| 摘要 |
748,520. Photographic packing paper. KODAK, Ltd. Oct. 1, 1953 [Oct. 1, 1952], No. 26952/53. Class 98 (2). An opaque photographic packing and interleaving paper has an electrical resistance of over 80,000 ohms per square inch measured through the thickness of the paper and is dyed with a black dye which does not contain any sodium chloride (i.e. " salt-free "). The paper may contain also a yellow "salt-free" " dye. The black dye may be the sodium salt of 2-benzeneazo - 3 : 6 - disulpho - 8 - amino - 1 - naphthol - 7 - (azo - diphenyl - azo - m - phenylenediamine) which has a colour index No. 581 (e.g. Du Pont Fibre Black VF, Diamine Black Cap Extra Cone. or Direct D Black EA Extra CF). The yellow dye may be the sodium salt of dinitroazo - distilbene - tetrasulphonic acid (colour index No. 622). Aluminium sulphate and dry corn-starch may be added to the pulp during the manufacture of the paper. |
