Abstract: It is the object of the present invention to provide an industrially useful process for the manufacture of polyguluronic acids having degrees of polymerization less than 20 and substantially free of mannuronic acid contamination. Alginate salts of organic bases are quite soluble in aqueous solution, and remain soluble in aqueous solution throughout a hydrolysis reaction in the range of pH values at which the acidic hydrolysis is effected at a reasonably fast rate. Based on this finding, a solution containing 5 wt. % or more of alginic acid prepared by dissolving alginic acid in water by neutralization with an organic base is provided and then hydrolyzed under acidic conditions, followed by selective precipitation of polyguluronic acids under acidic conditions.

Abstract: A method of treating alginic acid to produce polyguluronic acids.

Abstract: Pigment dispersed aqueous ink jet ink compositions suitable for printing on plain paper. The ink comprises water as the principal solvent, a pigment and a pigment dispersant. The pigment dispersant is a derivative of a polyuronic acid in which a hydrophobic polymer is covalently attached to the reducing terminus of the polyuronic acid. The polyuronic acid is composed primarily of 1,4-linked polygalacturonic acid, polyguluronic acid, polyiduronic acid, or mixed polymers thereof.

Abstract: An ink composition including water as the principal solvent, a pigment dispersion or dye, and a polyoxyalkylenated polyfluoro-isopropylidene glycerol compound. The composition may be formed by using a pigment dispersion having a pigment and a pigment dispersant. The pigment dispersant may be a derivative of a polyuronic acid in which a hydrophobic polymer is covalently attached to the reducing terminus of the polyuronic acid. The polyuronic acid may be composed primarily of 1,4-linked polygalacturonic acid, polyguluronic acid, polyiduronic acid, or mixed polymers thereof.

Abstract: An aqueous solution ink composition is provided which yields a waterfast printed image, is fast drying, and is stable under typical printing conditions in an ink-jet printer. The ink composition is excellent with regard to its stability and the waterfastness of the printed image. The aqueous solution ink composition comprises an alkali-soluble polymer resin, a basic dye or an oil-soluble salt-type dye with the color imparting portion of the salt being cationic, and an alkali in an amount sufficient to completely dissolve both the alkali-soluble polymer resin and the dye.

Abstract: An aqueous ink composition for ink jet printers, which gives reliable printing performance and yields printed images which have excellent print quality and which dry rapidly is disclosed. The ink compositions are suitable for printing on plain paper. The ink comprises water as the principal solvent, an anionic colorant, pectic acid, a base, and at least one of a penetrable solvent and/or a penetrability-imparting surfactant. The pectic acid is composed primarily of .alpha.-1,4 linked polygalacturonic acid having a degree of esterification not more than 5% where the degree of esterification is defined as the percentage of the total number of galacturonic acid units in the pectic acid which are esterified.