JPS5934294B2 - Multilayer photosensitive elements and imaging methods - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improved photosensitive element.

The prior art describes a variety of photopolymer elements and methods of use, including toning unexposed portions of the photopolymer layer, creating images by image transfer, and creating images by separately peeling off the photosensitive element. .

Additionally, the prior art, e.g., U.S. Pat. No. 3,469,982 and U.S. Pat. No. 3,526,504, teaches The production of resist images from photopolymerized surrounds or photocrosslinking layers is described.

Each of the elements of the prior art has a specific use and likewise has limitations that limit their usefulness in other applications. For example, in the development of photoresists, washing away the unexposed portions of the photoresist layer produces a polymer image only in the exposed portions. There is a need for an element for graphic arts and other applications that is capable of producing images of the unexposed portions of polymeric materials by solvent development and that is capable of producing images of colored polymeric materials having high optical density. There is. According to the invention,
(1) a peelable cover sheet and (2) a photoadhesive layer comprising and in contact with layer 2 and (3) a solvent-soluble adjacent layer present after imagewise exposure of the element to actinic radiation. has either the exposed or non-exposed portions of the photoadhesive layer have greater adhesion to the cover sheet than to the adjacent layer and the other portion of the photoadhesive layer has greater adhesion to the cover sheet than to the adjacent layer. A photosensitive element is provided which is characterized in that it has greater adhesion to the adjacent layer than to the sheet and is insoluble, said adjacent layer being solvent-poured. Elements of the invention include:
A duplicate or inverse image (ie, a corresponding or complementary image) can be generated as desired. Thus, with the elements of the present invention, polymeric images can be produced by exposing the element, peeling off the cover sheet, and washing away with a solvent. The soluble adjacent layer provides a layer into which a high concentration of colorant can be incorporated, if desired, without interfering with the photosensitivity or operational properties of the element, and the composition of this layer is such that the adjacent layer is on a separate surface. If it is to be laminated it can be chosen to give good adhesion. The attached drawing shows removable cover sheet 1
, a preferred embodiment comprising a photoadhesive layer 2 , an adjacent bath medium soluble layer 3 and a support 4 .

Portion 5 of the photoadhesive layer adheres to the cover sheet after exposure of the element to actinic radiation and is removed therewith, leaving an insoluble portion 6 of the photoadhesive layer on the adjacent layer. In a particularly preferred embodiment, portion 5 is the exposed portion of the photoadhesive layer and portion 6 is the unexposed portion.
The portion 7 of the adjacent layer lying between the remaining insoluble portions of the photoadhesive layer is then washed away with a solvent, in which case portion 7 is soluble and portion 6 is insoluble. In particularly preferred embodiments, a duplicate polymeric image is produced on an adjacent layer.
The present invention can be applied to various images, most preferably as photoresists and, if the images are colored, as photographic masks,
It is a versatile (multi-purpose) light sensitive element that can produce replicative polymeric images for use as lithographic transparencies and the like. The photoadhesive layer, which is preferably the only photosensitive layer of the element, is such that the relative adhesion between the cover sheet and adjacent layers changes upon exposure to actinic radiation (or actinic radiation). As a result, after exposure, either the exposed or unexposed portions of the photoadhesive layer adhere more firmly to the cover sheet than to the adjacent layer and are removed together with the cover sheet, with the This allows the other part to remain. In a particularly preferred embodiment, the exposed portions of the photoadhesive layer adhere more firmly to the cover sheet after exposure and are removed therewith, leaving the unexposed portions of the photoadhesive layer on the adjacent layer. The portion of the photoadhesive layer that remains on the adjacent layer after removal of the cover sheet must be insoluble under conditions in which the adjacent layer is soluble. As a result, that portion of the adjacent layer is imagewise washed away, whereas the remaining portion of the photoadhesive l-layer, which is insoluble in the solvent, prevents the portion of the adjacent layer below it from being washed away. A solubility difference between the photoadhesive layer and the adjacent layer can be present in the element in its initial conditions, or this difference can be removed by intermediate treatments, such as exposure to actinic radiation, depending on the specific material of the element. , treatment with reagents, heating, etc. For example, after imagewise exposure and removal of the cover sheet, the element is subjected to general exposure to actinic radiation, thereby curing and rendering the remaining portions of the photoadhesive layer insoluble, while adjacent layers are exposed to actinic radiation. remain unaffected if they are insensitive to Under certain conditions, it is only necessary that the portion of the photoadhesive layer remaining on the adjacent layer be insoluble in the solvent in which the adjacent layer is soluble. "Washout" means the removal of substances by the use of a solvent, but it can also include agitation in a solvent bath with the aid of mechanical movements, such as brushing or spraying.

The insolubility of the residual fraction of the photoadhesive layer and the solubility of adjacent layers may result from the respective degree of photocuring or polymerization or the respective degree of absorption, hydrophilicity or reactivity with respect to the solvent. A variety of solvents suitable for use are disclosed in the art.

The particular solvent to be used will depend on the materials of which the photoadhesive layer and adjacent layers are constructed and the use of the elements (e.g. whether total exposure to actinic radiation is provided after peeling off the cover sheet). do. Hydrocarbon solvents such as 1,1,1-trichloroethane, benzene, toluene and hexane are known in the art for washing portions of the polymer layer for image development. In the case of certain polymers, water and dilute alkaline or acid solutions may be used, depending on the particular material of the element. The releasable cover sheet of the element of the invention, with only exposed or unexposed portions of the photoadhesive layer,
It must be able to be peeled off (ie removed by peeling it apart) from the rest of the element.

The cover sheet is preferably oxygen impermeable and transparent to actinic radiation so that the element can be exposed through the cover sheet. Preferred materials for the cover sheet are polymeric films, especially polyester films such as polyethylene terephthalate. Polyamide, polyimide, polystyrene or polyolefins such as polyethylene or polypropylene films can also be used. The surface of the cover sheet can be modified to better adhere the exposed portions of the photoadhesive layer to the cover sheet. For example, surface treatments such as electrostatic discharge or flame treatments can change the surface topography and increase the porosity. For polyethylene terephthalate films having a thickness of 0.0005 inches (0.013!7!U), at least 0.0
An electrostatic discharge treatment of 25 coulombs/Ft2 (0.27 coulombs/wl) and preferably about 0.07 coulombs/Ft2 (0.75 coulombs/il) is suitable.

However, further processing can be used. Flame treatment of the film also provides good photoadhesion. An air-propane flame can be used. The thickness of the cover sheet may vary within a wide range, but may be less than 0.
Particularly preferred are films having a thickness of 0.001 inch (0.025 m77!) or less.

Thin cover sheets produce good halftone dots with sharp edges. In addition,
Obtain a full range of halftone resolution from 2% to 98% when using thin films (using a 150 lines/inch (~59 lines/cm) line halftone screen) and rapid cover sheet peeling speeds be able to. By "total range" is meant the range of resolvable halftone dot sizes as a percentage of the maximum halftone dot size. In general, faster cover sheet peel speeds produce better image quality. The cover sheet should be of sufficient thickness that electrostatic discharge or flame treatment can remove it without damaging it and tearing it. The cover sheet may further include auxiliary treatments or layers to improve adhesion, strength and other properties. After exposure, the photoadhesive l layer may adhere to the cover sheet more strongly than adjacent layers in either exposed or unexposed areas.

In the latter case, the photoadhesive layer is e.g.
No. 770,438, or other compositions that adhere more strongly to the cover sheet than to adjacent layers in unexposed areas and to adjacent layers than to the cover sheet in exposed areas. can be included. In a preferred embodiment, the exposed portion of the photoadhesive layer adheres more strongly to the cover sheet than to the adjacent layer in the exposed portion and adheres more strongly to the adjacent layer than to the cover sheet in the non-exposed portion.

In such embodiments, photocurable materials are preferred for the photoadhesive layer. Such materials usually have ethylenically unsaturated groups or benzophenone type groups, and an increase in molecular weight and thus an increase in adhesion to the cover sheet is brought about by exposure to actinic radiation. It includes substances such as Preference is given to known photocurable materials consisting of ethylenically unsaturated materials that are photopolymerizable, photocrosslinkable or photodimerizable. Such materials are described, for example, in US Pat. No. 3,649,268. Particularly preferred are photopolymerizable compositions comprising a high molecular weight organic polymer binder and an addition polymerizable ethylenically unsaturated monomer. The binder is preferably a polymeric material such as an acid-surrounding polymer having at least 1.5 mole percent free acid groups to impart polarity to the polymer. This monomer has at least 1
and preferably two or more terminal ethylenically unsaturated groups capable of free radical initiated chain extension addition polymerization. The monomer preferably has some degree of polarity, and is compatible with the polar surfaces of the binder and cover sheet, but is substantially non-diffusible into the adjacent tomable layer. be. The photopolymerizable composition also contains a free radical-generating addition polymerizing photoinitiation system (ie, at least one organic photoinitiator compound) activatable by actinic radiation, such as ultraviolet radiation and street light.
Among the acidic binders found to be useful are the monoethyl esters of co(methyl methacrylate/methacrylic acid) and poly(methyl vinyl ether/maleic anhydride), each of which Can be copolymerized in various ratios. Many other polar polymers and copolymers known in the art have been found useful as binders in this photopolymerizable layer. Among the ethylenically unsaturated monomers that have been found to be useful are U.S. Pat.
No. 1 and No. 3,573,918. Examples include dipentaerythritol acrylate (50% tetra and 50% penta), pentaerythritol triacrylate and tetraacrylate, polypropylene glycol (50) ether of pentaerythritol tetraacrylate, polyethylene glycol (200) dimethacrylate, dipentaerythritol mono hydroxypentaacrylate,
Pentaerythritol triacrylate β-hydroxyethyl ether, polypropylene glycol (550) ether of pentaerythritol tetramethacrylate, pentaerythritol tetramethacrylate, polypropylene glycol (425) dimethacrylate, trimethylolpropane trimethacrylate, and trimethylolpropane trimethacrylate. Mention may be made of polypropylene glycol (340) ether of acrylate. The binder can vary widely in ratio with its monomers, but generally it should be in the range of 3:1 to 1:3. This monomer should be compatible with the binder and may be a solvent for the binder and/or may have plasticizing effects. The selection and ratio of monomers and binders are made according to selective photoadhesion and solvent insolubility requirements for adjacent layers. Usually this photoadhesive layer is transparent, but a colored layer may be desired for certain applications. Free radical-generating addition polymerization initiator systems that can be activated by actinic irradiation are described, for example, in U.S. Pat. Nos. 2,951,752 and 3,549,3.
No. 67, No. 3,558,322 and No. 3,92
It may be any one disclosed in each specification of No. 6,643.

Another particularly useful initiator system is U.S. Pat. No. 3,615,45
No. 4, No. 3,647,467, No. 3,652,2
No. 75, No. 3,661,558 and No. 3,697
, No. 280.

The photopolymerizable layer may also contain other ingredients including plasticizers, antihalation agents and optical brighteners.
By incorporating optical brighteners into the photoadhesive layer, an image record is produced that is free from distortions due to halation effects and free from discoloration due to element components. Suitable optical brighteners can be found in US Pat. No. 2,784,183 and US Pat. No. 3,644,394. A particularly useful compound in the photopolymerizable layer of the present invention is 2-(stilbyl-4''), hereinafter referred to as lightening agent 1.
Naphtho-1,2':4,5)-1,2,3-triazole-2''-sulfonic acid phenyl ester and 7-(4'-chloro6'-diethylamino-1', hereinafter referred to as lightening agent) ,3',5'-triazine-4'-ino(
c) Amino-3-phenylcoumarin. These compounds, when toned with colorants as shown in U.S. Pat. No. 3,854,950, are useful for producing sharp, bright, multicolored images on clean white backgrounds. It is. Although the coating weight of the photoadhesive composition can vary, the preferred range is from 20 to 100 mm/day (with a dry thickness of about 0.00006 to 0.00033 inches (0.0015 to 0.0084 mm)). has been found to give good image quality and toning range. The adjacent layer can be selected from a number of materials that are soluble for the photopolymerizable layer at least after imagewise exposure of the element to active radiation.

Preferably, this adjacent layer is a non-light sensitive elastomeric polymeric material that is soluble in common solvents. However, it may be a photosensitive (e.g., light-soluble) material that is soluble only after exposure to actinic radiation, such as that disclosed in U.S. Pat. No. 3,837,860. If the use of a solvent is desired, a polymer soluble in aqueous solution can be used in the adjacent layer. For an element to have good stability over time, suitable materials for adjacent layers should inhibit monomer diffusion from the photoadhesive layer into adjacent layers. Such materials can be selected from resins, polymers in which the monomers in the photoadhesive monomer are non-diffusible, adhesive compositions, and the like. Particularly preferred materials are elastomeric polymers and mixtures thereof that have a second order transition temperature of -1'C or less and are non-migratory to the photoadhesive layer. Rubber-type polymers, both natural and synthetic, such as isobutylene, Thiokol A1
Nitrile rubber, butyl rubber, chlorinated rubber, butadiene polymer, poly(vinyl isobutyl ether) isobrene,
Random butadiene copolymers copolymerized with styrene, isoprene and neoprene, teleproc and proc copolymers, silicone elastomers and the like can be used in various proportions. In a preferred embodiment,
By the use of these materials, a stable adhesive balance between the photoadhesive phase and the support to the adjacent layer can be achieved for elements useful in the production of color proofs by overlay or surprint methods. Such elastomeric materials are soluble in hydrocarbon solvents such as hexane. These elastomeric materials are also characterized by their tackiness, which provides good adhesion to the photoadhesive layer, good separation of the element when peeling off the cover sheet, and good adhesion to the substrate when laminating the element to the substrate. It is also preferred because it provides good adhesion. Elastomers inherently have some degree of tackiness (though tackiness in this case is not essential). This tackiness, if present, may also be affected by adhesives such as Skeist's "HandbOO".
Further improvements can be made by adding those described in "KOfAdhesives" Chapter 14 (published by Reinhold Publishing Co., Ltd., 1962).

Such tackifiers include polyterpene resins, coumaron-indene resins, stabilized glycerol esters of abietic acid resins, stabilized acidic utudolodins, β-
Pinene polymers and cycloaliphatic resins may be included. Particularly useful are highly stabilized glycerol esters of abietic acid resins and low molecular weight cycloaliphatic hydrocarbon resins, both types having softening points of about 85°C. This tackifying agent probably combines with the rubber network of the elastomer and increases the volume fraction (VOlume) of the rubber phase.
frac-TiOn). This tends to reduce hardness and causes migration of adjacent layer components into the photoadhesive layer when two layers (adjacent layer and photocurable layer) that provide positive tack are coated simultaneously. Any suitable solvent can be used to coat the adjacent layer unless otherwise specified. Although the coating weight of this adjacent layer can vary over a wide range, the coating weight is generally about 40 mm/day [generally about 0.00 mm/day].
015 inches (gives a dry thickness of 0.038 m0)
should be satisfied. This adjacent layer can also be coated as a dispersion, for example an aqueous dispersion, with satisfactory results. In the preferred embodiment illustrated in the drawing, this element has a support 4 for the adjacent layer 3. This support 4 determines how the element is to be used (i.e. for surprint color proofs or overlay color proofs or for the production of photomasks, lithography negatives etc. or for photochemical processes). Depending on the layer 3, it can be any suitable film having the necessary properties for proper adhesion. For color proofing, e.g. by the overlay method, photographic grade polyethylene terephthalate films are used with or without a tethering layer, e.g. as described in U.S. Pat. No. 2,779,684. can do. Similar films with or without release coatings such as silicone coatings can also be used. When the support 4 is made to be easily peelable from the layer 3 and further heat laminated or heat delaminated, the layers 3 and 4
Thermoplastic layers may also be used to hold the materials together.
If a thermoplastic coating is used, the stripping operation leaves the thermoplastic layer attached to the adjacent layer 3.

Releaseable films that do not require any special treatment are clearly the most convenient. The manufacture of the element can be accomplished in several different ways.

For example, the photoadhesive layer 2 can be coated onto the cover sheet 1 and then after drying the adjacent layer 3 can be coated from a solvent solution and then the support 4 can be laminated to the surface of the layer 3 after drying. The solvent for the adjacent layer 3 should not have any solubilizing effect or adverse effect on the photoadhesive layer 2. Another method involves coating the photoadhesive layer 2 on the cover sheet 1 and the coating layer 3 on the support 4 and then drying each coated layer under pressure and at room temperature or elevated temperature. , the surfaces of layers 2 and 3 are laminated. Layers 2 and 3 can also be coated in that order onto support 1 at the same time and then support 4 is laminated to the outer surface of layer 3. All these methods are known to those skilled in the art of multilayer film coatings. In use of the novel film element of the present invention, the photoadhesive layer of the film element is exposed to the most sensitive actinic radiation (e.g. ultraviolet rich carbon arc), e.g. conventional halftone color separation. Expose to a transparency that has a positive-like image.

Other radiation sources that may be used include mercury vapor or pulsed xenon lamps and lasers. This exposed element is then delaminated and cured onto the cover sheet by peeling off the cover sheet 1 at room temperature under conditions of moderate to rapid continuous motion, generally at an angle of at least 135. A negative image remains and an image of the uncovered adjacent layer remains on the element.
The unexposed, insoluble image portions of the photoadhesive layer 2 remain on the adjacent layer 3. The bare areas on the adjacent layers are then washed away with a solvent to produce a positive image.The following examples are intended to illustrate the invention.Example 1 Printed on a copper coated epoxy circuit board as follows: Generated the circuit.

1. Photoadhesive Layer: Photopolymerizable Coating Composition A coating solution of photopolymerizable coating composition was prepared for the photoadhesive curved layer by mixing together the following ingredients.

This solution was surface treated by electrostatic discharge at 0.07 coulombs/Ft2 (0.75 coulombs/M°).
The coating was applied onto a polyethylene terephthalate film having a thickness of 0.0005 inches (0.013 mm).

The coating weight was approximately 43-47 mm/Dm2. ．． Adjacent Layer: Elastomeric Coating Composition A coating composition was prepared by mixing together the following ingredients.

A releasable layer was applied onto the coated polyethylene terephthalate film sample phase to give a coating weight of 100 η/d and dried to form a layer of copolymer of cis-polyisobutadiene and polystyrene in a 60/40 ratio. generated.

．． The elements obtained from Lamination Operation I and 4 per square inch
Each coated layer was laminated surface-to-surface at room temperature using a pressure of 0 pounds (2812.289/0d).

．． Operation for Printed Circuit Construction The peelable layer coated film is peeled from the elastomer layer of the element resulting from the operation and the elastomer layer surface of this element is heated to room temperature and about 4
It was laminated to the surface of a copper-coated epoxy board commonly used in printed circuit manufacturing at a pressure of 0 pounds per square inch (2812,289/Cli).

The copper surface was degreased and cleaned as known in the art. The resulting element was exposed through a positive transparency of the desired printed circuit through a transparent film cover sheet adjacent to the photopolymerizable layer. The clear film cover sheet was then peeled off in continuous motion at a moderate speed. The exposed portions were photoadhered to the cover sheet, leaving the desired circuit image on the elastomer layer covered by an unexposed photopolymerizable layer. This copper-coated circuit board with the circuit diagram in the coated elastomer layer is immersed in a hexane solution that dissolves only the bare elastomer layer so that the elastomer layer and the unexposed photopolymerizable layer (which acts as a resist) are removed. This left the desired copper circuitry coated. The circuit board was then immersed in a conventional ferric chloride etching solution to remove the unwanted copper layer. The remaining photopolymer layer and underlying elastomer layer were then removed with methylene chloride to produce a good quality printed circuit. This method is known as Metzki, chemical milling or U.S. Patent No. 3,469,98.
It is useful in that the exposure of the transparency can be configured in a manner that allows the desired conductive pattern to be created by other modification methods such as those taught in the '2 patent.

For example, etched metal surfaces include magnesium,...
It can be zinc, copper, alloys of such metals, aluminum, anodized and colored anodized aluminum, steel alloys, copper beryllium alloys, and others.

Example 2 An element in which the photoadhesive layer contained a colorant was prepared as follows.

1. Photoadhesive layer: photopolymerizable coating composition 0.00
A photographic grade polyethylene terephthalate film having a thickness of 0.05 inches (0.013 mm) and surface treated by exposure to an electrostatic discharge of 0.75 coulombs/Tll was coated with the following photopolymerizable composition.

The coating weight was 37.8 pieces/di.

．． Adjacent Layer: Elastomeric Coating Composition A stereospecific polybutadiene (98% cis, 2% trans) rubber was used to prepare the coating solution. This solution was made up to 9% concentration in methylene chloride. This is about 80 instant/Dm2
was applied onto a 0.0025 inch (0.064 mm) thick polyethylene terephthalate film. ．． Elements from Lamination Operation I and from at room temperature and about 40
Each coated layer was laminated in surface-to-surface contact at a pressure of pounds per square inch (2812.289/(V7f)).

．． Exposure and Delamination The element is exposed to an image transparency by an exposure device called a "Nuark Plate Maker" manufactured by Nuark Company (Chicago, IL, USA).

Photographic tools i.e. visual aid slides, which provide good photoadhesion and serve as negatives on treated cover sheets;
A good image was formed which could be used for exposure transparencies, color proofs, etc. The exposed portion of the photoadhesive layer adhered to the cover sheet and was removed with it when the cover sheet was peeled off. The bare portions of the elastomeric layer could be removed with a suitable solvent that did not have any adverse effect on the unexposed colored photopolymerizable layer to give the product in a positive manner.

The foregoing examples represent preferred embodiments of the invention in which the exposed portions of the photoadhesive layer adhere to the cover sheet and are removed by peeling the cover sheet while remaining on the adjacent layer. Portions of the photoadhesive layer are insoluble in solvents in which the adjacent layer is soluble due to differences in solubility of the raw materials from which these layers are constructed.

However, solubility differences can be influenced in other embodiments by intermediate treatments such as exposure to actinic radiation. For example, exposure of the element to non-image actinic radiation after peeling off the coversheet will photocure and thereby insolubilize the remaining portions of the photoadhesive layer and at the same time expose exposed portions of the adjacent layer (
It helps to solubilize (if it is composed of light town solubilizing substances). Accordingly, as used herein, a "soluble" adjacent layer includes an adjacent layer that is soluble without intermediate treatment and an adjacent layer that becomes soluble through intermediate treatment. Similarly, "insoluble" means a substance that is or can be rendered insoluble. This expression, of course, refers to the same solvent. In a preferred embodiment, an intermediate treatment △
No treatment is required, and the solubility difference exists at least immediately after peeling off the cover sheet. As illustrated, the elements of the present invention can be used to create a resist image on a surface by laminating adjacent layers to the surface.

If a sheet support is present on the adjacent layer, it is removed prior to lamination. The cover sheet is then peeled off and a portion of the adjacent layer is washed away leaving the polymeric resist image on the surface. It is desirable that the resist image be easily visible, so colorants can be included in adjacent layers. For this purpose, the colorant does not need to be of any particular type, since this adjacent layer does not need to be photosensitive. This resist image permanently etches adjacent portions of the surface not protected by the resist image by using a reagent capable of etching adjacent portions of the surface or by depositing (e.g. plating) a substance onto said adjacent portions. It can be used in a method that changes the

In such cases, cleaning at the same time as the surface modification of the adjacent layer or in the same medium (eg, an etching bath) used for the surface modification is within the scope of this invention. Example 3 An element was manufactured as follows.

1. Photoadhesive Layer (Another Type) Another type of photoadhesive layer that adheres to the cover sheet only in the unexposed areas was prepared from a photosensitive composition prepared from the following ingredients.

Mix these ingredients thoroughly and use a 0.002 inch (0.05 mm) doctor knife to
Coated onto a 1 inch (0.025 mm) clear polyethylene terephthalate base.

．． Adhesive Layer: Elastomeric Coating Composition A coating composition was prepared by mixing together the following ingredients. Pour the resulting solution into 0.0025 inch (0.064
mm) thick polyethylene terephthalate film to give a dry coating weight of 100 mg/Dm''.

．． Lamination Procedure Photoadhesive layer 1 and adjacent layers were laminated together in surface-to-surface relationship at room temperature and at a pressure of 40 pounds per square inch (2812.289/~).

．． The laminated element obtained from the exposure and imaging operation step was exposed for 2 minutes through a halftone color separation transparency (next to the cover sheet) with a pulsed xenon lamp (Nuark Fliptop type 17 amp). I let it happen.

After 5 minutes of exposure, the element is fed with a 0.001 inch (0.025 m1) polyethylene terephthalate cover sheet at an angle of at least 135 degrees and at a rate of about 9000 inches/minute (3543.3?/minute). It twisted and separated. The unexposed part of the blue photopolymerized material layer is 0.
．． 001 inch (0.025 mm) polyethylene terephthalate cover sheet and was removed as an image that worked positively with the cover sheet. The complementary exposed blue image areas remaining on the adjacent layer and the bare areas of the continuous layer were washed with n-hexane to 0.00
Polymer images were produced on a 25 inch (0.13 mm) thick polyethylene terephthalate film substrate. Among the preferred materials for the adjacent layer that can be washed out according to the present invention are polymeric materials that are soluble in aqueous solutions such as polyvinyl alcohol, polyvinylpyrrolidone, polyvinylpyrrolidone/vinyl acetate, Sodium carboxymethylcellulose and others. Example 4 An aqueous developable element was prepared as follows.

1. Photoadhesive layer: photopolymerizable coating composition 0.00
A polyethylene terephthalate film having a thickness of 1 inch (0.025 mm) and surface treated by exposure to electrostatic discharge (0.75 coulombs/ml) was coated with the following photopolymerizable composition.

．． Adjacent Layer A water-soluble adjacent layer coating composition was prepared from the following ingredients.

This composition was coated onto polyethylene terephthalate film with a gelatin subbing layer.

．． Lamination Procedure The elements of 1 and above were laminated at 50° C. with surface-to-surface contact of each coated layer.

．． Exposure and Delamination Procedure The element was exposed to an image transparency for 30 seconds using a xenon arc.

A 0.001 inch (0.025 mm) thick electrostatic discharge treated polyethylene terephthalate cover sheet was peeled off and the exposed portion of the photopolymerizable layer was adhered thereto.

This element was then subjected to a total non-image exposure to actinic radiation to cure the remainder of the photopolymerizable layer. The bare portions of the black adjacent layer were washed away with cold water leaving a black image with an optical density of approximately 3.5. This manufactured image-bearing element is useful as a lithographic film that serves as a positive.

[Brief explanation of drawings]

The accompanying drawings illustrate a multilayer photosensitive element according to one embodiment of the invention. 1...Removable cover sheet, 2...
...Photoadhesive layer, 3...Solvent-soluble adjacent layer, 4
...Support.

Claims (1)

Claims: 1 A peelable cover sheet 1 and a photoadhesive layer 2 are included on a sheet-like support 4, so that layer 2 and support 4
Between and in contact with layer 2 is a solvent soluble polymeric non-photosensitive adjacent layer 3 which, after imagewise exposure of the element to actinic radiation, exposes the exposed portions of the photoadhesive layer or either one of the unexposed portions has greater adhesion to the cover sheet than to the adjacent layer and the other portion of the photoadhesive layer has greater adhesion to the adjacent layer than to the cover sheet. 1. A peel-apart type photosensitive element, characterized in that it has a property and is insoluble under conditions in which an adjacent layer is solvent soluble. 2. Element according to claim 1, characterized in that the peelable cover sheet is a polymeric film transparent to actinic radiation and surface-treated by electrostatic discharge or flame treatment. 3. The element according to item 2 above, wherein the releasable cover sheet is a polyethylene terephthalate film. 4. Element according to any of the preceding clauses, characterized in that the adjacent layer is composed of an elastomeric material that is insensitive to light. 5. After imagewise exposure of the element to actinic radiation, the exposed portions of the photoadhesive layer have greater adhesion to the cover sheet than to adjacent layers, and non-exposure of the photoadhesive layer Element according to any of the preceding clauses, characterized in that the parts have greater adhesion to the adjacent layer than to the cover sheet. 6. After imagewise exposure of the element to actinic radiation, the exposed portions of the photoadhesive layer have greater adhesion to the adjacent layer than to the cover sheet and the unexposed portions of the photoadhesive layer have greater adhesion to the adjacent layer than to the cover sheet. has greater adhesion to the cover sheet than to adjacent layers,
The element according to any one of items 1 to 4 above. 7. Element according to any of the preceding clauses, characterized in that the adjacent layer is composed of a polymeric material soluble in an aqueous solution. 8. characterized in that the adjacent layer contains a colorant,
An element according to any of the preceding sections.