DE1247859B - Process for the production of images or printing forms by image-wise polymerization with the aid of a peroxy compound and a silver salt - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

G03c

German class: 57 b-10

Number: 1247 859

File number: P 29079 IX a / 57 b

Filing date: March 29 , 1962

Opened on: August 17 , 1967

The invention relates to a photographic process for the production of images or printing forms, in which a polymerizable layer - optionally located on a substrate - containing an addition polymerizable compound with at least one terminal ethylenic group, optionally a dye or pigment and optionally between 3 and 97 percent by weight based on the total weight of the polymerizable layer, containing a solid thermoplastic compound at 50 ° C , is image-wise polymerized with the aid of a peroxy compound and a silver salt, whereupon the unpolymerized image parts of the layer can be removed or transferred to an image-receiving material.

It is known that the quantum yield is a little below 1 for the generation of a latent image in a superhalogenous layer. The development increases the quantum yield to IO ⁶ to IO ⁹ ; that is, for each absorbed light quantum IO ⁶ to IO ⁹ silver atoms are present in the silver image. In the case of processes that do not work with silver halides, the quantum yield is generally much lower, since there is no amplification. Process such as B. those using diazonium compounds or dichromate-containing binders give a quantum yield of about 0.5. Exceptions are those processes in which the exposure sets a chain reaction in motion, such as, for example. in addition photopolymerization. In these cases, the total quantum yield is significantly higher than in other processes which work without silver halide; however, it is still below the total quantum yield that can be achieved with processes using silver halides. As a rule, a difference in the quantum yield is primarily noticeable in a difference in the photographic sensitivity. Other factors, e.g. B. the Bihl · structure and the opacity, however, have an influence on the ratio of quantum yield to sensitivity.

It has been proposed to use silver nitrate or silver halide to initiate imagewise photopolymerization. (Phot. Sei. And Eng., 4, p. 1951 [1960]). However, the proposed process is slow compared with conventional silver halide processes or with conventional photopolymerization processes using organic initiators. It has also been suggested that the overall quantum yield in silver halide photography can be increased by a factor of 10 ⁶ by using the Seni imaging processes produced during development
or printing forms through pictorial
Polymerization with the help of a
Peroxy compound and a silver salt

Applicant:

EI du Pont de Nemours and Company,
Wilmington, Del. (V. St. A.)

Representative: · -

DipL-Ing. E. Prince, Dr. G. Houses

and Dipl.-Ing. G. Leiser, patent attorneys,

Munich 60, Ernsbergerstr. 19th

Named as inventor:

Abraham B. Cohen, Springfield, Ν. J .;

Joseph A. Sincius, Little Silver, Ν. J. (V. St. Ä.)

Claimed priority:

V. St. v. America April 6 , 1961 (101 074)

quinone intermediates used as initiators for the polymerization (Nature, Dec., 7, 1959, p. 1275). In the processes mentioned, however, the polymerization serves only to modify the density of the silver image, that is to say, no increase in the amount of silver is actually achieved.

It has also been suggested "to use silver ions to catalyze pefoxide initiated imagewise polymerizations ^.:

The object of the invention is to provide a method for producing images or printing forms, that has an overall quantum yield that is higher than that of processes using silver halides.

The subject matter of the invention relates to a process for the production of pictures or printing forms, in which a polymerizable layer, optionally located on a substrate, containing an addition polymerizable compound with at least one terminal ethylenic group, optionally a dye or pigment and optionally between 3 and contains 97 percent by weight based on the total weight of the polymerizable layer, a solid at 50 ⁰ C thermoplastic compound, imagewise with the aid of a peroxy compound and a silver salt is polymerized, after which the non-polymerized image parts removed

709 637/618

or can be transferred to an image receiving material, and is characterized in that a imagewise exposed recording material with a silver salt image, optionally a layer support and optionally gelatin as a binder during the action of a peroxy compound and one itself no polymerization-inducing solvent for the silver salt so long in contact with the polymerizable Layer is held until an image-wise polymerization has taken place in the latter.

According to one embodiment of the invention, the recording material is used as the image receiving material used in the silver salt image.

An exposed and developed but unfixed silver halide emulsion layer can be used as the silver salt image which contain silver halide in the unexposed parts of the image Other silver salts, such as silver oxalate, silver acetylide or silver azide can also be used. The developed silver may have been removed using standard photographic bleaching baths. The rigid or flexible The silver halide emulsion layer can be on a support. If the substrate is translucent, exposure can be done through him.

Another object of the invention relates to a process for the production of images or printing forms in which a polymerizable layer - optionally located on a substrate - containing an addition polymerizable compound with at least one terminal ethylenic group, a silver salt and optionally a dye or pigment , is imagewise exposed, whereupon the unpolymerized image parts can optionally be removed or transferred to an image receiving material, and is characterized in that the polymerizable layer is treated after exposure with a peroxy compound and a solvent for the silver salt which itself does not cause polymerization.

As a rule, the addition-polymerized image parts differ due to a change in the optical density in appearance of the non-addition polymerized image parts. The contrast can be through The presence of a finely divided pigment or dye in the polymerizable layer is improved will.

The solvents for the silver salt form stable silver salt complexes. Those derived from these complexes Silver ions initiate addition polymerization. Suitable solvents for silver salts are aqueous solutions of sodium, potassium or ammonium thiosulfate or rhodanide, sodium or Potassium cyanide, ammonia, thiourea, thiosinamine, sodium chloride or potassium iodide. According to In one embodiment of the invention, a solvent with a pH between 6 and 8 is used.

However, the solvent can also have a pH between 5 and 8.5 and as a viscous solution are present. The solvent for the silver salt is applied to the layer or layer containing the silver salt image applied the photopolymerizable layer. This solvent contains (1) water, (2) one with silver salts a complex-forming salt, (3) optionally a buffer to adjust the pH the preferred range of 6 to 8 and (4) a thickener for easier even spreading of the solvent on the layer.

According to a further embodiment of the invention, an aqueous thiosulfate solution is used as the solvent, possibly with a viscosity between 10 and 300 cP and with a pH value between 6 and 8, used. In general, solutions with a viscosity of 10 to 300 cP are suitable. Suitable Thickeners are polyethylene oxide, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, Polyvinylpyrrolidone, glycerine, ethylene glycol, diethylene glycol or their derivatives.

When the polymerizable layer contains the silver salt, this layer is 0.0025 to 0.25 mm thick.

The unpolymerized parts of the image are removed by washing out and / or leaching out. the The unpolymerized parts of the image are transferred thermally or by means of a solvent.

Suitable thermal transfer methods are in Belgian patents 593 834, 594 909 and 596,644 and Canadian Patent 619,391. As an image receiving material z. B. Paper with a rough surface is used.

The addition-polymerisable compound used in the polymerisable layer contains at least one terminal ethylenic group (CH ₂ = C <), has a boiling point above 80 ° C. at 760 mm Hg and, when set in motion by free radicals, "with chain growth progressing addition polymerisation in The presence of an addition polymerization initiator will rapidly form an insoluble high molecular weight polymer. It is preferably a monomer and can be either liquid or solid. If it is liquid, such an amount of a solid filler should be added that the layer becomes solid. For purposes in which the layer may be applied during the processing, but may also be liquid layers used Suitable polymerizable layers are described in United States -. writings patent 2760863, 2 791 504, 2892 716, 2893 868, 2902365, 2923673, 2 927 022, 2 927 023, 2 929 710, 2 948 611 and 2 951 758.

If the recording material with the polymerizable layer is to be used in a thermal transfer process, it must be solid below 40 ° C. and softenable between 40 ° C. and 220 ° C .; it contains (a) a thermoplastic at 50 ° Cfeste compound and (b) a polymerizable compound having at least one terminal ethylenic group, and a boiling point at 760 mm Hg of about IOO ⁰ C ₅ rapidly at a set free radical initiated addition polymerization of a can form high molecular weight polymer and has a plasticizing effect on the thermoplastic compound. Ingredients (a) and (b) are present in amounts of 3 to 97 and 97 to 3 parts by weight, respectively. All combinations of thermoplastic compounds and polymerizable compounds described in Belgian patent specification 593 834 can be used for this process.

Polymerizable compounds suitable for non-transferring processes are: acrylic acid, methacrylic acid, Acrylamide, methacrylamide, methyl acrylate, ethyl acrylate, methyl methacrylate, Vinyl acetate, methyl vinyl ketone, 2-methyl-5-vinylpyridine or styrene. Are particularly suitable Alkylene and polyalkylene glycol diacrylates consisting of

Alkylene glycols having 2 to 15 carbon atoms or polyalkylene glycols having 1 to 10 ether bonds and the addition polymerizable monomers described in U.S. Patent 2,927,022 having a large number of ethylene bonds can be obtained, and in particular those in which at least one and preferably most of the terminal ethylene bonds are obtained are conjugated with at least one further double bond, a carbon-carbon, carbon-nitrogen, carbon-oxygen or carbon-sulfur double bond being present as a further double bond. Compounds in which the terminal, ethylenically unsaturated groups are conjugated with ester or amide groups are also excellent. These are unsaturated esters with polyhydric alcohols, in particular di-acrylic acid ethylene glycol ester, diethylene glycol ester, -1,4-cyclohexanediol ester, -1,3-propanediol ester, -glycerol ester, triacrylic acid glycerol ester, dimethacrylic acid ethylene glycol ester, -1, 5-pentanediol ester, hydroquinone ester, -1,3-propanediol ester, trimethacrylic acid-l, 2,4-butanetriol ester, tetra-methacrylic acid pentaerythritol ester and di-acrylic acid and dimethacrylic acid polyethylene glycol ester with molecular weights between 200 and 500, unsaturated amides, especially methylene bis-acrylamide, methylene-bis-methacrylamide, ethylene-bis-methacrylamide, 1,6-hexamethylene-bis-acrylamide, diethylenetriamine trismethacrylamide, bis- (y-methacrylamide-propoxy) -ethane, / J-methacrylamide methacrylic acid ethyl ester, N - (/? - hydroxyethyl) - β - (methacrylamide) - acrylic acid _{ethyl ester and N 3} N - bis - {ß - methacrylyloxyethyl) acrylamide, vinyl ester, succinic acid, such as divinyl ester, divinyl adipate, divinyl phthalate, terephthalic acid di vinyl esters, benzene-1,3-i "sulfonic acid divinyl ester and butane-1,4-disulfonic acid divinyl ester, acrylate salts, such as calcium acrylate or magnesium acrylate, and unsaturated aldehydes, such as sorbic aldehyde.

The peroxide compound functions as a polymerization initiator. Potassium persulfate is particularly suitable; there are, however, suitable also sodium and ammonium persulfate, hydrogen peroxide, benzoyl peroxide, Bernsteinsäureperoxyd, tert-butyl hydroperoxide and sodium perborate.

The concentration of the solution of the peroxide compounds is 0.01 to 2 molar, preferably 0.05 to 0.2 molar. A higher concentration makes a shorter contact time of the two layers possible, however, the concentration of some peroxide compounds is limited by their solubility.

If a certain contrast of the images is required, pigments are used, which are used by the Oxidizing agents are not decomposed or changed, e.g. B. Soot. In general it is Pigment in an amount of 2 to 50%, based on the total weight of the polymerizable layer, present.

The optical density of the image is independent of the optical density of the silver salt image. she decides from the amount and type of pigment or dye added to the polymerizable layer and the layer thickness. For example, low-density silver salt images can decompose through catalysis Peroxide compounds with strongly pigmented, polymerizable layers give optically dense images.

The binder should be permeable to the solvent used to dissolve the peroxide compound be. Water-permeable Bmdemittel, z. B. gelatin, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, Cellulose acetate succinate, polyethylene oxide, bone glue, agar-agar, methylcellulose, Copolymers of hydrophobic vinyl monomers and hydrophilic monomers, e.g. B. from acrylic acid, Acrylamide, and sodium styrene sulfonic acid, polyamides, e.g. B. alkoxymethyl polyamides or those in of Canadian Patent 619,391. When using water-insoluble Peroxides are used with binders that are permeable to the solvent used. With benzoyl peroxide are suitable e.g. B. alcohol-permeable binders, e.g. B. a mixture of cellulose acetate and cellulose acetate butyrate, Polyvinyl acetate, polyvinyl butyral, ethyl cellulose or certain polyamides. The choice of the The binder depends to a certain extent on the treatment of the layer. If a relief image is to be developed by washing out with water, the binder should be soluble in water; for Washed out with alcohol, it should be alcohol-soluble. You cannot use any tools at all, if you have a film-forming polymerizable. Connection dials.

The invention achieves that the quantum yield is greater than with conventional silver halides working procedures. This is surprising since the amplification reaction has so far only been in solution was carried out under ideal conditions, while the method according to the invention with solid Layers and diffusion works.

Another advantage of the .Erfindung is that from photographic silver salt images with low contrast can produce satisfactory, high-contrast offset printing forms without special Process steps to increase the contrast must be used.

Although the reaction mechanism has not yet been fully established, it is possible to use a thiosulfate as a solvent for the silver salt, a persulfate as a peroxy compound and an acrylic acid alkyl ester the following reaction scheme is likely to be the polymerizable compound:

Quantum yield

light

1. AgBr

2. Ag ⁰ (latent image) + AgBr _A g ^fl (image)

- »Ag ⁰ (latent image)

IO ⁶ to IO ⁹

3. AgBr (unexposed parts of the image) + S ₂ Oj-

pH -> Ag + ¹ (fast reaction)

3a. Ag ⁰ (BHd) + S ₂ O ₃ " ²

pH

-> (no reaction)

Continuation of the table

Quantum yield

4. Ag + ¹ + S ₂ O ₈

-2 PH ~ 7 _ ar, + 2 _l cn- _ l ση -2 4a. Ag »(image) + S ₂ O ₈ - ²

Ag + ² + SOi + SOr ² (fast response)

pH ~ 7

-> Ag + ¹ (slow reaction)

5. Ag + ² + H ₂ O

6. · OH + η CH ₂ = CH - COOR

7. SOi + η CH ₂ = CH - COOR

8. Total: AgBr>

-> Ag + ¹ + OH + H + IO ²

COOR \

-> \ - CH ₂ - CH - Jn
- COORY

- \ - CH ₂ - CH - / η
C00R \

CH, —CH-IO ⁴ to IO ⁶

IO ¹² to IO ¹⁷

The polymerization reaction depends on the fact that silver ions from the silver salt image are distributed in batches either in the presence or absence of a developed silver image in contact with the polymerizable layer 'brings. These silver ions are produced in situ by reacting a silver salt solvent with unexposed! Silver salt formed, with the presence of a silver image the oxidation the latter, which could also lead to the formation of silver ions, is suppressed.

The recording materials containing silver salts can be used for various types of radiation, e.g. B. visible Light, ultraviolet or infrared rays, X-rays, alpha, beta or gamma rays be sensitive or to mechanical influences, e.g. B. pressure, address.

The polymerization reaction is carried out by contacting the polymerizable layer with a silver salt image in the presence of a peroxide compound and a solvent for the silver salt set. Although both of the. must be present, they do not necessarily have to be together be admitted; so can z. B. the peroxide compound already in the polymerisierbajen layer and all that is needed during processing is the solvent for the silver salt to be admitted.

It is essential that total non-image polymerization does not occur and that if both Silver as well as silver salt are present, the oxidation of silver by, the peroxide compound avoided will. This is achieved by controlling the pH value, since the peroxide compound oxidizes silver only proceeds quickly at low pH values. Although the polymerization also occurs in Presence of a silver image is going on, the silver image can first follow one of the usual photographic bleaching process. For this, the pH value of the peroxide compound must be containing solution above the range in which it would attack the silver. The peroxide compound and the solvent for the silver salt can be in the form of a solution between are introduced to the silver salt image and the polymerizable layer. This makes every danger one premature decomposition of the extremely reactive peroxide compound avoided and the duration of storage the polymerizable layer extended.

Since lateral diffusion can occur and the image sharpness can deteriorate, the contact time should be as short and the layers as thin as possible being held. The latter is easily possible because the opacity of the pigment-containing layers is very high and because the amount of silver salt required is only small. When a silver salt layer and a polymerizable Layer can be applied on top of each other on the same substrate or if one addition polymerizable compound added to a silver salt emulsion and then the mixture If a layer support is applied, the peroxide compound is not added to the layers, but rather treats the exposed recording material with a solution of the peroxide compound and the silver salt solvent. If the peroxide compound is incorporated into a polymerizable layer, it is sufficient an amount of 1 to 30%> preferably 10 to 20%> based on the weight of the polymerizable compound, higher amounts causing faster polymerization.

The method according to the invention can be used for the production of planographic printing plates, which are extremely Mark out flat reliefs, for the production of possibly screened relief printing forms, for the production of screen printing forms, for the production of printed circuits and for the production of anti-etching layers be used commercially.

In the examples, all percentages are percentages by weight.

For example

A dilute aqueous carbon black dispersion was prepared by rapidly stirring 52 g of a mixture of a 40% aqueous carbon black dispersion with an average particle size of 41 μm, 340 ecm ■ distilled water and 340 g of sand with a particle size of 20 to 30 mesh (sieve openings 0.83 to * 0.53 mm, ASTM Description C-190). After stirring for 5 minutes at room temperature In a stainless steel container with a capacity of 1500 ecm, the sand was passed through a

1.6 mm thick layer of fiber was filtered off from the mixture. A portion of 40 ecm of the filtrate was added 400 ecm of a solution which contained 8% of a photographic gelatin and 20% methanol stopped 30 to 40 ° C and then gave the gelatin-carbon black dispersion 15 ecm of a 5% aqueous solution of the Sodium salt of technical grade lauryl alcohol sulfonate. Then the following coating liquid became manufactured:

10

Gelatin-carbon black dispersion 100 ecm

Potassium persulfate solution (1.33%) x x x 100 ecm

Diacrylic acid polyethylene glycol ester,
in which there are on average eight ether groups per molecule
(Mplecular weight 300) 6.65 g

The coating liquid was at 35 ⁰ C on a support of polyethylene terephthalate, of an adhesive layer of a copolymer. of VmyMene chloride, acrylic acid ester and itaconic acid ester (described in US Pat. Nos. 2,627,088 and 2,779,684) and containing ^{a gelatin layer (0.5 mg / dm 2) above it.}

A photographic recording material with a superhalide gelatin emulsion layer which is 70% Containing AgCl and 30% AgBr, was exposed through a negative line and halftone copy master, Developed in an aqueous developer with N-methyl-p-aminophenol and hydroquinone, washed in water and dried without fixation. The emulsion layer bearing the silver-silver salt image was with an aqueous solution of 0.1 mol of sodium thiosulfate and 2% of a polyethylene oxide with a Molecular weight of 100,000 treated. The emulsion layer treated in this way was then immersed in intimate, brought even contact with the polymerizable gelatin-carbon black layer by touching the two Sending materials between rubber rollers under slight pressure, and then 1 minute into one Brought vacuum copy frame.

Under these conditions (neutral sodium thiosulfate-polyethylene oxide solution) only one complete slow oxidation of the silver image, while sodium thiosulphate rapidly dissolves its dissolving effect the over halide exerts. In this way, the silver ion concentration required to catalyze the polymerization becomes reached much faster in the image parts corresponding to the silver halide image than in the parts of the picture corresponding to the silver picture. The polymerization in the first parts of the image is then ended before the silver ion concentration in the second Bildteüen to achieve a larger amount of polymer would be enough.

After separating the two materials, those corresponding to the silver powder of the emulsion layer became unpolymerized parts of the image by washing for 3 minutes in a water bath kept moving from 40 ° C. The black image obtained was positive with respect to the original.

Example 2

Example 1 was repeated, except that sodium thiosulfate ₅ Imolaren lmolare a sodium chloride solution was used in the aqueous polyethylene oxide solution 2gewichtsprozentigen in place of the O. Similar results were obtained.

Example 3

Example 2 was repeated except that the polymerizable layer did not contain potassium persulfate contained. For this, the sodium chloride-polyethylene oxide solution still contained so much potassium persulphate, that she was 0.1 molar off. The results were similar to those of the previous examples.

Example4

Example 3 was repeated, except that the diacrylic acid polyethylene glycol ester was replaced by the same amount of the corresponding diacrylamide. The results were similar to those in the previous examples.

Example 5

The following coating liquid was prepared:

8% gelatin in 20% aqueous

Methanol 100 ecm

5% aqueous solution of sodium

dodecyl sulfate 4 ecm

Di-acrylic acid polyethylene glycol

ester 6.65 g

o-methacrylamidophenol (20% in

Ethanol) 5 ecm

and as in Example 1, applied to a substrate made of polyethylene terephthalate. As in Example 3, an imolar sodium chloride-polyethylene oxide solution (2%) was used which was O ₃ imolar of potassium persulfate. After separating the two materials, the unpolymerized parts of o-methacrylamidophenol were removed by washing for 3 minutes in a solution of 3 parts of ethanol and 1 part of water. The polymerized, colorless image was then colored with an alkaline, potassium ferricyanide-containing solution of p-atnine or diethylaniline. A blue positive halftone image of the master was obtained.

Example 6

A pigment-gelatin dispersion was made at 35 to 40 ° C by stirring 8 g of "Monastral Green" Pigment (Color Index No. 74260) in 400 g of an 8% solution of photographic gelatin in 20% aqueous methanol and addition of 80 ecm of a 5% aqueous solution of the sodium salt of technical lauryl alcohol sulfonate produced. With this mixture, the following coating liquid was prepared from:

Pigment-gelatin dispersion ..... IOg

5% aqueous solution of the sodium salt of technical lauryl alcohol sulfonate 4 ecm

6% solution of a polyethylene oxide with a molecular weight
from 100 000 20 ecm

Di-acrylic acid polyethylene glycol

ester 2 g

Potassium persulfate 0.2 g

709 637/618

Claims (2)

This coating liquid was applied to the polyethylene terephthalate substrate described in Example 1 at 35 ° C., dried and further processed. When the materials were separated, the unpolymerized image parts adhered to the silver halide image and were completely peeled off from the gelatin pigment layer. A mirror-inverted positive image was obtained in this way. The unpolymerized image parts on the silver halide image then polymerized, so that a directly readable, colored negative image was obtained after the silver image had been bleached in a photographic bleaching bath. EXAMPLE 7 A dilute dispersion of carbon black in isopropanol is prepared by adding, at room temperature, 52 g of a 15% strength 1 aqueous carbon black dispersion with an average particle size of 9 μm with 340 ecm isopropanol and sand such as. in example 1 is milled. After filtration through felt, this dispersion was used to produce the following coating liquid: Cellulose acetate butyrate 90 g of di-acrylic acid polyethylene glycol ester 27 g of 30 carbon black dispersion 170 ecm Acetone 1312 ecm This coating liquid was applied to a substrate made of polyethylene terephthalate in such an amount that the . polymerizable, dry pigment-containing layer was 0.005 mm thick. A rinsed but unfixed positive silver halide-silver line image was lightly brushed with an aqueous solution containing 2% polyethylene oxide and 2% hydrogen peroxide, 2 molar sodium chloride and pH 7.0. The silver halide-silver line image treated in this way was brought into intimate contact with the polymerizable layer for 10 seconds by clamping the materials in a vacuum copier frame. When the two materials were separated, the image parts that had come into contact with the silver halide image parts were polymerized. The pigment-containing layer was then covered with white paper and the whole thing was passed through between hot rollers at 120 ° C., which were pressed against one another with a total force of 2.3 kg. The unpolymerized parts of the image were transferred to the paper. A colored image was obtained which was positive with respect to the master copy. Patent claims: 1. Process for the production of images or printing forms, in which a - ■ optionally on A layer support located - polymerizable layer, which is an addition polymerizable Compound with at least one terminal ethylenic group, optionally a dye or a pigment and optionally between 3 and 97 percent by weight, based on the Total weight of the polymerizable layer, a thermoplastic compound that is solid at 50 ° C contains, image-wise polymerized with the aid of a peroxy compound and a silver salt whereupon the unpolymerized parts of the image are optionally removed or onto an image-receiving material can be transferred, characterized in that an imagewise exposed recording material with a silver salt image, optionally a support and optionally gelatin as a binder during the action of a peroxy compound and a solvent which itself does not cause polymerization for the silver salt is kept in contact with the polymerizable layer for as long as until an image-wise polymerization has taken place in the latter. ■ 2. Process for the production of images or printing forms, in which one - if necessary on A layer support located - polymerizable layer, which is an addition polymerizable Compound with at least one terminal ethylenic group, a silver salt and optionally contains a dye or pigment, is imagewise exposed, whereupon the not polymerized parts of the image can be removed or transferred to an image receiving material, characterized in that the polymerizable layer after exposure to a peroxy compound and a solvent for the silver salt which itself does not cause polymerization is treated. 3. The method according to claim 1, characterized in that the recording material is used as the image receiving material is used with the silver salt picture. 4. The method according to claim 1 or 2, characterized in that a solvent with a pH between 6 and 8 is used. 5. The method according to claim 4, characterized in that an aqueous solvent is used Thiosulfate solution, optionally with a viscosity between 10 and 300 cP, is used. 6. The method according to claim 1 or 2, characterized in that. the unpolymerized image parts are transferred to an image receiving material with heating. 709 637/618 8.67 © Bundesdruckerei Berlin