Abstract: The aqueous ink of a pigment type comprises a pigment, water, a water-soluble solvent and a sulfite, and may further comprise a dispersant. An example of the dispersant comprises a copolymer of a monomer (a) represented by general formula (A), and one or more monomers (b) selected from the group consisting of compounds represented by general formulae (B) and (C): ##STR1## wherein AO represents an oxyalkylene group having 2 to 3 carbon atoms, and n represents an integer of 110 to 300.

Abstract: An aqueous ink for ink jet recording comprises a dye and a polymeric compound which can undergo a decarboxylation reaction. In an ink jet recording method, a recording operation is carried out by jetting a liquid droplet of the ink from a nozzle to a recording medium by using thermal energy.

Abstract: Disclosed is a thermal transfer recording medium comprising a substrate provided thereon at least an ink layer which is to be transferred by heat application, characterized in that the loss tangent (tan .delta.) of the ink layer in viscoelasticity measurement at a temperature of from 60.degree. to 100.degree. C. ranges from 0.4 to 2.5.

Abstract: Disclosed is a recording material employing an electron donating colorless dye and an electron accepting compound, an improvement being present in that said electron accepting compound is a compound represented by the formula: ##STR1## wherein Ar represents a phenyl group, a substituted phenyl group, a benzyl group, a substituted benzyl group, a naphthyl group or a substituted naphthyl group.

Abstract: A method for purifying human growth hormone which comprises purifying an aqueous solution of crude human growth hormone by chromatography using a water-insoluble carrier having hydrophobic groups. High purity human growth hormone can be obtained by this hydrophobic interaction chromatography.

Abstract: A process for purifying urokinase by contacting a crude urokinase-containing solution with a strongly acidic cation exchanger having sulfonic acid groups and adjusted to the NH.sub.4.sup.+ type to adsorb urokinase on said cation exchanger and then eluting urokinase from said exchanger, characterized in that urea is previously added to the crude urokinase-containing solution in such a rate that the final molar concentration of urea in the solution is 3 to 8 M. This process is capable of providing purified urokinase having substantially constant and high specific activity from a crude urokinase-containing solution with a high recovery regardless of purity of the crude urokinase.

Abstract: A process for purifying urokinase which comprises contacting a crude aqueous solution of urokinase with an ionic pullulan gel and thereafter separating and recovering an aqueous solution of urokinase devoid of harmful impurities.