| 摘要 |
941,835. Light sensitive materials for photomechanical procedures. KALLE A. G. July 22, 1960 [July 29, 1959, No. 25599/60. Heading G2M. A coating contains a reaction product of an aromatic amine diazonium salt and a water-soluble product of high molecular weight obtained by condensation of a sulphonated aromatic hydroxy compound with formaldehyde. An alkali-soluble resin may be present as well. Exposure under a diapositive and development by acqueous alkaline solution produces a positive image which accepts greasy ink and also may be used as etching resist. A number of the diazonium salts are listed and seven preparations of the condensation products are provided. In the first'of ten examples the reaction product of 1-dimethylamino-benzene-4- diazonium chloride with the condensation product of o-cresolsulphonic acid and formaldehyde, together with a proprietary phenol formaldehyde "novolak" in glycol monomethyl ether is whirlcoated upon roughened aluminium foil, dried, exposed, wiped down with sodium silicate solution, treated with an aqueous solution of dextrin, phosphoric acid and formaldehyde and then inked up for printing. The other examples describe operation with comparable reaction products. Examples 6, 8 and 9 use paper, zinc and copper supports respectively, the last two for etching. |
