DE69908239T2 - Heat sensitive recording element for the production of lithographic printing plates - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a heat sensitive Imaging element.

The present invention relates to especially a residue-free one thermosensitive Imaging element for producing a lithographic printing plate, the no dissolving Processing requires.

GENERAL STATE OF THE ART

Lithographic printing is the process in which the printing of specially manufactured surfaces of which certain areas attract lithographic paint and other areas after wetting with water will repel the paint. The ink-attracting areas form the printing image areas, the ink repellent Areas the background areas.

In the field of photolithography a photographic material in the photo-exposed areas (negative working) or in the non-exposed areas (positive working) on one hydrophilic background imagewise oily or made bold colors attractive.

More common in manufacturing lithographic printing plates, also as surface lithographic plates or planographic printing plates, becomes a support that has an affinity for water has or such affinity obtained through chemical processing with a thin layer coated with a radiation sensitive composition. As layers with a radiation-sensitive composition are photosensitive polymer layers, the diazo compounds, dichromate-sensitized hydrophilic colloids and a variety of synthetic ones Contain photopolymers. In particular, diazo-sensitized layer dressings widely used.

While the imagewise exposure the exposed areas of the photosensitive layer insoluble and the unexposed areas remain soluble. The printing plate is then with a suitable liquid designed to contain that contained in the unexposed areas Remove diazonium salt or diazo resin.

Printing plates are also known which have a light-sensitive layer, which with imagewise exposure soluble in the exposed areas is made. While Subsequent development then becomes the exposed areas away. A typical example of such a photosensitive Layer is a layer based on quinonediazide.

The photographic described above Materials used to make the printing plates, are usually exposed through in a contact copier a photographic film made using a lithographic printing process contains the image to be reproduced. Such a procedure is cumbersome and labor-intensive, on the other hand, however, the printing plates thus obtained wait with one excellent lithographic quality.

Tests have been made been on the use of a photographic film as described above To be able to do without procedures and in particular a printing plate directly based on that too embodying reproductive image To generate computer data. The sensitivity of the above-mentioned photosensitive However, layers are not sufficient for direct laser exposure. Accordingly, it has been proposed to use a photosensitive layer Coating silver halide layer. The silver halide can then directly under computer control by means of exposed by a laser. Then the silver halide layer develops and a silver image is developed on the light-sensitive layer receive. This silver picture then serves as a mask during a all-over Exposure of the photosensitive layer. After full exposure the silver image is removed and the light-sensitive layer is developed. Such a method is described for example in JP-A 60-61 752, however, has the disadvantage of being a complex development and related developing liquids needed become.

GB 1 492 070 describes a process in which a metal layer or a layer containing gas black is applied to a photosensitive layer. This layer of metal is then ablated by means of a laser, whereby on the photosensitive layer an image mask is obtained. The photosensitive layer is then through the image mask through a full-surface ultraviolet exposure subjected. After removing the image mask, the photosensitive Developed layer and received a printing plate. This method but still has the disadvantage that the image mask on cumbersome Paths removed before developing the photosensitive layer must become.

On the other hand, there are also methods in which imaging elements are used to produce printing plates, which are more sensitive to heat than to radiation. The radiation-sensitive imaging elements used to produce a printing plate as described above have the particular disadvantage that they must be protected from light. Furthermore, sensitivity to storage stability is also problematic and they have a lower point sharpness. There is a clear trend on the market towards heat-sensitive printing plate precursors.

In EP-A 444 786, JP-63-208036 and JP-63-274592 are for the near infrared region sensitized photopolymer etching reserve layers disclosed. So far, none of them have proven to be commercially viable and all require wet development for washing out the unexposed areas. In EP-A 514 145 described a laser addressed plate, in which the by the Laser exposure generated heat the particles in the plate coating melt and coalesce lets and doing a change of their solubility properties causes. Here, too, wet development is required.

A somewhat different approach is being used in U.S. Patent No. 3,787,210, U.S. Patent No. 3,962,513, EP-A 001 068 and JP-04-140191 disclosed. The one generated by laser exposure of a donor sheet Heat will used a physical transmission a resinous material from the donor to one in intimate contact with to effect the receiving element held by the donor. Indicates the surface of the Receiving elements have suitable hydrophilic properties, so can the receiving element can then be used as a printing plate. With this The process has the advantage that no wet development is required. However, is to achieve realistic writing times YAG high power lasers (or similar Laser type), which requires a limitation in the usability of this Procedure entails.

On the other hand are from the current State of the art also known polymer layers, their surface properties change in response to exposure. WO-92/09934 Imaging elements disclosed which are hydrophilic when irradiated future layers. These layers contain an acid sensitive Polymer and a photochemical source of strong acid. In is both cases the preferred acid sensitive Polymer derived from a cyclic acetal ester of acrylic or methacrylic acid, such as tetrahydropyranyl (meth) acrylate.

In WO-92/02855 the acid sensitive Polymer with a low Tg polymer added to a layer to make, which is initially non-sticky, but when irradiated due to the chemical conversion of the acid sensitive polymer Undergoes phase separation and becomes sticky. It is true that here possibility mentioned by laser exposure, However, details are not given and there is no sensitivity across from Infrared radiation mentioned only opposite Ultraviolet radiation and visible light. The same materials are, however, in an article entitled "Advances in Phototackification", presented in "Paper 1912-36" on the occasion of the "1993 IS & T / SPIE Conference, Symposium on Electronic Science and Technology ", is discussed in this article further discloses that the Photo acid generator with an infrared dye (especially a squarylium dye with thiopyrylium end groups) and the exposure with a Diode laser device can be made. From this dye are not acid-generating Properties known. This technology is described in US Pat. No. 5,286,604 discussed.

This is possible from WO-92/09934 Mixing of an acid sensitive Polymer known with one or more photo acid generators. To the imagewise exposure with ultraviolet radiation or visible light, the exposed Areas preferably wetted with water and the layers can be developed without wet development can be used as lithographic printing plates. Laser addressing is not mentioned.

In WO-92/2855 the acid sensitive Polymer with a low Tg polymer added to a layer to make, which is initially non-sticky, but when irradiated due to the chemical conversion of the acid sensitive polymer Undergoes phase separation and becomes sticky. It is true that here possibility mentioned by laser exposure, However, details are not given and there is no sensitivity across from Infrared radiation mentioned only opposite Ultraviolet radiation and visible light. The same materials are, however, in an article entitled "Advances in Phototackification", presented in "Paper 1912-36" on the occasion of the "1993 IS & T / SPIE Conference, Symposium on Electronic Science and Technology ", is discussed in this article further discloses that the Photo acid generator with an infrared dye (especially a squarylium dye with thiopyrylium end groups) and the exposure with a Diode laser device can be made. From this dye are not acid-generating Properties known. This technology is described in US Pat. No. 5,286,604 discussed.

In EP-A 652 483 a lithographic Printing plate disclosed that does not require resolving processing. The lithographic printing plate contains a substrate with an encapsulated one heat sensitive layer, the under the influence of heat becomes relatively hydrophilic. This system is a positive one Preserved printing plate. An analog system that works negatively Pressure plate results, but is not known. In EP-A 507 008 Homopolymers and copolymers provided the aryldiazosulfonate units with a maximum spectral sensitivity of at least 320 nm included. These polymers are particularly suitable for production of printing plates.

In US-P 5 713 287 a printing plate described with hydrophobic polymers that when heated in hydrophilic polymers are converted and with infrared dyes are mixed.

GB-A 1 195 841 discloses a heat-sensitive imaging element containing a support and at least one layer containing a radiation converting substance and a thermally decomposable polymer consisting of repeating units linked by azo groups holds.

TASKS OF PRESENT INVENTION

Object of the present invention is an imaging element for making a negative working, no resolving To provide processing-requiring lithographic printing plate.

Another task of the present Invention is an imaging element for making a to provide lithographic printing plate that has no resolving processing requires good color attraction in the exposed areas and has no foaming in the unexposed areas.

Other tasks of the present Invention will be apparent from the description below.

BRIEF PRESENTATION THE PRESENT INVENTION

The tasks according to the invention are solved through a heat sensitive Imaging element for producing a lithographic printing plate, the one carrier and as a top layer a thermally switchable imaging layer with a hardened hydrophilic binder and a thermally switchable polymer contains wherein the cover layer or a layer adjacent to the cover layer a light in warmth converting connection contains characterized in that the thermally switchable polymer containing an aryldiazosulfonate unit Is polymer.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

in der
R⁰, R¹ und R² unabhängig voneinander jeweils ein Wasserstoffatom, eine Alkylgruppe, eine Nitrilgruppe oder ein Halogenatom, z. B. Cl, bedeuten,
L eine zweiwertige Verbindungsgruppe bedeutet,
n 0 oder 1 bedeutet,
A eine Arylgruppe bedeutet und
M ein Kation bedeutet.
L bedeutet vorzugsweise eine zweiwertige Verbindungsgruppe aus der Gruppe bestehend aus
-(X)_t-CONR³-, -(X)_t-COO-, -X- und -(X)_t-CO-, wobei
t 0 oder 1 bedeutet,
R³ ein Wasserstoffatom, eine Alkylgruppe oder eine Arylgruppe bedeutet, und
X eine Alkylengruppe, eine Arylengruppe, eine Alkylenoxygruppe, eine Arylenoxygruppe, eine Alkylenthiogruppe, eine Arylenthiogruppe, eine Alkylenaminogruppe, eine Arylenaminogruppe, Sauerstoff, Schwefel oder eine Aminogruppe bedeutet.The image-forming layer, which becomes more hydrophobic when exposed to heat, contains a thermally switchable polymer, a light-to-heat converting compound and a hardened hydrophilic binder. A thermally switchable polymer is a polymer or copolymer that is subjected to a polarity change from hydrophilic to hydrophobic or vice versa under the action of heat. In the present invention, a switchable binder is used which is hydrophilic before the heating and is made hydrophobic by the heating. This difference in surface polarity is sufficient to produce a conventional offset printing plate. The switchable binders according to the invention are polymers or copolymers which contain aryldiazosulfonate units. A radiation-sensitive polymer with aryldiazosulfonate units, also referred to as aryldiazosulfonate resin, is preferably a polymer with aryldiazosulfonate units of the following formula:

in the
R ⁰ , R ¹ and R ² each independently represent a hydrogen atom, an alkyl group, a nitrile group or a halogen atom, e.g. B. Cl, mean
L represents a divalent connecting group,
n means 0 or 1,
A represents an aryl group and
M is a cation.
L preferably denotes a divalent connecting group from the group consisting of
- (X) _t -CONR ³ -, - (X) _t -COO-, -X- and - (X) _t -CO-, where
t means 0 or 1,
R ^{3 represents} a hydrogen atom, an alkyl group or an aryl group, and
X represents an alkylene group, an arylene group, an alkyleneoxy group, an aryleneoxy group, an alkylene thio group, an arylene thio group, an alkylene amino group, an arylene amino group, oxygen, sulfur or an amino group.

A is preferably an unsubstituted one Aryl group, e.g. B. an unsubstituted phenyl group, or especially preferably an aryl group, e.g. B. a phenyl group with a or more alkyl groups, aryl groups, alkoxy groups, aryloxy groups or amino groups is substituted.

M preferably denotes a cation such as NH4 ⁺ or a metal ion such as a cation of Al, Cu, Zn Alkaline earth metal or an alkali metal.

A polymer with aryldiazosulfonate units is preferably obtained by radical polymerization of a corresponding monomer. Suitable monomers for use in the present invention are described in EP-A 339 393 and EP-A 507 008. Typical examples are

Aryldiazosulfonate monomers, e.g. B. as described above with other aryldiazosulfonate monomers and / or with vinyl monomers such as (meth) acrylic acid or their esters formed therefrom, (meth) acrylamide, acrylonitrile, Vinyl acetate, vinyl chloride, vinylidene chloride, styrene, α-methylstyrene etc., homopolymerized or copolymerized. For copolymers however, care should be taken to ensure that the water solubility of the polymer is not to affect. The amount of aryldiazosulfonate units in a copolymer according to the invention is preferably between 10 mol% and 60 mol%.

According to a further embodiment according to the invention an aryldiazosulfonate-containing polymer can be obtained by to make a polymer with e.g. B. Acid groups or acid halide groups react with an amino or hydroxy substituted aryldiazosulfonate leaves. more accurate Information about this process can be found in EP-A 507 008.

The aryldiazosulfonate monomer copolymerized one preferably with monomers, the reactive groups with formaldehyde, Glyoxal, polyisocyanates or a hydrolyzed tetraalkyl orthosilicate able to react contain.

The imaging layer or a layer adjacent to this layer contains a compound that can convert light into heat. Infrared absorbing components are preferably used as suitable light to heat converting compounds, although the absorption wavelength is not of great importance as long as the absorption of the compound used falls within the wavelength range of the light source used for imagewise exposure. Particularly useful compounds are, for example, dyes and, in particular, infrared-absorbing dyes and pigments and, in particular, infrared-absorbing pigments. Examples of infrared-absorbing dyes are described in EP-A 97 203 131.4. Examples of infrared absorbing pigments are carbon black, metal carbides, metal borides, metal nitrides, metal carbonitrides, oxides with a bronze structure and oxides with a structure related to the bronze family, but without the A component, e.g. B. WO _2.9 . Conductive polymeric dispersions can also be used, such as conductive polymeric dispersions based on polypyrrole or polyaniline. Although the light converting compound is preferably embedded in the cover layer, it can also be embedded in the adjacent layer.

The compound which is capable of converting light into heat is preferably in an amount between 1 and 25% by weight, based on the total weight of the image-forming layer, particularly preferably in an amount between 2 and 20% by weight, based on the total weight the imaging layer, in bil the generating element included.

A particularly suitable hardened hydrophilic Layer can be made of a hydrophilic, with a crosslinking agent such as formaldehyde, glyoxal, polyisocyanate or a hydrolyzed Tetraalkyl orthosilicate crosslinked binders can be obtained. The latter Crosslinking agents are particularly preferred.

Come as a hydrophilic binder hydrophilic (co) polymers such as homopolymers and copolymers of vinyl alcohol, acrylamide, methylolacrylamide, methylolmethacrylamide, Acrylic acid, methacrylic acid, Hydroxyethyl acrylate, hydroxyethyl methacrylate or maleic anhydride-vinyl methyl ether copolymers in question. The hydrophilicity of the (co) polymer or (co) polymer mixture used is preferably higher or equal to the hydrophilicity of at least 60% by weight, preferably to at least 80% by weight hydrolyzed polyvinyl acetate.

The amount of crosslinking agent, in particular Tetraalkyl orthosilicate preferably at least 0.2 part by weight per part by weight of hydrophilic Binder, is preferably between 0.5 and 5 parts by weight, particularly preferably between 1.0 part by weight and 3 parts by weight per part by weight of hydrophilic binder.

One according to this embodiment crosslinked hydrophilic layer used preferably also contains substances, which improve the mechanical strength and porosity of the layer. To colloidal silica can be used for this purpose. The colloidal silica can be in the form of any commercially available water dispersion of colloidal silica for example with an average particle size up to 40 nm, e.g. B. 20 nm, to be used. Next to it inert particles with a larger grain size than that colloidal silica be added, e.g. B. silica, which, as in J. Colloid and Interface Sci., Volume 26, 1968, pages 62 to 69, by Stöber is made, or alumina particles or particles with an average diameter of at least 100 nm, it being are particles of titanium dioxide or other heavy metal oxides. By embedding these particles, the surface of the cross-linked hydrophilic layer with a uniform rough texture microscopic peaks and valleys, which as bearings for Serve water in background areas.

The image-forming layer is preferably applied in a ratio between 0.1 and 5 g / m ² , particularly preferably in a ratio between 0.25 and 3 g / m ² .

The carrier can be both hydrophobic and be hydrophilic and be both a rigid support and a flexible support.

In the imaging element of the present Invention can be the carrier be an anodized aluminum beam. A particularly preferred carrier is an electrochemically grained and anodized aluminum support.

According to another embodiment of the invention is the carrier a flexible beam like a paper support or a plastic film. As a flexible support according to this embodiment is particularly preferred a plastic film, for. B. a subbed Polyethylene terephthalate film, a cellulose acetate film, a polystyrene film, a polycarbonate film, etc. The plastic film carrier can opaque or translucent his.

A polyester film carrier coated with an adhesion-improving layer is particularly preferred. Adhesion-improving layers which are particularly suitable for the use according to the invention contain a hydrophilic binder and colloidal silica, as described in EP-A 619 524, EP-A 620 502 and EP-A 619 525. The amount of silica in the adhesion-promoting layer is preferably between 200 mg / m ² and 750 mg / m ² . Furthermore, the ratio of silica to hydrophilic binder is preferably above 1 and the specific surface area of the colloidal silica is preferably at least 300 m ² / g, particularly preferably at least 500 m ² / g.

Can between the carrier and the top layer the imaging element other layers such as adhesive layers and Antihalation layers included.

The imaging element can after any known technique by applying the various Layers are made. Alternatively, the imaging element using one or more located in close proximity to the press coating equipment on the press on which the carrier is already appropriate.

The exposure according to the invention is an imagewise scanning exposure using a laser, particularly preferably one in the infrared range or near infrared, i.e. in the wavelength range between 700 and 1,500 nm, emitting laser. Are very particularly preferred near infrared emitting laser diodes. The exposure of the Imaging element can be used with lasers with both short and long Pixel retention time can be made. Lasers with are preferred a pixel dwell time between 0.005 μs and 20 μs.

After exposure is the imaging element ready to use and can be used as a lithographic printing plate become.

In a further embodiment according to the invention, the imaging element can be exposed with the imaging element already clamped in the printing press. A computer or other information source then leads the printhead or a laser via a line graphic and text information too.

The printing plate according to the invention can also in the form of a seamless sleeve can be used as a printing plate in a printing cycle. This cylindrical Printing plate has a diameter such that it is on the printing drum can be pushed. More detailed information about sleeve pressure plates can be found in "Grafisch Nieuws", publisher Keesing, 15, 1995, pages 4 to 6.

The printing plate according to the invention can also in the form of a seamless sleeve can be used as a printing plate in a printing cycle. This cylindrical Printing plate, the diameter of which corresponds to the diameter of the printing drum is the same, is pushed onto the printing drum instead of the conventional one Ways than in conventional Made printing plate arranged on the printing press become. More details about Sleeve printing plates can be found in "Grafisch Nieuws ", publisher Keesing, 15, 1995, pages 4 to 6.

After the imagewise exposure, the imagewise exposed Imaging element with the back of the imaging member (i.e., the side of the support that opposite to the side containing the photosensitive side) mounted on a printing drum of a printing press. After a preferred embodiment the printing press is then started and rotating the printing drum with the imaging element clamped thereon, the Fountain water supply Dampening rollers and then the inking rollers are lowered onto the imaging member.

The present invention will now illustrated by the following examples, but without them to restrict. All parts are parts by weight unless otherwise noted.

EXAMPLES

example 1

To 11 g of a dispersion containing 21.5% TiO ₂ (with an average particle size between 0.3 and 0.4 μm) and 2.5% polyvinyl alcohol in demineralized water, 7.5 g are added in succession with stirring an aqueous 4% glyoxal solution, 33.3 g of an aqueous 1% solution of IR-1, 12.95 g of a 6% solution of the diazosulfonate copolymer P20 (which is a copolymer of 20 mol% diazosulfonate monomer and 80 mol% methyl methacrylate is) in methanol and 0.30 g of a 10% solution of a wetting agent. The pH of this mixture is adjusted to 6.8.

The dispersion thus obtained is in a wet layer thickness of 30 μm encapsulate a polyethylene terephthalate film support (coated with a hydrophilic adhesive layer), at 30 ° C dried and then one 12 hours hardening at a temperature of 67 ° C and subjected to a relative humidity of 50%.

For the imaging of the printing plate thus obtained, a CREO 3244 TRENDSETTER ^™ (sold by Creo) is used, which is operated at 2400 dpi, a drum speed of 70 rpm and a laser power of 11 watts.

After exposure, the plate for printing in a GTO46 press clamped, using Van Son Rubberbase as printing ink and fountain solution a Rotamatic solution containing 2% Tame can be used. there become deductions good quality received, i.e. deductions with good color attraction in the exposed areas and none Foaming in the unexposed areas.

Example 2

To 22 g of a dispersion containing 21.5% TiO ₂ (with an average particle size between 0.3 and 0.4 μm) and 2.5% polyvinyl alcohol in demineralized water, 6.05 g are added in succession with stirring an aqueous 24% solution of a tetramethyl orthosilicate emulsion, 60 g of an aqueous 1% solution of IR-2, 12.5 g of a 5% aqueous polyvinyl alcohol solution, 30.31 g of a 6% solution of the diazosulfonate copolymer P20 in methanol and 0, 60 g of a 10% solution of a wetting agent. The pH of this mixture is adjusted to 5.5.

The dispersion thus obtained is in a wet layer thickness of 30 μm cast an aluminum substrate, dry at 30 ° C and then one 12 hours hardening at a temperature of 67 ° C and subjected to a relative humidity of 50%.

For the imaging of the printing plate thus obtained, a CREO 3244 TRENDSETTER ^™ (sold by Creo) is used, which is operated at 2400 dpi, a drum speed of 50 rpm and a laser power of 11 watts.

After exposure, the plate for printing in a GTO46 press clamped, using Van Son Rubberbase as printing ink and fountain solution a Rotamatic solution containing 2% Tame can be used. there become deductions good quality received, d. H. deductions with good color attraction in the exposed areas and none Foaming in the unexposed areas.

Synthesis of the diazosulfonate Polymers P20 Synthesis of Monomer A The azo group-containing Protect substances from light z. B. by darkening the chamber or by wrapping the piston with an aluminum foil.

The reagents are available from Fluka and Aldrich, the solvents are distilled before use.

• a) Prepare 3 solutions
• 1 24 g of sodium sulfite and 40 g of sodium carbonate are dissolved in 250 ml of water dissolved,
• 2 15.02 g of p-aminoacetanilide are dissolved in 100 ml of water and 36.8 ml of concentrated HCl (32%) diluted and with a cooling bath cooled to 0–5 ° C,
• 3 6.8 g of sodium nitrite are diluted in 15 ml of water.

solution 3 is cooling (below 5 ° C) to solution 2 was added dropwise, after which the solution thus obtained was stirred for 10 minutes. After filtering, the solution under vigorous stir quickly in solution 1 poured. Subsequently will be the solution Stirred for 30 minutes. To begin with, the solution may be be red, but after a few minutes the solution will turn to yellow. The solid product is filtered off from the solution and without further Cleaning used.

• b) The product is dissolved in 150 ml of water, after which 8 g of NaOH are added. After that, the solution Heated to 50 ° C for 1 h and then cooled to 0 ° C. With constant cooling, 19.66 ml concentrated HCl (32%) are added to the solution. Then 100 ml of 1% picric acid are added and a solution of 33.6 sodium carbonate in about 350 ml of water is poured into the mixture. The temperature of the solution must be below 5 ° C before adding the methacrylic acid chloride. 15 ml of methacrylic acid chloride are very slowly added dropwise to the solution from a dropping funnel (heavy foaming). The mixture must be stirred at 0-5 ° C for 1 h and then stirred for a further hour at room temperature. Then 300 ml of a saturated solution of sodium acetate are added and the solution is stored overnight in a refrigerator (about 4 ° C.). The solid product is filtered off and dried in vacuo at 50 ° C. for 17 h. To remove inorganic salts, the product is dissolved in 150 ml of DMF (dimethylformamide) and stirred and filtered at room temperature for at least 2 h. For the purpose of precipitation, the filtrate is poured into 2 l of diethyl ether and then filtered. To obtain a very low water content (2.5%) a 3 day drying at 50 ° C in a vacuum is required.

Synthesis of the polymer P 20

First, 2.11 g of monomer 1 diluted in 10 ml water, after which 3.1 g of methyl methacrylate, 0.300 g of azo-bis-isobutyronitrile and 40 ml of dioxane are added. To remove oxygen must the Solution several times be degassed. Afterwards the solution (under light protection) 17 h at 70 ° C touched. The polymerization is accomplished by adding a small amount of hydroquinone stopped the solvent is evaporated and the polymer redissolved in 80 ml of methanol. The solution is added dropwise to 2 1 of diethyl ether and then at 50 ° C. in a vacuum over phosphorus pentoxide dried. After 3 days Drying a polymer with a water content of 2.5%.

Claims (10)

A heat-sensitive imaging element for producing a lithographic printing plate, which contains a support and, as a cover layer, a thermally switchable image-forming layer with a hardened hydrophilic binder and a thermally switchable polymer, the cover layer or a layer adjacent to the cover layer containing a light-to-heat-converting compound, characterized in that the thermally switchable polymer is a polymer containing aryldiazosulfonate units. A heat sensitive Imaging element according to Claim 1, characterized in that the quantity Aryldiazosulfonate units in the polymer between 10 mol% and 60 mol% lies. A heat sensitive Imaging element according to claim 1 or 2, characterized in that the light in warmth converting compound is an infrared absorbing component. A heat sensitive Imaging element according to Claim 3, characterized in that the infrared-absorbing element Component is an infrared absorbing dye. A heat sensitive Imaging element according to Claim 3, characterized in that the infrared-absorbing element Component is an infrared absorbing pigment. A heat sensitive Imaging element according to one of Claims 1 to 5, characterized in that that the A crosslinking agent from the group consisting of formaldehyde, Glyoxal, polyisocyanate or a hydrolyzed tetraalkyl orthosilicate contains. A heat sensitive Imaging element according to one of Claims 1 to 6, characterized in that that the Cover layer consisting of a hydrophilic binder from the group from homopolymers and copolymers of vinyl alcohol, acrylamide, methylolacrylamide, Methylol methacrylamide, acrylic acid, methacrylic acid, Hydroxyethyl acrylate, hydroxyethyl methacrylate or maleic anhydride-vinyl methyl ether copolymers contains. A heat sensitive Imaging element according to one of Claims 1 to 7, characterized in that that this Aryldiazosulfonate monomer with monomers with reactive groups that with formaldehyde, glyoxal, polyisocyanates or a hydrolyzed Tetraalkyl orthosilicate are able to react, is copolymerized. A method of making a lithographic Printing plate, the step of exposing a heat sensitive An imaging element according to any one of claims 1 to 7. One identified by the steps below printing process - exposure of a heat sensitive Imaging element according to one of Claims 1 to 7, - clamp the printing plate into the printing press, - Supply of ink and fountain solution on the pressure plate and - To press with the pressure plate.