CS250123B1 - Positively working film for photomechanical printing - Google Patents

Abstract

On a transparent foil backing, preferably polyethylene terephthalate biaxially oriented foil is applied light-sensitive a positively working layer that is composed from dian ester with 1,2-naphthoquinone-2-diazido-5- -Sulfoacid in combination with novolak and a polyvinyl ether resin and which is colored to the desired optical density and color shade dye and finely dispersed pigments and fillers. The film is copied using UV light and provokes with an alkaline developer. Using the movie is in printing, cartography, electrical engineering etc.

Description

The invention relates to a positively operating film for photomechanical copying of a spring, line or raster image in a positive manner.

These materials are used in the field of printing, cartography, electrical engineering and generally wherever there is a contact, reproduction of spring, line or raster images, duplicates of images and texts and the like. Positive photocopying films for photomechanical copying replace phototechnical auto-service films with high steepness or technological processes to obtain a positive workflow for negative photoconductive films. The benefits of a positive-working film for photomechanical copying are in improved dimensional stability of materials, silver conservation and processing of materials outside the darkroom, only under modified lighting - yellow filters on fluorescent tubes and windows.

SUMMARY OF THE INVENTION The present invention relates to a photomechanical photocopying film comprising a film backing and a light-colored, positively colored photochemical photocopying layer, wherein the backing is a polyester or polyolefin film, preferably a polyethylene terephthalate biaxially oriented film whose transparency is at least 65 percent, and the photosensitive photomechanical photoconductive layer consists of 1,2-naphthoquinone-2-diazido-5-sulfonic acid ester or amide in combination with novolak and polyvinyl ether resins and is dyed to the desired optical density and color shade dissolved by the dye and finely dispersed pigments and fillers. The light-sensitive substance is preferably a diano monoester with 1,2-naphthoquinone-2-diazido-5-sulfoacid and is present in the dry light-sensitive layer in an amount of 0.1 to 20% by weight. The dry layer of the photosensitive composition comprises a novolak phenolaldehyde resin in an amount of 40 to 95% by weight. It may also contain 40 to 95 wt. novolak cresol-formaldehyde resins. The novolak phenolaldehyde resin may be partially esterified with cyclic dicarboxylic acid anhydrides. The polyvinyl ether resin is preferably a polyvinyl methyl ether which is present in the dry photosensitive layer in an amount of 1 to 15% by weight. The resin may also preferably be a polyvinyl ether or a polyvinyl butyl ether.

Positive copying films for photomechanical copying consist of a transparent backing and a copying positive-light-sensitive layer colored dye to near black to a density of about 1 ° D in white light (6000 ° K). A light source with a maximum emission in the UV range of 360 nm, copy films are illuminated over a positive optical density of the image.

The transparent backing is usually a polyester or polyolefin film, preferably a polyethylene terephthalate biaxially oriented film having a transparency of at least 65%.

The light-sensitive layer consists of a light-sensitive substance in combination with novolak and polyvinylet resin, light-fast dyes, pigments, fillers and varnish additives. The light-sensitive substances used are diano monoester, i.e. 2,2-his (4-hydroxyphenyl) propane with 1,2-naphthoquinone-2-diazido-5-sulfonic acid in combination with phenolaldehyde resins. The dyes are usually aniline, alcohol-soluble or fatty (methyl violet, rhodamine, victoriablau, nigrosine etc.), furthermore pigments, preferably versatile pigments, or fillers such as aerosols (silica Ji and the like).

The preparation of the layer mass is carried out by dissolving the individual fractions in ethylene glycol monoethyl ether (ethylene glycol monamethylether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate), followed by dispersion of pigments, dyes and fillers into the mixture. The dispersions are filtered and the foils are usually coated by dipping or pouring and then leveling with a trowel to a dry layer thickness of 1 - 15 μπι. The film is then dried at elevated temperature preferably in a countercurrent dryer. In this way, a copy film is prepared which works positively for photomechanical copying in the desired shade, preferably in violet-black color.

After exposure to a UV source, the image is developed in an alkaline developer.

Example 1

A light-sensitive dispersion of the following composition is applied to the polyethylene terephthalate film of 35, uin thickness by dipping and leveling with a stick.

dianu monoester with 1,2-naphthoquinone-

-2-diazido-5-sulfoacid 20 May G m-cresolacetaldehyde resin 80 G ethylene glycol monoethyl ether acetate 400 ml polyvinylethyl ether 10 G acetone 550 ml blue - Victoriablau 1.5 G Rhodamine 5 G methyl violet 2.5 G aerosil (silica) 3 G

The dispersion is diluted with acetone so that the dry coating layer has a thickness of 3 - 5 μτη. After drying in a countercurrent oven at a temperature of up to 100 ° C, the film is hung up to remove solvent residues by free drying for at least 24 hours under protective lighting (yellow filters). The image is exposed in a pneumatic frame to a UV source and developed with a 1% sodium or potassium hydroxide solution followed by a shower of lukewarm water.

Example 2

Composition of the coating dispersion:

dianu monoester with 1,2-naphthoquinone-

-2-diazido-5-sulfoacid 5 G phenol formaldehyde resin 30 G polyvinylmethyl ether 2.3 G ethylene glycol monoethyl ether 50 G xylene 20 May G acetone 27.5 G Varzálová červená R 3.3 G Block Blue 3.3 G Versal yellow G 2 G Black - Neozaponschwarz 0.5 G

Dispersions of the indicated composition in a dry film thickness of 4 - 6 μΐη are applied to the polyethylene terephthalate biaxially oriented film of 125, uin thickness by dipping and leveling with a stick. The film is then dried in a countercurrent drier at an air temperature of up to 100 ° C and allowed to dry freely for 24 hours under protective lighting. The film is exposed to a UV source and developed with a 1% sodium or potassium hydroxide solution.

Example 3

The coating dispersion composition as in Example 2.

Apply a dispersion diluted with acetone to the sheet of polypropylene film pre-treated with corona discharge, so that the dry layer has a thickness of 3 to 6 μΐη. The film sheet is allowed to dry freely for 24 hours under protective lighting. The film is copied and developed as in the previous examples.

Claims (8)

CLAIMS 1. A photomechanical photomechanical copying film comprising a film backing and a photoresist photomechanical photodepositing layer, wherein the substrate is a polyester or polyolefin film, preferably a polyethylene terephthalate biaxially oriented film having a transparency of at least 65 [deg.] , and a photosensitive photomechanical photocopy layer consisting of 1,2-naphthoquinone-2-diazido-5-sulfonic acid ester or amide in combination with novolak and polyvinyl ether resins, and colored to the desired optical density and color shade dissolved by the dye and finely dispersed pigments and fillers. 2. A film according to claim 1, characterized in that the photosensitive substance is a diano monoester with 1, 2-naphthoquinone-2-diazido-5-sulfoacid and is present in the dry photosensitive layer in an amount of 0.1 to 20% by weight. . 3. A positive-acting film according to claim 1, wherein the dry layer of the photosensitive material comprises a novolak phenolaldehyde resin in an amount of 40 to 95% by weight. YNÁLEZU 4. The positive-acting film of claim 1, wherein the dry layer of the photosensitive composition comprises a novolak cresol-formaldehyde resin in an amount of 40 to 95 percent by weight. 5. A film according to claim 1, wherein the dry layer of the photosensitive material comprises a novolak phenolaldehyde resin partially esterified with cyclic dicarboxylic acid anhydrides in an amount of 40 to 95% by weight. 6. A film according to any one of claims 1 to 5, wherein the polyvinyl ether resin is a polyvinyl methyl ether which is present in the dry photosensitive layer in an amount of 1 to 15% by weight. Positive-working film according to Claims 1 to 5, characterized in that the polyvinylether resin is a polyvinylethyl ether which is present in the dry photosensitive layer in an amount of 1 to 15% by weight. 8. A film according to any one of claims 1 to 5, wherein the polyvinyl ether resin is a polyvinyl butyl ether which is present in the dry photosensitive layer in an amount of 1 to 15% by weight.