Abstract: Leather can be pretreated to obtain good body, soft feel, and excellent grain smoothness and solidity with products having a molecular weight of 700 to 30,000 and which are obtainable by reaction ofA. polysuccinimide having a molecular weight, determined as the number-average, of 500 to 10,000, withB. 5 to 90 mol % based on the succinimide units of polysuccinimide A, and/or secondary amine, the nitrogen substituents of which contain 1 to 60 carbon atoms and which can be unsubstituted or substituted, at least 2.5 mol % of the nitrogen substituents of the amine containing at least 12 carbon atoms,C. optionally, (i) derivatives of C.sub.1 -C.sub.18 -monocarboxylic acids, C.sub.2 -C.sub.10 -dicarboxylic acids, and/or (ii) monoisocyanates, diisocyanates epichlorohydrin (for reaction of amino and/or hydroxyl groups on the nitrogen substituents of the reaction product of A and B), andD. 95 to 10 mol % of ring-opening base in the presence of water.

Abstract: Novel wood preservatives comprisingat least one copper compound and polyaspartic acid or a derivative of the same,a triazole compound andif appropriate at least one synergistically complementing other fungicide and/or insecticideif appropriate an emulsifier and/or a small amount of alkanolamine.

Abstract: Pigment preparations having a solids content of greater than 40% comprise, as dispersing agents, polymers having recurring succinyl units, in particular polyaspartic acid.

Abstract: Hydroxypivalic acid can be prepared by oxidation of hydroxypivalaldehyde with hydrogen peroxide by metering the hydrogen peroxide, as the oxidizing agent, into an aqueous hydroxypivalaldehyde reservoir in the temperature range from 60.degree. to 80.degree. C. such that a hydrogen peroxide concentration of 4% by weight, based on the total weight of the reaction mixture, is not exceeded, and ending the addition of hydrogen peroxide as soon as the concentration of hydroxypivalaldehyde in the reaction mixture falls below 1% by weight.

Abstract: A photographic silver halide material having a support and at least one layer which is deposited thereon and which contains a polypeptide, at least 90 mole % of which consists of structural units of formula I, ##STR1## where R represents OH, NH.sub.2, NHR.sub.1, NR.sub.1 R.sub.2, NH-- or NR.sub.1 --R.sub.1, R.sub.2 represent a hydrocarbon radical, which is optionally substituted,R.sub.4 represents NH or N--, andm represents 0 or 1,wherein the bond between two structural units of formula I is always an --N--C bond and m is equal to 1 in 2 to 35% of the structural units of formula I, is characterised by improved photographic properties.

Abstract: N-Substituted cyclic imides are obtained by reacting a cyclic acid anhydride with an amine in the presence of a solvent and an acid catalyst at 80.degree. to 200.degree. C. and with removal of the water formed, it being particularly advantageous to carry out this reaction in the presence of a stabilizer and an inert, dipolar aprotic cosolvent, optionally to add an inert organic solvent of low or zero polarity to the reaction mixture present after the reaction, to add a non-aqueous base in an amount of 0.5 to 50% by weight, based on the cyclic anhydride of the formula (II) used, and to separate off the precipitate formed to give a filtrate containing the N-substituted cyclic imide.

Abstract: Polymers with recurring succinyl units are prepared by reaction of maleic anhydride, maleic acid or fumaric acid with condensed liquid ammonia and polymerization of the resulting reaction product.

Abstract: Sulfonic acid group-containing polyaspartic acid derivatives, some of which are novel, having repeating units of the structures I and II ##STR1## in which ##STR2## are suitable for water treatment and as a detergent additive.

Abstract: Polyaspartic acid is prepared by polymerization of aspartic acid, maleic acid anhydride, maleic acid or fumaric acid in a solvent at from 130.degree. C. to 300.degree. C., optionally in the presence of ammonia.

Abstract: The polymers according to the invention with repeating succinyl units additionally contain iminodisuccinate units.

Abstract: N-containing polymers having repeating succinyl units are decolorized using activated hydrogen.

Abstract: Polysuccinimide and polyaspartic acid are prepared by polymerizing maleic anhydride, ammonia and water or maleic acid derivatives or fumaric acid derivatives in bulk or dissolved in solvents in a continuous kneading reactor. The polysuccinimide formed can be converted into polyaspartic acid and polyaspartate salts by hydrolysis.

Abstract: In a process for the continuous preparation of polymers with repeating succinyl units, maleic anhydride or a derivative thereof as educt A is mixed with ammonia or an ammonia-producing compound or amides of carbonic acid as educt B and in a first reaction stage these are reacted to give an N-containing low molecular derivative of maleic acid. This derivative is then polymerized in a subsequent second reaction stage. Reaction of the educts (A,B) takes place largely adiabatically in the first reaction stage. The heat of reaction thereby released is used to take the reaction mixture to the polymerization temperature and in the second reaction stage at least partially to polymerize the N-containing low molecular derivative to obtain a polymer with repeating succinyl units.

Abstract: Polyaspartic acid and its salts and anhydrides are outstandingly suitable as tanning agents, as retanning agents and as standardizing agents for dyestuffs.

Abstract: Polyaspartic acid is prepared by reacting maleic anhydride and ammonia to give maleamic acid, polymerizing the maleamic acid and subsequently hydrolyzing the product to give polyaspartic acid or a salt thereof.

Abstract: Molten maleic anhydride is introduced in the form of fine droplets at 53.degree. C. to 250.degree. C. and preferably at 60.degree. C. to 120.degree. C. into a gas atmosphere which consists either of pure gaseous ammonia or of a gas mixture of ammonia and at least one other gas and of which the temperature is between 20.degree. C. and 500.degree. C. The process is carried out at a temperature of 120.degree. C. to 180.degree. C. for the production of polysuccinimide and at a temperature of 10.degree. C. to 120.degree. C. for the production of maleic amide acid.

Abstract: An improved composition for water treatment and for alkaline cleaning contains polyaspartic acid or a derivative thereof and a phosphonic acid.

Abstract: Sulfonic acid group-containing polyaspartic acid derivatives, some of which are novel, having repeating units of the structures I and II ##STR1## in whichR.sup.1 has the meaning given in the description, are suitable for water treatment and as a detergent additive.

Abstract: The invention relates to an improved process for the preparation of polysuccinimide from maleic anhydride and ammonia, characterized in that the starting compounds are brought to reaction in liquid form in a tubular reactor with feed nozzle at temperatures of preferably 50.degree. C. to 500.degree. C. and residence times of preferably 0.1 to 600 seconds and the resulting reaction mixture is possibly further polymerized thermally in a high-viscosity reactor preferably continuously operated at 120.degree. C. to 300.degree. C.

Abstract: Polysuccinimide is prepared by reaction of fumaric acid, maleic acid or a derivative thereof with urea, isourea, carbamic acid, ammonium carbamide, ammonium bicarbonate, diammonium carbonate or mixtures of the abovementioned substances in a reactor at temperatures of preferably 100.degree. C. to 300.degree. C. over reaction times of preferably 0.5 minute to 300 minutes.