CA1271958A - Treating aluminum oxide layer with aqueous hexametaphosphate solution for producing printing plate support - Google Patents
Treating aluminum oxide layer with aqueous hexametaphosphate solution for producing printing plate supportInfo
- Publication number
- CA1271958A CA1271958A CA000481442A CA481442A CA1271958A CA 1271958 A CA1271958 A CA 1271958A CA 000481442 A CA000481442 A CA 000481442A CA 481442 A CA481442 A CA 481442A CA 1271958 A CA1271958 A CA 1271958A
- Authority
- CA
- Canada
- Prior art keywords
- aqueous solution
- substrate
- acid
- aqueous
- aluminum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
- B41N3/00—Preparing for use and conserving printing surfaces
- B41N3/03—Chemical or electrical pretreatment
- B41N3/038—Treatment with a chromium compound, a silicon compound, a phophorus compound or a compound of a metal of group IVB; Hydrophilic coatings obtained by hydrolysis of organometallic compounds
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D11/00—Electrolytic coating by surface reaction, i.e. forming conversion layers
- C25D11/02—Anodisation
- C25D11/04—Anodisation of aluminium or alloys based thereon
- C25D11/18—After-treatment, e.g. pore-sealing
- C25D11/24—Chemical after-treatment
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S205/00—Electrolysis: processes, compositions used therein, and methods of preparing the compositions
- Y10S205/921—Electrolytic coating of printing member, other than selected area coating
Abstract
ABSTRACT OF THE DISCLOSURE
A process for manufacturing materials in the form of sheets, foils or webs comprising chemically, mechanically and/or electrochemically roughened and anodically oxidized aluminum or one of its alloys, wherein the resultant aluminum oxide layers are post-treated with an aqueous solution containing phosphoroxo anions, is performed such that a post-treatment of the aluminum oxide layers is effected by immersion in an aqueous solution containing hexametaphosphate anion.
In a preferred embodiment, the aqueous solution is adjusted to a pH of 1 to 5 by addition of an acid. The resulting materials, which have reduced adsorption pro-perties, are preferably employed as support materials for offset printing plates.
A process for manufacturing materials in the form of sheets, foils or webs comprising chemically, mechanically and/or electrochemically roughened and anodically oxidized aluminum or one of its alloys, wherein the resultant aluminum oxide layers are post-treated with an aqueous solution containing phosphoroxo anions, is performed such that a post-treatment of the aluminum oxide layers is effected by immersion in an aqueous solution containing hexametaphosphate anion.
In a preferred embodiment, the aqueous solution is adjusted to a pH of 1 to 5 by addition of an acid. The resulting materials, which have reduced adsorption pro-perties, are preferably employed as support materials for offset printing plates.
Description
~L~7~5~S~
PROCESS FOR POST-TREATING ALUMINUM OXIDE LAYERS
WITH AQUEOUS SOLUTIONS CONTAINING PHOSP~OROXO
ANIONS AND USE THEREOF IN THE MANUFACTURE OF
SUPPORTS FOR OFFSET PRINTING PLATES
BACKGROUND OF THE INVENTION
The present invention relates to a process for post-treating roughened and anodically oxidized alumi-num, particularly support materials for offset printing plates, with aqueous solutions containing phosphoroxo anions.
Support materials for ofEset printing plates are provided, on one or both sides, with a radiation-sensitive ~photosensitive) layer (reproduction layer), either directly by users or by manufacturers of pre-coated printing plates. This layer permits the produc-tion of a printing image of an original by photomechanical means. When a printing form is pro-duced from the printing plate comprising such a repro-duction layer, the layer support carries image areas which accept ink in the subsequent printing process.
Concurrently, a hydrophilic image background for the lithographic printing operation is formed in the areas which are free from an image (non-image areas).
For the above reasons, the following require-ments are demanded of a layer support for reproductionlayers used in the manufacture of offset printing plates:
; ..
.
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-- Those portions of the radiation-sensitive layer which have become comparatively more soluble following exposure must be capable of being easily removed from the support by a developing opera-tion, in order to produce the hydrophilic non-image areas without leaving a residue.
-- The support, which has been laid bare in the non-image areas, must possess a high affinity for water, i.e., it must be strongly hydrophilic, in order to accept water rapidly and permanently during the lithographic printing operation, and to exert an adequate repelling effect with respect to the greasy printing ink.
-- The radiation-sensitive layer must exhibit an ade~uate degree of adhesion prior to expo-sure, and those portions of the layer which print mustexhibit adequate adhesion following exposure.
The base material employed for layer supports of this type preferably comprises aluminum. The base material is superficially roughened using known methods, such as dry brushing, wet brushing, sandblasting, chemical and/or electrochemical treat-ment. The roughened substrate then is optionally sub-jected to an anodizing treatment, during which a thin oxide layer is built up, to improve abrasion resistance In practice, the support materials, par-ticularly anodically oxidized support materials based on aluminum, are often subjected to a further treatment step before applying a radiation-sensitive layer. This treatment improves the adhesion of the layer, increases the hydrophilic properties of the support and/or im-proves the developability of the radiation-sensitive layer. Such treatments are, for example, carried out according to the following methods:
-- German Patent No. 16 71 614 (corresponding to United States Patent No. 3,511,661) essentially describes an anodic oxidation of support materials for printing plates in an aqueous solution of H3PO4. In a ccmparative example (Example 12), a two-stage process variant is performed in which the support material is first anodically oxidized in an aqueous solution of H2SO4 and then is post-treated by immersion into an aqueous solution of H3PO4 or Na2HPO4. The patent document teaches that it is necessary to apply a layer of hydroxyethyl cellulose before applying the layer comprising a radiation-sensitive composition.
-- German Offenlegungsschrift No. 22 51 710 (correspond-ing to Brit.ish Patent Specification No. 1,410,768) also discloses the non-electrolytic post-treatment, in an aqueous solution of H3PO4, of an aluminum support material for printing plates, the support material having heen anodically oxidized in an aqueous solution of H2SO4. A similar process is described by United States Patent No. 3,808,000.
In the process for producing a support material for printing plates according to German Patent No. 25 40 561 (corres-ponding to United S-tates Patent No. 4,116,6~5), immersion in an aqueous solution containing an acid (for example, meta-, pyro- or polyphosphoric acid) or a base (for example, Na3PO4 or K3PO4) is performed as an intermediate stage, prior to a treatment with steam or hot water and following a customary anodic oxidation of the aluminum (for example, in an a~[ueous solution of H2S04).
7~
In the two-stage process for the anodic oxidation of aluminum support materials for printing plates according to European Patent Application No. 0,086,957 filed on 20th January, 1983; Inventor: Mohr; Applicant: Hoechst AXtiengesellschaft (corresponding to South African Patent No. 83/0947), - 3a -~ 7~3~
electrochemical treatment is performed (a) in an aqueous solution of H2SO4 and (b) in an aqueous solu-tion comprising phosphorus-containing anions (phos-phoroxo anions, phosphorofluro anions and/or phosphor-oxofluoro anions). The following are mentioned as suitable compounds for step (b):
-- phosphoric acid (H3PO4);
-- sodium dihydrogen phosphate (NaH2PO4);
-- disodium hydrogen phosphate (Na2HPO4);
-- trisodium phosphate (Na3PO4);
-- phosphorous acid (H3PO3);
-- disodium phosphite (Na2HPO3);
-- diphosphGric acid (H4P2O7);
-- sodium pyrophosphate (Na4P2O7);
-- triphosphoric acid (HsP3Olo);
-- sodium triphosphate (NasP3Olo);
-- polyphosphoric acid (Hn+2Pn3n~
-- hexasodium tetrapolyphosphate ~Na6P4Ol3];
-- hexasodium metaphosphate (Na6(PO3)6);
-- disodium monofluorophosphate (Na2po3F);
and -- potassium hexafluorophosphate (KPF6).
It is true that these post-treatment processes often give satisfying results, but they cannot meet all of the increasingly stringent re~uirements made of a support material which is suitable for both the most up-to-date, practical applications and being coated with the most diverse radiation-sensitive reproduction layers. In particular, the known processes do not satisfy the re~uirements for an uncomplicated and inex-pensive method for producing such a support material.
This drawback to the known processes applies not onl~
to the resistance to alkaline media, which is of par-ticular importance when high-performance developers are 3 ~ 8 used with positive-working, radiation-sensitive repro-duction layers, but also to the adsorption charac-teristics of the oxide layers. The adsorption values are important, since staining (e.g., coloration) of the non-image areas, which most probably is caused by adsorptive effects, can occur, depending on the chemi-cal composition of the reproduction layers.
For the industrial manufacture of these sup-port materials in high-speed, high-performance installations, it is also desirable to develop a process for the post~treatment of oxide layers which can be performed in an energy-efficient manner, with the lowest possible malfunction rate. This means, for example, that an immersion treatment is generally pre-ferred over an electrochemical treatment, if therespectively treated oxide layers exhibit comparable surface properties.
SUMM~R~ OF THE INVENTION
It is therefore an object of the present invention to provide a process for post-treating sheet-like aluminum, which can be performed in addition to an anodic oxidation of the alumin-~, that results in an aluminum-based surface which meets the above-mentioned practical requirements demanded of a high-performance printing plate.
It is another object of the present invention to provide an offset printing plate comprising an aluminum-based substrate which displays little or no staining of non-image areas after developing.
In accomplishing the foregoing objects, there has been provided, in accordance with one aspect of the present invention, a process for manufacturing sheets, foils and webs comprised of alumir.um or an aluminum ~7~
alloy substrate, comprising the steps of (A) roughening and anodically oxidizing the substrate; and then (B) treating the substrate with an aqueous solution which contains an amount of hexametaphosphate anion suf-ficient to reduce dyestuff adsorption by thesubstrate.
In accordance with another aspect of the pre-sent invention, there has been provided an offset printing plate comprising a support and a radiation-sensitive reproduction layer provided thereon, which support comprises a sheet, foil or web manufacturedaccording to the above-described process.
Other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodi-ments. It should be understood, however, that thedetailed description and specific examples, while indi-cating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
DETAIL~D DESCRIPTION OF THE PREFE~RED EMBODIMENTS
The hexametaphosphate anions of the present invention are derived from polymetaphosphoric acid HnPnO3n, wherein n is equal to 6 (hexametaphosphoric acid). The anions can be obtained by dissolving a water-soluble salt of this acid, in particular an alkali metal salt, such as Na6P6Olg, in water. In a preferred embodiment of the present invention, this salt solution is adjusted to a pH of 1 to 5, in par-ticular of 1.5 to 4.5, by means of an acid (for example, tartaric acid, citric acid or phosphoric ~ ~ 7~
acid), particularly a water-soluble organic acid (preferably a hydroxycarboxylic acid), such as citric acid. As a rule, the aqueous solution contains between about 1 9/1 and 300 g/l, preferably 3 g/l to 150 9/1 (more preferably 5 9/1 to 100 9/1), of hexametaphos-phate anions.
Post-treatment is performed non-electrol~ti-cally as an immersion treatment, either discontinuously or, preferably, continuously in modern web-processing apparatus. It is expedient to select treatment times of 0.5 to 120 seconds and treatment temperatures of 15C to 80C, in particular of 20C to 75C. By the process of the present invention, the surface topo-graphy (such as roughness and oxide pores) produced before immersion is practically unchanged, or is changed only insignificantly. Therefore, the process according to the present invention is particularly suited for treating materials for which maintaining the sur~ace topography is of great importance, as is true, for example, in the case of support materials for printing plates.
Suitable base materials to be treated in accordance with the present invention include aluminum or one of its alloys which, for example, can have an Al content of more than 98.5% by weight and can addi-tionally contain small amounts of Si, Fe, Ti, Cu and Zn. Especially if support materials for printing plates are to be produced, the sheet-like aluminum is first roughened, mechanically (e.g., brushing and/or treatment with an abrasive agent), chemically (e.g., etching agents) and/or electrochemically (e.g., a.c.
treatment in aqueous acid or salt solutions), after an optional precleaning step. In the process accordiny to the present invention, electrochemical roughening is preferred, but prior to the electrochemical treatment step, aluminum support materials can additionally be roughened by mechanical means (for example, by brushing with wire or nylon brushes and/or by treatment with an abrasive agent). All process steps can be carried out discontinuously using plates or foils, but preferably are performed continuously using webs.
Particularly in continuous processing, the process parameters for the electrochemical roughenir.g step are normally within the following ranges: tempera-ture of the aqueous electrolyte, which in particular contains 0.3 to 5.0% by weight of acid(s) (in the case of salts this content can be higher), 20C to 60C;
current density, 3 to 200 A/dm2; dwell time of a material spot to be roughened in the electrolyte, 3 to 100 seconds; and rate of flow of the electrolyte on the surface of the material to be roughened, 5 to 100 cm/s.
In discontinuous processing, the required current den-sities tend to be in the lower region, and the dwell times in the upper region of the ranges indicated above, respectively, while the flow of the electrolyte can even be dispensed with. The type of current used is preferably ordinary alternating current having a frequency of 50 to 60 Hz, but it is also possible to use modified current types, such as alternating current having different current intensity amplitudes for the anodic and for the cathodic current, having lower fre-quencies, and having interruptions of current or super-position of two currents of different frequencies and wave shapes. The average peak-to-valley height (Rz) of the roughened surface is in a range from 1 to 15 /um, in particular from 1.5 to 8.0 /um. If the aqueous electrolyte contains acid(s~, in particular HCl and/or HNO3, aluminum ions in the form of aluminum salts, in ~ , . . :.. ; .. ~ , ~ ~:7~
particular Al (NO3)3 and/or ~lC13, can also be added.
It is also known to add certain other acids and salts, such as boric acid or borates, and to add corrosion-inhibiting substances, such as amines.
Precleaning includes, for example, treatment with an aqueous NaOH solution with or without a degreasing agent and/or complex formers, trichloro-ethylene, acetone, methanol or other commercially available substances known as aluminum treatment agents.
After roughening or, in the case of several roughening steps, between the individual steps, it is possible to perform an additional etching treatment, during which in particular a maximum amount of 2 g/m2 is removed (between the individual steps, up to 5 g/m2). Etching solutions in general are aqueous alkali metal hydroxide solutions or aqueous solutions of salts showing alka-line reactions or aqueous solutions of acids based on HNO3, H2S4 and H3PO4, respectively. Apart from an etching treatment step, performed between the roughening step and a subsequent anodizing step, there are also known non-electrochemical treatments which have what is essentially a purely rinsing and/or cleaning effect. These non-electrochemical treatments are employed, for example, to remove deposits formed during roughening ("smut"), or simply to remove electrolyte remainders; for example, dilute aqueous alkali metal hydroxide solutions or water can be used for these treatments.
The electrochemical roughening is followed by an anodic oxidation of the aluminum, in a further pro-cess step to improve, for example, the abrasion andadhesion properties of the surface of the support material. Conventional electrolytes, such as H2SO4, H3PO4, H2C2O4, amidosulfonic acidr sulfosuccinic acid, ~7~ s8 sulfosalicylic acid or mixtures thereof, may be used for the anodic oxidation. Particular preference is given to H2S04 and H3P04, which may be used alone or in a mixture and/or in a multi-stage anodizing process.
Most preferably, an aqueous solution containing H2S04 and Al3~ ions is employed. Usually, the oxide layer weights range from about 1 to 8 g/m2 (corresponding to layer thicknesses between about 0.3 and 2.5 /um).
The materials prepared in accordance with the present invention are preferably used as supports for offset printing plates, i.e., at least one surface of the support material is coated with a radiation-sensitive composition, either by the manufacturers of presensitized printing plates or directly by the users.
Radiation-sensitive (photosensitive) layers basically include all layers which after irradiation (exposure), if appropriate follo~ed by development and/or fixing, yield a surface in imagewise configuration which can be used for printing.
~ Apart from the silver halide-containing layers used for many applications, various other layers are known which are described, for example, in Light-Sensitive Systems, by Jaromir Kosar (John Wiley &
Sons, New York, 1965): colloid layers containing chro-mates and dichromates (Kosar, Chapter 2); layers con-taining unsaturated compounds, which, upon exposure ofthe layer, are is erized, rearranged, cycliæed, or crosslinked (Kosar, Chapter 4); layers containing com-pounds which can be photopolymerized, in which, on being exposed, monomers or prepolymers undergo poly-merization, optionally with the aid of an initiator(Kosar, Chapter 5); and layers containing o-diazo-quinones, such as naphthoquinone diazides, p-diazoquinones or condensation products of diazonium salts (Kosar, Chapter 7).
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Layers which are suitable for the present invention also include electrophotographic layers, i.e., layers which contain an inorganic or organic pho-toconductor. In addition to photosensitive substan-ces, these layers can, of course, also contain other constituents, such as resins, dyes and plasticizers.
In particular, the following photosensitive com-positions or compounds can be employed in the coating of the support materials prepared in accordance with the present invention:
Positive-working reproduction layers which contain, as the light-sensitive compounds, o-quinone diazides, preferably o-naphthoquinone diazides, such as high or low molecular-weight naphthoquinone-(1,2)-diazide-(2)-sulfonic acid esters and amides, which are described, for example in German Patents No. 854,890, No. 865,109, No. 879,203, No. 894,959, No. 938,233, No. 1,109,521, No. 1,1~4,705, No. 1,118,606, No. 1,120,273, No. 1,124,817, and No. 2,331,377; and in European Patent Applications No. 0,021,428 and No. 0,055,814.
Negative-working reproduction layers which contain condensation products from aromatic diazonium salts and compounds with active carbonyl groups, preferably condensation products formed from diphenylaminediazonium salts and formaldehyde, as described, for example, in German Patents No. 596,731, No. 1,138,399, No. 1,138,400, No~ 1,138,401, No. 1,142,871 and No. 1,154,123; in U.S. Patents No. 2,679,498 and No. 3,050,502; and in British Patent Specification No. 712,606.
Negative-working reproduction layers ~hich contain cocondensation products of aromatic diazonium compounds, such as described in German ~;~7~58 Patent No. 20 65 732, which comprise products possessing at least one unit each of (a) an aromatic diazonium salt compound capable of participating in a condensation reaction and (b) another com-pound that is also able to participate in a condensation reaction, such as a phenol ether or an aromatic thioether, which units are connected by a bivalent linking member derived from a carbonyl com-pound such as a methylene group, capable of participating in a condensation reaction group~
Positive-working layers according to German Offenlegungs-0 schriften No. 26 10 842 and No. 29 28 636, and German Patent No.
27 18 254, which contain (a) a compound that, on being irradiated, splits off an acid, (b) a monomeric or polymeric compound possess-ing at least one C-O-C group which can be split off by acid (e.g., an orthocarboxylic acid ester group or a carboxylic acid amide acetal group), and if appropriate, (c) a binder.
Negative-working layers, composed of photopolymerizable monomers, photoinitiatorsr binders and, if appropriate, further additives. In these layers, acrylic and methacrylic acid esters, or reaction products of diisocyanates with partial esters of poly-hydric alcohols are, for example, employed as monomers, as des-cribed, for example, in Vnited States Patents No. 2,760,863 and No. 3,060,023, and in German Offenlegungsschriften No. 20 64 079 and No. 23 61 041.
Negative-working layers according to German ~ffenlegungs-~ ~,b J~ s~l e c~
schrift No. 30 36 077 filed 25th September, 198Q, ~i~oscd 6th - ~ay 1982; Inventor. Bosse et al; Applicant: ~oechst~ktiengesellschaft, ,"
.
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which contain, as the photo-sensitive compound, a diazonium salt polycondensation product or an organic azido compound, and, as the binder, a high-molecular weight polymer with alkenylsulfonyl-urethane or cycloalkenylsulfonylurethane side groups.
- 12a -It is also possible to appl~ photosemicon-ducting layers to the support materials prepared in accordance with the present invention, such as are described, for example, in German Patents No. 11 17 391, No. 15 22 497, No. 15 72 312, No. 23 22 0~6, and No. 23 22 047, to obtain highly pho-tosensitive electrophotographic printing plates.
From the coated offset printing plates pre-pared using the support materials produced in accord-ance with the present invention, the desired printing forms are obtained in a known manner, by imagewise exposure or irradiation and subsequent washing out of the non~image areas by means of a developer, preferably an aqueous developer sol~tion.
Surprisingly, offset printing plates produced with base materials post-treated according to the pro-cess of the present invention are distinguished, in comparison with those plates for which the same base material has been post-treated with other aqueous solu-tions containing phosphoroxo anions, by a reduced ten-dency to staining (see Comparative Examples below).
This special effect of the hexametaphosphate anions in a pure immersion treatment was not foreseeable, because in an electrochemical treatment the whole group of anions generally has a similar effect.
In the preceding description and in the examples which follow, percentages always denote per-centages by weight, unless otherwise indicated. Parts by weight are related to parts by volume as g is related to cm3. Moreover, the following methods were used in the examples for the determination of parameters.
In order to examine whether the surface exhi-bits d~estuff adsorption (staining) properties, a cut piece of plate material which has been coated with a ~,., . ~ ., ~7~358 radiation-sensitive layer is exposed and developed, and then one half of it is treated with a deletion fluid. The greater the difference is in the color values between the untreated and the treated half, the more dyestuff was adsorbed on the untreated portion of the surface of the support material. The dyestuff adsorption values range from 0 to 5, 0 denoting no dyestuff adsorption, 1 denoting slight dyestuff adsorption and 5 denoting strong dyestuff adsorption; only half steps are indicated.
Values above 5 indicate that, additionally, the oxide layer has been removed.
Suitable radiation-sensitive layers, which are applied to the support material, include (A) a negative-working layer containing (i) a reaction product of polyvinyl butyral and pro-penylsulfonylisocyanate, (ii) a polycondensation product obtained from 1 mol of 3-methoxy-diphenylamine-4-diazonium sulfate and 1 mol of 4,4'-bismethoxymethyl diphenyl ether, precipitated as the mesitylene sulfonate, (iii) H3PO4, (iv) Viktoria Pure Blue FGA
registered under the name Basic Blue No. 81 and (v) phenylazo~
diphenylaminei and (B) a positive-working layer containing (i) a cresol/formaldehyde novolak, (ii) a 4-(2-phenylprop-2-yl)-phenyl ester of napthoquinone-(1,2)-diazide-(2)-sulfonic acid-(4), (iii) polyvinyl butyral, (iv) naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride-(4) and (v) crystal violet. Printing plates and printing forms which are suited for practical use are produced in this way.
Exam~le 1 and Comparative Example-Cl ..
In an aqueous solution containing 1.4% of HNO3 and 6%
of Al(NO3)3, an aluminum web was electrochemically roughened, ~7~
-14a- 20731-901 using alternating current (115 A/dm at 35C), and was then anodically oxidized, using direct ::; ,. .
~ ~ 7~
current, in an aqueous solution containing H2SO4 and ~13+ ions.
The resulting layer, which had a weight of about 2.5 g/m2, was immersed into an aqueous solution containing hexasodium-hexametaphosphate (Na6P6Olg) and having a pH of 7, at a temperature of 45C to 50C for a period of 15 seconds. The changes in dyestuff adsorption associated with increasing amounts of this salt are compiled in a table below.
The ~omparative Example (Cl) was performed as described above for Example l, but without a post-treatment.
Example 2 and Comparative Example C2 The procedure of Example l was followed, except that an aqueous solution containing 0.9~ of HCl was used.
Example 3 and Comparative Example C3 The procedure followed was the same as in Example 1, except that the solution of Na6P6Ol~ addi-tionally contained lO 9/1 of citric acid, and thus hada pH of 2.5.
Example 4 and Comparative Example C4 The procedure followed was the same as in Example 2, except that the solution of Na6P6Olg addi-tionally contained lO g/l of citric acid, and thus hada pH of 2.5.
Example 5 and Comparative Example C20 The procedure followed was the same as in Example l (C5 to Cl2) or Example 2 (Cl3 to C20), except ~L~711 95~3 that other compounds which also yield phosphoroxo anions (see Table) were used, or that no post-treatment was performed, respectively.
The tabulated data show that, with two conven-tional electrochemical roughening methods, the dyestuff adsorption was more significantly reduced when hexaso-diumhexametaphosphate was used than when other salts or acids which yield phosphoroxo anions were employed. The effect was even more pronounced when the pH was changed, for example, by adding citric acid; a similar effect was observed in a pH range of 1 to 5, when other, less strong, acids were added.
~X7~9~3 TAB LE
E~rG:~le or ¦ Electrolyte ¦ Dyestuff adsorp~ion of oxide layer C~ arative ¦ ¦ when an electrolyte of the following Exarrple ¦ ¦ concentration (q/l ) is used Cl I _ 1 4 ~
Na6P6O18 1 ~ 1 3 1 2 1 2 1 1-5 1 1 C2 1 _ 1 5
PROCESS FOR POST-TREATING ALUMINUM OXIDE LAYERS
WITH AQUEOUS SOLUTIONS CONTAINING PHOSP~OROXO
ANIONS AND USE THEREOF IN THE MANUFACTURE OF
SUPPORTS FOR OFFSET PRINTING PLATES
BACKGROUND OF THE INVENTION
The present invention relates to a process for post-treating roughened and anodically oxidized alumi-num, particularly support materials for offset printing plates, with aqueous solutions containing phosphoroxo anions.
Support materials for ofEset printing plates are provided, on one or both sides, with a radiation-sensitive ~photosensitive) layer (reproduction layer), either directly by users or by manufacturers of pre-coated printing plates. This layer permits the produc-tion of a printing image of an original by photomechanical means. When a printing form is pro-duced from the printing plate comprising such a repro-duction layer, the layer support carries image areas which accept ink in the subsequent printing process.
Concurrently, a hydrophilic image background for the lithographic printing operation is formed in the areas which are free from an image (non-image areas).
For the above reasons, the following require-ments are demanded of a layer support for reproductionlayers used in the manufacture of offset printing plates:
; ..
.
, ~ ~ 7~
-- Those portions of the radiation-sensitive layer which have become comparatively more soluble following exposure must be capable of being easily removed from the support by a developing opera-tion, in order to produce the hydrophilic non-image areas without leaving a residue.
-- The support, which has been laid bare in the non-image areas, must possess a high affinity for water, i.e., it must be strongly hydrophilic, in order to accept water rapidly and permanently during the lithographic printing operation, and to exert an adequate repelling effect with respect to the greasy printing ink.
-- The radiation-sensitive layer must exhibit an ade~uate degree of adhesion prior to expo-sure, and those portions of the layer which print mustexhibit adequate adhesion following exposure.
The base material employed for layer supports of this type preferably comprises aluminum. The base material is superficially roughened using known methods, such as dry brushing, wet brushing, sandblasting, chemical and/or electrochemical treat-ment. The roughened substrate then is optionally sub-jected to an anodizing treatment, during which a thin oxide layer is built up, to improve abrasion resistance In practice, the support materials, par-ticularly anodically oxidized support materials based on aluminum, are often subjected to a further treatment step before applying a radiation-sensitive layer. This treatment improves the adhesion of the layer, increases the hydrophilic properties of the support and/or im-proves the developability of the radiation-sensitive layer. Such treatments are, for example, carried out according to the following methods:
-- German Patent No. 16 71 614 (corresponding to United States Patent No. 3,511,661) essentially describes an anodic oxidation of support materials for printing plates in an aqueous solution of H3PO4. In a ccmparative example (Example 12), a two-stage process variant is performed in which the support material is first anodically oxidized in an aqueous solution of H2SO4 and then is post-treated by immersion into an aqueous solution of H3PO4 or Na2HPO4. The patent document teaches that it is necessary to apply a layer of hydroxyethyl cellulose before applying the layer comprising a radiation-sensitive composition.
-- German Offenlegungsschrift No. 22 51 710 (correspond-ing to Brit.ish Patent Specification No. 1,410,768) also discloses the non-electrolytic post-treatment, in an aqueous solution of H3PO4, of an aluminum support material for printing plates, the support material having heen anodically oxidized in an aqueous solution of H2SO4. A similar process is described by United States Patent No. 3,808,000.
In the process for producing a support material for printing plates according to German Patent No. 25 40 561 (corres-ponding to United S-tates Patent No. 4,116,6~5), immersion in an aqueous solution containing an acid (for example, meta-, pyro- or polyphosphoric acid) or a base (for example, Na3PO4 or K3PO4) is performed as an intermediate stage, prior to a treatment with steam or hot water and following a customary anodic oxidation of the aluminum (for example, in an a~[ueous solution of H2S04).
7~
In the two-stage process for the anodic oxidation of aluminum support materials for printing plates according to European Patent Application No. 0,086,957 filed on 20th January, 1983; Inventor: Mohr; Applicant: Hoechst AXtiengesellschaft (corresponding to South African Patent No. 83/0947), - 3a -~ 7~3~
electrochemical treatment is performed (a) in an aqueous solution of H2SO4 and (b) in an aqueous solu-tion comprising phosphorus-containing anions (phos-phoroxo anions, phosphorofluro anions and/or phosphor-oxofluoro anions). The following are mentioned as suitable compounds for step (b):
-- phosphoric acid (H3PO4);
-- sodium dihydrogen phosphate (NaH2PO4);
-- disodium hydrogen phosphate (Na2HPO4);
-- trisodium phosphate (Na3PO4);
-- phosphorous acid (H3PO3);
-- disodium phosphite (Na2HPO3);
-- diphosphGric acid (H4P2O7);
-- sodium pyrophosphate (Na4P2O7);
-- triphosphoric acid (HsP3Olo);
-- sodium triphosphate (NasP3Olo);
-- polyphosphoric acid (Hn+2Pn3n~
-- hexasodium tetrapolyphosphate ~Na6P4Ol3];
-- hexasodium metaphosphate (Na6(PO3)6);
-- disodium monofluorophosphate (Na2po3F);
and -- potassium hexafluorophosphate (KPF6).
It is true that these post-treatment processes often give satisfying results, but they cannot meet all of the increasingly stringent re~uirements made of a support material which is suitable for both the most up-to-date, practical applications and being coated with the most diverse radiation-sensitive reproduction layers. In particular, the known processes do not satisfy the re~uirements for an uncomplicated and inex-pensive method for producing such a support material.
This drawback to the known processes applies not onl~
to the resistance to alkaline media, which is of par-ticular importance when high-performance developers are 3 ~ 8 used with positive-working, radiation-sensitive repro-duction layers, but also to the adsorption charac-teristics of the oxide layers. The adsorption values are important, since staining (e.g., coloration) of the non-image areas, which most probably is caused by adsorptive effects, can occur, depending on the chemi-cal composition of the reproduction layers.
For the industrial manufacture of these sup-port materials in high-speed, high-performance installations, it is also desirable to develop a process for the post~treatment of oxide layers which can be performed in an energy-efficient manner, with the lowest possible malfunction rate. This means, for example, that an immersion treatment is generally pre-ferred over an electrochemical treatment, if therespectively treated oxide layers exhibit comparable surface properties.
SUMM~R~ OF THE INVENTION
It is therefore an object of the present invention to provide a process for post-treating sheet-like aluminum, which can be performed in addition to an anodic oxidation of the alumin-~, that results in an aluminum-based surface which meets the above-mentioned practical requirements demanded of a high-performance printing plate.
It is another object of the present invention to provide an offset printing plate comprising an aluminum-based substrate which displays little or no staining of non-image areas after developing.
In accomplishing the foregoing objects, there has been provided, in accordance with one aspect of the present invention, a process for manufacturing sheets, foils and webs comprised of alumir.um or an aluminum ~7~
alloy substrate, comprising the steps of (A) roughening and anodically oxidizing the substrate; and then (B) treating the substrate with an aqueous solution which contains an amount of hexametaphosphate anion suf-ficient to reduce dyestuff adsorption by thesubstrate.
In accordance with another aspect of the pre-sent invention, there has been provided an offset printing plate comprising a support and a radiation-sensitive reproduction layer provided thereon, which support comprises a sheet, foil or web manufacturedaccording to the above-described process.
Other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodi-ments. It should be understood, however, that thedetailed description and specific examples, while indi-cating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
DETAIL~D DESCRIPTION OF THE PREFE~RED EMBODIMENTS
The hexametaphosphate anions of the present invention are derived from polymetaphosphoric acid HnPnO3n, wherein n is equal to 6 (hexametaphosphoric acid). The anions can be obtained by dissolving a water-soluble salt of this acid, in particular an alkali metal salt, such as Na6P6Olg, in water. In a preferred embodiment of the present invention, this salt solution is adjusted to a pH of 1 to 5, in par-ticular of 1.5 to 4.5, by means of an acid (for example, tartaric acid, citric acid or phosphoric ~ ~ 7~
acid), particularly a water-soluble organic acid (preferably a hydroxycarboxylic acid), such as citric acid. As a rule, the aqueous solution contains between about 1 9/1 and 300 g/l, preferably 3 g/l to 150 9/1 (more preferably 5 9/1 to 100 9/1), of hexametaphos-phate anions.
Post-treatment is performed non-electrol~ti-cally as an immersion treatment, either discontinuously or, preferably, continuously in modern web-processing apparatus. It is expedient to select treatment times of 0.5 to 120 seconds and treatment temperatures of 15C to 80C, in particular of 20C to 75C. By the process of the present invention, the surface topo-graphy (such as roughness and oxide pores) produced before immersion is practically unchanged, or is changed only insignificantly. Therefore, the process according to the present invention is particularly suited for treating materials for which maintaining the sur~ace topography is of great importance, as is true, for example, in the case of support materials for printing plates.
Suitable base materials to be treated in accordance with the present invention include aluminum or one of its alloys which, for example, can have an Al content of more than 98.5% by weight and can addi-tionally contain small amounts of Si, Fe, Ti, Cu and Zn. Especially if support materials for printing plates are to be produced, the sheet-like aluminum is first roughened, mechanically (e.g., brushing and/or treatment with an abrasive agent), chemically (e.g., etching agents) and/or electrochemically (e.g., a.c.
treatment in aqueous acid or salt solutions), after an optional precleaning step. In the process accordiny to the present invention, electrochemical roughening is preferred, but prior to the electrochemical treatment step, aluminum support materials can additionally be roughened by mechanical means (for example, by brushing with wire or nylon brushes and/or by treatment with an abrasive agent). All process steps can be carried out discontinuously using plates or foils, but preferably are performed continuously using webs.
Particularly in continuous processing, the process parameters for the electrochemical roughenir.g step are normally within the following ranges: tempera-ture of the aqueous electrolyte, which in particular contains 0.3 to 5.0% by weight of acid(s) (in the case of salts this content can be higher), 20C to 60C;
current density, 3 to 200 A/dm2; dwell time of a material spot to be roughened in the electrolyte, 3 to 100 seconds; and rate of flow of the electrolyte on the surface of the material to be roughened, 5 to 100 cm/s.
In discontinuous processing, the required current den-sities tend to be in the lower region, and the dwell times in the upper region of the ranges indicated above, respectively, while the flow of the electrolyte can even be dispensed with. The type of current used is preferably ordinary alternating current having a frequency of 50 to 60 Hz, but it is also possible to use modified current types, such as alternating current having different current intensity amplitudes for the anodic and for the cathodic current, having lower fre-quencies, and having interruptions of current or super-position of two currents of different frequencies and wave shapes. The average peak-to-valley height (Rz) of the roughened surface is in a range from 1 to 15 /um, in particular from 1.5 to 8.0 /um. If the aqueous electrolyte contains acid(s~, in particular HCl and/or HNO3, aluminum ions in the form of aluminum salts, in ~ , . . :.. ; .. ~ , ~ ~:7~
particular Al (NO3)3 and/or ~lC13, can also be added.
It is also known to add certain other acids and salts, such as boric acid or borates, and to add corrosion-inhibiting substances, such as amines.
Precleaning includes, for example, treatment with an aqueous NaOH solution with or without a degreasing agent and/or complex formers, trichloro-ethylene, acetone, methanol or other commercially available substances known as aluminum treatment agents.
After roughening or, in the case of several roughening steps, between the individual steps, it is possible to perform an additional etching treatment, during which in particular a maximum amount of 2 g/m2 is removed (between the individual steps, up to 5 g/m2). Etching solutions in general are aqueous alkali metal hydroxide solutions or aqueous solutions of salts showing alka-line reactions or aqueous solutions of acids based on HNO3, H2S4 and H3PO4, respectively. Apart from an etching treatment step, performed between the roughening step and a subsequent anodizing step, there are also known non-electrochemical treatments which have what is essentially a purely rinsing and/or cleaning effect. These non-electrochemical treatments are employed, for example, to remove deposits formed during roughening ("smut"), or simply to remove electrolyte remainders; for example, dilute aqueous alkali metal hydroxide solutions or water can be used for these treatments.
The electrochemical roughening is followed by an anodic oxidation of the aluminum, in a further pro-cess step to improve, for example, the abrasion andadhesion properties of the surface of the support material. Conventional electrolytes, such as H2SO4, H3PO4, H2C2O4, amidosulfonic acidr sulfosuccinic acid, ~7~ s8 sulfosalicylic acid or mixtures thereof, may be used for the anodic oxidation. Particular preference is given to H2S04 and H3P04, which may be used alone or in a mixture and/or in a multi-stage anodizing process.
Most preferably, an aqueous solution containing H2S04 and Al3~ ions is employed. Usually, the oxide layer weights range from about 1 to 8 g/m2 (corresponding to layer thicknesses between about 0.3 and 2.5 /um).
The materials prepared in accordance with the present invention are preferably used as supports for offset printing plates, i.e., at least one surface of the support material is coated with a radiation-sensitive composition, either by the manufacturers of presensitized printing plates or directly by the users.
Radiation-sensitive (photosensitive) layers basically include all layers which after irradiation (exposure), if appropriate follo~ed by development and/or fixing, yield a surface in imagewise configuration which can be used for printing.
~ Apart from the silver halide-containing layers used for many applications, various other layers are known which are described, for example, in Light-Sensitive Systems, by Jaromir Kosar (John Wiley &
Sons, New York, 1965): colloid layers containing chro-mates and dichromates (Kosar, Chapter 2); layers con-taining unsaturated compounds, which, upon exposure ofthe layer, are is erized, rearranged, cycliæed, or crosslinked (Kosar, Chapter 4); layers containing com-pounds which can be photopolymerized, in which, on being exposed, monomers or prepolymers undergo poly-merization, optionally with the aid of an initiator(Kosar, Chapter 5); and layers containing o-diazo-quinones, such as naphthoquinone diazides, p-diazoquinones or condensation products of diazonium salts (Kosar, Chapter 7).
$;~
Layers which are suitable for the present invention also include electrophotographic layers, i.e., layers which contain an inorganic or organic pho-toconductor. In addition to photosensitive substan-ces, these layers can, of course, also contain other constituents, such as resins, dyes and plasticizers.
In particular, the following photosensitive com-positions or compounds can be employed in the coating of the support materials prepared in accordance with the present invention:
Positive-working reproduction layers which contain, as the light-sensitive compounds, o-quinone diazides, preferably o-naphthoquinone diazides, such as high or low molecular-weight naphthoquinone-(1,2)-diazide-(2)-sulfonic acid esters and amides, which are described, for example in German Patents No. 854,890, No. 865,109, No. 879,203, No. 894,959, No. 938,233, No. 1,109,521, No. 1,1~4,705, No. 1,118,606, No. 1,120,273, No. 1,124,817, and No. 2,331,377; and in European Patent Applications No. 0,021,428 and No. 0,055,814.
Negative-working reproduction layers which contain condensation products from aromatic diazonium salts and compounds with active carbonyl groups, preferably condensation products formed from diphenylaminediazonium salts and formaldehyde, as described, for example, in German Patents No. 596,731, No. 1,138,399, No. 1,138,400, No~ 1,138,401, No. 1,142,871 and No. 1,154,123; in U.S. Patents No. 2,679,498 and No. 3,050,502; and in British Patent Specification No. 712,606.
Negative-working reproduction layers ~hich contain cocondensation products of aromatic diazonium compounds, such as described in German ~;~7~58 Patent No. 20 65 732, which comprise products possessing at least one unit each of (a) an aromatic diazonium salt compound capable of participating in a condensation reaction and (b) another com-pound that is also able to participate in a condensation reaction, such as a phenol ether or an aromatic thioether, which units are connected by a bivalent linking member derived from a carbonyl com-pound such as a methylene group, capable of participating in a condensation reaction group~
Positive-working layers according to German Offenlegungs-0 schriften No. 26 10 842 and No. 29 28 636, and German Patent No.
27 18 254, which contain (a) a compound that, on being irradiated, splits off an acid, (b) a monomeric or polymeric compound possess-ing at least one C-O-C group which can be split off by acid (e.g., an orthocarboxylic acid ester group or a carboxylic acid amide acetal group), and if appropriate, (c) a binder.
Negative-working layers, composed of photopolymerizable monomers, photoinitiatorsr binders and, if appropriate, further additives. In these layers, acrylic and methacrylic acid esters, or reaction products of diisocyanates with partial esters of poly-hydric alcohols are, for example, employed as monomers, as des-cribed, for example, in Vnited States Patents No. 2,760,863 and No. 3,060,023, and in German Offenlegungsschriften No. 20 64 079 and No. 23 61 041.
Negative-working layers according to German ~ffenlegungs-~ ~,b J~ s~l e c~
schrift No. 30 36 077 filed 25th September, 198Q, ~i~oscd 6th - ~ay 1982; Inventor. Bosse et al; Applicant: ~oechst~ktiengesellschaft, ,"
.
.. . -:~ :
,:
:
'' -B
which contain, as the photo-sensitive compound, a diazonium salt polycondensation product or an organic azido compound, and, as the binder, a high-molecular weight polymer with alkenylsulfonyl-urethane or cycloalkenylsulfonylurethane side groups.
- 12a -It is also possible to appl~ photosemicon-ducting layers to the support materials prepared in accordance with the present invention, such as are described, for example, in German Patents No. 11 17 391, No. 15 22 497, No. 15 72 312, No. 23 22 0~6, and No. 23 22 047, to obtain highly pho-tosensitive electrophotographic printing plates.
From the coated offset printing plates pre-pared using the support materials produced in accord-ance with the present invention, the desired printing forms are obtained in a known manner, by imagewise exposure or irradiation and subsequent washing out of the non~image areas by means of a developer, preferably an aqueous developer sol~tion.
Surprisingly, offset printing plates produced with base materials post-treated according to the pro-cess of the present invention are distinguished, in comparison with those plates for which the same base material has been post-treated with other aqueous solu-tions containing phosphoroxo anions, by a reduced ten-dency to staining (see Comparative Examples below).
This special effect of the hexametaphosphate anions in a pure immersion treatment was not foreseeable, because in an electrochemical treatment the whole group of anions generally has a similar effect.
In the preceding description and in the examples which follow, percentages always denote per-centages by weight, unless otherwise indicated. Parts by weight are related to parts by volume as g is related to cm3. Moreover, the following methods were used in the examples for the determination of parameters.
In order to examine whether the surface exhi-bits d~estuff adsorption (staining) properties, a cut piece of plate material which has been coated with a ~,., . ~ ., ~7~358 radiation-sensitive layer is exposed and developed, and then one half of it is treated with a deletion fluid. The greater the difference is in the color values between the untreated and the treated half, the more dyestuff was adsorbed on the untreated portion of the surface of the support material. The dyestuff adsorption values range from 0 to 5, 0 denoting no dyestuff adsorption, 1 denoting slight dyestuff adsorption and 5 denoting strong dyestuff adsorption; only half steps are indicated.
Values above 5 indicate that, additionally, the oxide layer has been removed.
Suitable radiation-sensitive layers, which are applied to the support material, include (A) a negative-working layer containing (i) a reaction product of polyvinyl butyral and pro-penylsulfonylisocyanate, (ii) a polycondensation product obtained from 1 mol of 3-methoxy-diphenylamine-4-diazonium sulfate and 1 mol of 4,4'-bismethoxymethyl diphenyl ether, precipitated as the mesitylene sulfonate, (iii) H3PO4, (iv) Viktoria Pure Blue FGA
registered under the name Basic Blue No. 81 and (v) phenylazo~
diphenylaminei and (B) a positive-working layer containing (i) a cresol/formaldehyde novolak, (ii) a 4-(2-phenylprop-2-yl)-phenyl ester of napthoquinone-(1,2)-diazide-(2)-sulfonic acid-(4), (iii) polyvinyl butyral, (iv) naphthoquinone-(1,2)-diazide-(2)-sulfonic acid chloride-(4) and (v) crystal violet. Printing plates and printing forms which are suited for practical use are produced in this way.
Exam~le 1 and Comparative Example-Cl ..
In an aqueous solution containing 1.4% of HNO3 and 6%
of Al(NO3)3, an aluminum web was electrochemically roughened, ~7~
-14a- 20731-901 using alternating current (115 A/dm at 35C), and was then anodically oxidized, using direct ::; ,. .
~ ~ 7~
current, in an aqueous solution containing H2SO4 and ~13+ ions.
The resulting layer, which had a weight of about 2.5 g/m2, was immersed into an aqueous solution containing hexasodium-hexametaphosphate (Na6P6Olg) and having a pH of 7, at a temperature of 45C to 50C for a period of 15 seconds. The changes in dyestuff adsorption associated with increasing amounts of this salt are compiled in a table below.
The ~omparative Example (Cl) was performed as described above for Example l, but without a post-treatment.
Example 2 and Comparative Example C2 The procedure of Example l was followed, except that an aqueous solution containing 0.9~ of HCl was used.
Example 3 and Comparative Example C3 The procedure followed was the same as in Example 1, except that the solution of Na6P6Ol~ addi-tionally contained lO 9/1 of citric acid, and thus hada pH of 2.5.
Example 4 and Comparative Example C4 The procedure followed was the same as in Example 2, except that the solution of Na6P6Olg addi-tionally contained lO g/l of citric acid, and thus hada pH of 2.5.
Example 5 and Comparative Example C20 The procedure followed was the same as in Example l (C5 to Cl2) or Example 2 (Cl3 to C20), except ~L~711 95~3 that other compounds which also yield phosphoroxo anions (see Table) were used, or that no post-treatment was performed, respectively.
The tabulated data show that, with two conven-tional electrochemical roughening methods, the dyestuff adsorption was more significantly reduced when hexaso-diumhexametaphosphate was used than when other salts or acids which yield phosphoroxo anions were employed. The effect was even more pronounced when the pH was changed, for example, by adding citric acid; a similar effect was observed in a pH range of 1 to 5, when other, less strong, acids were added.
~X7~9~3 TAB LE
E~rG:~le or ¦ Electrolyte ¦ Dyestuff adsorp~ion of oxide layer C~ arative ¦ ¦ when an electrolyte of the following Exarrple ¦ ¦ concentration (q/l ) is used Cl I _ 1 4 ~
Na6P6O18 1 ~ 1 3 1 2 1 2 1 1-5 1 1 C2 1 _ 1 5
2 ¦ Na6P6O18 ¦ ¦ 4. ¦ l l l C3 1 _ 1 3 1 - I - I _ I _ I _
3 ¦ Na6P6O18 + ¦ - ¦ 1~5 ¦ 1 ¦ 1 ¦ 1 ¦ 1 citric acid ¦
C4 1 _ 1 4 1 - I ~ I _ I _ I _
C4 1 _ 1 4 1 - I ~ I _ I _ I _
4 ¦ Na6P6Ol8 ~ ¦ ~ ¦ 2 ¦1~5 ¦ 1 ¦1~5 ¦ 1-5 citric acid ¦ l l l l l - I 1. 1 1 --~ I I
C5 1 _ 1 3.51 _ I_ I _ I_ I _ H3PO4 ~85~) ¦ - ¦ 3 ¦ 3 ¦ 2-5 ¦ 3.5 ¦ 3 C6 1 _ 1 3'51 ~ I~ I ~ I ~ I ~
Na3P4 ¦ - ¦ 3-5 ¦ 4-5 ¦ 6 ¦ 8 ¦ 16 C7 1 _ 1 4 1 - II _ I _ I _ NaH2PO4 ¦ _ ¦ 4 C8 1 _ 1 4 1 - I - I _ I _ I _ Na6P4O13 ¦ _ ¦ 3~5 ¦ 3 ¦ 3 ¦ 2,5 ¦ 2,5 C9 1 _ 1 4 51 ~ I ~ I ~ I ~ I ~
Na2HPO4 ¦ - ¦ 4~5 ¦ 5~5 ¦ 5 ¦ 4~5 ¦ 6 ~.27~9~
Table (contd.) Exanple or ¦ Electrolyte ¦ Dyestuff adsorption of oxide layer C~nl?arative ¦ ¦ when an electrolyte of the following E~Tple ¦ ¦ concentration (q/l) is used 1 0 1 1 1 5 L lo 1 20 1 100 ¦ KPF~ ¦ - ¦ 3.5 ¦ 3~5 ¦ 3~5 ¦ 3 ¦ 4 ¦ H4P2O7 ¦ - ¦ 3 ¦ 2~5 ¦ 2 ¦ 2 ¦ 2 C12 1 _ 1 4~5 ~
¦ Na4P2O7¦ - ¦ 4-5 ¦ 4 ¦ 3'5 ¦ 4 ¦ 4 C13 1 _ 1 4,5 1 - I - I - I _ I _ ¦ H3PO4 (85 95) ¦ - ¦ 4 ¦ 5 ¦ 5-5 ¦ 7 ¦ 9 C14 1 _ 1 5 1 - I - I - I _ I _ C15 I Na3P04 ¦ - ¦ 6 ¦ 8 ¦ 9 ¦ 11 ¦ 20 ¦ NaH2PO41 _ ¦ 4-5 ¦ 4'5 ¦ 4' C16 1 _ 1 5 1 - I - I - I _ I _ ¦ Na6P4O13 ¦ - ¦ 4,5 ¦ 4 ¦ 4~5 ¦ 4~5 ¦ 4 ¦ Na2E~P04l l ¦ _ _ I _ Cl9 ¦ KPF6 ¦ - 4,5 ¦ 4 4 3.5 ¦ 4,5 ¦ H4P27 ¦ - ¦ 4.5 ¦ 4,5 ¦ 5 ¦ 5 ¦ 5,5 ¦ Na4P2O7 ¦ - ¦ 5~5 ¦ 4~5 ¦ 4,5 ¦ 4~5 ¦ 4~5
C5 1 _ 1 3.51 _ I_ I _ I_ I _ H3PO4 ~85~) ¦ - ¦ 3 ¦ 3 ¦ 2-5 ¦ 3.5 ¦ 3 C6 1 _ 1 3'51 ~ I~ I ~ I ~ I ~
Na3P4 ¦ - ¦ 3-5 ¦ 4-5 ¦ 6 ¦ 8 ¦ 16 C7 1 _ 1 4 1 - II _ I _ I _ NaH2PO4 ¦ _ ¦ 4 C8 1 _ 1 4 1 - I - I _ I _ I _ Na6P4O13 ¦ _ ¦ 3~5 ¦ 3 ¦ 3 ¦ 2,5 ¦ 2,5 C9 1 _ 1 4 51 ~ I ~ I ~ I ~ I ~
Na2HPO4 ¦ - ¦ 4~5 ¦ 5~5 ¦ 5 ¦ 4~5 ¦ 6 ~.27~9~
Table (contd.) Exanple or ¦ Electrolyte ¦ Dyestuff adsorption of oxide layer C~nl?arative ¦ ¦ when an electrolyte of the following E~Tple ¦ ¦ concentration (q/l) is used 1 0 1 1 1 5 L lo 1 20 1 100 ¦ KPF~ ¦ - ¦ 3.5 ¦ 3~5 ¦ 3~5 ¦ 3 ¦ 4 ¦ H4P2O7 ¦ - ¦ 3 ¦ 2~5 ¦ 2 ¦ 2 ¦ 2 C12 1 _ 1 4~5 ~
¦ Na4P2O7¦ - ¦ 4-5 ¦ 4 ¦ 3'5 ¦ 4 ¦ 4 C13 1 _ 1 4,5 1 - I - I - I _ I _ ¦ H3PO4 (85 95) ¦ - ¦ 4 ¦ 5 ¦ 5-5 ¦ 7 ¦ 9 C14 1 _ 1 5 1 - I - I - I _ I _ C15 I Na3P04 ¦ - ¦ 6 ¦ 8 ¦ 9 ¦ 11 ¦ 20 ¦ NaH2PO41 _ ¦ 4-5 ¦ 4'5 ¦ 4' C16 1 _ 1 5 1 - I - I - I _ I _ ¦ Na6P4O13 ¦ - ¦ 4,5 ¦ 4 ¦ 4~5 ¦ 4~5 ¦ 4 ¦ Na2E~P04l l ¦ _ _ I _ Cl9 ¦ KPF6 ¦ - 4,5 ¦ 4 4 3.5 ¦ 4,5 ¦ H4P27 ¦ - ¦ 4.5 ¦ 4,5 ¦ 5 ¦ 5 ¦ 5,5 ¦ Na4P2O7 ¦ - ¦ 5~5 ¦ 4~5 ¦ 4,5 ¦ 4~5 ¦ 4~5
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for manufacturing sheets, foils and webs comprised of aluminum or an aluminum alloy substrate, comprising the steps of:
(A) roughening and anodically oxidizing said substrate;
and then (B) treating said substrate with an aqueous solution which contains an amount of hexametaphosphate anion sufficient to reduce dyestuff adsorption by said substrate.
(A) roughening and anodically oxidizing said substrate;
and then (B) treating said substrate with an aqueous solution which contains an amount of hexametaphosphate anion sufficient to reduce dyestuff adsorption by said substrate.
2. A process as claimed in Claim 1, wherein said aqueous solution contains a water-soluble salt of hexametaphosphoric acid.
3. A process as claimed in Claim 1, wherein said aqueous solution contains hexasodiumhexametaphosphate.
4. A process as claimed in Claim 1, wherein said aqueous solution has been adjusted to a pH of between about 1 and 5 by adding an acid to said aqueous solution.
5. A process as claimed in Claim 4, wherein said acid comprises a hydroxycarboxylic acid.
6. A process as claimed in Claim 5, wherein said acid comprises a citric acid.
7. A process as claimed in Claim 1, wherein said amount of hexametaphosphate anion in said aqueous solution is between about 3 g/l and 150 g/l.
8. A process as claimed in Claim 1, wherein step (A) com-prises electrochemically roughening said substrate in an aqueous electrolyte solution comprising HCl or HNO3.
9. A process as claimed in Claim 1, wherein step (A) com-prises anodically oxidizing said substrate in an aqueous solution comprising H2SO4.
10. An offset printing plate comprising a support and a radiation-sensitive reproduction layer provided on said support, said support comprising a sheet, foil or web comprised of an aluminum or aluminum alloy substrate which is the product of a process comprising the steps of (A) roughening and anodically oxidizing said substrate; and then (B) treating said substrate with an aqueous solution which contains an amount of hexametaphosphate anion sufficient to reduce dyestuff adsorption by said substrate.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19843418111 DE3418111A1 (en) | 1984-05-16 | 1984-05-16 | METHOD FOR TREATING ALUMINUM OXIDE LAYERS WITH AQUEOUS SOLUTIONS CONTAINING PHOSPHOROXO ANIONS AND THE USE THEREOF IN THE PRODUCTION OF OFFSET PRINT PLATE CARRIERS |
| DEP3418111.3 | 1984-05-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1271958A true CA1271958A (en) | 1990-07-24 |
Family
ID=6235962
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000481442A Expired - Fee Related CA1271958A (en) | 1984-05-16 | 1985-05-14 | Treating aluminum oxide layer with aqueous hexametaphosphate solution for producing printing plate support |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4650739A (en) |
| EP (1) | EP0161608B1 (en) |
| JP (1) | JPS60253597A (en) |
| BR (1) | BR8502292A (en) |
| CA (1) | CA1271958A (en) |
| DE (2) | DE3418111A1 (en) |
| ZA (1) | ZA853680B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07119151B2 (en) * | 1987-12-07 | 1995-12-20 | 富士写真フイルム株式会社 | Support for lithographic printing plates |
| US5230988A (en) * | 1991-03-12 | 1993-07-27 | Fuji Photo Film Co., Ltd. | Method of making lithographic printing plate |
| EP1013469B1 (en) * | 1998-12-22 | 2006-08-16 | Fuji Photo Film Co., Ltd. | Process for the preparation of photosensitive lithographic printing plate |
| JP4868020B2 (en) * | 2008-12-26 | 2012-02-01 | 株式会社デンソー | Aluminum anodizing method and anodized aluminum |
Family Cites Families (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NL136718C (en) * | 1961-01-25 | |||
| BE630566A (en) * | 1962-04-03 | |||
| US3373021A (en) * | 1964-01-29 | 1968-03-12 | Harris Intertype Corp | Presensitized positive working lithographic plate |
| US3511661A (en) * | 1966-07-01 | 1970-05-12 | Eastman Kodak Co | Lithographic printing plate |
| ZA6807938B (en) * | 1967-12-04 | |||
| CH526399A (en) * | 1968-12-06 | 1972-08-15 | Hasek Josef | Method of making an offset printing plate |
| US3679419A (en) * | 1969-05-20 | 1972-07-25 | Azoplate Corp | Light-sensitive diazo condensate containing reproduction material |
| GB1410768A (en) * | 1971-10-22 | 1975-10-22 | Vickers Ltd | Lithographic printing plates comprising anodised aluminium |
| BE792852A (en) * | 1971-12-17 | 1973-06-15 | Henkel & Cie Gmbh | PROCESS FOR TREATING ALUMINUM SURFACES BY OXIDATION FOLLOWED BY DENSIFICATION |
| US3808000A (en) * | 1972-03-28 | 1974-04-30 | Grace W R & Co | Printing plate and method of preparation |
| CA1011279A (en) * | 1972-07-27 | 1977-05-31 | Yoshiaki Miyosawa | Method of after-treatment for lithographic printing plates |
| US4116695A (en) * | 1974-09-12 | 1978-09-26 | Fuji Photo Film Co., Ltd. | Method of producing a support for a printing plate |
| JPS51101741A (en) * | 1975-03-06 | 1976-09-08 | Yoshida Kogyo Kk | TAISHOKUSEIYOKYOKUSANKAHIMAKUNOTOSOHO |
| JPS52150104A (en) * | 1976-06-07 | 1977-12-13 | Fuji Photo Film Co Ltd | Photoosensitive lithographic press plate material |
| DE3006094A1 (en) * | 1980-02-19 | 1981-08-20 | Hoechst Ag, 6000 Frankfurt | METHOD FOR PRESERVATING FLAT PRINTING FORMS |
| DE3126636A1 (en) * | 1981-07-06 | 1983-01-27 | Hoechst Ag, 6000 Frankfurt | HYDROPHILIZED CARRIER MATERIALS FOR OFFSET PRINTING PLATES, A METHOD FOR THEIR PRODUCTION AND THEIR USE |
| DE3206470A1 (en) * | 1982-02-23 | 1983-09-01 | Hoechst Ag, 6230 Frankfurt | METHOD FOR THE PRODUCTION OF CARRIER MATERIALS FOR OFFSET PRINTING PLATES |
| US4414311A (en) * | 1982-03-18 | 1983-11-08 | American Hoechst Corporation | Cathodic deposition of light sensitive components |
| JPS58193194A (en) * | 1982-05-06 | 1983-11-10 | Fuji Photo Film Co Ltd | Surface protecting agent for lithographic plate |
| JPS59214651A (en) * | 1983-05-20 | 1984-12-04 | Fuji Photo Film Co Ltd | Plate making process using photo-sensitive lithographic printing plate |
-
1984
- 1984-05-16 DE DE19843418111 patent/DE3418111A1/en not_active Withdrawn
-
1985
- 1985-05-06 EP EP85105492A patent/EP0161608B1/en not_active Expired
- 1985-05-06 DE DE8585105492T patent/DE3560465D1/en not_active Expired
- 1985-05-14 CA CA000481442A patent/CA1271958A/en not_active Expired - Fee Related
- 1985-05-15 BR BR8502292A patent/BR8502292A/en not_active IP Right Cessation
- 1985-05-15 US US06/734,147 patent/US4650739A/en not_active Expired - Fee Related
- 1985-05-15 ZA ZA853680A patent/ZA853680B/en unknown
- 1985-05-16 JP JP60102825A patent/JPS60253597A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| EP0161608B1 (en) | 1987-08-12 |
| BR8502292A (en) | 1986-01-21 |
| DE3418111A1 (en) | 1985-11-21 |
| EP0161608A1 (en) | 1985-11-21 |
| ZA853680B (en) | 1985-12-24 |
| US4650739A (en) | 1987-03-17 |
| JPH0545437B2 (en) | 1993-07-09 |
| DE3560465D1 (en) | 1987-09-17 |
| JPS60253597A (en) | 1985-12-14 |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |