Abstract: The invention relates to a process for the preparation of novolak resins having a low amount of metal ions. In the process, a conventional resin in an organic solution is brought into contact with an acidic, preferably complex-forming compound which preferably is present in an aqueous phase. The resin solutions may be used in the production of photoresists.

Abstract: A process for the preparation of an o-naphthoquinonediazide sulfonic acid ester is disclosed. Esterification of an o-naphthoquinonediazide sulfonic acid halide with a mono- or polyvalent phenolic compound in a solvent is performed in the presence of ammonia, of ammonium salts of weak acids or of aliphatic derivatives of ammonia having 1 to 3 carbon atoms, at a pH within the range from about 1.5 to about 8.5 and a temperature within the range from about 15.degree. C. to about 40.degree. C. The esters of o-naphthoquinonediazide sulfonic acid which are obtained by this process contain only small amounts of metal ions and can be used in photosensitive mixtures satisfying high requirements of the microelectronics industry.

Abstract: A diagnostic agent for the visualization of RES-containing organs or of lymph vessels, containing .sup.99m Tc triphosphonates or tetraphosphonates in physiologic saline, and a process for their preparation.

Abstract: Monoalkyl phosphonites are prepared by the esterification of phosphonous acids with alcohols at temperatures of about 125.degree. to about 220.degree. C., preferably of about 130.degree. to about 180.degree. C.

Abstract: Novel phosphonocarboxylic acid compounds having the formula ##STR1## wherein the radicals R which may be identical or different and which represent alkyl radicals with 1-18 carbon atoms which may be optionally substituted by halogen, hydrogen, alkali metal ions or ammonium ions, are prepared by reacting methylene phosphonic acid alkyl esters with acrylic acid esters in the presence of strongly basic catalysts at temperatures of about 0.degree.-140.degree. C., and by possibly transesterifying the reaction products or by submitting the latter to acid or basic hydrolysis. The acid hydrolysis to yield the free, 3,3-diphosphono-pimelic acid is best carried out with at least the about 6-fold molar quantity of a carboxylic acid such as HCOOH, CH.sub.3 COOH, etc., optionally in the presence of catalytic quantities of strong acids or bases, at elevated temperatures.

Abstract: Novel phosphonocarboxylic acid compounds having the formula ##STR1## wherein the radicals R which may be identical or different and which represent alkyl radicals with 1-18 carbon atoms which may be optionally substituted by halogen, hydrogen, alkali metal ions or ammonium ions, are prepared by reacting methylene phosphonic acid alkyl esters with acrylic acid esters in the presence of strongly basic catalysts at temperatures of about 0.degree.-140.degree. C., and by possibly trans-esterifying the reaction products or by submitting the latter to acid or basic hydrolysis. The acid hydrolysis to yield the free 3,3-diphosphono-pimelic acid is best carried out with at least the about 6-fold molar quantity of a carboxylic acid such as HCOOH, CH.sub.3 COOH, etc., optionally in the presence of catalytic quantities of strong acids or bases, at elevated temperatures.

Abstract: Preparation of phosphonic and/or phosphinic acids by hydrolytic cleavage of phosphonic and/or phosphinic acid alkyl esters in the presence of the phosphonic and/or phosphinic acid by carrying out the hydrolysis at a temperature of from 160.degree. to 250.degree. C with the use of at least a stoichiometric amount of water, and by distilling off the alkanol formed, optionally together with water.