Abstract: An improved process for tanning leather by treating animal skins with a water-soluble melamine-formaldehyde resin in the presence of an acid catalyst towards the end is improved by using a melamine-formaldehyde resin which is at least partially etherified with a glycol ether, alkyl glycol ether, or both.

Abstract: Use of a resin mixture of, or of a mixed resin from, a melamine-formaldehyde resin and an anionically modified melamine-formaldehyde resin for tanning leather. The anionic modification of the melamine-formaldehyde resin is obtained by preparing the resin in the presence of alkali metal sulfite, alkali metal hydrogensulfite or alkali metal sulfamate. By partial modification it is possible to obtain a mixed resin, while mixing a modified with an unmodified resin gives a resin mixture.

Abstract: This invention relates to a process for the manufacture of methanol-etherified methylolmelamines which are largely monomeric containing more than 5 mols of formaldehyde and more than 4 mols of methyl-etherified methylol groups, per mol of melamine, and having a viscosity of less than 20 pascal-seconds at 25.degree. C. and a solids content of at least 95%, comprising (a) methylolating melamine with formaldehyde at a molar melamine:formaldehyde ratio of 1:6.5 to 1:8 for 11/2 to 5 hours at 50.degree. C. to 85.degree. C., with the formaldehyde source being an aqueous solution of formalin containing 30 to 50% by weight of formaldehyde and having a pH of 6.7 to 7.3, and (b) etherifying the resulting suspension of methylolmelamine with 15 to 30 mols of methanol per mol of melamine at temperatures of 30.degree. C. to 60.degree. C. in the presence of a strong acid.

Abstract: A process for the preparation of a substantially monomeric methylolmelamine etherified by methanol which contains per mol of melamine, more than 5 mols of formaldehyde and more than 4 mols of methyl-etherified methylol groups which has a viscosity of less than 10 Pa.s at 25.degree. C. at a solids content of at least 95%, said process comprising reacting melamine and formaldehyde in a molar ratio of from 1 : 6.2 to 1 : 8, at a temperature of from 40 to 60.degree. C., in the presence of a basic catalyst in a reaction mixture which contains from 10 to 40% by weight of water and from 40 to 20% by weight of methanol thereby producing a suspension of methylolmelamine, and then etherifying the methylol melamine in the presence of from 15 to 30 mols of methanol per mol of melamine, at a temperature of from 25 to 50.degree. C., in the presence of a strong acid.

Abstract: Spreadability and/or strength of water-setting inorganic bonding compositions are improved by incorporating in them a water-soluble condensation product of formaldehyde with a diphenol ##STR1## The condensation can also take place in the presence of a water-soluble sulfite, a water-soluble sulfamate, a water-soluble pyrosulfite, a phenol sulfonic acid or a naphthalene sulfonic acid.

Abstract: Melamine resins are effectively elasticized with an elasticizer having the formula R-C.sub.6 H.sub.4 --COO--X--OH wherein C.sub.6 H.sub.4 denotes a phenylene group, R denotes a hydrogen atom or a methyl or ethyl group, and X denotes an unbranched or branched alkylene group with 2 to 6 carbon atoms whose carbon chain is either uninterrupted or interrupted by one oxygen atom. Such elasticized resins are particularly suitable for bonding together laminates.

Abstract: Low-viscosity high-solids-content melamine-formaldehyde condensates having high reactivity, low content of free formaldehyde and good compatibility, are prepared by effecting condensation in an alcohol having up to 3 carbons, then concentrating the condensate and heating the concentrate in a higher alcohol having from 3 to 18 carbons and again concentrating. The final product cures on heating to a hard glossy film and can be added to other uncured resins to improve the hardness of their films.