,048, i ?? 63 303 343 and 01-062 139 (equivalent to EP-A 287 212) the resistance of printing plates to chemicals is also improved when high-molecular-weight, specific compounds are incorporated into the radiation-sensitive composition. . The high molecular weight compounds contain monomeopic units in which an aromatic group substituted with hydroxy, preferably a hydroxy phenyl group, is attached by means of an amide linkage. In the current Ldad there is no available P board that solves all the disadvantages discussed above. Accordingly, it was an object of the present invention to provide a radiation sensitive recording material, which works in a positive manner, which allows brief evacuation times in the vacuum contact area and avoids any inclusion of air or other gases between the film original and the engraving material. The photovelocity of the engraving material must be high and, therefore, allow 'short times of image formation. The latitude of the process of developing the image-irradiated engraving material should be sufficiently high to allow the use of water-alkaline developers having a normality of 0.6 mmol per liter or even less. Another objective was to provide a planographic printing plate that can be corrected with a correction fluid - and which is resistant to fountain solutions, cleaners, printing inks and other chemicals used during printing. Finally, it was an object of the invention to provide a printing plate which, after a press stop, produces free prints of cream shortly after printing. The above objects are achieved by means of an engraving material. radiation sensitive, which works in positive, for the production of planographic printing plates, comprising an aluminum support and a layer sensitive to the radiation applied on it; wherein: the aluminum support has been grained in nitric acid, then cleaned in sulfuric acid, anodized in sulfuric acid and, subsequently, hydrophilized with a compound comprising at least one unit with a phosphonic acid or a phosphonate group; and the radiation-sensitive layer comprises: a) a radiation-sensitive ester of 1,2-naphthoquone-2-dα-azide-4- or 5-sulphonic acid and a condensed poly having phenolic hydroxy groups; said polycondensate being obtained by reacting a phenol compound with an aldehyde or a ketone; b) a res to novolac or a polycondensation product obtained by reacting a poly phenol with an aldehyde or a ketone, such as an alkali-soluble resin; < .) a polymer of the vinyl type, which comprises at least one unit that has a lateral hydroxyphenium group; d) a clayer-forming compound; e) a low molecular weight compound, comprising at least one acid hydrogen atom; and f) silica gel particles having a maximum diameter of 15 μrn. The starting material for the support is generally an aluminum sheet having a preferred Al content of at least 99%, in particular, at least 99.5% by weight; the remainder being Si (not more than 0.20% by weight), Fe (not more than D.40% by weight), Cu (not more than 0.05% by weight), Zn (not more than 0.05% by weight) and Ti (not more than 0.02% by weight). Other elements, such as Mn or Mg, may be present in the aluminum alloy, in an amount of not more than 0.03% by weight, each. Before the grain forms on the aluminum foil and is cleaned, it can be degreased with an alkaline solution and / or subjected to a grain pre-treatment treatment, which can be carried out mechanically, chemically and / or electrochemically. The peak-to-valley height of the alumina support employed by the etching material, according to this invention, is in the range of 0.5 to 1.5 units (value). By means of the anodization treatment, an aluminum oxide layer is formed on the surface of the aluminum support. The oxide layer has a weight of 0.5 to 5.0 g / rn2. The amount of phosphorus-containing hydrophilizing agent can be determined by means of E ^ C (electronic spectacle for chemical analysis). The proportion of P: serial Al, determined by ESCA, is 0.1 or more. The surface reflection rate of the aluminum support is less than 50%. The polycondensate having phenolic groups, which is employed to produce the radiation-sensitive ester (a), is preferably obtained by reacting pyrogallol with an aldehyde or a ketone. Other useful polycondensates can be prepared by reacting alkylated phenols with formaldehyde. The condensed poly generally increase the oleophilic nature of the image areas of the iLsta printing plate to be used. The weight average molecular weight (Mw) of the radiation-sensitive polymepco ester of 1,2-naphthoquinone-2-d-azide-4 or 5-sulphonic acid is generally on the 3,000 scale to 10,000. Preferably, this ester is present in the radiation sensitive layer, in an amount of 5 to 60% by weight. Throughout the description, the percentages by weight are based on the total weight of the non-volatile components of the radiation-sensitive layer. Examples of the binder-soluble resin (b) include the compounds of the invention, such as the phenol / formaldehyde resin, the cresol / forrnaldehy resin, the phenol / creso / ormaldehyde resin and the like. The binder resin guarantees a high printing operation. CU amount in the engraving material is generally in the range of 5 to 95% by weight. The polymer (c) serves to increase the resistance of the image areas of the printing plate to the processing chemicals, normally employed during printing. Polymers containing N-hydroxifemyl-acrylamide and / or -rnetacri-lamide species are particularly suitable. It can derive other units of acid esters (inet) acnl? co and / or nitriles al a, bet -etiiénicarnente msaturados. The polymer (c) is present, generally, in the etching material, in an amount of 0.5 to 70% by weight. The clathrate (d) facilitates the use of the correction fluids, as described in JP-A 07-114 178. The preferred clathrate forming compounds are the cyclic D-glucans and the cyclophanes, in particular - Cyclodext squabbles. The cyclodextrins are optionally modified, for example, with ethylene oxide or with propylene oxide. The amount of clathrate in the etching material, in general, is in the range of 0.01 to 10% by weight.

The low molecular weight compound (e) continues the developing characteristics, in particular the speed of revolving Suitable compounds (e), which have hydr-oxy phenolic groups are described in EP-A 668 540. u examples include: 4, 4 ', "-trine droxy-pphene-methane, 1,1,1-tp s ~ (4-hydro-1-y1) -ethane, 4,4', 2" -tr? h? drox? -2, 5-2 ', 5' -tetramethyltin phenyl ethane, 2,3,4, 4-tetrahydroxy-benzophenone,, k'-dihydroxy-di-phenyl sulfone, 2,4-d? H? Drox ? -benzophenone, 2, 3, 4-t r-ihi droxibenzophenon, 5, 5 '-di f "orrm1-2, 3, 4, 2', 3 ', 4' -hexahydr-oxy-diphenyl ether and 5 , 5'-diacetyl -? , 3, 4- ', 3', 4 '-hexahydr-oxy-diferu-l-methane. In addition to the low molecular weight compounds with phenolic hydroxy groups, low molecular weight compounds with carboxy groups can be used. A preferred compound of this type is hexahydrophthalic acid. The amount of compound (e) in the radiation sensitive layer is in the range of 0.1 to 10% by weight. The particles (f) of silica gel have an average grain size on the scale of 3 to 5 j (determined with a Coulter counter) with an exclusion limit of 15 μm. The average pore volume of the silica gel particles exceeds 1 ml / g. These particles are used in such an amount that the Bekk uniformity of the radiation sensitive layer is less than 125 seconds (determined in accordance with DIN 53107, method A), which is generally achieved with a quantity of silica particles. from 0.01 to 10% by weight. In addition to components a) to f), the radiation-sensitive layer may contain an indicator dye, preferably a cationic dye of the trian linetan or rnet na type. The layer may also comprise compounds which, when exposed to actinic radiation, generate an acid. The preferred "photoacid generators" are the p-chloromethyl-triazines or -oxadiazoles, substituted with chromophore. Finally, the layer may comprise surfactants, in particular fluorinated surfactants or silicone-based surfactants, and polyalkylene oxides with acidity control of the phenolic hydroxy groups. The etching material according to the present invention is prepared by coating the alummium support with a reversing solution, followed by drying, in order to evaporate the volatile solvent. Suitable solvents include butanone (ie, methyl ethyl ketone), monomeric propylene glycol ether and the like. The solvent is conventionally removed by heating the etch material for about 1 minute at a temperature between 80 and 140 ° C. The planographic printing plates are obtained from the etching material according to the present invention by means of conventional process steps. For this purpose, the engraving material is first brought into intimate contact with the original of the film in a frame of vacuum contact, where the image forming irradi ation takes place. In the subsequent development step an aqueous-alkaline developer is used, based on silicate and having a normality of not more than 0.6 mol per liter. The proportion of S? 02cMe20 ((Alkali metal) in the developer-ref ribr emente is 1 or greater-than L. The preferred alkali oxides are Na20 and K20.This type of developer does not attack the aluminum oxide layer The developer can also contain pH regulating substances, complex formers, anti-scald agents, organic solvents, corrosion inhibitors, dyes and, above all, surfactants and hydrotropes. The pre-feasible development is carried out at a temperature of 20 to 40 ° C in an automatic re-veiling station. The engraving material is transported through the development station at a speed of 0.8 rn per minute or more. To allow continuous operation, developers * can be regenerated with a replenisher that has an alkali content of 0.6 to 2.0 moles per liter. In the replenishment solution, the proportion S 02: lvle? 0 may be -as in the developer-, or it may be different. Additives may also be present in the replenishment solution, as in the developer. The amount of replenisher needed to regenerate the developer depends on the type of development station, the number of plates revealed and the image coverage of the plates. In general, 1 to 50 ml of replenisher per square meter of engraving material is sufficient. The required amount of replenisher * can be determined by measuring the conductivity of the developer. The present invention is illustrated in greater detail in the following examples. The comparative examples, or the conparatives, are marked with an asterisk (*). Percentages are percentages by weight, unless indicated in a manner.

EXAMPLE 1 Five different types of supports were prepared. In each case, the aluminum support was first degreased for 10 seconds at a temperature of 65 ° C using a concentration of 3 weight percent aqueous sodium hydroxide solution. The support was then electrolytically grained in aqueous nitric acid at a concentration of 2% (examples 1 -1 and 1-2 and 1-3 *) or in aqueous hydrochloric acid of 1% concentration (examples 1-4 * and 1- 5 *), the grain formation being carried out for 30 seconds at a temperature of 35 ° 0, in each case. The voltage used in each case was 20V, the current density was 50 A / dm2. This step was followed by intermediate cleaning for 10 seconds at 70 ° C, with 15% aqueous sulfuric acid (examples 1-1, 1-2, 1-3 * and 1-4 *) or for 10 seconds at 60 ° C with 5% sodium hydroxide (example 1-5 *). The supporting materials were then anodized in 15% aqueous sulfuric acid for 60 seconds at 45 ° C (20 V, 5 A per * din?) And sealed. The sealing was carried out by rinsing with water for 5 seconds at 70 ° C (examples 1-1, 1-3 * and 1-4 *), rinsing with an aqueous solution at a concentration of 0.1%, of the sodium salt of N- osfonoinet? i -pol let i leniriima (DE-A 44 23 140) for 5 seconds at 70 ° C (example 1?) or rinsing with an aqueous solution of sodium nitrite at a concentration of 10%, for 5 seconds at 80 ° C (example 1-5 *). The sealed materials were hydrophilized with an aqueous solution of 0.3% concentration, of polyvinyl or phosphonic acid, allowed to act on the material for 10 seconds at 65 ° C (examples 1-1 and 1-4) or with a 0.1% aqueous solution of carboxymethylcellulose, which was allowed to act on the L material for 10 seconds at 85 ° C (example 1-5- *). In Example 1-3 * the support material * was not drilled. The P: A1 signal ratio (determined by ESCA) was 0.35 in examples 1-1, 1-4 * and l-5 *; of 1.4 in Example 1-2 and of 0 (there was no phosphorus present) in Examples 1-3 * and 1-5 *. Subsequently, the support materials were coated with a solution of a radiation sensitive composition and dried for one minute at 125 ° C. The solvent used in the coating solution was a mixture of butanone (40%) and propylene glycol (60%) methyl ether and LCO. The amount of non-volatile components in the coating solution was 8%. After drying the radiation sensitive layer had a weight of 2.0 g /? N2. The radiation-sensitive composition consisted of: 25.0% polycondensate of pyrogallol / acetone, esterified with 1,2-naphthoquamone-2-d-azido-5-sulphonic acid (degree of estepfication: 30%; average molecular Mw: 3,000); 1. 0% of 4- (l, l, 3,3-tetr met? Lbut? 1) -phenol / formally given -novolalp is stained with acid 1, 2 - na ftoqu nona-2- d? Az da-5-sul lom o, and that has an extinction coefficient of 7,000; 31. 0% of a phenol / cresol / fornaldehyde-novola, (phenol content: 5 mol%, viscosity of a 50% solution in ethanol: 144 centistokes (cSt)) 31.0% of a phenol / cresol / fornaldehyde-novolak (phenol content: 5 mol%, viscosity of a 50% solution in ethanol: 08 cSt); 3.0% hexahydrophthalic acid; 1.0% of 2- (4-? Netoxi-est? R? L) -4,6-f-tp-chloro-t'l-ri, 3.53-nazi; 1.0% pure blue BO Victoria (basic blue 7) 0.5% polieti lengicolol 2,000; 2.0% heptakis- (2-h? Drox? -? Rop? L) ~ beta-cyclodextabrae; 3.0% copolymer of N- (4-hydroxy-phen-1) -rnetacp-lamide / acplomt plo / methacrylate of rnet i lo / methacrylate of benzyl (molar ratio of monornépcas units: 30: 20: 40: 10); 0. 5% poly (nonacosafluorohexadecyl methacrylate); and 1.0% of silica gel particles having an average diameter of 4 μm, with an exclusion limit of 15 μm, a pore volume of 1.8 ml / g and which is coated with polyethelene wax. The engraving materials produced in this way were brought into contact with a film original in a vacuum contact frame (15 seconds of previous vacuum).; 15 seconds of empty LGIUO cont; remaining dur-ante pressure Vacuum application: 250 steams) and irradiated with a 5"mercury metal halide vapor lamp located at a distance of 110 crn, using a radiation dose of about 400 rnJ / cm2, The original film contained a UGRA offset test wedge and an extended 20% dot screen (60 lines per cm) and had an image area of 20%. immersion bath developer apparatus, by means of a potassium silicate developer having a molar ratio of K20: S? 02 of 1: 1 and a normality of U.40 mol / 1. image was treated with the developer in the developing apparatus for 12 seconds, at a temperature of 30 ° C. The following aspects of the revealed etching plates were identified and evaluated: 1. Photosensitivity, PS: The open wedge was determined. step of pitch with inuo (minimum: 3) 2. Playback of "enhancement", HL: It is values the reproduction of small half-tone points of the UGRA test element (minimum: 2%). 3. "Non-homogeneity" in the reproduction of the halftone points, RL: 4. Color spot, CS: The presence of undesirable constituents of the residual layer is checked in the non-image areas of the Ib plate. etching, which causes the color stain, with a correction fluid (SIR-16, Konica Corp.) (»- without color stain-; or: slight stain of color; -: stain of noticeable color). 5. Ease of correction: EC: Part of the image area is removed using the correction fluid described above; The area is then inked with a protective ink (SPO-1, Konica Corp.) and classified (+: ink repellent; -: ink acceptor), fi. Resistance to isopropanol, IR: One image area is treated for one minute with an isopropanol solution, with 50% concentration, and subsequently classified ("•: the layer shows no damage; -: visible damage). 7.- Print Operations, PR: Determined on a Heidelberg GTO press, using 2% of a fountain solution, 10% isopropanol on plain paper that does not contain mechanical wood pulp (minimum: 100,000). 8.- Behavior after stopping the printing, BS: The printing is re-used after a one-hour stop time in the printing machine; Determine the number of wasted sheets, produced before satisfactory prints are obtained: (+: considerably less than 20 wasted sheets, or: about 20 wasted sheets, -: considerably more than 20 wasted sheets). The results are summarized in the following table 1: TABLE 1 For example - For example - For example - For example - For example 1-1 pio 1-2 pio 1-3 * pio 1-4 * pio 1-5 * PS HL RL CS EC GO PR 120T 120T 150T 120T 120T BS EXAMPLE 2 The support materials of Example 1 (indicated as -l, -2, -3 *, -4 * and -5 *) were coated with a solution of a radiation-sensitive composition and were dried for 1 minute at 125 ° C. . The solvent present in the coating solution was a mixture of tetrahydrofuran (45%) and propylene glycol methyl ester (55%). The amount of non-volatile components present in the coating solution was 8%. After drying, the radiation sensitive layer had a weight of 2.0 g / m2. The radiation sensitive composition consisted of: 26.0% of a pyrogallol / acetone polycondensate, esterified with 1,2-naph oquinone-3-d-azide-5-sulfonic acid (degree of esterification: 30%, average molecular weight Mw) : 3,000); 31.0% of a phenol / cresol / aldehyde novolak resin (phenol content: 5 mol%, viscosity of a 50% solution in ethanol: 144 cSt, 31.0% of a novolak phenol / cresol / fopnaldehyde resin (content of phenol: 5 mol%, viscosity of a 50% solution in ethanol: 88 cSt), 3.0% of hexahydrocalcic acid, 0.5% of 2- (4-estiri Ifenil) -4,6-bis-trichlororneti l [1 , 3,51-tnazine, 1.0% pure Victoria blue BO (basic blue 7), 0.5% polyethylene glycol 2,000; L9 2. 0% hexak ís- (2-hydroxy-propyl) -bet to -cyclodext p na; 3.9% copolymer of N- (4-hydroxyphenyl) acrylate? da / acr? lo-nitp l / methyl meta-plate (molar ratio of mono-rich units: 35:20:45); 0.1% of a copolymer of dirnethylsiloxane / ethylene oxide / propylene oxide (molar ratio of Rnonorne units: 40:50:10); and 1.0% silica gel particles, which have an average diameter of 4 μ, with an exclusion limit of 15 μm and a pore volume of 1.2 ml / g. The etching materials produced in this manner were irradiated with imaging and development as described in Example 1. The results are summarized in the following Table 2.

TABLE 2 For example - For example - For example - For example - For example 2-1 pio 2-2 pio 2-3 * pio 2-4 * pio 2-5 * PS HL RL CS EC GO PR 120T 120T 150T 120T 120T BS EXAMPLE 3-1 The support material of Example 2-1 was coated with a solution of a radiation sensitive composition and dried for 1 minute at 125 ° C. The solvent in the coating solution was a mixture of tetrahydrofuran (45%) and rnonornetilate ether of propylene glycol (55%). The amount of non-volatile constituents in the coating solution was 8%. After drying, the radiation-sensitive layer had a weight of 2.0 g /? N2. The radiation-sensitive composition consisted of 25.0% of a polycondensate of rogalol / acetone, which was ficated with l, 2-naphtho-naphtha- 2-d? Aznla -5- sul fóm co (degree of estep ication 30%; average molecular weight, Mu 3,000); 1.0% of a novola resin of 4- (1, l,, 3 -te ramethyl-butyl) -phenol / formaldehyde, esterified with 1,2-naphthoic acid nona-? -d? az? da-5-sulphonic, and having an extinction coefficient of 7,000; 31.0% of a novolak ream of phenol / cresol / fopnaldehyde (phenol content: 5 mol%, viscosity of a 50% solution in ethanol: 144 cS) - 31.0% of a phenol novolak resin / cresol / formaldehyde (phenol content: 5 mol%, viscosity of a solution 50% in ethanol: 88 cSt); 3.0% hexahydrof acid ico; 1.0% of 2- (4-rneto? -est? Pl) -4,6 -b s-tr? Chlorornet.?. 1 Cl, 3,53-nazi na; 1.0% pure Victoria Blue BO (basic blue 7); 0.5% pol i et ilenglicol 2,000; 2.0% of heptak? - (2-hydroxyl) -beta-cyclodextrin; '.- > ? 3. 0% of a copolymer of N-hydroxy-phenyl-1-acrylamide / acryl-methyl / meta-platelet of rnet-ilo / etacp-lat / benzyl (molar ratio of the rnononoin units: 30: 20: 40: 10); 0.5% of a poly (inetacp lato of nonacosafluorohexadecyl) and 1. 0% of silica gel particles having an average diameter of 4 μm, with an exclusion limit of 15 μm and a pore volume of 1.8 nm / g and which is coated with a polyethylene wax. The etching materials produced from that metal were irradiated to image and developed as described in Example 1. The results are summarized in the following table 3.

TABLE 3 Example - Example - Example - Example - Item 3-1 peep 4 * 1 peep 5 * 1 peep 6 * - 1 peep 7 * 1 PS 3 2 2 3 3 HL 2 2 2 2 2 RL + + + + + CS + or o + + EC + + - + + IR + + + - + PR 120T 120T 120T 120T 120T BS + + + + + EXAMPLE 4 * -he repeated Example 3-1, except that a radiation-sensitive composition was used that did not contain hexahydroalkyl acid (instead, the amount of novolaI- of phenol / cresol was increased to 34%). for aldehyde having a f-enol content of 5 mol% and a viscosity (in a 50% solution in ethanol) of 144 cSt). The results are shown in Table 3 above.

EXAMPLE 5 * -l Example 3-1 was repeated, except that a radiation-sensitive composition that did not contain the substituted beta-cyclodextrm was used (instead, it was increased to 33% The amount of phenol novolak / cresol / formaldehyde it had? n phenol content of 5 mol% and a viscosity (in a 50% solution in ethanol) of 144 cSt). The results are summarized in table 3 above.

EXAMPLE 6 * -l Example 3-1 was repeated, except that a radiation-sensitive composition was used which did not contain the N- (4-hydroxy-phenyl) -acplamide / acr-type copolymer. Lon? Tr? Lo / rnetacr-ylate of inethyl / benzyl methacrylate (instead increased to 34%) The amount of phenol novolak / cresol / formaldehyde having a phenol content of 5 mol% and a viscosity (in a 50% solution in ethanol) of 144 cSt). The results are summarized in table 3 above EXAMPLE 7 * -l Example 3-1 was repeated, except that a radiation sensitive composition which did not contain the silica gel particles was used (instead, the amount of the phenol / cresol / fopnaldehyde novolak having an increase of 32% was increased to 32%). phenol content of 5 mol% and a viscosity (in a 50% solution in ethanol) of 144 cSt). The results are summarized in table 3 above).

Claims (3)

NOVELTY OF THE INVENTION CLAIMS

1. - A radiation-sensitive recording material, which works in a positive way, for the production of planographic printing plates, consisting of an aluminum support and a layer sensitive to the radiation applied to it; characterized because: the aluminum support has been grained in nitric acid, Then Cleaned in sulfuric acid, anodized in sulfuric acid and, subsequently, hydrophilized with a compound comprising at least one unit with a phosphoric acid or a phosphate group; and the radiation sensitive layer comprises: a) a radiation-sensitive ester of 1,2-naphthoquone ~ 2 ~ d? az? 4-or 5-sulphonic acid and? n polycondensed having hydroxy groups phenolic; said polycondensate being obtained by reacting a phenol compound with an aldehyde or a ketone; b) a novolac ream or a polycondensation product obtained by reacting a poly phenol with an aldehyde or a ketone, such as an alkali-soluble resin; c) a polymer of the vinyl type, comprising at least one unit having a lateral hydroxylmetal group; d) a clathrate forcing compound; e) a low molecular weight compound, comprising at least one acid hydrogen atom; and 1) silica gel particles that have a maximum diameter of 15 μin. 2. The engraving material according to claim 1, further characterized in that the aluminum support is an aluminum foil having an aluminum content of at least 99% by weight. 3. The engraving material according to claim 1, further characterized in that the support has a roughness on the scale of 0.5 to 1.5 μm (value ra). 4. The engraving material according to claim 1, further characterized in that the molecular weight Mw of the radiation-sensitive ester (a) is in the range of 3,000 to 10,000. 5. The engraving material according to claim 1, further characterized in that the amount of the stress (a) in the radiation sensitive layer is in the range of 5 to 60% by weight. 6. The engraving material according to claim 1, further characterized in that the olcondensate having phenolic hydroxyl groups is obtained by reacting pyrogallol with an aldehyde or a ketone. 7. The etching material according to the invention. claim 1, further characterized in that the amount of the binder-soluble resin (b), present in the radiation-sensitive layer, is in the range of 5 to 95% by weight. 8. The engraving material according to claim 1, further characterized in that the polymer c) contains units of N-h? Drox? Fen 1 -acp lamí da and / or metacri Lamí da. 9. The engraving material "according to claim 1, further characterized in that the amount of polymer (c) in the radiation sensitive layer is in the range of 0.5 to 70% by weight. 10. The material of conforming etching with the r-e v i ntion 1, further characterized in that the compound (< 1) former is a cyclic D-giucano or cyclophon. 11.- Fl engraving material < 1 according to claim 1, further characterized in that the amount of the clathrate-forming compound (d) in the radiation-sensitive layer is in the scale "Je 0.01 to 10% by weight. 12. The engraving material according to claim 1, further characterized in that the amount of compound (e) in the radiation-sensitive layer is in the range of 0.1 to 10% by weight. 13. The engraving material "according to claim 1, characterized by" particles "because the particles (f) Silica gel have an average grain size of 3 to 5 μn, with a limit < the exclusion of 15 μm and an average pore volume of more than 1 inl / g. 14. The engraving material according to claim V, further characterized in that the silica gel particles are coated with a wax of pol? Et? log. L5.- The engraving material according to Claim L, further characterized in that the amount of silica particles in the layer sensitive to the ladiation is in the range of 0.01 to 10% by weight. 16. The engraving material according to claim 1, further characterized in that the uniformity of Bek in the radiation sensitive layer is less than 125 seconds (determined according to DIN 53 1.07, method A). SUMMARY OF THE DESCRIPTION

A radiation sensitive recording material is described, < - which works in a positive way, for the production of planogravure plates, comprising an aluminum support and a layer sensitive to the radiation applied on the surface; wherein: the aluminum support has been grained in nitric acid, then defatted in sulfuric acid, anodized in sulfuric acid and, subsequently, hydrophilized with a compound comprising at least one unit with a phosphonic acid or a phosphonate group; and the radiation sensitive layer comprises: a) a radiation-sensitive ester of 1,2-naphthoquinone-2-dα-azide-4- or 5-sulphonic acid and a polycondensate having groups phenolic hydroxy; said polycondensate being obtained by reacting a phenol compound with an aldehyde or a ketone; b) a novolac resin or a poly condensation product obtained by reacting a poly phenol with an aldehyde or a ketone, such as an alkali soluble resin; c) a polymer of the vinyl type, comprising at least one unit having a lateral hydroxylmetal group; < l) a clayer forming compound; e) a low molecular weight compound, comprising at least one acid hydrogen atom; Y

3. 1. f) silica gel particles having a maximum diameter of 15 μrn. P96 / 772 CR