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AssigneeSandoz Ltd.
InventorsAlfred Frei, Helmut Moser, Georg Schoefberger, August Schweizer
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A process for the dyeing of paper with granulated dyeing preparations, preferably dissolved in water. For the process granulated dyeing preparations are used which consist of (a) a dye soluble to at least 2% in water at 25.degree. C. and (b) in an amount not greater than 50%, a salt which dissociates in water, the average size of the granules being at least 20 microns. This application is a continuation of application Ser. No. 239,360, filed Mar. 29, 1972 and now abandoned, which in turn is a continuation-in-part of application Ser. No. 60,115, filed July 31, 1970 and now abandoned, which in turn is a continuation-in-part of application Ser. No. 761,333, filed Sept. 20, 1968 and now abandoned.
In a process for producing colored paper comprising incorporating a dye composition into paper stock and forming paper from said paper stock the improvement wherein said dye composition is a granulated dye composition, said granulated dye composition comprising (a) the dye of the formula ##STR11## and (b) 5 to 50% of a salt selected from the group consisting of NaCl, KCl, Na.sub.2 SO.sub.4, K.sub.2 SO.sub.4, NaPO.sub.3, Na.sub.2 CO.sub.3, K.sub.2 CO.sub.3, NaHPO.sub.4, Na.sub.4 P.sub.2 O.sub.7 and K.sub.4 P.sub.2 O.sub.7, or a mixture thereof, with the proviso that the average size of the granules of said granulated dye composition is at least 20 microns.
In a process for producing colored paper comprising incorporating a dye composition into paper stock and forming paper from said paper stock, the improvement wherein said dye composition is a granulated dye composition, said granulated dye composition consisting essentially of (a) a dye of the formula ##STR12## (b) 5 to 50% of a salt selected from the group consisting of NaCl, KCl, Na.sub.2 SO.sub.4, K.sub.2 SO.sub.4, NaPO.sub.3, Na.sub.2 CO.sub.3, K.sub.2 CO.sub.3, Na.sub.2 HPO.sub.4, Na.sub.4 P.sub.2 O.sub.7 or K.sub.4 P.sub.2 O.sub.7, or a mixture thereof, and, optionally, (c) urea, dextrin or sodium ligninsulfonate, or a mixture thereof, with the proviso that the average size of the granules of said granulated dye composition is at least 20 microns.
Dependencies are inferred from the claim text.