CS223448B1 - ) In this case, they have positively worked the light-sensitive layer - Google Patents

Abstract

The invention belonging to the field of printing industry solves the method of preparing a positively working light-sensitive layer. The essence of the method according to the invention is that the cellulose derivative is condensed with aromatic or heterocyclic orthonitroaldehydes and chlorides of aromatic or heterocyclic compounds with a nitro group in the ortho position to the methylene or methine group. To prepare the basic polymer system, the properties of the cellulose derivative are modified by acetylation. The method of preparing a positively working light-sensitive layer according to the invention can be used in planar technology, in microelectronics, or in polygraphy for the preparation of printing valid.

Description

(54) They have therefore benefited from a positively working light-sensitive layer

2

The invention in the field of the printing industry solves the process of preparing a positive-working light-sensitive layer.

According to the present invention, the cellulose derivative is condensed with aromatic or heterocyclic orthonitroaldehydes and chlorides of aromatic or heterocyclic compounds with an nitro group in an ortho position relative to a methylene or meth group. To prepare the base polymer system, the properties of the cellulose derivative are adjusted by acetylation.

The process for preparing a positive-light-sensitive layer according to the invention can be used in planar technology, microelectronics, or in printing printing.

The invention relates to a process for the preparation of a positively working sensitive layer.

The light sensitivity of the nitro system on the aromatic nucleus with active hydrogen in the ortho position has been known since the beginning of this century. In recent years, however, such a system was designed to record optical information in photomechanical reproduction. Podlá čs. U.S. Patent No. 5,768,549; 95,637, a light-sensitive polymer system was prepared by condensing o-nitrobenzaldehyde with polyvinyl alcohol. Such a polymer works negatively, whereby the exposed sites become insoluble as a result of the crosslinking reaction. Polymer systems of this type can also work positively when an o-nitrocarbinol ester is used as the photosensitive group (U.S. Patent No. 3,489,137).

The described photo-sensitive polymers of the positive type are characterized by improved resistance to atmospheric oxygen oxidation, increased thermal stability and chemical resistance compared to previously used systems under industrial conditions based on o-diazoketones. Another advantage of the system is that the photochemical reaction is not sensitive to the transition metals present.

The drawbacks of the prior art have no method for the preparation of a positively working light-sensitive layer according to the invention, which consists in condensing a cellulose derivative with aromatic or heterocyclic orthonitroaldehydes and chlorides of aromatic or heterocyclic compounds with nitro group in ortho position relative to methylene or methino the heterocyclic chromophore with active hydrogen in the ortho position relative to the nitro group binds to a water-soluble cellulose ether or ester, preferably hydroxyethyl or carboxymethylcellulose.

The properties of the cellulose derivative can be adjusted by aceylation so that sufficient hydroxyl groups remain free for the subsequent condensation reaction with the photosensitive substance. A light-sensitive cellulose derivative of the general formula:

Cel q — p-Ce ^lab

I

Wherein R represents a nitroaryl or nitroheterocyclic radical with a nitro group in ortho position to the formyl or methylene group.

The photosensitive polymer of the invention is applied in a 2 to 20 μτη layer on the desired substrate. Contact copying positive template shall obtain mercy on exposed rniestach to fotodeštrukčným reactions as a result of which ¹ they can cause dissolution of degradation products in alkaline aqueous solutions. This will directly obtain a positive copy of the copy original.

3% by weight, based on the polymer, of ferric chloride as a sensitizer may be added to the photosensitive solution prior to application to the substrate, whereby the exposure time for copying decreases.

The advantages of the light-sensitive layer according to the invention are high adhesion, resistance to inorganic and organic bases and good solubility of photodegradation products in hygienically harmless solvents.

In the following, the present invention is illustrated by way of example.

Example 1 g of water-soluble hydroxyethylcellulose are mixed with 150 ml of glacial acetic acid] and heated to boiling. 10 g of o-nitrobenzaldehyde is slowly added to the reaction mixture.

Cel ZV * · '

i.

R

After dissolution of the o-nitrobenzaldehyde, 4 ml of sulfuric acid in 20 ml of glacial acetic acid are added dropwise. After all the sulfuric acid had been added, the reaction mixture was stirred for 1.5 hours. Stirring is then stopped, the reaction mixture is cooled and the polymer is precipitated by slow pouring into distilled water. Finally, it is dissolved in acetone and ablated into water. Yield: 7 g.

A 3% solution in acetone-dioxane solvents in a ratio of 1: 1 is prepared from the dried photosensitive polymer and applied in a thin layer to an anodized aluminum sheet. After free evaporation of the solvents, the positive template is copied from a distance of 20 cm from the source (high pressure mercury lamp) for 5 minutes. Finally, the copied image is developed in 0.5% sodium hydroxide solution.

Example 2 g of hydroxyethyl cellulose (polymerization step 397, ethoxy content: 21.6%) is partially acetylated. Acetylation mixture: benzene-acetic anhydride in a ratio of 4: 6. Perchloric acid is added as a catalyst in an amount of 0.1% by volume, based on the volume of the acetylation mixture. The acetylation time is 2.5 hours. at 30 ° C. Yield 18.1 g, content of acetylated groups is 42.3%.

g of o-nitrobenzaldehyde and 4 g of partially acetylated hydroxyethylcellulose are dissolved in 11 ml of toluene and 4.2 mg of p-toluene-sulfonic acid catalyst are added. Condensation takes 10 hours. at 140 ° C. The reaction product obtained is dissolved in 1,2-dichloroethane and precipitated in diethyl ether. A brown color polymer is obtained. Yield 4.2 g.

A 2% solution in acetone is prepared from the obtained polymer and applied in a thin layer to an anodized aluminum sheet. The positive template is copied for 90 min. from a distance of 20 cm. The source is a medium pressure mercury lamp. The copied image is developed in 0.5% aqueous sodium hydroxide solution.

Example 3

A light-sensitive layer according to Example 2 was prepared with the addition of 3% by weight, based on the ferric chloride polymer as sensitizer, to the light-sensitive solution. This reduces the exposure time for copying to 10 minutes.

Example 4

To 100 parts of a saturated soda solution was added 3 g of partially acetylated hydroxyethylcellulose and 9 g of o-nitrobenzyl chloride. The resulting mixture was heated on a water bath for 20 min with stirring. at boiling point. The reaction is then complete. The yellow product obtained is precipitated into methanol and dried. 3.2 g are obtained. A 2% solution in acetone is prepared from the prepared photosensitive cellulose derivative to which 3% by weight, based on polymer, of ferric chloride is added. Applying to an anodized aluminum surface yields a film which is exposed at a distance of 15 cm for 12 minutes. (source is medium pressure mercury lamp). Finally, the copied image is developed in 0.5% sodium hydroxide solution.

The process for preparing a positive-working light-sensitive layer according to the invention can be used in printing printing or in planar technology in microelectronics.

Claims (2)

SUBJECT A process for the preparation of a positively working light-sensitive layer, characterized in that the cellulose derivative is condensed with aromatic or heterocyclic orthonitroaldehydes and chlorides of aromatic or heterocyclic compounds with a nitro group in an orvynalezion of a poplar over a methylene or methine group. 2. The process of claim 1, wherein the cellulose derivative is treated by acetylation to prepare the base polymer system.