Phenol-formaldehyde condensates, their preparation and their use as dispersing agents, liquefaction agents and tanning agents
AssigneeBayer Aktiengesellschaft
InventorsGunther Reitz, Vaclav Kaspar, Karlhans Jakobs, Kurt Schaupp
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Abstract
Polycondensates of phenols and formaldehyde which contain sulphonic acid groups and salts thereof bonded to the phenol either directly or via a methylene bridge are prepared by reacting a neutralized reaction product of phenols and sulphonating agents, which contains a mixture of the starting phenol, phenolsulphonic acid and bis-(hydroxyphenyl) sulphones, with formaldehyde and a bisulphite at a pH value of 4-8.
Claims2
Polycondensates of phenols and formaldehyde which contain sulphonic acid groups and salts thereof bonded to the phenol either directly or via a methylene bridge, characterized in that they are prepared in a one-kettle reaction, by reaction of 1 mol of the phenol with 0.3-0.9 mol of sulphonating agent in a strongly acid medium, neutralization of the product to a pH value of 7-8, further reaction with 0.6-2 mols of formaldehyde, reaction with 0.3-0.9 mol of bisulphite and then with 0.8-1.5 mols of formaldehyde at a pH value of 4-8.
Dependencies are inferred from the claim text.