JPH1031311A - Planographic printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support of a planographic printing plate having excellent printing characteristics. SOLUTION: The supporting for a planographic printing plate is composed of an aluminum base and a coating film derived from a water-based compsn. which contains a hydrated metal oxide sol such as zirconia and a polycarboxylic org. polymer material such as polyacrylic acid. The coating film has at least 30nm thickness. The obtd. support for a planographic printing plate does not require expensive electrolytic polishing or anodic oxidizing process or other surface treatment, but it gives excellent printing quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a lithographic support. The lithographic support typically comprises a steel, aluminum, plastic or paper substrate with a surface coating of critical nature. The present invention relates to providing an improved surface coating.

[0002]

BACKGROUND OF THE INVENTION Lithographic printing methods rely on the different wetting properties of hydrophobic and hydrophilic surfaces. When an aluminum sheet is used as a substrate, the aluminum surface is in fact roughened, anodized, conditioned and then coated with a photosensitive coating. Positive and negative images are usually formed photographically on the surface of the printing plate. Image development removes organic coating from exposed or unexposed areas. The organic portion is lipophilic and will accept the oil-based ink but will not wet with water. In contrast, a conditioned anodic oxide has surface energy and can accept water or ink, but when wet it will not accept ink. In conventional practice, the roughening step is important for print quality and requires a uniform morphology with surface features in the range of 0.01-4 μm. The actual range used for a particular plate will depend primarily on the quality of the paper and the required print finish. When very long print times are required, it is a common practice to bake the plate (after development) above 200 ° C. This treatment enhances the interaction between the organic and oxide layers.

[0003] The most common method of achieving the high standard of surface roughening required for lithographic printing is to electrochemically treat the surface. However, this method has some limitations. In particular, it can only be performed at low speeds and it requires very large amounts of power and the use of special materials. The production of these materials requires special and costly practices to ensure high quality of the final product. There is also a need for costly waste treatment plants to treat waste chemicals from aluminum anodization and granulation.

Thus, a common practice is to anodize the roughened surface to provide a suitable water-wetting ink-wetting anodic oxide coating. Like the roughening method, the anodic oxidation method is relatively time-consuming and expensive.

It is known to produce lithographic printing plates by applying a suspension or sol of preformed particles to a substrate and removing this liquid leaving a coating comprising the particles. These particles can be bound together by a polymer or by partial immersion,
Organic polymers may affect the hydrophilic-lipophilic balance of the surface, while partial immersion may require high-temperature heating that damages the substrate.

[0006] WO 91/12140 (Alcan Internati)
onal Limeted) describe a lithographic plate comprising a substrate having an oxide layer derived from Form A sol. The substrate may be a metal, such as aluminum or steel, and may be milled or granulated or otherwise formed. The sol may include an inorganic passenger powder that provides the desired morphology to the coating layer.

US Pat. No. 3,971,660 describes a lithographic plate comprising a support having a hydrophilic surface comprising a homogeneous reaction product of hydrolyzed polyvinyl acetate and hydrolyzed tetraethyl orthosilicate. ing.

[0008] US 3,608,489 is a water-soluble urea.
Or a lithographic plate comprising a support coated with the reaction product of a melamine-formaldehyde resin and a water-soluble colloid containing free acid groups. The coating can contain titanium dioxide or silica.

US Pat. No. 3,298,852 describes a lithographic plate comprising a support which has been treated with a solution containing polyacrylic acid.

JP 61/63497 describes a lithographic plate comprising a support coated with, for example, a mixture of a styrene-maleic acid copolymer and a silicate.

US Pat. No. 3,912,548 describes the contact of a metal surface with an aqueous composition consisting of a soluble zirconium compound and a polymeric substance such as polyacrylic acid.

JP 63/54287 describes a lithographic plate comprising an image-receiving layer comprising an inorganic pigment containing alumina and a water-soluble binder.

JP 62/60695 describes a lithographic plate containing a silica-alumina colloidal pigment and a hydrophilic binder such as polyacrylate.

US Pat. No. 4,046,946 describes a lithographic printing surface wherein the lithographic printing surface comprises a coating of colloidal silica and a hydrophilic polymer rendered insoluble. Polycarboxy organic polymers are not mentioned there.

[0015] US 3,922,441 describes a lithographic printing plate comprising a lithographic printing surface, said surface comprising a coating of colloidal silica and a rendered insoluble hydrophilic polymer.

DE 1,210,437 describes a lithographic printing plate comprising a dry hydrophilic substance in a water-insoluble layer consisting of polyacrylic resin and zinc oxide.

[0017]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lithographic support having excellent printing properties.

Further objects of the present invention will become clear from the description hereinafter.

In one aspect, the invention provides a lithographic support comprising a coating comprising a substrate and a polycarboxy organic polymeric material disposed thereon, wherein the thickness of the coating is at least 30 nm. A lithographic support is provided.

In another aspect, the present invention is directed to a lithographic plate comprising a coating derived from an aqueous composition comprising a substrate and an inorganic sol or metal salt solution thereon and a polycarboxy organic polymeric material. Provide a support.

In another aspect, the present invention relates to a group of Al (III), Fe and Fe that form a substrate and an inorganic polymer thereon.
(III), Zr (IV), Th (IV), Ce (IV), Ti
A lithographic support comprising a coating derived from a coating composition comprising a basic unit which is a polynuclear ion selected from (IV).

In another aspect, the invention provides a lithographic plate comprising a support as defined above and an imaging or emissive or photosensitive layer thereon.

In another aspect of the invention, the lithographic printing plate is exposed image-wise to a radiation or photosensitive layer on a support, developed in an aqueous developer solution, rinsed with water and heated to 100 ° C.
Comprising a support that is baked at a temperature between 230C for a period of 40 minutes to 5 minutes.

[0024]

DETAILED DESCRIPTION OF THE INVENTION In one aspect of the invention, an essential component of the coating on the substrate is a polycarboxy organic polymeric material. Examples of polycarboxy organic polymeric materials include polyacrylic acid, polymethacrylic acid, polyethylacrylic acid, polydimethylaminoethyleneacrylic acid, and copolymers and terpolymers of these monomer components. You. These materials are typically soluble in water or at least emulsifiable.

[0025] The coating applied to the substrate constitutes an important feature of one aspect of the invention. The coating comprises a polycarboxy organic polymeric material and preferably an inorganic sol or metal salt solution, more preferably a hydrated oxide sol. Aqueous sols can be divided into three categories: type A, type B and type C.

Type A sols consist of basic units, which are polynuclear ions which form an "inorganic polymer" and are produced by the hydrolysis and polymerization of monomeric cations. Although the molecular weight of the polynuclear cation depends on the degree of hydrolysis, these sols generally have an anion to metal ratio of about 1: 1. The sol and resulting gel are optically clean because these polymer species are not large enough to effectively diffuse light. The gel has an X-ray diffraction pattern consisting of a high concentration, low porosity and a very wide band. JDF Ramsa
y "Neutron and Light Scattering Studies of Aqueous
Solutions of Polynuclear Ions. Water and Aqueous S
olutions ", 207-218 1986 (ed GW Neilson and JE
Enderby; Bristol. Adam Hilger). A-type sols are Al (III), Fe (I
II), Zr (IV), polynuclear ions including those containing Th (IV), for example, _{Al 13 O 4 (OH) 24} (H 2 O) 12 may be manufactured from ^7+.

The B-type sol has a certain shape, for example, spherical, rod-like or plate-like, and consists of basic units or particles which are amorphous or microcrystalline. This sol is made by extensive hydrolysis of the salt and has a low anion to metal atomic ratio of about 0.3: 1. These sols can also be prepared by peptization of fresh precipitate.
The colloidal units do not agglomerate and the sol and gel formed will both be clean. B-type sol is Al (II
I), Zr (IV), Ce (IV), Ti (IV), Fe (I
V). Production of B-type Al (III) sol is GB 1.1
74.648. The preparation of Ce B sol is described in GB 1.3342.893. B-type alumina sol is commercially available.

In the C-type sol, basic colloidal units are aggregated. They are crystalline and gels produced by the removal of water have a low density. These sols diffuse the light and are consequently opaque. Sols made from ultrafine powders produced by gas phase technology, ie flame hydrolysed powders, belong to this category.

Form A and Form B sols when hydrolyzed yield gels that are> 45% of the theoretical density of the oxide. C
Gels derived from type sols are porous and have a density of> 45% of the theoretical density of the oxide.

The inorganic sol for use in the present invention is preferably a hydrated oxide sol, such as a hydrated metal oxide sol, ie, an A-type sol. Examples are zirconia sol, ceria sol, titania sol, hafnia sol, alumina sol, and iron oxyhydroxide sol. Silica sol is an example of a non-metal oxide sol.

The zirconia A-type sol is easily produced by peptizing basic zirconium carbonate in a mineral acid. The structure of zirconia sol when the combined anion is nitrate or bromide or chloride is
UKAEA Re by JL Woodhead and JM Fletcher
search Group Report, reference AERE-R5257 (1966)
Discussed in The zirconia sol contains a highly hydrolyzed inorganic polymer having a primary particle size of less than 10 nm. This polymer is believed to constitute the hydrated oxyhydroxide species of zirconia. When nitric acid is used, these species have the formula: [Zr ₄ (OH) ₁₂ (NO ₃ ) ₂ (H ₂ O) ₄ ] _n (NO ₃ ) _2n .2 nH ₂
O, where n is about 1 in the diluted sol and appears to be greater than 1 at relatively high concentrations.

[0032] MEL Chemicals has sold A-type sols based on zirconyl ammonium carbonate under the trademarks AZC and BACO.
Sold as TE20, the latter containing a tartaric acid stabilizer.

Alumina A type sol is, for example, a trademark Prime
n Can be prepared by denitration of an aqueous solution of aluminum nitrate using a water-immiscible organic amine such as that sold as JMT.

Type A sols can also be prepared by controlled hydrolysis of metal alkoxides. The alkoxide is supplied in solution in an organic solvent, and a controlled amount of water is added to produce a polynuclear cation. The same technique can be used to produce A-type silica sol from organic solutions of alkoxysilanes. However, this method is unsatisfactory and requires removal of the organic groups from the coating,
Organic solutions are combustion hazards. The A-type sol used in the present invention is preferably derived from an inorganic precursor (including a carbonate).

In the gelation of the A-type sol, the polynuclear cation is polymerized by a chemical reaction to form a crosslinked inorganic network structure. In contrast to the gelling of type B or C sols, the sol particles simply agglomerate or physically fuse together. As a result, coatings made from Type A sols are more adhesive than those made from Type B or C sols and do not need to be cured at a temperature high enough to sinter the particles.

A-type sols of ceria and titania and other hydrated metal oxides can be prepared by peptizing the corresponding hydrated metal oxide with a mineral acid.

The nature of the substrate is not critical. Substrates commonly used for lithographic printing can be used in the present invention. The most preferred substrate is an aluminum sheet, but other metals, including steel, are used, as well as plastic sheets, metallized plastics and paper. The metal substrate may have a continuous electroplated coating of, for example, nickel or chromium. The aluminum or steel or other substrate may have a grained or contoured surface, but the substrate is milled or supplied as supplied without the need for special surface contouring. Since it is an advantage of the present invention that the alloy can be used in the state described above, a wide range of Al alloys can be used. For example, the required lithographic substrate strength is obtained by the use of relatively thin sheets of a relatively highly alloyed composition.

The aqueous composition can be prepared by combining the hydrated oxide sol of type A with a polycarboxy organic polymeric material in an aqueous solution or an aqueous emulsion. When the aqueous composition is applied to a substrate and dried to form a coating thereon, the metal or other oxide of the sol acts to cross-link the polycarboxy organic polymeric material and consequently It is believed to be insoluble. In a preferred example, the polycarboxy organic polymeric material is polyacrylic acid, and the sol is an A-type zirconia sol with zirconia acting to bridge the polyacrylic acid by carboxyl groups. Crosslinking of the polycarboxy organic polymeric material reduces the water sensitivity of the coating and allows for increased print times.

Polycarboxy organic polymeric substances include acrylic acid, methacrylic acid, itaconic acid, mesaconic acid and citraconic acid, other alkyl-substituted acrylic acids having an alkyl group having 2 to 6 carbon atoms, Number four
A half-ester of an α, β-unsaturated vinylidene dicarboxylic acid wherein the alcohol group is selected from linear and branched saturated and unsaturated hydrocarbons having 1 to 12 carbon atoms, and 6 carbon atoms It may be a homopolymer or a copolymer having one or more repeating groups selected from the group consisting of -20 dialkylaminoalkylacrylic acids.

In these coating compositions and in the coatings produced therefrom, ZrO ₂ or other metal oxides and polyacrylic acid or other polycarboxy organic polymeric materials derived from the sol are preferably used. 99.5 / 0.5-0.5 / 99.5, especially 20: 1-1
It is present in a weight ratio ranging from 1:20. As the following example shows, the addition of polyacrylic acid as low as 1% to 99% sol results in a significant improvement, but at the other end of the above range polyacrylic acid is not soluble in sols or metal salts. It has properties useful as a coating even in the complete absence of a solution. It is convenient to gel the sol either before or after application of the aqueous composition to produce a coating on the substrate. Known chemical techniques for gelling the Form A sol can be used.

The aqueous composition may contain a powder that can be used to impart the desired surface morphology to the coating on the substrate.

When used, the powder is preferably an inert metal oxide such as silica, zirconia, titania or alumina. This may be a C-type sol or a powder produced for example by grinding. 1-300 gl
^-1 , preferably 5-150 gl ^-1 , more preferably 10-7
A powder loading of 5 gl ^-1 is appropriate. This powder is 10μ
m, preferably 5 μm or less, for example 3-500n
It may have an average particle size in the range of m and is preferably a substantially uniform particle size. The powder is added into a layer on the surface of the substrate when the fluid causes gelation of the sol.

However, it has been found that the use of particulate matter can have disadvantages and is generally not necessary in the present invention. This finding is rather staggering.
The prior perception was that the lithographic support needed to be roughened to firmly bond the photosensitive layer over the lithographic plate. Such a surface roughness is generally not required in the coatings of the present invention.

The zirconia sol / polyacrylic acid system which has been applied to improve the adhesion of metals and other substrates to organic layers such as paints, varnishes and adhesives applied subsequently has been widely described. , The system is not itself new. One such publication is U.S. Pat. No. 3,912,548 (Faig
en, 1975). However, the properties required for adhesion-reinforced coatings are quite different from those required for lithographic support coatings. In that regard, the thickness of the coating containing the zirconia sol / polyacrylic acid system has not been previously defined. The advantageous print qualities shown in the following examples were not expected from the known adhesion-reinforcing properties of such coatings in the prior art.

Based on the foregoing, it is likely that other adhesion-reinforced coating compositions described in the literature may also have useful properties as coatings for lithographic supports. Can be For example, four commercially available aqueous formulations are sold as adhesion-reinforced compositions. These are Accomet C (based on chromium VI / chromium III), Alodine 1453 (hydrofluoric acid), Alodine NR779 (based on titania) and NR62707R (based on chromium III). A lithographic support having a submicron coating of these and similar materials is also contemplated according to the invention. The surface to which the coating is to be applied can be cleaned by general means suitable for the substrate. For aluminum, this is for example IC
I under the trademarks Ridolene 124 and 124E
An acid or alkali cleaning process using commercially available chemicals such as those sold as
Alternatively, the metal surface may be pre-treated to form an artificially applied oxide layer thereon. Such treatments include acid etching (Forest Products Laboratories) and anodizing using sulfuric acid, chromic acid or phosphoric acid. However, these pretreatments are very expensive and are preferably omitted as unnecessary for the lithographic support according to the invention.

The composition can be applied to the substrate surface (optionally having a contoured surface) by conventional techniques such as rotary coating, dipping, flow or roller coating,
It can be applied by brushing or by spraying. For aluminum strips, roller coating appears to be an attractive option. The formulation may need to be adjusted to give a convenient viscosity for application in the desired manner. After application and drying, the coating on the surface may be cured. The curing temperature is from ambient temperature to the decomposition temperature of the hydrophilic organic polymeric substance,
It is generally (although not necessarily) lower than that required for complete sintering of the particles, and is preferably in the range of 50-400C, and more preferably 100C-400C, where the substrate is stable. It is in the range of 350 ° C. The removal of water takes place gradually and is not complete even at 400 ° C.

The substrate surface preferably has a coating of at least 30 nm, preferably at least 50 nm, and most preferably at least 75 nm. The maximum thickness of the coating is not critical, but is preferably 4 μm
Below, more preferably 2.5 μm or less, most preferably 1 μm
m or less. If a more pronounced surface texture is required, thick coatings of up to 5 gm ^-2 are preferred and passenger powders having an average particle size of up to 1 or 10 microns may be used. The invention also contemplates the application of one or more layers to subsequent coating layers, such as those common in lithographic printing, as an additional process step.

The lithographic plate can also have an image-forming layer or a radiation-sensitive or light-sensitive layer, each coated on a coated substrate support. Photosensitive imaging layers are well known in the art. They can be applied by wipe-on technology before sale by the manufacturer or before use by the user. The lithographic plate is exposed and then developed to obtain a printing plate. Suitably the printing plate undergoes a baking step after development. The baking is performed at 100C to 25C.
It can be carried out at a temperature of 0 ° C. for a time of 40 minutes to 1 minute. Depending on the chemistry of the photosensitive layer, either the exposed or unexposed portions can be removed.

The lithographic support is required to bond firmly the part of the image bearing layer that should be present during printing, but to readily release the part of the image layer that is not present during printing.
As described in the examples below, printing tests have shown that the lithographic plates according to the invention have excellent quality in this regard. The lithographic plates used in the examples do not have the granulated surface conventionally present on aluminum lithographic plates, and this is also an advantage in allowing for better print sharpness.

[0050]

EXAMPLE 1 (according to the invention) 4.2 g of a sol-gel formulation 25% by weight solution of polyacrylic acid (1.05 g)
PAA equivalent) (trade name A from Rohm and Haas)
cumer 1510) was added to 100 g of water and stirred. 5.2 g of a 20% by weight solution of ammonium zirconium carbonate (1.04 g of ZrO ₂ equivalent) (trade name B)
acote 20) was added and the mixture was stirred to produce a coating solution. This production could be scaled up to higher volume production, producing 10 liters of solution in a single batch for testing.

Metal Cleaning Three methods of cleaning the lithographic sheet prior to coating were used: caustic, phosphoric acid and sulfuric acid. The preferred method is caustic cleaning (subsequent nitrous acid decontamination)
It is. Technical advantages may be obtained by cleaning in phosphoric acid. It is known that zirconium flakes in solution bind strongly to phosphate groups, and phosphoric acid cleaning, which leaves residual phosphate groups on the cleaned surface, improves coat adhesion and abrasion resistance Maybe. Sulfuric acid was used during testing to evaluate large-scale production methods.

1. Caustic Cleaning Caustic Cleaning / Etching A solution of 20 gl ⁻¹ NaOH at 60 ° C.-The plate was immersed for more than 60 seconds beyond the required cleaning time, but the surface etching was a matte finish of the quality desired by the printer. Occurred. Rinse the plate with water.

Nitric acid desmut A solution-plate of 12 gl ^-1 NaOH at room temperature was soaked for 60 seconds, which also exceeded "normal" decontamination conditions. The additional cleaning time increases the amount of intermetallic compound on the metal surface and consequently increases the decontamination time to ensure proper removal. The plate is rinsed with water and air-dried naturally before coating.

2. Phosphoric acid cleaning A 20% w / v solution at 90 ° C. (ie 20
g of concentrated H ₃ PO ₄ diluted to a total volume of 100ml). The plate is soaked for 60 seconds, then rinsed with water and air dried naturally before coating.

3. Sulfuric acid / hydrofluoric acid cleaning During a line test to evaluate the feasibility of coating with large-scale zirconia: polyacrylic acid, an aluminum coil was cleaned in a continuous web. Sulfuric acid (1.1% by weight) and hydrofluoric acid (80 pp
The metal passed through the cleaning bath containing m).
The bath temperature was 70 ° C. and the immersion time was 12 seconds.

Although the samples produced for optimization of coating and hardening coatings and printing tests are produced by rotary coating, it is believed that large scale production would be achieved by roller coating aluminum coils. Can be The coating solutions described above, unlike some commercially available pre-treatment solutions, do not contain aggressive chemical reagents, such as hydrofluoric acid, which provide some degree of cleaning.
It is therefore important to coat the plate as soon as possible after cleaning. The coating thickness is adjusted by adjusting the solution concentration and the spin speed.
The coating thickness is not fully optimized, but the thickness used in metal pretreatment (typically <25n
m) is known to provide insufficient wear resistance for use as a lithographic plate. Three coating thicknesses (75
-150 nm) is provided for overall print evaluation. The plate is rotated at a predefined speed (depositing a known film thickness), and the coating solution is applied to the center of the plate, moving outwards to the edges.
After application of the solution, the plate is rotated for a further 60 seconds. The plate is stored flat and air-dried naturally.
The plate is then immersed in a preheated oven (180 ° C.) for 60 seconds and allowed to cool.

The photosensitive coating is then applied by spin coating (which may be either a positive or negative coating) and the coating is imagewise cured and developed by exposing the coating through a mask. This forms an image on the plate, the image parts being wetted with ink and the non-image parts (sol-gel film) wetted with water.

Plates produced by this additive graining technique were evaluated in a printing test and were limited to a length of up to 30,000 impressions. These results were compared to the performance of a "standard" anodized lithographic plate. The results are as follows:-Photosensitivity-better than standard-Photosensitive coating-better than standard-Water consumption-better than standard-Run-up step-better than standard-Contrast after development-better than standard-Screen Reproduction-ok-film edge-ok-contrast after exposure-ok Subjective commentary and judgment from the print finishing plant was very favorable. When the test was terminated after 30,000 impressions, the general print quality of all plates tested was still excellent.

The lithographic plate having the photosensitive layer is image-wise exposed, developed in an aqueous solution of a developing agent, rinsed with water and
Baking was performed at a temperature between 230 ° C. for a period of 40 minutes to 5 minutes. The version so processed is 20
Prints with excellent print quality of more than 000 sheets were given. Exposed and developed plate at, for example, 230 ° C.
At 150 ° C. for 5 minutes
Bake for 30 minutes or at a temperature of 120 ° C. for 30 minutes. In each case, the temperature must be equal to or higher than 100 ° C.

Example 2 (according to the invention) A lithographic plate was produced in the same manner as in Example 1, except that the plate was inserted into a preheated furnace. 120,000 prints with excellent print quality were obtained before the end of the experiment.

When the printing plate has not been baked at a temperature between 100 ° C. and 230 ° C. for a time period between 40 minutes and 5 minutes, 100,000 prints with excellent print quality are obtained before the end of the experiment. Was done.

When the printing plate was manufactured in the same manner as in Example 1 except that the printing plate was not baked at a temperature between 100 ° C. and 230 ° C. for a time period of 40 minutes to 5 minutes, before the end of the experiment 1 with excellent print quality
50,000 prints were obtained.

Example 3 (comparative) A photosensitive coating (EP-A-292801, page 6, 31-) was applied to a sheet of an aluminum sample delivered from a supplier that had not been further processed (as rolls).
(Cited in line 33) and coated on a printing press after image-wise radiation and development. Initially it gave satisfactory results, but after only 300 impressions the photosensitive coating (image area) peeled off and the printing was completely unacceptable.

Example 4 (according to the invention) Alo was applied to a sheet of an aluminum sample delivered from a supplier that had not been further processed (as rolled).
A mixture of dine NR779 (a composition made by Henkel comprising titanium fluorides, fluoric acid and phosphoric acid) and 1% by weight of polyacrylic acid was coated to a dry thickness of about 100 nm. . A photosensitive coating (EP-A-2928)
01, page 6, lines 31-33) and placed on a printing machine after image-wise radiation and development. From the beginning it gave satisfactory results and the print quality was good until a number of lengths of 90000 was performed.

Example 5 (According to the Invention) Polyacrylic acid was coated to a dry thickness of about 100 nm on a sheet of an aluminum sample delivered from a supplier that had not been further processed (as rolled). A photosensitive coating (EP-A-2928)
01, page 6, lines 31-33) and placed on a printing press after image-wise radiation and development. From the beginning it gave satisfactory results and the print quality was good until a number of times of 30,000 was performed.

The main features and aspects of the present invention are as follows.

1. A lithographic support comprising a coating comprising a substrate and a polycarboxy organic polymeric material thereon, wherein the thickness of the coating is at least 30 nm.

2. A lithographic support comprising a coating derived from an aqueous composition comprising a substrate and an inorganic sol or metal salt solution thereon and a polycarboxy organic polymeric material.

3. The lithographic support of claim 2, wherein the metal salt or inorganic sol oxide in the aqueous composition is capable of crosslinking and rendering the polycarboxy organic polymeric material insoluble.

4. Group A in which an inorganic sol forms an inorganic polymer
l (III), Fe (III), Zr (IV), Th (IV), C
The lithographic support according to the above 2, which is an A-type sol comprising a base unit which is a polynuclear ion selected from e (IV) and Ti (IV).

5. The polycarboxy organic polymeric material is selected from the group consisting of polyacrylic acid, polymethacrylic acid, polyethylacrylic acid, polydimethylaminoethyleneacrylic acid and copolymers and terpolymers of these monomer components. The lithographic support of any one of the above 1 to 4.

6. The lithographic support of claim 5, wherein the polycarboxy organic polymeric material is polyacrylic acid.

7. The lithographic support according to any one of the above items 1 to 4, wherein the polycarboxy organic polymeric substance is a polymer of acrylamidoisobutylenephosphonic acid or a copolymer of acrylamidoisobutylenephosphonic acid and acrylamide.

8. The lithographic support according to 4 above, wherein the A-type sol is selected from the group consisting of zirconia, ceria, titania, hafnia, alumina, iron oxyhydroxide, and vanadium sol.

9. The lithographic support of claim 4, wherein the A-type sol is a zirconia sol and the polycarboxy organic polymeric material is polyacrylic acid.

10. The lithographic support of claim 9, wherein the zirconia sol ZrO ₂ and polyacrylic acid are present in a weight ratio in the range of 20: 1 to 1:20.

11. 11. The lithographic support according to any one of 1 to 10 above, wherein the substrate is made of aluminum.

12. Substrate and the following chemical components on it: chromic acid (Cr (IV)), amorphous silica, chromium (III) compound, hydrofluoric acid, propylene glycol ether, chromium (III) compound and hydrofluoric acid , Titanium oxide, a coating derived from a coating composition selected from the group consisting of:
1. The lithographic support of any one of 1.

13. Coating at least 50 nm
The lithographic support according to any one of the above items 1 to 12, which is present at a thickness of:

14. A lithographic plate comprising the support of any one of the above items 1 to 13 and an image forming layer or a radiation or photosensitive layer thereon.

15. The overlying radiation or photosensitive layer is imagewise exposed, developed in an aqueous developer solution, rinsed with water and at a temperature between 100 ° C and 230 ° C for 40 minutes to 5 minutes.
The lithographic plate of any of the above items 1 to 14, which is baked for a period of minutes.

16. Exposed and developed plate at 230 ° C
Baking at a temperature of 5 minutes for 5 minutes.
5 lithography.

17. Exposed and developed plate at 150 ° C
The lithographic plate of 15 above, which is baked at a temperature of 10 minutes for 10 minutes.

18. Exposed and developed plate at 120 ° C
The lithographic plate of 15 above, which is baked at a temperature of 30 minutes for 30 minutes.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Gijonathan Bowl, UK, Wokswick Bee 49 6 AA Alsester Exhol Globe Armhouse (No Address) (72) Inventor, Nijelle Cleton Davies United Kingdom・ Ochsfjord Oeks17 1 Ezet Mohrint-Fonbiyu (no address) (72) Inventor Peter Carl Ferdinand Limbatsch Germany Day-37,075 Getteingen Gen-Muhochenbrunnen 21

Claims (3)

[Claims] 1. A lithographic support comprising a coating comprising a substrate and a polycarboxy organic polymeric material thereon, wherein the thickness of the coating is at least 30 nm. body. 2. A lithographic support comprising a coating derived from an aqueous composition comprising a substrate and an inorganic sol or metal salt solution thereon and a polycarboxy organic polymeric material. 3. A lithographic plate comprising a support according to claim 1 or 2 and an image forming layer or a radiation or photosensitive layer thereon.