BE720508A - - Google Patents

Description

  

   <EMI ID = 1.1> The present invention relates to photo masses -

  
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which can be further processed eg into relief shapes for printing, when mixing high molecular weight polymeric substances with unsaturated monomers containing more than one polymerizable double bond and photoinducers. The plaouea, the films or the leaves obtained from these masses are illuminated during. treatment by a model and the places not illuminated are removed by appropriate solvents to the desired depth of relief. Such raised tons are suitable for offset printing in

  
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linear saturated ticks, monomers having at least two double bonds and photoinducers for the preparation of

  
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Aromatic bonyls of the benzoph &#65533; none or benzole methyl ether type exhibit early absorption bands at wavelengths of around 360 m &#65533;. While dicarbonyl compounds such as benzyl or phenanthrene.

  
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Lighting of the light-curing material takes place

  
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arc lamps which have a large continuous emission spectrum in the visual field The use of a photo-inducer

  
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for example, the use of dicarbonyl compounds thus contributes, during the use of the usual light sources, to the reduction in the duration of illumination. A disadvantage of the light sensitive material thus sensitized * consists on the other hand

  
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mes embossed for printing, carefully exclude daylight to avoid an unwanted crosslinking reaction.

  
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do not attempt the above-mentioned drawbacks.

  
Ketooxetanes are adducts of dicarbonyl compounds to olefins under the action of light.

  
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39, 4783-4788 and Chem, Ber. 100, (1967). A-ketooxetanes are also well known as adducts of dicar compounds.

  
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shooting of 1,4-dicarbonyl compounds and olefins,

  
Ketooxetanes do not absorb light in the

  
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window glass, the usual precautions necessary in this process for the elimination of daylight are superfluous.

  
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the ketooxetanes according to the invention as sensitizers are those which are usually used in the manufacture of plates, films or sheets. By way of example, we can cite

  
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higher tionnols. Alkyd resins of these alcohols and of polybasic acids, cellulose derivatives, A particular class of synthetic polymers which can be used as starting materials are linear polyamides. The synthetic linear polyamides which are suitable are preferably copolyamides which are soluble in the usual solvents or mixtures of solvents, for example lower aliphatic alcohols or water-alcohol mixtures, ketones, aromatic compounds or benzene-alcohol-water mixtures. So, for example, the copolyamides which are. prepared by polycondensation or activated anionic polymerization of two or more lactams containing 5 to 13 ring members.

   As particularly suitable copolyamides there may be mentioned those which are prepared by co-condensation of a mixture consisting of one or more lactams and at least one salt of diamine and of acid.

  
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diamine, or polyamines and other amines which are branched, interrupted by hetero atoms or contain ring systems, Also suitable are monomers which, apart from amide groups, still contain urdtha groups.

  
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the corresponding reaction products of diaminea monoacrylamides with diisocyanates. Among the monomers containing <EMI ID = 18.1>

  
acrylates or methacrylates of divalent or polyvalent alcohols and phenols. The use of bifunctional or polyfunctional polymerizable monomers is in no way limited to those mentioned above. It is also possible to use other monomers containing at least two polymerizable double bonds, provided that they are at least 30% compatible with the abovementioned copolyamides, which can easily be seen by a simple test.

  
The usual thermal polymerization inhibitors which can be used in the preparation of sensitive masses

  
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p-quinone, cuprous chloride, methylene blue, pnaphthylamine, {3-naphthol, phenols, salts of N-nitroso-

  
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dissolving the constituents, removing the solvent} pressing, extrusion and subsequent calendering of the finely divided mixture, In addition, the solutions of the constituents can be cast into sheets or films,

  
For lighting we use high energy decamps such as arc lamps, mercury vapor lamps,. xenon lamps or luminescent tubes.

  
The parts mentioned in the exemptas are by weight,

EXAMPLE 1,

  
100 parts of a polyemide prepared by polycondensation of equal parts of caprolactam, salt

  
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diaminodicyclohexylmethane and adipic acid, 15 parts of m-xylylenebisacrylamide, 11 parts of triethyl diacrylate

  
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coumarone:

  

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,
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  <EMI ID = 26.1>

  
Xanthotoxin:

  

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Khelline:

  

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Bergapten;

  

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In addition, the corresponding solutions are prepared

  
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pressed on a metal support and the sensitive plates

  
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The superior resistance of the materials prepared according to the invention to daylight can be demonstrated as follows:

  
Plates prepared according to Examples 1 to 5 are exposed together with plates containing only carbonyl compounds as activator for 10 to 30 minutes in diffused daylight. The subsequent illumination and washing results in relief shapes usable but only with the plates containing ketooxetanes as activators. Plates sensitized by dicarbonyl compounds are already crosslinked by daylight.

 

Claims (1)

CLAIM. <EMI ID = 35.1>