| 摘要 |
<p>1378862 Stripping films KALLE AG 24 Nov 1971 [26 Nov 1970] 54593/71 Heading G2C A process for producing screen printing stencils, wherein a temporary support with a layer containing a binder and a diazonium salt of formula:- wherein R 1 to R 4 are hydrogen, halogen, alkyl with 1-2 carbon atoms or alkoxy with 1-4 carbon atoms, Y is a single bond, O, S, NH or CONH and X is an anion is pressed into contact with a permanent screen support which before or after contact is wetted with (a) an aldehyde, (b) a compound containing at least one group of formula -CH 2 Z wherein Z is hydroxyl or etherified or esterified hydroxyl with 1 to 4 C atoms in the alkyl or acyl radical, or (c) a compound containing an acetal, semiacetal or cyclic acetal obtained by reaction of a methylol group with an aldehyde with 1-4 C atoms, the material is dried, imagewise exposed and developed, the temporary support being removed at any stage before development. The binders diazonium salts and hardeners are preferably those disclosed in Specification 1378861 but the diazonium salt may be admixed with a diazo resin (e.g. as disclosed in Specification 1312925 and 1312926) and the developed stencil may be coupled by treating it with a coupler solution.</p> |
