Abstract: Paper, board, and cardboard having high dry strength are made by adding to the paper stock a dry strength agent which is obtainable by mixing enzymatically digested starch having a viscosity of from 20 to 2,000 mPa.s (measured in 7.5% strength aqueous solution at 45.degree. C.) and a cationic polymer which contains, as typical copolymerized monomers,(a) diallyldimethylammonium chloride,(b) N-vinylamine or(c) an unsubstituted or substituted N-vinylimidazoline, the K value of the cationic polymer in each case being not less than 30, and draining the paper stock with sheet formation.

Abstract: Paper and paperboard of high dry strength are produced by adding a dry strength enhancer to the paper stock and dewatering the paper stock with sheet formation by using as the dry strength enhancer a mixture of a cationic polymer which contains as characteristic monomers copolymerized units of(a) diallyldimethylammonium chloride,(b) N-vinylamine or(c) a substituted or unsubstituted N-vinylimidazoline and has a K value of not less than 30, and natural potato starch which is converted into a water-soluble form by heating in an aqueous medium at above the gelatinization temperature of natural potato starch in the absence of any oxidizing agents or alkali.

Abstract: Paper having a high dry strength is made using water-soluble homopolymers of salts or quaternary 1-vinyl-2-imidazolines and copolymers of these salts or quaternary compounds with acrylamide and/or methacrylamide as agents for increasing the dry strength of paper.

Abstract: Engine sizes for paper are based on aqueous emulsions of C.sub.14 -C.sub.20 -alkyl diketenes and cationic copolymers of(a) from 40 to 99% by weight of acrylamide and/or methacrylamide,(b) from 1 to 40% by weight of an unsubstituted or substituted N-vinylimidazoline and(c) from 0 to 30% by weight of an unsubstituted or substituted N-vinylimidazole.

Abstract: A process for the preparation of dyes which contain sulfonic acid groups and have a low electrolyte content, wherein an aqueous solution or suspension, which may or may not contain inorganic salts, of the dye containing sulfonic acid groups is(a) mixed with an amount, equivalent to the said dye, of a non-emulsifying, water-insoluble amine of a total of 12 to 40 carbon atoms, which forms, with the said dye, a salt which is sufficiently lipophilic for it to separate spontaneously from the aqueous phase,(b) the pH is brought to <5 with an acid and the batch is mixed thoroughly,(c) the two resulting phases of different density are separated, and(d) the phase which consists of the lipophilic ammonium salt of the dye is mixed, with or without prior washing with water, with a water-soluble base whose sulfonate salt is to be prepared, and with water, the resulting phases are separated, and the salt is left in the aqueous solution or is isolated therefrom.

Abstract: A process for dyeing textile materials, consisting of wool or nylon fibers, with anionic dyes in an aqueous liquor at up to 110.degree. C., wherein dyeing is commenced at a pH of from 7 to 9 and from 0.2 to 5 parts by weight, per 1,000 parts by weight of liquor, of an ester of a saturated C.sub.2 -C.sub.4 -carboxylic acid with an alcohol having a tertiary amino group in the 2-position are added at the dyeing temperature to act as a pH regulator.

Abstract: Alkanes substituted by chlorine atoms and/or sulfochloride groups are prepared by reacting alkanes with chlorine, with or without sulfur dioxide, in a particular throughput ratio, in a reaction chamber inclined to the horizontal, the starting materials being passed through the reaction chamber in co-current, from below. The substituted alkanes or paraffins obtainable by the process of the invention are pesticides, plasticizers, solvents and starting materials for the preparation of such products, as well as of fat liquors, detergents, lubricating oils, synthetic resins and slip agents.